/* build: `node build.js modules=ALL exclude=gestures,accessors requirejs minifier=uglifyjs` */
/*! Fabric.js Copyright 2008-2015, Printio (Juriy Zaytsev, Maxim Chernyak) */

var fabric = fabric || { version: '2.3.2' };
if (typeof exports !== 'undefined') {
  exports.fabric = fabric;
}
/* _AMD_START_ */
else if (typeof define === 'function' && define.amd) {
  define([], function() { return fabric; });
}
/* _AMD_END_ */
if (typeof document !== 'undefined' && typeof window !== 'undefined') {
  fabric.document = document;
  fabric.window = window;
}
else {
  // assume we're running under node.js when document/window are not present
  fabric.document = require('jsdom')
    .jsdom(
      decodeURIComponent('%3C!DOCTYPE%20html%3E%3Chtml%3E%3Chead%3E%3C%2Fhead%3E%3Cbody%3E%3C%2Fbody%3E%3C%2Fhtml%3E'),
      { features: {
        FetchExternalResources: ['img']
      }
      });
  fabric.jsdomImplForWrapper = require('jsdom/lib/jsdom/living/generated/utils').implForWrapper;
  fabric.nodeCanvas = require('jsdom/lib/jsdom/utils').Canvas;
  fabric.window = fabric.document.defaultView;
  DOMParser = require('xmldom').DOMParser;
}

/**
 * True when in environment that supports touch events
 * @type boolean
 */
fabric.isTouchSupported = 'ontouchstart' in fabric.window;

/**
 * True when in environment that's probably Node.js
 * @type boolean
 */
fabric.isLikelyNode = typeof Buffer !== 'undefined' &&
                      typeof window === 'undefined';

/* _FROM_SVG_START_ */
/**
 * Attributes parsed from all SVG elements
 * @type array
 */
fabric.SHARED_ATTRIBUTES = [
  "display",
  "transform",
  "fill", "fill-opacity", "fill-rule",
  "opacity",
  "stroke", "stroke-dasharray", "stroke-linecap",
  "stroke-linejoin", "stroke-miterlimit",
  "stroke-opacity", "stroke-width",
  "id", "paint-order",
  "instantiated_by_use"
];
/* _FROM_SVG_END_ */

/**
 * Pixel per Inch as a default value set to 96. Can be changed for more realistic conversion.
 */
fabric.DPI = 96;
fabric.reNum = '(?:[-+]?(?:\\d+|\\d*\\.\\d+)(?:e[-+]?\\d+)?)';
fabric.fontPaths = { };
fabric.iMatrix = [1, 0, 0, 1, 0, 0];
fabric.canvasModule = 'canvas';

/**
 * Pixel limit for cache canvases. 1Mpx , 4Mpx should be fine.
 * @since 1.7.14
 * @type Number
 * @default
 */
fabric.perfLimitSizeTotal = 2097152;

/**
 * Pixel limit for cache canvases width or height. IE fixes the maximum at 5000
 * @since 1.7.14
 * @type Number
 * @default
 */
fabric.maxCacheSideLimit = 4096;

/**
 * Lowest pixel limit for cache canvases, set at 256PX
 * @since 1.7.14
 * @type Number
 * @default
 */
fabric.minCacheSideLimit = 256;

/**
 * Cache Object for widths of chars in text rendering.
 */
fabric.charWidthsCache = { };

/**
 * if webgl is enabled and available, textureSize will determine the size
 * of the canvas backend
 * @since 2.0.0
 * @type Number
 * @default
 */
fabric.textureSize = 2048;

/**
 * Enable webgl for filtering picture is available
 * A filtering backend will be initialized, this will both take memory and
 * time since a default 2048x2048 canvas will be created for the gl context
 * @since 2.0.0
 * @type Boolean
 * @default
 */
fabric.enableGLFiltering = true;

/**
 * Device Pixel Ratio
 * @see https://developer.apple.com/library/safari/documentation/AudioVideo/Conceptual/HTML-canvas-guide/SettingUptheCanvas/SettingUptheCanvas.html
 */
fabric.devicePixelRatio = fabric.window.devicePixelRatio ||
                          fabric.window.webkitDevicePixelRatio ||
                          fabric.window.mozDevicePixelRatio ||
                          1;
/**
 * Browser-specific constant to adjust CanvasRenderingContext2D.shadowBlur value,
 * which is unitless and not rendered equally across browsers.
 *
 * Values that work quite well (as of October 2017) are:
 * - Chrome: 1.5
 * - Edge: 1.75
 * - Firefox: 0.9
 * - Safari: 0.95
 *
 * @since 2.0.0
 * @type Number
 * @default 1
 */
fabric.browserShadowBlurConstant = 1;

fabric.initFilterBackend = function() {
  if (fabric.enableGLFiltering && fabric.isWebglSupported && fabric.isWebglSupported(fabric.textureSize)) {
    console.log('max texture size: ' + fabric.maxTextureSize);
    return (new fabric.WebglFilterBackend({ tileSize: fabric.textureSize }));
  }
  else if (fabric.Canvas2dFilterBackend) {
    return (new fabric.Canvas2dFilterBackend());
  }
};


if (typeof document !== 'undefined' && typeof window !== 'undefined') {
  // ensure globality even if entire library were function wrapped (as in Meteor.js packaging system)
  window.fabric = fabric;
}


(function() {

  /**
   * @private
   * @param {String} eventName
   * @param {Function} handler
   */
  function _removeEventListener(eventName, handler) {
    if (!this.__eventListeners[eventName]) {
      return;
    }
    var eventListener = this.__eventListeners[eventName];
    if (handler) {
      eventListener[eventListener.indexOf(handler)] = false;
    }
    else {
      fabric.util.array.fill(eventListener, false);
    }
  }

  /**
   * Observes specified event
   * @deprecated `observe` deprecated since 0.8.34 (use `on` instead)
   * @memberOf fabric.Observable
   * @alias on
   * @param {String|Object} eventName Event name (eg. 'after:render') or object with key/value pairs (eg. {'after:render': handler, 'selection:cleared': handler})
   * @param {Function} handler Function that receives a notification when an event of the specified type occurs
   * @return {Self} thisArg
   * @chainable
   */
  function observe(eventName, handler) {
    if (!this.__eventListeners) {
      this.__eventListeners = { };
    }
    // one object with key/value pairs was passed
    if (arguments.length === 1) {
      for (var prop in eventName) {
        this.on(prop, eventName[prop]);
      }
    }
    else {
      if (!this.__eventListeners[eventName]) {
        this.__eventListeners[eventName] = [];
      }
      this.__eventListeners[eventName].push(handler);
    }
    return this;
  }

  /**
   * Stops event observing for a particular event handler. Calling this method
   * without arguments removes all handlers for all events
   * @deprecated `stopObserving` deprecated since 0.8.34 (use `off` instead)
   * @memberOf fabric.Observable
   * @alias off
   * @param {String|Object} eventName Event name (eg. 'after:render') or object with key/value pairs (eg. {'after:render': handler, 'selection:cleared': handler})
   * @param {Function} handler Function to be deleted from EventListeners
   * @return {Self} thisArg
   * @chainable
   */
  function stopObserving(eventName, handler) {
    if (!this.__eventListeners) {
      return;
    }

    // remove all key/value pairs (event name -> event handler)
    if (arguments.length === 0) {
      for (eventName in this.__eventListeners) {
        _removeEventListener.call(this, eventName);
      }
    }
    // one object with key/value pairs was passed
    else if (arguments.length === 1 && typeof arguments[0] === 'object') {
      for (var prop in eventName) {
        _removeEventListener.call(this, prop, eventName[prop]);
      }
    }
    else {
      _removeEventListener.call(this, eventName, handler);
    }
    return this;
  }

  /**
   * Fires event with an optional options object
   * @deprecated `fire` deprecated since 1.0.7 (use `trigger` instead)
   * @memberOf fabric.Observable
   * @alias trigger
   * @param {String} eventName Event name to fire
   * @param {Object} [options] Options object
   * @return {Self} thisArg
   * @chainable
   */
  function fire(eventName, options) {
    if (!this.__eventListeners) {
      return;
    }

    var listenersForEvent = this.__eventListeners[eventName];
    if (!listenersForEvent) {
      return;
    }

    for (var i = 0, len = listenersForEvent.length; i < len; i++) {
      listenersForEvent[i] && listenersForEvent[i].call(this, options || { });
    }
    this.__eventListeners[eventName] = listenersForEvent.filter(function(value) {
      return value !== false;
    });
    return this;
  }

  /**
   * @namespace fabric.Observable
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-2#events}
   * @see {@link http://fabricjs.com/events|Events demo}
   */
  fabric.Observable = {
    observe: observe,
    stopObserving: stopObserving,
    fire: fire,

    on: observe,
    off: stopObserving,
    trigger: fire
  };
})();


/**
 * @namespace fabric.Collection
 */
fabric.Collection = {

  _objects: [],

  /**
   * Adds objects to collection, Canvas or Group, then renders canvas
   * (if `renderOnAddRemove` is not `false`).
   * in case of Group no changes to bounding box are made.
   * Objects should be instances of (or inherit from) fabric.Object
   * Use of this function is highly discouraged for groups.
   * you can add a bunch of objects with the add method but then you NEED
   * to run a addWithUpdate call for the Group class or position/bbox will be wrong.
   * @param {...fabric.Object} object Zero or more fabric instances
   * @return {Self} thisArg
   * @chainable
   */
  add: function () {
    this._objects.push.apply(this._objects, arguments);
    if (this._onObjectAdded) {
      for (var i = 0, length = arguments.length; i < length; i++) {
        this._onObjectAdded(arguments[i]);
      }
    }
    this.renderOnAddRemove && this.requestRenderAll();
    return this;
  },

  /**
   * Inserts an object into collection at specified index, then renders canvas (if `renderOnAddRemove` is not `false`)
   * An object should be an instance of (or inherit from) fabric.Object
   * Use of this function is highly discouraged for groups.
   * you can add a bunch of objects with the insertAt method but then you NEED
   * to run a addWithUpdate call for the Group class or position/bbox will be wrong.
   * @param {Object} object Object to insert
   * @param {Number} index Index to insert object at
   * @param {Boolean} nonSplicing When `true`, no splicing (shifting) of objects occurs
   * @return {Self} thisArg
   * @chainable
   */
  insertAt: function (object, index, nonSplicing) {
    var objects = this.getObjects();
    if (nonSplicing) {
      objects[index] = object;
    }
    else {
      objects.splice(index, 0, object);
    }
    this._onObjectAdded && this._onObjectAdded(object);
    this.renderOnAddRemove && this.requestRenderAll();
    return this;
  },

  /**
   * Removes objects from a collection, then renders canvas (if `renderOnAddRemove` is not `false`)
   * @param {...fabric.Object} object Zero or more fabric instances
   * @return {Self} thisArg
   * @chainable
   */
  remove: function() {
    var objects = this.getObjects(),
        index, somethingRemoved = false;

    for (var i = 0, length = arguments.length; i < length; i++) {
      index = objects.indexOf(arguments[i]);

      // only call onObjectRemoved if an object was actually removed
      if (index !== -1) {
        somethingRemoved = true;
        objects.splice(index, 1);
        this._onObjectRemoved && this._onObjectRemoved(arguments[i]);
      }
    }

    this.renderOnAddRemove && somethingRemoved && this.requestRenderAll();
    return this;
  },

  /**
   * Executes given function for each object in this group
   * @param {Function} callback
   *                   Callback invoked with current object as first argument,
   *                   index - as second and an array of all objects - as third.
   *                   Callback is invoked in a context of Global Object (e.g. `window`)
   *                   when no `context` argument is given
   *
   * @param {Object} context Context (aka thisObject)
   * @return {Self} thisArg
   * @chainable
   */
  forEachObject: function(callback, context) {
    var objects = this.getObjects();
    for (var i = 0, len = objects.length; i < len; i++) {
      callback.call(context, objects[i], i, objects);
    }
    return this;
  },

  /**
   * Returns an array of children objects of this instance
   * Type parameter introduced in 1.3.10
   * @param {String} [type] When specified, only objects of this type are returned
   * @return {Array}
   */
  getObjects: function(type) {
    if (typeof type === 'undefined') {
      return this._objects;
    }
    return this._objects.filter(function(o) {
      return o.type === type;
    });
  },

  /**
   * Returns object at specified index
   * @param {Number} index
   * @return {Self} thisArg
   */
  item: function (index) {
    return this.getObjects()[index];
  },

  /**
   * Returns true if collection contains no objects
   * @return {Boolean} true if collection is empty
   */
  isEmpty: function () {
    return this.getObjects().length === 0;
  },

  /**
   * Returns a size of a collection (i.e: length of an array containing its objects)
   * @return {Number} Collection size
   */
  size: function() {
    return this.getObjects().length;
  },

  /**
   * Returns true if collection contains an object
   * @param {Object} object Object to check against
   * @return {Boolean} `true` if collection contains an object
   */
  contains: function(object) {
    return this.getObjects().indexOf(object) > -1;
  },

  /**
   * Returns number representation of a collection complexity
   * @return {Number} complexity
   */
  complexity: function () {
    return this.getObjects().reduce(function (memo, current) {
      memo += current.complexity ? current.complexity() : 0;
      return memo;
    }, 0);
  }
};


/**
 * @namespace fabric.CommonMethods
 */
fabric.CommonMethods = {

  /**
   * Sets object's properties from options
   * @param {Object} [options] Options object
   */
  _setOptions: function(options) {
    for (var prop in options) {
      this.set(prop, options[prop]);
    }
  },

  /**
   * @private
   * @param {Object} [filler] Options object
   * @param {String} [property] property to set the Gradient to
   */
  _initGradient: function(filler, property) {
    if (filler && filler.colorStops && !(filler instanceof fabric.Gradient)) {
      this.set(property, new fabric.Gradient(filler));
    }
  },

  /**
   * @private
   * @param {Object} [filler] Options object
   * @param {String} [property] property to set the Pattern to
   * @param {Function} [callback] callback to invoke after pattern load
   */
  _initPattern: function(filler, property, callback) {
    if (filler && filler.source && !(filler instanceof fabric.Pattern)) {
      this.set(property, new fabric.Pattern(filler, callback));
    }
    else {
      callback && callback();
    }
  },

  /**
   * @private
   * @param {Object} [options] Options object
   */
  _initClipping: function(options) {
    if (!options.clipTo || typeof options.clipTo !== 'string') {
      return;
    }

    var functionBody = fabric.util.getFunctionBody(options.clipTo);
    if (typeof functionBody !== 'undefined') {
      this.clipTo = new Function('ctx', functionBody);
    }
  },

  /**
   * @private
   */
  _setObject: function(obj) {
    for (var prop in obj) {
      this._set(prop, obj[prop]);
    }
  },

  /**
   * Sets property to a given value. When changing position/dimension -related properties (left, top, scale, angle, etc.) `set` does not update position of object's borders/controls. If you need to update those, call `setCoords()`.
   * @param {String|Object} key Property name or object (if object, iterate over the object properties)
   * @param {Object|Function} value Property value (if function, the value is passed into it and its return value is used as a new one)
   * @return {fabric.Object} thisArg
   * @chainable
   */
  set: function(key, value) {
    if (typeof key === 'object') {
      this._setObject(key);
    }
    else {
      if (typeof value === 'function' && key !== 'clipTo') {
        this._set(key, value(this.get(key)));
      }
      else {
        this._set(key, value);
      }
    }
    return this;
  },

  _set: function(key, value) {
    this[key] = value;
  },

  /**
   * Toggles specified property from `true` to `false` or from `false` to `true`
   * @param {String} property Property to toggle
   * @return {fabric.Object} thisArg
   * @chainable
   */
  toggle: function(property) {
    var value = this.get(property);
    if (typeof value === 'boolean') {
      this.set(property, !value);
    }
    return this;
  },

  /**
   * Basic getter
   * @param {String} property Property name
   * @return {*} value of a property
   */
  get: function(property) {
    return this[property];
  }
};


(function(global) {

  var sqrt = Math.sqrt,
      atan2 = Math.atan2,
      pow = Math.pow,
      abs = Math.abs,
      PiBy180 = Math.PI / 180,
      PiBy2 = Math.PI / 2;

  /**
   * @namespace fabric.util
   */
  fabric.util = {

    /**
     * Calculate the cos of an angle, avoiding returning floats for known results
     * @static
     * @memberOf fabric.util
     * @param {Number} angle the angle in radians or in degree
     * @return {Number}
     */
    cos: function(angle) {
      if (angle === 0) { return 1; }
      if (angle < 0) {
        // cos(a) = cos(-a)
        angle = -angle;
      }
      var angleSlice = angle / PiBy2;
      switch (angleSlice) {
        case 1: case 3: return 0;
        case 2: return -1;
      }
      return Math.cos(angle);
    },

    /**
     * Calculate the sin of an angle, avoiding returning floats for known results
     * @static
     * @memberOf fabric.util
     * @param {Number} angle the angle in radians or in degree
     * @return {Number}
     */
    sin: function(angle) {
      if (angle === 0) { return 0; }
      var angleSlice = angle / PiBy2, sign = 1;
      if (angle < 0) {
        // sin(-a) = -sin(a)
        sign = -1;
      }
      switch (angleSlice) {
        case 1: return sign;
        case 2: return 0;
        case 3: return -sign;
      }
      return Math.sin(angle);
    },

    /**
     * Removes value from an array.
     * Presence of value (and its position in an array) is determined via `Array.prototype.indexOf`
     * @static
     * @memberOf fabric.util
     * @param {Array} array
     * @param {*} value
     * @return {Array} original array
     */
    removeFromArray: function(array, value) {
      var idx = array.indexOf(value);
      if (idx !== -1) {
        array.splice(idx, 1);
      }
      return array;
    },

    /**
     * Returns random number between 2 specified ones.
     * @static
     * @memberOf fabric.util
     * @param {Number} min lower limit
     * @param {Number} max upper limit
     * @return {Number} random value (between min and max)
     */
    getRandomInt: function(min, max) {
      return Math.floor(Math.random() * (max - min + 1)) + min;
    },

    /**
     * Transforms degrees to radians.
     * @static
     * @memberOf fabric.util
     * @param {Number} degrees value in degrees
     * @return {Number} value in radians
     */
    degreesToRadians: function(degrees) {
      return degrees * PiBy180;
    },

    /**
     * Transforms radians to degrees.
     * @static
     * @memberOf fabric.util
     * @param {Number} radians value in radians
     * @return {Number} value in degrees
     */
    radiansToDegrees: function(radians) {
      return radians / PiBy180;
    },

    /**
     * Rotates `point` around `origin` with `radians`
     * @static
     * @memberOf fabric.util
     * @param {fabric.Point} point The point to rotate
     * @param {fabric.Point} origin The origin of the rotation
     * @param {Number} radians The radians of the angle for the rotation
     * @return {fabric.Point} The new rotated point
     */
    rotatePoint: function(point, origin, radians) {
      point.subtractEquals(origin);
      var v = fabric.util.rotateVector(point, radians);
      return new fabric.Point(v.x, v.y).addEquals(origin);
    },

    /**
     * Rotates `vector` with `radians`
     * @static
     * @memberOf fabric.util
     * @param {Object} vector The vector to rotate (x and y)
     * @param {Number} radians The radians of the angle for the rotation
     * @return {Object} The new rotated point
     */
    rotateVector: function(vector, radians) {
      var sin = fabric.util.sin(radians),
          cos = fabric.util.cos(radians),
          rx = vector.x * cos - vector.y * sin,
          ry = vector.x * sin + vector.y * cos;
      return {
        x: rx,
        y: ry
      };
    },

    /**
     * Apply transform t to point p
     * @static
     * @memberOf fabric.util
     * @param  {fabric.Point} p The point to transform
     * @param  {Array} t The transform
     * @param  {Boolean} [ignoreOffset] Indicates that the offset should not be applied
     * @return {fabric.Point} The transformed point
     */
    transformPoint: function(p, t, ignoreOffset) {
      if (ignoreOffset) {
        return new fabric.Point(
          t[0] * p.x + t[2] * p.y,
          t[1] * p.x + t[3] * p.y
        );
      }
      return new fabric.Point(
        t[0] * p.x + t[2] * p.y + t[4],
        t[1] * p.x + t[3] * p.y + t[5]
      );
    },

    /**
     * Returns coordinates of points's bounding rectangle (left, top, width, height)
     * @param {Array} points 4 points array
     * @return {Object} Object with left, top, width, height properties
     */
    makeBoundingBoxFromPoints: function(points) {
      var xPoints = [points[0].x, points[1].x, points[2].x, points[3].x],
          minX = fabric.util.array.min(xPoints),
          maxX = fabric.util.array.max(xPoints),
          width = maxX - minX,
          yPoints = [points[0].y, points[1].y, points[2].y, points[3].y],
          minY = fabric.util.array.min(yPoints),
          maxY = fabric.util.array.max(yPoints),
          height = maxY - minY;

      return {
        left: minX,
        top: minY,
        width: width,
        height: height
      };
    },

    /**
     * Invert transformation t
     * @static
     * @memberOf fabric.util
     * @param {Array} t The transform
     * @return {Array} The inverted transform
     */
    invertTransform: function(t) {
      var a = 1 / (t[0] * t[3] - t[1] * t[2]),
          r = [a * t[3], -a * t[1], -a * t[2], a * t[0]],
          o = fabric.util.transformPoint({ x: t[4], y: t[5] }, r, true);
      r[4] = -o.x;
      r[5] = -o.y;
      return r;
    },

    /**
     * A wrapper around Number#toFixed, which contrary to native method returns number, not string.
     * @static
     * @memberOf fabric.util
     * @param {Number|String} number number to operate on
     * @param {Number} fractionDigits number of fraction digits to "leave"
     * @return {Number}
     */
    toFixed: function(number, fractionDigits) {
      return parseFloat(Number(number).toFixed(fractionDigits));
    },

    /**
     * Converts from attribute value to pixel value if applicable.
     * Returns converted pixels or original value not converted.
     * @param {Number|String} value number to operate on
     * @param {Number} fontSize
     * @return {Number|String}
     */
    parseUnit: function(value, fontSize) {
      var unit = /\D{0,2}$/.exec(value),
          number = parseFloat(value);
      if (!fontSize) {
        fontSize = fabric.Text.DEFAULT_SVG_FONT_SIZE;
      }
      switch (unit[0]) {
        case 'mm':
          return number * fabric.DPI / 25.4;

        case 'cm':
          return number * fabric.DPI / 2.54;

        case 'in':
          return number * fabric.DPI;

        case 'pt':
          return number * fabric.DPI / 72; // or * 4 / 3

        case 'pc':
          return number * fabric.DPI / 72 * 12; // or * 16

        case 'em':
          return number * fontSize;

        default:
          return number;
      }
    },

    /**
     * Function which always returns `false`.
     * @static
     * @memberOf fabric.util
     * @return {Boolean}
     */
    falseFunction: function() {
      return false;
    },

    /**
     * Returns klass "Class" object of given namespace
     * @memberOf fabric.util
     * @param {String} type Type of object (eg. 'circle')
     * @param {String} namespace Namespace to get klass "Class" object from
     * @return {Object} klass "Class"
     */
    getKlass: function(type, namespace) {
      // capitalize first letter only
      type = fabric.util.string.camelize(type.charAt(0).toUpperCase() + type.slice(1));
      return fabric.util.resolveNamespace(namespace)[type];
    },

    /**
     * Returns array of attributes for given svg that fabric parses
     * @memberOf fabric.util
     * @param {String} type Type of svg element (eg. 'circle')
     * @return {Array} string names of supported attributes
     */
    getSvgAttributes: function(type) {
      var attributes = [
        'instantiated_by_use',
        'style',
        'id',
        'class'
      ];
      switch (type) {
        case 'linearGradient':
          attributes = attributes.concat(['x1', 'y1', 'x2', 'y2', 'gradientUnits', 'gradientTransform']);
          break;
        case 'radialGradient':
          attributes = attributes.concat(['gradientUnits', 'gradientTransform', 'cx', 'cy', 'r', 'fx', 'fy', 'fr']);
          break;
        case 'stop':
          attributes = attributes.concat(['offset', 'stop-color', 'stop-opacity']);
          break;
      }
      return attributes;
    },

    /**
     * Returns object of given namespace
     * @memberOf fabric.util
     * @param {String} namespace Namespace string e.g. 'fabric.Image.filter' or 'fabric'
     * @return {Object} Object for given namespace (default fabric)
     */
    resolveNamespace: function(namespace) {
      if (!namespace) {
        return fabric;
      }

      var parts = namespace.split('.'),
          len = parts.length, i,
          obj = global || fabric.window;

      for (i = 0; i < len; ++i) {
        obj = obj[parts[i]];
      }

      return obj;
    },

    /**
     * Loads image element from given url and passes it to a callback
     * @memberOf fabric.util
     * @param {String} url URL representing an image
     * @param {Function} callback Callback; invoked with loaded image
     * @param {*} [context] Context to invoke callback in
     * @param {Object} [crossOrigin] crossOrigin value to set image element to
     */
    loadImage: function(url, callback, context, crossOrigin) {
      if (!url) {
        callback && callback.call(context, url);
        return;
      }

      var img = fabric.util.createImage();

      /** @ignore */
      var onLoadCallback = function () {
        callback && callback.call(context, img);
        img = img.onload = img.onerror = null;
      };

      img.onload = onLoadCallback;
      /** @ignore */
      img.onerror = function() {
        fabric.log('Error loading ' + img.src);
        callback && callback.call(context, null, true);
        img = img.onload = img.onerror = null;
      };

      // data-urls appear to be buggy with crossOrigin
      // https://github.com/kangax/fabric.js/commit/d0abb90f1cd5c5ef9d2a94d3fb21a22330da3e0a#commitcomment-4513767
      // see https://code.google.com/p/chromium/issues/detail?id=315152
      //     https://bugzilla.mozilla.org/show_bug.cgi?id=935069
      if (url.indexOf('data') !== 0 && crossOrigin) {
        img.crossOrigin = crossOrigin;
      }

      // IE10 / IE11-Fix: SVG contents from data: URI
      // will only be available if the IMG is present
      // in the DOM (and visible)
      if (url.substring(0,14) === 'data:image/svg') {
        img.onload = null;
        fabric.util.loadImageInDom(img, onLoadCallback);
      }

      img.src = url;
    },

    /**
     * Attaches SVG image with data: URL to the dom
     * @memberOf fabric.util
     * @param {Object} img Image object with data:image/svg src
     * @param {Function} callback Callback; invoked with loaded image
     * @return {Object} DOM element (div containing the SVG image)
     */
    loadImageInDom: function(img, onLoadCallback) {
      var div = fabric.document.createElement('div');
      div.style.width = div.style.height = '1px';
      div.style.left = div.style.top = '-100%';
      div.style.position = 'absolute';
      div.appendChild(img);
      fabric.document.querySelector('body').appendChild(div);
      /**
       * Wrap in function to:
       *   1. Call existing callback
       *   2. Cleanup DOM
       */
      img.onload = function () {
        onLoadCallback();
        div.parentNode.removeChild(div);
        div = null;
      };
    },

    /**
     * Creates corresponding fabric instances from their object representations
     * @static
     * @memberOf fabric.util
     * @param {Array} objects Objects to enliven
     * @param {Function} callback Callback to invoke when all objects are created
     * @param {String} namespace Namespace to get klass "Class" object from
     * @param {Function} reviver Method for further parsing of object elements,
     * called after each fabric object created.
     */
    enlivenObjects: function(objects, callback, namespace, reviver) {
      objects = objects || [];

      function onLoaded() {
        if (++numLoadedObjects === numTotalObjects) {
          callback && callback(enlivenedObjects);
        }
      }

      var enlivenedObjects = [],
          numLoadedObjects = 0,
          numTotalObjects = objects.length;

      if (!numTotalObjects) {
        callback && callback(enlivenedObjects);
        return;
      }

      objects.forEach(function (o, index) {
        // if sparse array
        if (!o || !o.type) {
          onLoaded();
          return;
        }
        var klass = fabric.util.getKlass(o.type, namespace);
        klass.fromObject(o, function (obj, error) {
          error || (enlivenedObjects[index] = obj);
          reviver && reviver(o, obj, error);
          onLoaded();
        });
      });
    },

    /**
     * Create and wait for loading of patterns
     * @static
     * @memberOf fabric.util
     * @param {Array} patterns Objects to enliven
     * @param {Function} callback Callback to invoke when all objects are created
     * called after each fabric object created.
     */
    enlivenPatterns: function(patterns, callback) {
      patterns = patterns || [];

      function onLoaded() {
        if (++numLoadedPatterns === numPatterns) {
          callback && callback(enlivenedPatterns);
        }
      }

      var enlivenedPatterns = [],
          numLoadedPatterns = 0,
          numPatterns = patterns.length;

      if (!numPatterns) {
        callback && callback(enlivenedPatterns);
        return;
      }

      patterns.forEach(function (p, index) {
        if (p && p.source) {
          new fabric.Pattern(p, function(pattern) {
            enlivenedPatterns[index] = pattern;
            onLoaded();
          });
        }
        else {
          enlivenedPatterns[index] = p;
          onLoaded();
        }
      });
    },

    /**
     * Groups SVG elements (usually those retrieved from SVG document)
     * @static
     * @memberOf fabric.util
     * @param {Array} elements SVG elements to group
     * @param {Object} [options] Options object
     * @param {String} path Value to set sourcePath to
     * @return {fabric.Object|fabric.Group}
     */
    groupSVGElements: function(elements, options, path) {
      var object;
      if (elements.length === 1) {
        return elements[0];
      }
      if (options) {
        if (options.width && options.height) {
          options.centerPoint = {
            x: options.width / 2,
            y: options.height / 2
          };
        }
        else {
          delete options.width;
          delete options.height;
        }
      }
      object = new fabric.Group(elements, options);
      if (typeof path !== 'undefined') {
        object.sourcePath = path;
      }
      return object;
    },

    /**
     * Populates an object with properties of another object
     * @static
     * @memberOf fabric.util
     * @param {Object} source Source object
     * @param {Object} destination Destination object
     * @return {Array} properties Properties names to include
     */
    populateWithProperties: function(source, destination, properties) {
      if (properties && Object.prototype.toString.call(properties) === '[object Array]') {
        for (var i = 0, len = properties.length; i < len; i++) {
          if (properties[i] in source) {
            destination[properties[i]] = source[properties[i]];
          }
        }
      }
    },

    /**
     * Draws a dashed line between two points
     *
     * This method is used to draw dashed line around selection area.
     * See <a href="http://stackoverflow.com/questions/4576724/dotted-stroke-in-canvas">dotted stroke in canvas</a>
     *
     * @param {CanvasRenderingContext2D} ctx context
     * @param {Number} x  start x coordinate
     * @param {Number} y start y coordinate
     * @param {Number} x2 end x coordinate
     * @param {Number} y2 end y coordinate
     * @param {Array} da dash array pattern
     */
    drawDashedLine: function(ctx, x, y, x2, y2, da) {
      var dx = x2 - x,
          dy = y2 - y,
          len = sqrt(dx * dx + dy * dy),
          rot = atan2(dy, dx),
          dc = da.length,
          di = 0,
          draw = true;

      ctx.save();
      ctx.translate(x, y);
      ctx.moveTo(0, 0);
      ctx.rotate(rot);

      x = 0;
      while (len > x) {
        x += da[di++ % dc];
        if (x > len) {
          x = len;
        }
        ctx[draw ? 'lineTo' : 'moveTo'](x, 0);
        draw = !draw;
      }

      ctx.restore();
    },

    /**
     * Creates canvas element
     * @static
     * @memberOf fabric.util
     * @return {CanvasElement} initialized canvas element
     */
    createCanvasElement: function() {
      return fabric.document.createElement('canvas');
    },

    /**
     * Creates image element (works on client and node)
     * @static
     * @memberOf fabric.util
     * @return {HTMLImageElement} HTML image element
     */
    createImage: function() {
      return fabric.document.createElement('img');
    },

    /**
     * @static
     * @memberOf fabric.util
     * @deprecated since 2.0.0
     * @param {fabric.Object} receiver Object implementing `clipTo` method
     * @param {CanvasRenderingContext2D} ctx Context to clip
     */
    clipContext: function(receiver, ctx) {
      ctx.save();
      ctx.beginPath();
      receiver.clipTo(ctx);
      ctx.clip();
    },

    /**
     * Multiply matrix A by matrix B to nest transformations
     * @static
     * @memberOf fabric.util
     * @param  {Array} a First transformMatrix
     * @param  {Array} b Second transformMatrix
     * @param  {Boolean} is2x2 flag to multiply matrices as 2x2 matrices
     * @return {Array} The product of the two transform matrices
     */
    multiplyTransformMatrices: function(a, b, is2x2) {
      // Matrix multiply a * b
      return [
        a[0] * b[0] + a[2] * b[1],
        a[1] * b[0] + a[3] * b[1],
        a[0] * b[2] + a[2] * b[3],
        a[1] * b[2] + a[3] * b[3],
        is2x2 ? 0 : a[0] * b[4] + a[2] * b[5] + a[4],
        is2x2 ? 0 : a[1] * b[4] + a[3] * b[5] + a[5]
      ];
    },

    /**
     * Decomposes standard 2x2 matrix into transform componentes
     * @static
     * @memberOf fabric.util
     * @param  {Array} a transformMatrix
     * @return {Object} Components of transform
     */
    qrDecompose: function(a) {
      var angle = atan2(a[1], a[0]),
          denom = pow(a[0], 2) + pow(a[1], 2),
          scaleX = sqrt(denom),
          scaleY = (a[0] * a[3] - a[2] * a [1]) / scaleX,
          skewX = atan2(a[0] * a[2] + a[1] * a [3], denom);
      return {
        angle: angle  / PiBy180,
        scaleX: scaleX,
        scaleY: scaleY,
        skewX: skewX / PiBy180,
        skewY: 0,
        translateX: a[4],
        translateY: a[5]
      };
    },

    customTransformMatrix: function(scaleX, scaleY, skewX) {
      var skewMatrixX = [1, 0, abs(Math.tan(skewX * PiBy180)), 1],
          scaleMatrix = [abs(scaleX), 0, 0, abs(scaleY)];
      return fabric.util.multiplyTransformMatrices(scaleMatrix, skewMatrixX, true);
    },

    resetObjectTransform: function (target) {
      target.scaleX = 1;
      target.scaleY = 1;
      target.skewX = 0;
      target.skewY = 0;
      target.flipX = false;
      target.flipY = false;
      target.rotate(0);
    },

    /**
     * Returns string representation of function body
     * @param {Function} fn Function to get body of
     * @return {String} Function body
     */
    getFunctionBody: function(fn) {
      return (String(fn).match(/function[^{]*\{([\s\S]*)\}/) || {})[1];
    },

    /**
     * Returns true if context has transparent pixel
     * at specified location (taking tolerance into account)
     * @param {CanvasRenderingContext2D} ctx context
     * @param {Number} x x coordinate
     * @param {Number} y y coordinate
     * @param {Number} tolerance Tolerance
     */
    isTransparent: function(ctx, x, y, tolerance) {

      // If tolerance is > 0 adjust start coords to take into account.
      // If moves off Canvas fix to 0
      if (tolerance > 0) {
        if (x > tolerance) {
          x -= tolerance;
        }
        else {
          x = 0;
        }
        if (y > tolerance) {
          y -= tolerance;
        }
        else {
          y = 0;
        }
      }

      var _isTransparent = true, i, temp,
          imageData = ctx.getImageData(x, y, (tolerance * 2) || 1, (tolerance * 2) || 1),
          l = imageData.data.length;

      // Split image data - for tolerance > 1, pixelDataSize = 4;
      for (i = 3; i < l; i += 4) {
        temp = imageData.data[i];
        _isTransparent = temp <= 0;
        if (_isTransparent === false) {
          break; // Stop if colour found
        }
      }

      imageData = null;

      return _isTransparent;
    },

    /**
     * Parse preserveAspectRatio attribute from element
     * @param {string} attribute to be parsed
     * @return {Object} an object containing align and meetOrSlice attribute
     */
    parsePreserveAspectRatioAttribute: function(attribute) {
      var meetOrSlice = 'meet', alignX = 'Mid', alignY = 'Mid',
          aspectRatioAttrs = attribute.split(' '), align;

      if (aspectRatioAttrs && aspectRatioAttrs.length) {
        meetOrSlice = aspectRatioAttrs.pop();
        if (meetOrSlice !== 'meet' && meetOrSlice !== 'slice') {
          align = meetOrSlice;
          meetOrSlice = 'meet';
        }
        else if (aspectRatioAttrs.length) {
          align = aspectRatioAttrs.pop();
        }
      }
      //divide align in alignX and alignY
      alignX = align !== 'none' ? align.slice(1, 4) : 'none';
      alignY = align !== 'none' ? align.slice(5, 8) : 'none';
      return {
        meetOrSlice: meetOrSlice,
        alignX: alignX,
        alignY: alignY
      };
    },

    /**
     * Clear char widths cache for the given font family or all the cache if no
     * fontFamily is specified.
     * Use it if you know you are loading fonts in a lazy way and you are not waiting
     * for custom fonts to load properly when adding text objects to the canvas.
     * If a text object is added when its own font is not loaded yet, you will get wrong
     * measurement and so wrong bounding boxes.
     * After the font cache is cleared, either change the textObject text content or call
     * initDimensions() to trigger a recalculation
     * @memberOf fabric.util
     * @param {String} [fontFamily] font family to clear
     */
    clearFabricFontCache: function(fontFamily) {
      fontFamily = (fontFamily || '').toLowerCase();
      if (!fontFamily) {
        fabric.charWidthsCache = { };
      }
      else if (fabric.charWidthsCache[fontFamily]) {
        delete fabric.charWidthsCache[fontFamily];
      }
    },

    /**
     * Given current aspect ratio, determines the max width and height that can
     * respect the total allowed area for the cache.
     * @memberOf fabric.util
     * @param {Number} ar aspect ratio
     * @param {Number} maximumArea Maximum area you want to achieve
     * @return {Object.x} Limited dimensions by X
     * @return {Object.y} Limited dimensions by Y
     */
    limitDimsByArea: function(ar, maximumArea) {
      var roughWidth = Math.sqrt(maximumArea * ar),
          perfLimitSizeY = Math.floor(maximumArea / roughWidth);
      return { x: Math.floor(roughWidth), y: perfLimitSizeY };
    },

    capValue: function(min, value, max) {
      return Math.max(min, Math.min(value, max));
    },

    findScaleToFit: function(source, destination) {
      return Math.min(destination.width / source.width, destination.height / source.height);
    },

    findScaleToCover: function(source, destination) {
      return Math.max(destination.width / source.width, destination.height / source.height);
    }
  };
})(typeof exports !== 'undefined' ? exports : this);


(function() {

  var arcToSegmentsCache = { },
      segmentToBezierCache = { },
      boundsOfCurveCache = { },
      _join = Array.prototype.join;

  /* Adapted from http://dxr.mozilla.org/mozilla-central/source/content/svg/content/src/nsSVGPathDataParser.cpp
   * by Andrea Bogazzi code is under MPL. if you don't have a copy of the license you can take it here
   * http://mozilla.org/MPL/2.0/
   */
  function arcToSegments(toX, toY, rx, ry, large, sweep, rotateX) {
    var argsString = _join.call(arguments);
    if (arcToSegmentsCache[argsString]) {
      return arcToSegmentsCache[argsString];
    }

    var PI = Math.PI, th = rotateX * PI / 180,
        sinTh = fabric.util.sin(th),
        cosTh = fabric.util.cos(th),
        fromX = 0, fromY = 0;

    rx = Math.abs(rx);
    ry = Math.abs(ry);

    var px = -cosTh * toX * 0.5 - sinTh * toY * 0.5,
        py = -cosTh * toY * 0.5 + sinTh * toX * 0.5,
        rx2 = rx * rx, ry2 = ry * ry, py2 = py * py, px2 = px * px,
        pl = rx2 * ry2 - rx2 * py2 - ry2 * px2,
        root = 0;

    if (pl < 0) {
      var s = Math.sqrt(1 - pl / (rx2 * ry2));
      rx *= s;
      ry *= s;
    }
    else {
      root = (large === sweep ? -1.0 : 1.0) *
              Math.sqrt( pl / (rx2 * py2 + ry2 * px2));
    }

    var cx = root * rx * py / ry,
        cy = -root * ry * px / rx,
        cx1 = cosTh * cx - sinTh * cy + toX * 0.5,
        cy1 = sinTh * cx + cosTh * cy + toY * 0.5,
        mTheta = calcVectorAngle(1, 0, (px - cx) / rx, (py - cy) / ry),
        dtheta = calcVectorAngle((px - cx) / rx, (py - cy) / ry, (-px - cx) / rx, (-py - cy) / ry);

    if (sweep === 0 && dtheta > 0) {
      dtheta -= 2 * PI;
    }
    else if (sweep === 1 && dtheta < 0) {
      dtheta += 2 * PI;
    }

    // Convert into cubic bezier segments <= 90deg
    var segments = Math.ceil(Math.abs(dtheta / PI * 2)),
        result = [], mDelta = dtheta / segments,
        mT = 8 / 3 * Math.sin(mDelta / 4) * Math.sin(mDelta / 4) / Math.sin(mDelta / 2),
        th3 = mTheta + mDelta;

    for (var i = 0; i < segments; i++) {
      result[i] = segmentToBezier(mTheta, th3, cosTh, sinTh, rx, ry, cx1, cy1, mT, fromX, fromY);
      fromX = result[i][4];
      fromY = result[i][5];
      mTheta = th3;
      th3 += mDelta;
    }
    arcToSegmentsCache[argsString] = result;
    return result;
  }

  function segmentToBezier(th2, th3, cosTh, sinTh, rx, ry, cx1, cy1, mT, fromX, fromY) {
    var argsString2 = _join.call(arguments);
    if (segmentToBezierCache[argsString2]) {
      return segmentToBezierCache[argsString2];
    }

    var costh2 = fabric.util.cos(th2),
        sinth2 = fabric.util.sin(th2),
        costh3 = fabric.util.cos(th3),
        sinth3 = fabric.util.sin(th3),
        toX = cosTh * rx * costh3 - sinTh * ry * sinth3 + cx1,
        toY = sinTh * rx * costh3 + cosTh * ry * sinth3 + cy1,
        cp1X = fromX + mT * ( -cosTh * rx * sinth2 - sinTh * ry * costh2),
        cp1Y = fromY + mT * ( -sinTh * rx * sinth2 + cosTh * ry * costh2),
        cp2X = toX + mT * ( cosTh * rx * sinth3 + sinTh * ry * costh3),
        cp2Y = toY + mT * ( sinTh * rx * sinth3 - cosTh * ry * costh3);

    segmentToBezierCache[argsString2] = [
      cp1X, cp1Y,
      cp2X, cp2Y,
      toX, toY
    ];
    return segmentToBezierCache[argsString2];
  }

  /*
   * Private
   */
  function calcVectorAngle(ux, uy, vx, vy) {
    var ta = Math.atan2(uy, ux),
        tb = Math.atan2(vy, vx);
    if (tb >= ta) {
      return tb - ta;
    }
    else {
      return 2 * Math.PI - (ta - tb);
    }
  }

  /**
   * Draws arc
   * @param {CanvasRenderingContext2D} ctx
   * @param {Number} fx
   * @param {Number} fy
   * @param {Array} coords
   */
  fabric.util.drawArc = function(ctx, fx, fy, coords) {
    var rx = coords[0],
        ry = coords[1],
        rot = coords[2],
        large = coords[3],
        sweep = coords[4],
        tx = coords[5],
        ty = coords[6],
        segs = [[], [], [], []],
        segsNorm = arcToSegments(tx - fx, ty - fy, rx, ry, large, sweep, rot);

    for (var i = 0, len = segsNorm.length; i < len; i++) {
      segs[i][0] = segsNorm[i][0] + fx;
      segs[i][1] = segsNorm[i][1] + fy;
      segs[i][2] = segsNorm[i][2] + fx;
      segs[i][3] = segsNorm[i][3] + fy;
      segs[i][4] = segsNorm[i][4] + fx;
      segs[i][5] = segsNorm[i][5] + fy;
      ctx.bezierCurveTo.apply(ctx, segs[i]);
    }
  };

  /**
   * Calculate bounding box of a elliptic-arc
   * @param {Number} fx start point of arc
   * @param {Number} fy
   * @param {Number} rx horizontal radius
   * @param {Number} ry vertical radius
   * @param {Number} rot angle of horizontal axe
   * @param {Number} large 1 or 0, whatever the arc is the big or the small on the 2 points
   * @param {Number} sweep 1 or 0, 1 clockwise or counterclockwise direction
   * @param {Number} tx end point of arc
   * @param {Number} ty
   */
  fabric.util.getBoundsOfArc = function(fx, fy, rx, ry, rot, large, sweep, tx, ty) {

    var fromX = 0, fromY = 0, bound, bounds = [],
        segs = arcToSegments(tx - fx, ty - fy, rx, ry, large, sweep, rot);

    for (var i = 0, len = segs.length; i < len; i++) {
      bound = getBoundsOfCurve(fromX, fromY, segs[i][0], segs[i][1], segs[i][2], segs[i][3], segs[i][4], segs[i][5]);
      bounds.push({ x: bound[0].x + fx, y: bound[0].y + fy });
      bounds.push({ x: bound[1].x + fx, y: bound[1].y + fy });
      fromX = segs[i][4];
      fromY = segs[i][5];
    }
    return bounds;
  };

  /**
   * Calculate bounding box of a beziercurve
   * @param {Number} x0 starting point
   * @param {Number} y0
   * @param {Number} x1 first control point
   * @param {Number} y1
   * @param {Number} x2 secondo control point
   * @param {Number} y2
   * @param {Number} x3 end of beizer
   * @param {Number} y3
   */
  // taken from http://jsbin.com/ivomiq/56/edit  no credits available for that.
  function getBoundsOfCurve(x0, y0, x1, y1, x2, y2, x3, y3) {
    var argsString = _join.call(arguments);
    if (boundsOfCurveCache[argsString]) {
      return boundsOfCurveCache[argsString];
    }

    var sqrt = Math.sqrt,
        min = Math.min, max = Math.max,
        abs = Math.abs, tvalues = [],
        bounds = [[], []],
        a, b, c, t, t1, t2, b2ac, sqrtb2ac;

    b = 6 * x0 - 12 * x1 + 6 * x2;
    a = -3 * x0 + 9 * x1 - 9 * x2 + 3 * x3;
    c = 3 * x1 - 3 * x0;

    for (var i = 0; i < 2; ++i) {
      if (i > 0) {
        b = 6 * y0 - 12 * y1 + 6 * y2;
        a = -3 * y0 + 9 * y1 - 9 * y2 + 3 * y3;
        c = 3 * y1 - 3 * y0;
      }

      if (abs(a) < 1e-12) {
        if (abs(b) < 1e-12) {
          continue;
        }
        t = -c / b;
        if (0 < t && t < 1) {
          tvalues.push(t);
        }
        continue;
      }
      b2ac = b * b - 4 * c * a;
      if (b2ac < 0) {
        continue;
      }
      sqrtb2ac = sqrt(b2ac);
      t1 = (-b + sqrtb2ac) / (2 * a);
      if (0 < t1 && t1 < 1) {
        tvalues.push(t1);
      }
      t2 = (-b - sqrtb2ac) / (2 * a);
      if (0 < t2 && t2 < 1) {
        tvalues.push(t2);
      }
    }

    var x, y, j = tvalues.length, jlen = j, mt;
    while (j--) {
      t = tvalues[j];
      mt = 1 - t;
      x = (mt * mt * mt * x0) + (3 * mt * mt * t * x1) + (3 * mt * t * t * x2) + (t * t * t * x3);
      bounds[0][j] = x;

      y = (mt * mt * mt * y0) + (3 * mt * mt * t * y1) + (3 * mt * t * t * y2) + (t * t * t * y3);
      bounds[1][j] = y;
    }

    bounds[0][jlen] = x0;
    bounds[1][jlen] = y0;
    bounds[0][jlen + 1] = x3;
    bounds[1][jlen + 1] = y3;
    var result = [
      {
        x: min.apply(null, bounds[0]),
        y: min.apply(null, bounds[1])
      },
      {
        x: max.apply(null, bounds[0]),
        y: max.apply(null, bounds[1])
      }
    ];
    boundsOfCurveCache[argsString] = result;
    return result;
  }

  fabric.util.getBoundsOfCurve = getBoundsOfCurve;

})();


(function() {

  var slice = Array.prototype.slice;

  /**
   * Invokes method on all items in a given array
   * @memberOf fabric.util.array
   * @param {Array} array Array to iterate over
   * @param {String} method Name of a method to invoke
   * @return {Array}
   */
  function invoke(array, method) {
    var args = slice.call(arguments, 2), result = [];
    for (var i = 0, len = array.length; i < len; i++) {
      result[i] = args.length ? array[i][method].apply(array[i], args) : array[i][method].call(array[i]);
    }
    return result;
  }

  /**
   * Finds maximum value in array (not necessarily "first" one)
   * @memberOf fabric.util.array
   * @param {Array} array Array to iterate over
   * @param {String} byProperty
   * @return {*}
   */
  function max(array, byProperty) {
    return find(array, byProperty, function(value1, value2) {
      return value1 >= value2;
    });
  }

  /**
   * Finds minimum value in array (not necessarily "first" one)
   * @memberOf fabric.util.array
   * @param {Array} array Array to iterate over
   * @param {String} byProperty
   * @return {*}
   */
  function min(array, byProperty) {
    return find(array, byProperty, function(value1, value2) {
      return value1 < value2;
    });
  }

  /**
   * @private
   */
  function fill(array, value) {
    var k = array.length;
    while (k--) {
      array[k] = value;
    }
    return array;
  }

  /**
   * @private
   */
  function find(array, byProperty, condition) {
    if (!array || array.length === 0) {
      return;
    }

    var i = array.length - 1,
        result = byProperty ? array[i][byProperty] : array[i];
    if (byProperty) {
      while (i--) {
        if (condition(array[i][byProperty], result)) {
          result = array[i][byProperty];
        }
      }
    }
    else {
      while (i--) {
        if (condition(array[i], result)) {
          result = array[i];
        }
      }
    }
    return result;
  }

  /**
   * @namespace fabric.util.array
   */
  fabric.util.array = {
    fill: fill,
    invoke: invoke,
    min: min,
    max: max
  };

})();


(function() {
  /**
   * Copies all enumerable properties of one js object to another
   * Does not clone or extend fabric.Object subclasses.
   * @memberOf fabric.util.object
   * @param {Object} destination Where to copy to
   * @param {Object} source Where to copy from
   * @return {Object}
   */

  function extend(destination, source, deep) {
    // JScript DontEnum bug is not taken care of
    // the deep clone is for internal use, is not meant to avoid
    // javascript traps or cloning html element or self referenced objects.
    if (deep) {
      if (!fabric.isLikelyNode && source instanceof Element) {
        // avoid cloning deep images, canvases,
        destination = source;
      }
      else if (source instanceof Array) {
        destination = [];
        for (var i = 0, len = source.length; i < len; i++) {
          destination[i] = extend({ }, source[i], deep);
        }
      }
      else if (source && typeof source === 'object') {
        for (var property in source) {
          if (source.hasOwnProperty(property)) {
            destination[property] = extend({ }, source[property], deep);
          }
        }
      }
      else {
        // this sounds odd for an extend but is ok for recursive use
        destination = source;
      }
    }
    else {
      for (var property in source) {
        destination[property] = source[property];
      }
    }
    return destination;
  }

  /**
   * Creates an empty object and copies all enumerable properties of another object to it
   * @memberOf fabric.util.object
   * TODO: this function return an empty object if you try to clone null
   * @param {Object} object Object to clone
   * @return {Object}
   */
  function clone(object, deep) {
    return extend({ }, object, deep);
  }

  /** @namespace fabric.util.object */
  fabric.util.object = {
    extend: extend,
    clone: clone
  };
  fabric.util.object.extend(fabric.util, fabric.Observable);
})();


(function() {

  /**
   * Camelizes a string
   * @memberOf fabric.util.string
   * @param {String} string String to camelize
   * @return {String} Camelized version of a string
   */
  function camelize(string) {
    return string.replace(/-+(.)?/g, function(match, character) {
      return character ? character.toUpperCase() : '';
    });
  }

  /**
   * Capitalizes a string
   * @memberOf fabric.util.string
   * @param {String} string String to capitalize
   * @param {Boolean} [firstLetterOnly] If true only first letter is capitalized
   * and other letters stay untouched, if false first letter is capitalized
   * and other letters are converted to lowercase.
   * @return {String} Capitalized version of a string
   */
  function capitalize(string, firstLetterOnly) {
    return string.charAt(0).toUpperCase() +
      (firstLetterOnly ? string.slice(1) : string.slice(1).toLowerCase());
  }

  /**
   * Escapes XML in a string
   * @memberOf fabric.util.string
   * @param {String} string String to escape
   * @return {String} Escaped version of a string
   */
  function escapeXml(string) {
    return string.replace(/&/g, '&amp;')
      .replace(/"/g, '&quot;')
      .replace(/'/g, '&apos;')
      .replace(/</g, '&lt;')
      .replace(/>/g, '&gt;');
  }

  /**
   * Divide a string in the user perceived single units
   * @memberOf fabric.util.string
   * @param {String} textstring String to escape
   * @return {Array} array containing the graphemes
   */
  function graphemeSplit(textstring) {
    var i = 0, chr, graphemes = [];
    for (i = 0, chr; i < textstring.length; i++) {
      if ((chr = getWholeChar(textstring, i)) === false) {
        continue;
      }
      graphemes.push(chr);
    }
    return graphemes;
  }

  // taken from mdn in the charAt doc page.
  function getWholeChar(str, i) {
    var code = str.charCodeAt(i);

    if (isNaN(code)) {
      return ''; // Position not found
    }
    if (code < 0xD800 || code > 0xDFFF) {
      return str.charAt(i);
    }

    // High surrogate (could change last hex to 0xDB7F to treat high private
    // surrogates as single characters)
    if (0xD800 <= code && code <= 0xDBFF) {
      if (str.length <= (i + 1)) {
        throw 'High surrogate without following low surrogate';
      }
      var next = str.charCodeAt(i + 1);
      if (0xDC00 > next || next > 0xDFFF) {
        throw 'High surrogate without following low surrogate';
      }
      return str.charAt(i) + str.charAt(i + 1);
    }
    // Low surrogate (0xDC00 <= code && code <= 0xDFFF)
    if (i === 0) {
      throw 'Low surrogate without preceding high surrogate';
    }
    var prev = str.charCodeAt(i - 1);

    // (could change last hex to 0xDB7F to treat high private
    // surrogates as single characters)
    if (0xD800 > prev || prev > 0xDBFF) {
      throw 'Low surrogate without preceding high surrogate';
    }
    // We can pass over low surrogates now as the second component
    // in a pair which we have already processed
    return false;
  }


  /**
   * String utilities
   * @namespace fabric.util.string
   */
  fabric.util.string = {
    camelize: camelize,
    capitalize: capitalize,
    escapeXml: escapeXml,
    graphemeSplit: graphemeSplit
  };
})();


(function() {

  var slice = Array.prototype.slice, emptyFunction = function() { },

      IS_DONTENUM_BUGGY = (function() {
        for (var p in { toString: 1 }) {
          if (p === 'toString') {
            return false;
          }
        }
        return true;
      })(),

      /** @ignore */
      addMethods = function(klass, source, parent) {
        for (var property in source) {

          if (property in klass.prototype &&
              typeof klass.prototype[property] === 'function' &&
              (source[property] + '').indexOf('callSuper') > -1) {

            klass.prototype[property] = (function(property) {
              return function() {

                var superclass = this.constructor.superclass;
                this.constructor.superclass = parent;
                var returnValue = source[property].apply(this, arguments);
                this.constructor.superclass = superclass;

                if (property !== 'initialize') {
                  return returnValue;
                }
              };
            })(property);
          }
          else {
            klass.prototype[property] = source[property];
          }

          if (IS_DONTENUM_BUGGY) {
            if (source.toString !== Object.prototype.toString) {
              klass.prototype.toString = source.toString;
            }
            if (source.valueOf !== Object.prototype.valueOf) {
              klass.prototype.valueOf = source.valueOf;
            }
          }
        }
      };

  function Subclass() { }

  function callSuper(methodName) {
    var parentMethod = null,
        _this = this;

    // climb prototype chain to find method not equal to callee's method
    while (_this.constructor.superclass) {
      var superClassMethod = _this.constructor.superclass.prototype[methodName];
      if (_this[methodName] !== superClassMethod) {
        parentMethod = superClassMethod;
        break;
      }
      // eslint-disable-next-line
      _this = _this.constructor.superclass.prototype;
    }

    if (!parentMethod) {
      return console.log('tried to callSuper ' + methodName + ', method not found in prototype chain', this);
    }

    return (arguments.length > 1)
      ? parentMethod.apply(this, slice.call(arguments, 1))
      : parentMethod.call(this);
  }

  /**
   * Helper for creation of "classes".
   * @memberOf fabric.util
   * @param {Function} [parent] optional "Class" to inherit from
   * @param {Object} [properties] Properties shared by all instances of this class
   *                  (be careful modifying objects defined here as this would affect all instances)
   */
  function createClass() {
    var parent = null,
        properties = slice.call(arguments, 0);

    if (typeof properties[0] === 'function') {
      parent = properties.shift();
    }
    function klass() {
      this.initialize.apply(this, arguments);
    }

    klass.superclass = parent;
    klass.subclasses = [];

    if (parent) {
      Subclass.prototype = parent.prototype;
      klass.prototype = new Subclass();
      parent.subclasses.push(klass);
    }
    for (var i = 0, length = properties.length; i < length; i++) {
      addMethods(klass, properties[i], parent);
    }
    if (!klass.prototype.initialize) {
      klass.prototype.initialize = emptyFunction;
    }
    klass.prototype.constructor = klass;
    klass.prototype.callSuper = callSuper;
    return klass;
  }

  fabric.util.createClass = createClass;
})();


(function () {

  var unknown = 'unknown';

  /* EVENT HANDLING */

  function areHostMethods(object) {
    var methodNames = Array.prototype.slice.call(arguments, 1),
        t, i, len = methodNames.length;
    for (i = 0; i < len; i++) {
      t = typeof object[methodNames[i]];
      if (!(/^(?:function|object|unknown)$/).test(t)) {
        return false;
      }
    }
    return true;
  }

  /** @ignore */
  var getElement,
      setElement,
      getUniqueId = (function () {
        var uid = 0;
        return function (element) {
          return element.__uniqueID || (element.__uniqueID = 'uniqueID__' + uid++);
        };
      })();

  (function () {
    var elements = { };
    /** @ignore */
    getElement = function (uid) {
      return elements[uid];
    };
    /** @ignore */
    setElement = function (uid, element) {
      elements[uid] = element;
    };
  })();

  function createListener(uid, handler) {
    return {
      handler: handler,
      wrappedHandler: createWrappedHandler(uid, handler)
    };
  }

  function createWrappedHandler(uid, handler) {
    return function (e) {
      handler.call(getElement(uid), e || fabric.window.event);
    };
  }

  function createDispatcher(uid, eventName) {
    return function (e) {
      if (handlers[uid] && handlers[uid][eventName]) {
        var handlersForEvent = handlers[uid][eventName];
        for (var i = 0, len = handlersForEvent.length; i < len; i++) {
          handlersForEvent[i].call(this, e || fabric.window.event);
        }
      }
    };
  }

  var shouldUseAddListenerRemoveListener = (
        areHostMethods(fabric.document.documentElement, 'addEventListener', 'removeEventListener') &&
        areHostMethods(fabric.window, 'addEventListener', 'removeEventListener')),

      shouldUseAttachEventDetachEvent = (
        areHostMethods(fabric.document.documentElement, 'attachEvent', 'detachEvent') &&
        areHostMethods(fabric.window, 'attachEvent', 'detachEvent')),

      // IE branch
      listeners = { },

      // DOM L0 branch
      handlers = { },

      addListener, removeListener;

  if (shouldUseAddListenerRemoveListener) {
    /** @ignore */
    addListener = function (element, eventName, handler, options) {
      // since ie10 or ie9 can use addEventListener but they do not support options, i need to check
      element && element.addEventListener(eventName, handler, shouldUseAttachEventDetachEvent ? false : options);
    };
    /** @ignore */
    removeListener = function (element, eventName, handler, options) {
      element && element.removeEventListener(eventName, handler, shouldUseAttachEventDetachEvent ? false : options);
    };
  }

  else if (shouldUseAttachEventDetachEvent) {
    /** @ignore */
    addListener = function (element, eventName, handler) {
      if (!element) {
        return;
      }
      var uid = getUniqueId(element);
      setElement(uid, element);
      if (!listeners[uid]) {
        listeners[uid] = { };
      }
      if (!listeners[uid][eventName]) {
        listeners[uid][eventName] = [];

      }
      var listener = createListener(uid, handler);
      listeners[uid][eventName].push(listener);
      element.attachEvent('on' + eventName, listener.wrappedHandler);
    };
    /** @ignore */
    removeListener = function (element, eventName, handler) {
      if (!element) {
        return;
      }
      var uid = getUniqueId(element), listener;
      if (listeners[uid] && listeners[uid][eventName]) {
        for (var i = 0, len = listeners[uid][eventName].length; i < len; i++) {
          listener = listeners[uid][eventName][i];
          if (listener && listener.handler === handler) {
            element.detachEvent('on' + eventName, listener.wrappedHandler);
            listeners[uid][eventName][i] = null;
          }
        }
      }
    };
  }
  else {
    /** @ignore */
    addListener = function (element, eventName, handler) {
      if (!element) {
        return;
      }
      var uid = getUniqueId(element);
      if (!handlers[uid]) {
        handlers[uid] = { };
      }
      if (!handlers[uid][eventName]) {
        handlers[uid][eventName] = [];
        var existingHandler = element['on' + eventName];
        if (existingHandler) {
          handlers[uid][eventName].push(existingHandler);
        }
        element['on' + eventName] = createDispatcher(uid, eventName);
      }
      handlers[uid][eventName].push(handler);
    };
    /** @ignore */
    removeListener = function (element, eventName, handler) {
      if (!element) {
        return;
      }
      var uid = getUniqueId(element);
      if (handlers[uid] && handlers[uid][eventName]) {
        var handlersForEvent = handlers[uid][eventName];
        for (var i = 0, len = handlersForEvent.length; i < len; i++) {
          if (handlersForEvent[i] === handler) {
            handlersForEvent.splice(i, 1);
          }
        }
      }
    };
  }

  /**
   * Adds an event listener to an element
   * @function
   * @memberOf fabric.util
   * @param {HTMLElement} element
   * @param {String} eventName
   * @param {Function} handler
   */
  fabric.util.addListener = addListener;

  /**
   * Removes an event listener from an element
   * @function
   * @memberOf fabric.util
   * @param {HTMLElement} element
   * @param {String} eventName
   * @param {Function} handler
   */
  fabric.util.removeListener = removeListener;

  /**
   * Cross-browser wrapper for getting event's coordinates
   * @memberOf fabric.util
   * @param {Event} event Event object
   */
  function getPointer(event) {
    event || (event = fabric.window.event);

    var element = event.target ||
                  (typeof event.srcElement !== unknown ? event.srcElement : null),

        scroll = fabric.util.getScrollLeftTop(element);
    return {
      x: pointerX(event) + scroll.left,
      y: pointerY(event) + scroll.top
    };
  }

  var pointerX = function(event) {
        return event.clientX;
      },

      pointerY = function(event) {
        return event.clientY;
      };

  function _getPointer(event, pageProp, clientProp) {
    var touchProp = event.type === 'touchend' ? 'changedTouches' : 'touches';
    var pointer, eventTouchProp = event[touchProp];

    if (eventTouchProp && eventTouchProp[0]) {
      pointer = eventTouchProp[0][clientProp];
    }

    if (typeof pointer === 'undefined') {
      pointer = event[clientProp];
    }

    return pointer;
  }

  if (fabric.isTouchSupported) {
    pointerX = function(event) {
      return _getPointer(event, 'pageX', 'clientX');
    };
    pointerY = function(event) {
      return _getPointer(event, 'pageY', 'clientY');
    };
  }

  fabric.util.getPointer = getPointer;

})();


(function () {

  /**
   * Cross-browser wrapper for setting element's style
   * @memberOf fabric.util
   * @param {HTMLElement} element
   * @param {Object} styles
   * @return {HTMLElement} Element that was passed as a first argument
   */
  function setStyle(element, styles) {
    var elementStyle = element.style;
    if (!elementStyle) {
      return element;
    }
    if (typeof styles === 'string') {
      element.style.cssText += ';' + styles;
      return styles.indexOf('opacity') > -1
        ? setOpacity(element, styles.match(/opacity:\s*(\d?\.?\d*)/)[1])
        : element;
    }
    for (var property in styles) {
      if (property === 'opacity') {
        setOpacity(element, styles[property]);
      }
      else {
        var normalizedProperty = (property === 'float' || property === 'cssFloat')
          ? (typeof elementStyle.styleFloat === 'undefined' ? 'cssFloat' : 'styleFloat')
          : property;
        elementStyle[normalizedProperty] = styles[property];
      }
    }
    return element;
  }

  var parseEl = fabric.document.createElement('div'),
      supportsOpacity = typeof parseEl.style.opacity === 'string',
      supportsFilters = typeof parseEl.style.filter === 'string',
      reOpacity = /alpha\s*\(\s*opacity\s*=\s*([^\)]+)\)/,

      /** @ignore */
      setOpacity = function (element) { return element; };

  if (supportsOpacity) {
    /** @ignore */
    setOpacity = function(element, value) {
      element.style.opacity = value;
      return element;
    };
  }
  else if (supportsFilters) {
    /** @ignore */
    setOpacity = function(element, value) {
      var es = element.style;
      if (element.currentStyle && !element.currentStyle.hasLayout) {
        es.zoom = 1;
      }
      if (reOpacity.test(es.filter)) {
        value = value >= 0.9999 ? '' : ('alpha(opacity=' + (value * 100) + ')');
        es.filter = es.filter.replace(reOpacity, value);
      }
      else {
        es.filter += ' alpha(opacity=' + (value * 100) + ')';
      }
      return element;
    };
  }

  fabric.util.setStyle = setStyle;

})();


(function() {

  var _slice = Array.prototype.slice;

  /**
   * Takes id and returns an element with that id (if one exists in a document)
   * @memberOf fabric.util
   * @param {String|HTMLElement} id
   * @return {HTMLElement|null}
   */
  function getById(id) {
    return typeof id === 'string' ? fabric.document.getElementById(id) : id;
  }

  var sliceCanConvertNodelists,
      /**
       * Converts an array-like object (e.g. arguments or NodeList) to an array
       * @memberOf fabric.util
       * @param {Object} arrayLike
       * @return {Array}
       */
      toArray = function(arrayLike) {
        return _slice.call(arrayLike, 0);
      };

  try {
    sliceCanConvertNodelists = toArray(fabric.document.childNodes) instanceof Array;
  }
  catch (err) { }

  if (!sliceCanConvertNodelists) {
    toArray = function(arrayLike) {
      var arr = new Array(arrayLike.length), i = arrayLike.length;
      while (i--) {
        arr[i] = arrayLike[i];
      }
      return arr;
    };
  }

  /**
   * Creates specified element with specified attributes
   * @memberOf fabric.util
   * @param {String} tagName Type of an element to create
   * @param {Object} [attributes] Attributes to set on an element
   * @return {HTMLElement} Newly created element
   */
  function makeElement(tagName, attributes) {
    var el = fabric.document.createElement(tagName);
    for (var prop in attributes) {
      if (prop === 'class') {
        el.className = attributes[prop];
      }
      else if (prop === 'for') {
        el.htmlFor = attributes[prop];
      }
      else {
        el.setAttribute(prop, attributes[prop]);
      }
    }
    return el;
  }

  /**
   * Adds class to an element
   * @memberOf fabric.util
   * @param {HTMLElement} element Element to add class to
   * @param {String} className Class to add to an element
   */
  function addClass(element, className) {
    if (element && (' ' + element.className + ' ').indexOf(' ' + className + ' ') === -1) {
      element.className += (element.className ? ' ' : '') + className;
    }
  }

  /**
   * Wraps element with another element
   * @memberOf fabric.util
   * @param {HTMLElement} element Element to wrap
   * @param {HTMLElement|String} wrapper Element to wrap with
   * @param {Object} [attributes] Attributes to set on a wrapper
   * @return {HTMLElement} wrapper
   */
  function wrapElement(element, wrapper, attributes) {
    if (typeof wrapper === 'string') {
      wrapper = makeElement(wrapper, attributes);
    }
    if (element.parentNode) {
      element.parentNode.replaceChild(wrapper, element);
    }
    wrapper.appendChild(element);
    return wrapper;
  }

  /**
   * Returns element scroll offsets
   * @memberOf fabric.util
   * @param {HTMLElement} element Element to operate on
   * @return {Object} Object with left/top values
   */
  function getScrollLeftTop(element) {

    var left = 0,
        top = 0,
        docElement = fabric.document.documentElement,
        body = fabric.document.body || {
          scrollLeft: 0, scrollTop: 0
        };

    // While loop checks (and then sets element to) .parentNode OR .host
    //  to account for ShadowDOM. We still want to traverse up out of ShadowDOM,
    //  but the .parentNode of a root ShadowDOM node will always be null, instead
    //  it should be accessed through .host. See http://stackoverflow.com/a/24765528/4383938
    while (element && (element.parentNode || element.host)) {

      // Set element to element parent, or 'host' in case of ShadowDOM
      element = element.parentNode || element.host;

      if (element === fabric.document) {
        left = body.scrollLeft || docElement.scrollLeft || 0;
        top = body.scrollTop ||  docElement.scrollTop || 0;
      }
      else {
        left += element.scrollLeft || 0;
        top += element.scrollTop || 0;
      }

      if (element.nodeType === 1 && element.style.position === 'fixed') {
        break;
      }
    }

    return { left: left, top: top };
  }

  /**
   * Returns offset for a given element
   * @function
   * @memberOf fabric.util
   * @param {HTMLElement} element Element to get offset for
   * @return {Object} Object with "left" and "top" properties
   */
  function getElementOffset(element) {
    var docElem,
        doc = element && element.ownerDocument,
        box = { left: 0, top: 0 },
        offset = { left: 0, top: 0 },
        scrollLeftTop,
        offsetAttributes = {
          borderLeftWidth: 'left',
          borderTopWidth:  'top',
          paddingLeft:     'left',
          paddingTop:      'top'
        };

    if (!doc) {
      return offset;
    }

    for (var attr in offsetAttributes) {
      offset[offsetAttributes[attr]] += parseInt(getElementStyle(element, attr), 10) || 0;
    }

    docElem = doc.documentElement;
    if ( typeof element.getBoundingClientRect !== 'undefined' ) {
      box = element.getBoundingClientRect();
    }

    scrollLeftTop = getScrollLeftTop(element);

    return {
      left: box.left + scrollLeftTop.left - (docElem.clientLeft || 0) + offset.left,
      top: box.top + scrollLeftTop.top - (docElem.clientTop || 0)  + offset.top
    };
  }

  /**
   * Returns style attribute value of a given element
   * @memberOf fabric.util
   * @param {HTMLElement} element Element to get style attribute for
   * @param {String} attr Style attribute to get for element
   * @return {String} Style attribute value of the given element.
   */
  var getElementStyle;
  if (fabric.document.defaultView && fabric.document.defaultView.getComputedStyle) {
    getElementStyle = function(element, attr) {
      var style = fabric.document.defaultView.getComputedStyle(element, null);
      return style ? style[attr] : undefined;
    };
  }
  else {
    getElementStyle = function(element, attr) {
      var value = element.style[attr];
      if (!value && element.currentStyle) {
        value = element.currentStyle[attr];
      }
      return value;
    };
  }

  (function () {
    var style = fabric.document.documentElement.style,
        selectProp = 'userSelect' in style
          ? 'userSelect'
          : 'MozUserSelect' in style
            ? 'MozUserSelect'
            : 'WebkitUserSelect' in style
              ? 'WebkitUserSelect'
              : 'KhtmlUserSelect' in style
                ? 'KhtmlUserSelect'
                : '';

    /**
     * Makes element unselectable
     * @memberOf fabric.util
     * @param {HTMLElement} element Element to make unselectable
     * @return {HTMLElement} Element that was passed in
     */
    function makeElementUnselectable(element) {
      if (typeof element.onselectstart !== 'undefined') {
        element.onselectstart = fabric.util.falseFunction;
      }
      if (selectProp) {
        element.style[selectProp] = 'none';
      }
      else if (typeof element.unselectable === 'string') {
        element.unselectable = 'on';
      }
      return element;
    }

    /**
     * Makes element selectable
     * @memberOf fabric.util
     * @param {HTMLElement} element Element to make selectable
     * @return {HTMLElement} Element that was passed in
     */
    function makeElementSelectable(element) {
      if (typeof element.onselectstart !== 'undefined') {
        element.onselectstart = null;
      }
      if (selectProp) {
        element.style[selectProp] = '';
      }
      else if (typeof element.unselectable === 'string') {
        element.unselectable = '';
      }
      return element;
    }

    fabric.util.makeElementUnselectable = makeElementUnselectable;
    fabric.util.makeElementSelectable = makeElementSelectable;
  })();

  (function() {

    /**
     * Inserts a script element with a given url into a document; invokes callback, when that script is finished loading
     * @memberOf fabric.util
     * @param {String} url URL of a script to load
     * @param {Function} callback Callback to execute when script is finished loading
     */
    function getScript(url, callback) {
      var headEl = fabric.document.getElementsByTagName('head')[0],
          scriptEl = fabric.document.createElement('script'),
          loading = true;

      /** @ignore */
      scriptEl.onload = /** @ignore */ scriptEl.onreadystatechange = function(e) {
        if (loading) {
          if (typeof this.readyState === 'string' &&
              this.readyState !== 'loaded' &&
              this.readyState !== 'complete') {
            return;
          }
          loading = false;
          callback(e || fabric.window.event);
          scriptEl = scriptEl.onload = scriptEl.onreadystatechange = null;
        }
      };
      scriptEl.src = url;
      headEl.appendChild(scriptEl);
      // causes issue in Opera
      // headEl.removeChild(scriptEl);
    }

    fabric.util.getScript = getScript;
  })();

  function getNodeCanvas(element) {
    var impl = fabric.jsdomImplForWrapper(element);
    return impl._canvas || impl._image;
  };

  fabric.util.getById = getById;
  fabric.util.toArray = toArray;
  fabric.util.makeElement = makeElement;
  fabric.util.addClass = addClass;
  fabric.util.wrapElement = wrapElement;
  fabric.util.getScrollLeftTop = getScrollLeftTop;
  fabric.util.getElementOffset = getElementOffset;
  fabric.util.getElementStyle = getElementStyle;
  fabric.util.getNodeCanvas = getNodeCanvas;

})();


(function() {

  function addParamToUrl(url, param) {
    return url + (/\?/.test(url) ? '&' : '?') + param;
  }

  var makeXHR = (function() {
    var factories = [
      function() { return new ActiveXObject('Microsoft.XMLHTTP'); },
      function() { return new ActiveXObject('Msxml2.XMLHTTP'); },
      function() { return new ActiveXObject('Msxml2.XMLHTTP.3.0'); },
      function() { return new XMLHttpRequest(); }
    ];
    for (var i = factories.length; i--; ) {
      try {
        var req = factories[i]();
        if (req) {
          return factories[i];
        }
      }
      catch (err) { }
    }
  })();

  function emptyFn() { }

  /**
   * Cross-browser abstraction for sending XMLHttpRequest
   * @memberOf fabric.util
   * @param {String} url URL to send XMLHttpRequest to
   * @param {Object} [options] Options object
   * @param {String} [options.method="GET"]
   * @param {String} [options.parameters] parameters to append to url in GET or in body
   * @param {String} [options.body] body to send with POST or PUT request
   * @param {Function} options.onComplete Callback to invoke when request is completed
   * @return {XMLHttpRequest} request
   */
  function request(url, options) {

    options || (options = { });

    var method = options.method ? options.method.toUpperCase() : 'GET',
        onComplete = options.onComplete || function() { },
        xhr = makeXHR(),
        body = options.body || options.parameters;

    /** @ignore */
    xhr.onreadystatechange = function() {
      if (xhr.readyState === 4) {
        onComplete(xhr);
        xhr.onreadystatechange = emptyFn;
      }
    };

    if (method === 'GET') {
      body = null;
      if (typeof options.parameters === 'string') {
        url = addParamToUrl(url, options.parameters);
      }
    }

    xhr.open(method, url, true);

    if (method === 'POST' || method === 'PUT') {
      xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    }

    xhr.send(body);
    return xhr;
  }

  fabric.util.request = request;
})();


/**
 * Wrapper around `console.log` (when available)
 * @param {*} [values] Values to log
 */
fabric.log = function() { };

/**
 * Wrapper around `console.warn` (when available)
 * @param {*} [values] Values to log as a warning
 */
fabric.warn = function() { };

/* eslint-disable */
if (typeof console !== 'undefined') {

  ['log', 'warn'].forEach(function(methodName) {

    if (typeof console[methodName] !== 'undefined' &&
        typeof console[methodName].apply === 'function') {

      fabric[methodName] = function() {
        return console[methodName].apply(console, arguments);
      };
    }
  });
}
/* eslint-enable */


(function() {

  function noop() {
    return false;
  }

  /**
   * Changes value from one to another within certain period of time, invoking callbacks as value is being changed.
   * @memberOf fabric.util
   * @param {Object} [options] Animation options
   * @param {Function} [options.onChange] Callback; invoked on every value change
   * @param {Function} [options.onComplete] Callback; invoked when value change is completed
   * @param {Number} [options.startValue=0] Starting value
   * @param {Number} [options.endValue=100] Ending value
   * @param {Number} [options.byValue=100] Value to modify the property by
   * @param {Function} [options.easing] Easing function
   * @param {Number} [options.duration=500] Duration of change (in ms)
   */
  function animate(options) {

    requestAnimFrame(function(timestamp) {
      options || (options = { });

      var start = timestamp || +new Date(),
          duration = options.duration || 500,
          finish = start + duration, time,
          onChange = options.onChange || noop,
          abort = options.abort || noop,
          onComplete = options.onComplete || noop,
          easing = options.easing || function(t, b, c, d) {return -c * Math.cos(t / d * (Math.PI / 2)) + c + b;},
          startValue = 'startValue' in options ? options.startValue : 0,
          endValue = 'endValue' in options ? options.endValue : 100,
          byValue = options.byValue || endValue - startValue;

      options.onStart && options.onStart();

      (function tick(ticktime) {
        if (abort()) {
          onComplete(endValue, 1, 1);
          return;
        }
        time = ticktime || +new Date();
        var currentTime = time > finish ? duration : (time - start),
            timePerc = currentTime / duration,
            current = easing(currentTime, startValue, byValue, duration),
            valuePerc = Math.abs((current - startValue) / byValue);
        onChange(current, valuePerc, timePerc);
        if (time > finish) {
          options.onComplete && options.onComplete();
          return;
        }
        requestAnimFrame(tick);
      })(start);
    });

  }

  var _requestAnimFrame = fabric.window.requestAnimationFrame       ||
                          fabric.window.webkitRequestAnimationFrame ||
                          fabric.window.mozRequestAnimationFrame    ||
                          fabric.window.oRequestAnimationFrame      ||
                          fabric.window.msRequestAnimationFrame     ||
                          function(callback) {
                            return fabric.window.setTimeout(callback, 1000 / 60);
                          };

  var _cancelAnimFrame = fabric.window.cancelAnimationFrame || fabric.window.clearTimeout;

  /**
   * requestAnimationFrame polyfill based on http://paulirish.com/2011/requestanimationframe-for-smart-animating/
   * In order to get a precise start time, `requestAnimFrame` should be called as an entry into the method
   * @memberOf fabric.util
   * @param {Function} callback Callback to invoke
   * @param {DOMElement} element optional Element to associate with animation
   */
  function requestAnimFrame() {
    return _requestAnimFrame.apply(fabric.window, arguments);
  }

  function cancelAnimFrame() {
    return _cancelAnimFrame.apply(fabric.window, arguments);
  }

  fabric.util.animate = animate;
  fabric.util.requestAnimFrame = requestAnimFrame;
  fabric.util.cancelAnimFrame = cancelAnimFrame;
})();


(function() {
  // Calculate an in-between color. Returns a "rgba()" string.
  // Credit: Edwin Martin <edwin@bitstorm.org>
  //         http://www.bitstorm.org/jquery/color-animation/jquery.animate-colors.js
  function calculateColor(begin, end, pos) {
    var color = 'rgba('
        + parseInt((begin[0] + pos * (end[0] - begin[0])), 10) + ','
        + parseInt((begin[1] + pos * (end[1] - begin[1])), 10) + ','
        + parseInt((begin[2] + pos * (end[2] - begin[2])), 10);

    color += ',' + (begin && end ? parseFloat(begin[3] + pos * (end[3] - begin[3])) : 1);
    color += ')';
    return color;
  }

  /**
   * Changes the color from one to another within certain period of time, invoking callbacks as value is being changed.
   * @memberOf fabric.util
   * @param {String} fromColor The starting color in hex or rgb(a) format.
   * @param {String} toColor The starting color in hex or rgb(a) format.
   * @param {Number} [duration] Duration of change (in ms).
   * @param {Object} [options] Animation options
   * @param {Function} [options.onChange] Callback; invoked on every value change
   * @param {Function} [options.onComplete] Callback; invoked when value change is completed
   * @param {Function} [options.colorEasing] Easing function. Note that this function only take two arguments (currentTime, duration). Thus the regular animation easing functions cannot be used.
   */
  function animateColor(fromColor, toColor, duration, options) {
    var startColor = new fabric.Color(fromColor).getSource(),
        endColor = new fabric.Color(toColor).getSource();

    options = options || {};

    fabric.util.animate(fabric.util.object.extend(options, {
      duration: duration || 500,
      startValue: startColor,
      endValue: endColor,
      byValue: endColor,
      easing: function (currentTime, startValue, byValue, duration) {
        var posValue = options.colorEasing
          ? options.colorEasing(currentTime, duration)
          : 1 - Math.cos(currentTime / duration * (Math.PI / 2));
        return calculateColor(startValue, byValue, posValue);
      }
    }));
  }

  fabric.util.animateColor = animateColor;

})();


(function() {

  function normalize(a, c, p, s) {
    if (a < Math.abs(c)) {
      a = c;
      s = p / 4;
    }
    else {
      //handle the 0/0 case:
      if (c === 0 && a === 0) {
        s = p / (2 * Math.PI) * Math.asin(1);
      }
      else {
        s = p / (2 * Math.PI) * Math.asin(c / a);
      }
    }
    return { a: a, c: c, p: p, s: s };
  }

  function elastic(opts, t, d) {
    return opts.a *
      Math.pow(2, 10 * (t -= 1)) *
      Math.sin( (t * d - opts.s) * (2 * Math.PI) / opts.p );
  }

  /**
   * Cubic easing out
   * @memberOf fabric.util.ease
   */
  function easeOutCubic(t, b, c, d) {
    return c * ((t = t / d - 1) * t * t + 1) + b;
  }

  /**
   * Cubic easing in and out
   * @memberOf fabric.util.ease
   */
  function easeInOutCubic(t, b, c, d) {
    t /= d / 2;
    if (t < 1) {
      return c / 2 * t * t * t + b;
    }
    return c / 2 * ((t -= 2) * t * t + 2) + b;
  }

  /**
   * Quartic easing in
   * @memberOf fabric.util.ease
   */
  function easeInQuart(t, b, c, d) {
    return c * (t /= d) * t * t * t + b;
  }

  /**
   * Quartic easing out
   * @memberOf fabric.util.ease
   */
  function easeOutQuart(t, b, c, d) {
    return -c * ((t = t / d - 1) * t * t * t - 1) + b;
  }

  /**
   * Quartic easing in and out
   * @memberOf fabric.util.ease
   */
  function easeInOutQuart(t, b, c, d) {
    t /= d / 2;
    if (t < 1) {
      return c / 2 * t * t * t * t + b;
    }
    return -c / 2 * ((t -= 2) * t * t * t - 2) + b;
  }

  /**
   * Quintic easing in
   * @memberOf fabric.util.ease
   */
  function easeInQuint(t, b, c, d) {
    return c * (t /= d) * t * t * t * t + b;
  }

  /**
   * Quintic easing out
   * @memberOf fabric.util.ease
   */
  function easeOutQuint(t, b, c, d) {
    return c * ((t = t / d - 1) * t * t * t * t + 1) + b;
  }

  /**
   * Quintic easing in and out
   * @memberOf fabric.util.ease
   */
  function easeInOutQuint(t, b, c, d) {
    t /= d / 2;
    if (t < 1) {
      return c / 2 * t * t * t * t * t + b;
    }
    return c / 2 * ((t -= 2) * t * t * t * t + 2) + b;
  }

  /**
   * Sinusoidal easing in
   * @memberOf fabric.util.ease
   */
  function easeInSine(t, b, c, d) {
    return -c * Math.cos(t / d * (Math.PI / 2)) + c + b;
  }

  /**
   * Sinusoidal easing out
   * @memberOf fabric.util.ease
   */
  function easeOutSine(t, b, c, d) {
    return c * Math.sin(t / d * (Math.PI / 2)) + b;
  }

  /**
   * Sinusoidal easing in and out
   * @memberOf fabric.util.ease
   */
  function easeInOutSine(t, b, c, d) {
    return -c / 2 * (Math.cos(Math.PI * t / d) - 1) + b;
  }

  /**
   * Exponential easing in
   * @memberOf fabric.util.ease
   */
  function easeInExpo(t, b, c, d) {
    return (t === 0) ? b : c * Math.pow(2, 10 * (t / d - 1)) + b;
  }

  /**
   * Exponential easing out
   * @memberOf fabric.util.ease
   */
  function easeOutExpo(t, b, c, d) {
    return (t === d) ? b + c : c * (-Math.pow(2, -10 * t / d) + 1) + b;
  }

  /**
   * Exponential easing in and out
   * @memberOf fabric.util.ease
   */
  function easeInOutExpo(t, b, c, d) {
    if (t === 0) {
      return b;
    }
    if (t === d) {
      return b + c;
    }
    t /= d / 2;
    if (t < 1) {
      return c / 2 * Math.pow(2, 10 * (t - 1)) + b;
    }
    return c / 2 * (-Math.pow(2, -10 * --t) + 2) + b;
  }

  /**
   * Circular easing in
   * @memberOf fabric.util.ease
   */
  function easeInCirc(t, b, c, d) {
    return -c * (Math.sqrt(1 - (t /= d) * t) - 1) + b;
  }

  /**
   * Circular easing out
   * @memberOf fabric.util.ease
   */
  function easeOutCirc(t, b, c, d) {
    return c * Math.sqrt(1 - (t = t / d - 1) * t) + b;
  }

  /**
   * Circular easing in and out
   * @memberOf fabric.util.ease
   */
  function easeInOutCirc(t, b, c, d) {
    t /= d / 2;
    if (t < 1) {
      return -c / 2 * (Math.sqrt(1 - t * t) - 1) + b;
    }
    return c / 2 * (Math.sqrt(1 - (t -= 2) * t) + 1) + b;
  }

  /**
   * Elastic easing in
   * @memberOf fabric.util.ease
   */
  function easeInElastic(t, b, c, d) {
    var s = 1.70158, p = 0, a = c;
    if (t === 0) {
      return b;
    }
    t /= d;
    if (t === 1) {
      return b + c;
    }
    if (!p) {
      p = d * 0.3;
    }
    var opts = normalize(a, c, p, s);
    return -elastic(opts, t, d) + b;
  }

  /**
   * Elastic easing out
   * @memberOf fabric.util.ease
   */
  function easeOutElastic(t, b, c, d) {
    var s = 1.70158, p = 0, a = c;
    if (t === 0) {
      return b;
    }
    t /= d;
    if (t === 1) {
      return b + c;
    }
    if (!p) {
      p = d * 0.3;
    }
    var opts = normalize(a, c, p, s);
    return opts.a * Math.pow(2, -10 * t) * Math.sin((t * d - opts.s) * (2 * Math.PI) / opts.p ) + opts.c + b;
  }

  /**
   * Elastic easing in and out
   * @memberOf fabric.util.ease
   */
  function easeInOutElastic(t, b, c, d) {
    var s = 1.70158, p = 0, a = c;
    if (t === 0) {
      return b;
    }
    t /= d / 2;
    if (t === 2) {
      return b + c;
    }
    if (!p) {
      p = d * (0.3 * 1.5);
    }
    var opts = normalize(a, c, p, s);
    if (t < 1) {
      return -0.5 * elastic(opts, t, d) + b;
    }
    return opts.a * Math.pow(2, -10 * (t -= 1)) *
      Math.sin((t * d - opts.s) * (2 * Math.PI) / opts.p ) * 0.5 + opts.c + b;
  }

  /**
   * Backwards easing in
   * @memberOf fabric.util.ease
   */
  function easeInBack(t, b, c, d, s) {
    if (s === undefined) {
      s = 1.70158;
    }
    return c * (t /= d) * t * ((s + 1) * t - s) + b;
  }

  /**
   * Backwards easing out
   * @memberOf fabric.util.ease
   */
  function easeOutBack(t, b, c, d, s) {
    if (s === undefined) {
      s = 1.70158;
    }
    return c * ((t = t / d - 1) * t * ((s + 1) * t + s) + 1) + b;
  }

  /**
   * Backwards easing in and out
   * @memberOf fabric.util.ease
   */
  function easeInOutBack(t, b, c, d, s) {
    if (s === undefined) {
      s = 1.70158;
    }
    t /= d / 2;
    if (t < 1) {
      return c / 2 * (t * t * (((s *= (1.525)) + 1) * t - s)) + b;
    }
    return c / 2 * ((t -= 2) * t * (((s *= (1.525)) + 1) * t + s) + 2) + b;
  }

  /**
   * Bouncing easing in
   * @memberOf fabric.util.ease
   */
  function easeInBounce(t, b, c, d) {
    return c - easeOutBounce (d - t, 0, c, d) + b;
  }

  /**
   * Bouncing easing out
   * @memberOf fabric.util.ease
   */
  function easeOutBounce(t, b, c, d) {
    if ((t /= d) < (1 / 2.75)) {
      return c * (7.5625 * t * t) + b;
    }
    else if (t < (2 / 2.75)) {
      return c * (7.5625 * (t -= (1.5 / 2.75)) * t + 0.75) + b;
    }
    else if (t < (2.5 / 2.75)) {
      return c * (7.5625 * (t -= (2.25 / 2.75)) * t + 0.9375) + b;
    }
    else {
      return c * (7.5625 * (t -= (2.625 / 2.75)) * t + 0.984375) + b;
    }
  }

  /**
   * Bouncing easing in and out
   * @memberOf fabric.util.ease
   */
  function easeInOutBounce(t, b, c, d) {
    if (t < d / 2) {
      return easeInBounce (t * 2, 0, c, d) * 0.5 + b;
    }
    return easeOutBounce(t * 2 - d, 0, c, d) * 0.5 + c * 0.5 + b;
  }

  /**
   * Easing functions
   * See <a href="http://gizma.com/easing/">Easing Equations by Robert Penner</a>
   * @namespace fabric.util.ease
   */
  fabric.util.ease = {

    /**
     * Quadratic easing in
     * @memberOf fabric.util.ease
     */
    easeInQuad: function(t, b, c, d) {
      return c * (t /= d) * t + b;
    },

    /**
     * Quadratic easing out
     * @memberOf fabric.util.ease
     */
    easeOutQuad: function(t, b, c, d) {
      return -c * (t /= d) * (t - 2) + b;
    },

    /**
     * Quadratic easing in and out
     * @memberOf fabric.util.ease
     */
    easeInOutQuad: function(t, b, c, d) {
      t /= (d / 2);
      if (t < 1) {
        return c / 2 * t * t + b;
      }
      return -c / 2 * ((--t) * (t - 2) - 1) + b;
    },

    /**
     * Cubic easing in
     * @memberOf fabric.util.ease
     */
    easeInCubic: function(t, b, c, d) {
      return c * (t /= d) * t * t + b;
    },

    easeOutCubic: easeOutCubic,
    easeInOutCubic: easeInOutCubic,
    easeInQuart: easeInQuart,
    easeOutQuart: easeOutQuart,
    easeInOutQuart: easeInOutQuart,
    easeInQuint: easeInQuint,
    easeOutQuint: easeOutQuint,
    easeInOutQuint: easeInOutQuint,
    easeInSine: easeInSine,
    easeOutSine: easeOutSine,
    easeInOutSine: easeInOutSine,
    easeInExpo: easeInExpo,
    easeOutExpo: easeOutExpo,
    easeInOutExpo: easeInOutExpo,
    easeInCirc: easeInCirc,
    easeOutCirc: easeOutCirc,
    easeInOutCirc: easeInOutCirc,
    easeInElastic: easeInElastic,
    easeOutElastic: easeOutElastic,
    easeInOutElastic: easeInOutElastic,
    easeInBack: easeInBack,
    easeOutBack: easeOutBack,
    easeInOutBack: easeInOutBack,
    easeInBounce: easeInBounce,
    easeOutBounce: easeOutBounce,
    easeInOutBounce: easeInOutBounce
  };

})();


(function(global) {

  'use strict';

  /**
   * @name fabric
   * @namespace
   */

  var fabric = global.fabric || (global.fabric = { }),
      extend = fabric.util.object.extend,
      clone = fabric.util.object.clone,
      toFixed = fabric.util.toFixed,
      parseUnit = fabric.util.parseUnit,
      multiplyTransformMatrices = fabric.util.multiplyTransformMatrices,

      svgValidTagNames = ['path', 'circle', 'polygon', 'polyline', 'ellipse', 'rect', 'line',
        'image', 'text', 'linearGradient', 'radialGradient', 'stop'],
      svgViewBoxElements = ['symbol', 'image', 'marker', 'pattern', 'view', 'svg'],
      svgInvalidAncestors = ['pattern', 'defs', 'symbol', 'metadata', 'clipPath', 'mask', 'desc'],
      svgValidParents = ['symbol', 'g', 'a', 'svg'],

      attributesMap = {
        cx:                   'left',
        x:                    'left',
        r:                    'radius',
        cy:                   'top',
        y:                    'top',
        display:              'visible',
        visibility:           'visible',
        transform:            'transformMatrix',
        'fill-opacity':       'fillOpacity',
        'fill-rule':          'fillRule',
        'font-family':        'fontFamily',
        'font-size':          'fontSize',
        'font-style':         'fontStyle',
        'font-weight':        'fontWeight',
        'letter-spacing':     'charSpacing',
        'paint-order':        'paintFirst',
        'stroke-dasharray':   'strokeDashArray',
        'stroke-linecap':     'strokeLineCap',
        'stroke-linejoin':    'strokeLineJoin',
        'stroke-miterlimit':  'strokeMiterLimit',
        'stroke-opacity':     'strokeOpacity',
        'stroke-width':       'strokeWidth',
        'text-decoration':    'textDecoration',
        'text-anchor':        'textAnchor',
        opacity:              'opacity'
      },

      colorAttributes = {
        stroke: 'strokeOpacity',
        fill:   'fillOpacity'
      };

  fabric.svgValidTagNamesRegEx = getSvgRegex(svgValidTagNames);
  fabric.svgViewBoxElementsRegEx = getSvgRegex(svgViewBoxElements);
  fabric.svgInvalidAncestorsRegEx = getSvgRegex(svgInvalidAncestors);
  fabric.svgValidParentsRegEx = getSvgRegex(svgValidParents);

  fabric.cssRules = { };
  fabric.gradientDefs = { };

  function normalizeAttr(attr) {
    // transform attribute names
    if (attr in attributesMap) {
      return attributesMap[attr];
    }
    return attr;
  }

  function normalizeValue(attr, value, parentAttributes, fontSize) {
    var isArray = Object.prototype.toString.call(value) === '[object Array]',
        parsed;

    if ((attr === 'fill' || attr === 'stroke') && value === 'none') {
      value = '';
    }
    else if (attr === 'strokeDashArray') {
      if (value === 'none') {
        value = null;
      }
      else {
        value = value.replace(/,/g, ' ').split(/\s+/).map(function(n) {
          return parseFloat(n);
        });
      }
    }
    else if (attr === 'transformMatrix') {
      if (parentAttributes && parentAttributes.transformMatrix) {
        value = multiplyTransformMatrices(
          parentAttributes.transformMatrix, fabric.parseTransformAttribute(value));
      }
      else {
        value = fabric.parseTransformAttribute(value);
      }
    }
    else if (attr === 'visible') {
      value = value !== 'none' && value !== 'hidden';
      // display=none on parent element always takes precedence over child element
      if (parentAttributes && parentAttributes.visible === false) {
        value = false;
      }
    }
    else if (attr === 'opacity') {
      value = parseFloat(value);
      if (parentAttributes && typeof parentAttributes.opacity !== 'undefined') {
        value *= parentAttributes.opacity;
      }
    }
    else if (attr === 'textAnchor' /* text-anchor */) {
      value = value === 'start' ? 'left' : value === 'end' ? 'right' : 'center';
    }
    else if (attr === 'charSpacing') {
      // parseUnit returns px and we convert it to em
      parsed = parseUnit(value, fontSize) / fontSize * 1000;
    }
    else if (attr === 'paintFirst') {
      var fillIndex = value.indexOf('fill');
      var strokeIndex = value.indexOf('stroke');
      var value = 'fill';
      if (fillIndex > -1 && strokeIndex > -1 && strokeIndex < fillIndex) {
        value = 'stroke';
      }
      else if (fillIndex === -1 && strokeIndex > -1) {
        value = 'stroke';
      }
    }
    else {
      parsed = isArray ? value.map(parseUnit) : parseUnit(value, fontSize);
    }

    return (!isArray && isNaN(parsed) ? value : parsed);
  }

  /**
    * @private
    */
  function getSvgRegex(arr) {
    return new RegExp('^(' + arr.join('|') + ')\\b', 'i');
  }

  /**
   * @private
   * @param {Object} attributes Array of attributes to parse
   */
  function _setStrokeFillOpacity(attributes) {
    for (var attr in colorAttributes) {

      if (typeof attributes[colorAttributes[attr]] === 'undefined' || attributes[attr] === '') {
        continue;
      }

      if (typeof attributes[attr] === 'undefined') {
        if (!fabric.Object.prototype[attr]) {
          continue;
        }
        attributes[attr] = fabric.Object.prototype[attr];
      }

      if (attributes[attr].indexOf('url(') === 0) {
        continue;
      }

      var color = new fabric.Color(attributes[attr]);
      attributes[attr] = color.setAlpha(toFixed(color.getAlpha() * attributes[colorAttributes[attr]], 2)).toRgba();
    }
    return attributes;
  }

  /**
   * @private
   */
  function _getMultipleNodes(doc, nodeNames) {
    var nodeName, nodeArray = [], nodeList, i, len;
    for (i = 0, len = nodeNames.length; i < len; i++) {
      nodeName = nodeNames[i];
      nodeList = doc.getElementsByTagName(nodeName);
      nodeArray = nodeArray.concat(Array.prototype.slice.call(nodeList));
    }
    return nodeArray;
  }

  /**
   * Parses "transform" attribute, returning an array of values
   * @static
   * @function
   * @memberOf fabric
   * @param {String} attributeValue String containing attribute value
   * @return {Array} Array of 6 elements representing transformation matrix
   */
  fabric.parseTransformAttribute = (function() {
    function rotateMatrix(matrix, args) {
      var cos = fabric.util.cos(args[0]), sin = fabric.util.sin(args[0]),
          x = 0, y = 0;
      if (args.length === 3) {
        x = args[1];
        y = args[2];
      }

      matrix[0] = cos;
      matrix[1] = sin;
      matrix[2] = -sin;
      matrix[3] = cos;
      matrix[4] = x - (cos * x - sin * y);
      matrix[5] = y - (sin * x + cos * y);
    }

    function scaleMatrix(matrix, args) {
      var multiplierX = args[0],
          multiplierY = (args.length === 2) ? args[1] : args[0];

      matrix[0] = multiplierX;
      matrix[3] = multiplierY;
    }

    function skewMatrix(matrix, args, pos) {
      matrix[pos] = Math.tan(fabric.util.degreesToRadians(args[0]));
    }

    function translateMatrix(matrix, args) {
      matrix[4] = args[0];
      if (args.length === 2) {
        matrix[5] = args[1];
      }
    }

    // identity matrix
    var iMatrix = [
          1, // a
          0, // b
          0, // c
          1, // d
          0, // e
          0  // f
        ],

        // == begin transform regexp
        number = fabric.reNum,

        commaWsp = '(?:\\s+,?\\s*|,\\s*)',

        skewX = '(?:(skewX)\\s*\\(\\s*(' + number + ')\\s*\\))',

        skewY = '(?:(skewY)\\s*\\(\\s*(' + number + ')\\s*\\))',

        rotate = '(?:(rotate)\\s*\\(\\s*(' + number + ')(?:' +
                    commaWsp + '(' + number + ')' +
                    commaWsp + '(' + number + '))?\\s*\\))',

        scale = '(?:(scale)\\s*\\(\\s*(' + number + ')(?:' +
                    commaWsp + '(' + number + '))?\\s*\\))',

        translate = '(?:(translate)\\s*\\(\\s*(' + number + ')(?:' +
                    commaWsp + '(' + number + '))?\\s*\\))',

        matrix = '(?:(matrix)\\s*\\(\\s*' +
                  '(' + number + ')' + commaWsp +
                  '(' + number + ')' + commaWsp +
                  '(' + number + ')' + commaWsp +
                  '(' + number + ')' + commaWsp +
                  '(' + number + ')' + commaWsp +
                  '(' + number + ')' +
                  '\\s*\\))',

        transform = '(?:' +
                    matrix + '|' +
                    translate + '|' +
                    scale + '|' +
                    rotate + '|' +
                    skewX + '|' +
                    skewY +
                    ')',

        transforms = '(?:' + transform + '(?:' + commaWsp + '*' + transform + ')*' + ')',

        transformList = '^\\s*(?:' + transforms + '?)\\s*$',

        // http://www.w3.org/TR/SVG/coords.html#TransformAttribute
        reTransformList = new RegExp(transformList),
        // == end transform regexp

        reTransform = new RegExp(transform, 'g');

    return function(attributeValue) {

      // start with identity matrix
      var matrix = iMatrix.concat(),
          matrices = [];

      // return if no argument was given or
      // an argument does not match transform attribute regexp
      if (!attributeValue || (attributeValue && !reTransformList.test(attributeValue))) {
        return matrix;
      }

      attributeValue.replace(reTransform, function(match) {

        var m = new RegExp(transform).exec(match).filter(function (match) {
              // match !== '' && match != null
              return (!!match);
            }),
            operation = m[1],
            args = m.slice(2).map(parseFloat);

        switch (operation) {
          case 'translate':
            translateMatrix(matrix, args);
            break;
          case 'rotate':
            args[0] = fabric.util.degreesToRadians(args[0]);
            rotateMatrix(matrix, args);
            break;
          case 'scale':
            scaleMatrix(matrix, args);
            break;
          case 'skewX':
            skewMatrix(matrix, args, 2);
            break;
          case 'skewY':
            skewMatrix(matrix, args, 1);
            break;
          case 'matrix':
            matrix = args;
            break;
        }

        // snapshot current matrix into matrices array
        matrices.push(matrix.concat());
        // reset
        matrix = iMatrix.concat();
      });

      var combinedMatrix = matrices[0];
      while (matrices.length > 1) {
        matrices.shift();
        combinedMatrix = fabric.util.multiplyTransformMatrices(combinedMatrix, matrices[0]);
      }
      return combinedMatrix;
    };
  })();

  /**
   * @private
   */
  function parseStyleString(style, oStyle) {
    var attr, value;
    style.replace(/;\s*$/, '').split(';').forEach(function (chunk) {
      var pair = chunk.split(':');

      attr = pair[0].trim().toLowerCase();
      value =  pair[1].trim();

      oStyle[attr] = value;
    });
  }

  /**
   * @private
   */
  function parseStyleObject(style, oStyle) {
    var attr, value;
    for (var prop in style) {
      if (typeof style[prop] === 'undefined') {
        continue;
      }

      attr = prop.toLowerCase();
      value = style[prop];

      oStyle[attr] = value;
    }
  }

  /**
   * @private
   */
  function getGlobalStylesForElement(element, svgUid) {
    var styles = { };
    for (var rule in fabric.cssRules[svgUid]) {
      if (elementMatchesRule(element, rule.split(' '))) {
        for (var property in fabric.cssRules[svgUid][rule]) {
          styles[property] = fabric.cssRules[svgUid][rule][property];
        }
      }
    }
    return styles;
  }

  /**
   * @private
   */
  function elementMatchesRule(element, selectors) {
    var firstMatching, parentMatching = true;
    //start from rightmost selector.
    firstMatching = selectorMatches(element, selectors.pop());
    if (firstMatching && selectors.length) {
      parentMatching = doesSomeParentMatch(element, selectors);
    }
    return firstMatching && parentMatching && (selectors.length === 0);
  }

  function doesSomeParentMatch(element, selectors) {
    var selector, parentMatching = true;
    while (element.parentNode && element.parentNode.nodeType === 1 && selectors.length) {
      if (parentMatching) {
        selector = selectors.pop();
      }
      element = element.parentNode;
      parentMatching = selectorMatches(element, selector);
    }
    return selectors.length === 0;
  }

  /**
   * @private
   */
  function selectorMatches(element, selector) {
    var nodeName = element.nodeName,
        classNames = element.getAttribute('class'),
        id = element.getAttribute('id'), matcher, i;
    // i check if a selector matches slicing away part from it.
    // if i get empty string i should match
    matcher = new RegExp('^' + nodeName, 'i');
    selector = selector.replace(matcher, '');
    if (id && selector.length) {
      matcher = new RegExp('#' + id + '(?![a-zA-Z\\-]+)', 'i');
      selector = selector.replace(matcher, '');
    }
    if (classNames && selector.length) {
      classNames = classNames.split(' ');
      for (i = classNames.length; i--;) {
        matcher = new RegExp('\\.' + classNames[i] + '(?![a-zA-Z\\-]+)', 'i');
        selector = selector.replace(matcher, '');
      }
    }
    return selector.length === 0;
  }

  /**
   * @private
   * to support IE8 missing getElementById on SVGdocument
   */
  function elementById(doc, id) {
    var el;
    doc.getElementById && (el = doc.getElementById(id));
    if (el) {
      return el;
    }
    var node, i, len, nodelist = doc.getElementsByTagName('*');
    for (i = 0, len = nodelist.length; i < len; i++) {
      node = nodelist[i];
      if (id === node.getAttribute('id')) {
        return node;
      }
    }
  }

  /**
   * @private
   */
  function parseUseDirectives(doc) {
    var nodelist = _getMultipleNodes(doc, ['use', 'svg:use']), i = 0;

    while (nodelist.length && i < nodelist.length) {
      var el = nodelist[i],
          xlink = el.getAttribute('xlink:href').substr(1),
          x = el.getAttribute('x') || 0,
          y = el.getAttribute('y') || 0,
          el2 = elementById(doc, xlink).cloneNode(true),
          currentTrans = (el2.getAttribute('transform') || '') + ' translate(' + x + ', ' + y + ')',
          parentNode, oldLength = nodelist.length, attr, j, attrs, len;

      applyViewboxTransform(el2);
      if (/^svg$/i.test(el2.nodeName)) {
        var el3 = el2.ownerDocument.createElement('g');
        for (j = 0, attrs = el2.attributes, len = attrs.length; j < len; j++) {
          attr = attrs.item(j);
          el3.setAttribute(attr.nodeName, attr.nodeValue);
        }
        // el2.firstChild != null
        while (el2.firstChild) {
          el3.appendChild(el2.firstChild);
        }
        el2 = el3;
      }

      for (j = 0, attrs = el.attributes, len = attrs.length; j < len; j++) {
        attr = attrs.item(j);
        if (attr.nodeName === 'x' || attr.nodeName === 'y' || attr.nodeName === 'xlink:href') {
          continue;
        }

        if (attr.nodeName === 'transform') {
          currentTrans = attr.nodeValue + ' ' + currentTrans;
        }
        else {
          el2.setAttribute(attr.nodeName, attr.nodeValue);
        }
      }

      el2.setAttribute('transform', currentTrans);
      el2.setAttribute('instantiated_by_use', '1');
      el2.removeAttribute('id');
      parentNode = el.parentNode;
      parentNode.replaceChild(el2, el);
      // some browsers do not shorten nodelist after replaceChild (IE8)
      if (nodelist.length === oldLength) {
        i++;
      }
    }
  }

  // http://www.w3.org/TR/SVG/coords.html#ViewBoxAttribute
  // matches, e.g.: +14.56e-12, etc.
  var reViewBoxAttrValue = new RegExp(
    '^' +
    '\\s*(' + fabric.reNum + '+)\\s*,?' +
    '\\s*(' + fabric.reNum + '+)\\s*,?' +
    '\\s*(' + fabric.reNum + '+)\\s*,?' +
    '\\s*(' + fabric.reNum + '+)\\s*' +
    '$'
  );

  /**
   * Add a <g> element that envelop all child elements and makes the viewbox transformMatrix descend on all elements
   */
  function applyViewboxTransform(element) {

    var viewBoxAttr = element.getAttribute('viewBox'),
        scaleX = 1,
        scaleY = 1,
        minX = 0,
        minY = 0,
        viewBoxWidth, viewBoxHeight, matrix, el,
        widthAttr = element.getAttribute('width'),
        heightAttr = element.getAttribute('height'),
        x = element.getAttribute('x') || 0,
        y = element.getAttribute('y') || 0,
        preserveAspectRatio = element.getAttribute('preserveAspectRatio') || '',
        missingViewBox = (!viewBoxAttr || !fabric.svgViewBoxElementsRegEx.test(element.nodeName)
                           || !(viewBoxAttr = viewBoxAttr.match(reViewBoxAttrValue))),
        missingDimAttr = (!widthAttr || !heightAttr || widthAttr === '100%' || heightAttr === '100%'),
        toBeParsed = missingViewBox && missingDimAttr,
        parsedDim = { }, translateMatrix = '', widthDiff = 0, heightDiff = 0;

    parsedDim.width = 0;
    parsedDim.height = 0;
    parsedDim.toBeParsed = toBeParsed;

    if (toBeParsed) {
      return parsedDim;
    }

    if (missingViewBox) {
      parsedDim.width = parseUnit(widthAttr);
      parsedDim.height = parseUnit(heightAttr);
      return parsedDim;
    }

    minX = -parseFloat(viewBoxAttr[1]);
    minY = -parseFloat(viewBoxAttr[2]);
    viewBoxWidth = parseFloat(viewBoxAttr[3]);
    viewBoxHeight = parseFloat(viewBoxAttr[4]);

    if (!missingDimAttr) {
      parsedDim.width = parseUnit(widthAttr);
      parsedDim.height = parseUnit(heightAttr);
      scaleX = parsedDim.width / viewBoxWidth;
      scaleY = parsedDim.height / viewBoxHeight;
    }
    else {
      parsedDim.width = viewBoxWidth;
      parsedDim.height = viewBoxHeight;
    }

    // default is to preserve aspect ratio
    preserveAspectRatio = fabric.util.parsePreserveAspectRatioAttribute(preserveAspectRatio);
    if (preserveAspectRatio.alignX !== 'none') {
      //translate all container for the effect of Mid, Min, Max
      if (preserveAspectRatio.meetOrSlice === 'meet') {
        scaleY = scaleX = (scaleX > scaleY ? scaleY : scaleX);
        // calculate additional translation to move the viewbox
      }
      if (preserveAspectRatio.meetOrSlice === 'slice') {
        scaleY = scaleX = (scaleX > scaleY ? scaleX : scaleY);
        // calculate additional translation to move the viewbox
      }
      widthDiff = parsedDim.width - viewBoxWidth * scaleX;
      heightDiff = parsedDim.height - viewBoxHeight * scaleX;
      if (preserveAspectRatio.alignX === 'Mid') {
        widthDiff /= 2;
      }
      if (preserveAspectRatio.alignY === 'Mid') {
        heightDiff /= 2;
      }
      if (preserveAspectRatio.alignX === 'Min') {
        widthDiff = 0;
      }
      if (preserveAspectRatio.alignY === 'Min') {
        heightDiff = 0;
      }
    }

    if (scaleX === 1 && scaleY === 1 && minX === 0 && minY === 0 && x === 0 && y === 0) {
      return parsedDim;
    }

    if (x || y) {
      translateMatrix = ' translate(' + parseUnit(x) + ' ' + parseUnit(y) + ') ';
    }

    matrix = translateMatrix + ' matrix(' + scaleX +
                  ' 0' +
                  ' 0 ' +
                  scaleY + ' ' +
                  (minX * scaleX + widthDiff) + ' ' +
                  (minY * scaleY + heightDiff) + ') ';

    if (element.nodeName === 'svg') {
      el = element.ownerDocument.createElement('g');
      // element.firstChild != null
      while (element.firstChild) {
        el.appendChild(element.firstChild);
      }
      element.appendChild(el);
    }
    else {
      el = element;
      matrix = el.getAttribute('transform') + matrix;
    }

    el.setAttribute('transform', matrix);
    return parsedDim;
  }

  function hasAncestorWithNodeName(element, nodeName) {
    while (element && (element = element.parentNode)) {
      if (element.nodeName && nodeName.test(element.nodeName.replace('svg:', ''))
        && !element.getAttribute('instantiated_by_use')) {
        return true;
      }
    }
    return false;
  }

  /**
   * Parses an SVG document, converts it to an array of corresponding fabric.* instances and passes them to a callback
   * @static
   * @function
   * @memberOf fabric
   * @param {SVGDocument} doc SVG document to parse
   * @param {Function} callback Callback to call when parsing is finished;
   * It's being passed an array of elements (parsed from a document).
   * @param {Function} [reviver] Method for further parsing of SVG elements, called after each fabric object created.
   * @param {Object} [parsingOptions] options for parsing document
   * @param {String} [parsingOptions.crossOrigin] crossOrigin settings
   */
  fabric.parseSVGDocument = function(doc, callback, reviver, parsingOptions) {
    if (!doc) {
      return;
    }

    parseUseDirectives(doc);

    var svgUid =  fabric.Object.__uid++, i, len,
        options = applyViewboxTransform(doc),
        descendants = fabric.util.toArray(doc.getElementsByTagName('*'));
    options.crossOrigin = parsingOptions && parsingOptions.crossOrigin;
    options.svgUid = svgUid;

    if (descendants.length === 0 && fabric.isLikelyNode) {
      // we're likely in node, where "o3-xml" library fails to gEBTN("*")
      // https://github.com/ajaxorg/node-o3-xml/issues/21
      descendants = doc.selectNodes('//*[name(.)!="svg"]');
      var arr = [];
      for (i = 0, len = descendants.length; i < len; i++) {
        arr[i] = descendants[i];
      }
      descendants = arr;
    }

    var elements = descendants.filter(function(el) {
      applyViewboxTransform(el);
      return fabric.svgValidTagNamesRegEx.test(el.nodeName.replace('svg:', '')) &&
            !hasAncestorWithNodeName(el, fabric.svgInvalidAncestorsRegEx); // http://www.w3.org/TR/SVG/struct.html#DefsElement
    });

    if (!elements || (elements && !elements.length)) {
      callback && callback([], {});
      return;
    }

    fabric.gradientDefs[svgUid] = fabric.getGradientDefs(doc);
    fabric.cssRules[svgUid] = fabric.getCSSRules(doc);
    // Precedence of rules:   style > class > attribute
    fabric.parseElements(elements, function(instances, elements) {
      if (callback) {
        callback(instances, options, elements, descendants);
      }
    }, clone(options), reviver, parsingOptions);
  };

  var reFontDeclaration = new RegExp(
    '(normal|italic)?\\s*(normal|small-caps)?\\s*' +
    '(normal|bold|bolder|lighter|100|200|300|400|500|600|700|800|900)?\\s*(' +
      fabric.reNum +
    '(?:px|cm|mm|em|pt|pc|in)*)(?:\\/(normal|' + fabric.reNum + '))?\\s+(.*)');

  extend(fabric, {
    /**
     * Parses a short font declaration, building adding its properties to a style object
     * @static
     * @function
     * @memberOf fabric
     * @param {String} value font declaration
     * @param {Object} oStyle definition
     */
    parseFontDeclaration: function(value, oStyle) {
      var match = value.match(reFontDeclaration);

      if (!match) {
        return;
      }
      var fontStyle = match[1],
          // font variant is not used
          // fontVariant = match[2],
          fontWeight = match[3],
          fontSize = match[4],
          lineHeight = match[5],
          fontFamily = match[6];

      if (fontStyle) {
        oStyle.fontStyle = fontStyle;
      }
      if (fontWeight) {
        oStyle.fontWeight = isNaN(parseFloat(fontWeight)) ? fontWeight : parseFloat(fontWeight);
      }
      if (fontSize) {
        oStyle.fontSize = parseUnit(fontSize);
      }
      if (fontFamily) {
        oStyle.fontFamily = fontFamily;
      }
      if (lineHeight) {
        oStyle.lineHeight = lineHeight === 'normal' ? 1 : lineHeight;
      }
    },

    /**
     * Parses an SVG document, returning all of the gradient declarations found in it
     * @static
     * @function
     * @memberOf fabric
     * @param {SVGDocument} doc SVG document to parse
     * @return {Object} Gradient definitions; key corresponds to element id, value -- to gradient definition element
     */
    getGradientDefs: function(doc) {
      var tagArray = [
            'linearGradient',
            'radialGradient',
            'svg:linearGradient',
            'svg:radialGradient'],
          elList = _getMultipleNodes(doc, tagArray),
          el, j = 0, id, xlink,
          gradientDefs = { }, idsToXlinkMap = { };
      j = elList.length;

      while (j--) {
        el = elList[j];
        xlink = el.getAttribute('xlink:href');
        id = el.getAttribute('id');
        if (xlink) {
          idsToXlinkMap[id] = xlink.substr(1);
        }
        gradientDefs[id] = el;
      }

      for (id in idsToXlinkMap) {
        var el2 = gradientDefs[idsToXlinkMap[id]].cloneNode(true);
        el = gradientDefs[id];
        while (el2.firstChild) {
          el.appendChild(el2.firstChild);
        }
      }
      return gradientDefs;
    },

    /**
     * Returns an object of attributes' name/value, given element and an array of attribute names;
     * Parses parent "g" nodes recursively upwards.
     * @static
     * @memberOf fabric
     * @param {DOMElement} element Element to parse
     * @param {Array} attributes Array of attributes to parse
     * @return {Object} object containing parsed attributes' names/values
     */
    parseAttributes: function(element, attributes, svgUid) {

      if (!element) {
        return;
      }

      var value,
          parentAttributes = { },
          fontSize;

      if (typeof svgUid === 'undefined') {
        svgUid = element.getAttribute('svgUid');
      }
      // if there's a parent container (`g` or `a` or `symbol` node), parse its attributes recursively upwards
      if (element.parentNode && fabric.svgValidParentsRegEx.test(element.parentNode.nodeName)) {
        parentAttributes = fabric.parseAttributes(element.parentNode, attributes, svgUid);
      }
      fontSize = (parentAttributes && parentAttributes.fontSize ) ||
                 element.getAttribute('font-size') || fabric.Text.DEFAULT_SVG_FONT_SIZE;

      var ownAttributes = attributes.reduce(function(memo, attr) {
        value = element.getAttribute(attr);
        if (value) { // eslint-disable-line
          memo[attr] = value;
        }
        return memo;
      }, { });
      // add values parsed from style, which take precedence over attributes
      // (see: http://www.w3.org/TR/SVG/styling.html#UsingPresentationAttributes)
      ownAttributes = extend(ownAttributes,
        extend(getGlobalStylesForElement(element, svgUid), fabric.parseStyleAttribute(element)));

      var normalizedAttr, normalizedValue, normalizedStyle = {};
      for (var attr in ownAttributes) {
        normalizedAttr = normalizeAttr(attr);
        normalizedValue = normalizeValue(normalizedAttr, ownAttributes[attr], parentAttributes, fontSize);
        normalizedStyle[normalizedAttr] = normalizedValue;
      }
      if (normalizedStyle && normalizedStyle.font) {
        fabric.parseFontDeclaration(normalizedStyle.font, normalizedStyle);
      }
      var mergedAttrs = extend(parentAttributes, normalizedStyle);
      return fabric.svgValidParentsRegEx.test(element.nodeName) ? mergedAttrs : _setStrokeFillOpacity(mergedAttrs);
    },

    /**
     * Transforms an array of svg elements to corresponding fabric.* instances
     * @static
     * @memberOf fabric
     * @param {Array} elements Array of elements to parse
     * @param {Function} callback Being passed an array of fabric instances (transformed from SVG elements)
     * @param {Object} [options] Options object
     * @param {Function} [reviver] Method for further parsing of SVG elements, called after each fabric object created.
     */
    parseElements: function(elements, callback, options, reviver, parsingOptions) {
      new fabric.ElementsParser(elements, callback, options, reviver, parsingOptions).parse();
    },

    /**
     * Parses "style" attribute, retuning an object with values
     * @static
     * @memberOf fabric
     * @param {SVGElement} element Element to parse
     * @return {Object} Objects with values parsed from style attribute of an element
     */
    parseStyleAttribute: function(element) {
      var oStyle = { },
          style = element.getAttribute('style');

      if (!style) {
        return oStyle;
      }

      if (typeof style === 'string') {
        parseStyleString(style, oStyle);
      }
      else {
        parseStyleObject(style, oStyle);
      }

      return oStyle;
    },

    /**
     * Parses "points" attribute, returning an array of values
     * @static
     * @memberOf fabric
     * @param {String} points points attribute string
     * @return {Array} array of points
     */
    parsePointsAttribute: function(points) {

      // points attribute is required and must not be empty
      if (!points) {
        return null;
      }

      // replace commas with whitespace and remove bookending whitespace
      points = points.replace(/,/g, ' ').trim();

      points = points.split(/\s+/);
      var parsedPoints = [], i, len;

      for (i = 0, len = points.length; i < len; i += 2) {
        parsedPoints.push({
          x: parseFloat(points[i]),
          y: parseFloat(points[i + 1])
        });
      }

      // odd number of points is an error
      // if (parsedPoints.length % 2 !== 0) {
      //   return null;
      // }

      return parsedPoints;
    },

    /**
     * Returns CSS rules for a given SVG document
     * @static
     * @function
     * @memberOf fabric
     * @param {SVGDocument} doc SVG document to parse
     * @return {Object} CSS rules of this document
     */
    getCSSRules: function(doc) {
      var styles = doc.getElementsByTagName('style'), i, len,
          allRules = { }, rules;

      // very crude parsing of style contents
      for (i = 0, len = styles.length; i < len; i++) {
        // IE9 doesn't support textContent, but provides text instead.
        var styleContents = styles[i].textContent || styles[i].text;

        // remove comments
        styleContents = styleContents.replace(/\/\*[\s\S]*?\*\//g, '');
        if (styleContents.trim() === '') {
          continue;
        }
        rules = styleContents.match(/[^{]*\{[\s\S]*?\}/g);
        rules = rules.map(function(rule) { return rule.trim(); });
        // eslint-disable-next-line no-loop-func
        rules.forEach(function(rule) {

          var match = rule.match(/([\s\S]*?)\s*\{([^}]*)\}/),
              ruleObj = { }, declaration = match[2].trim(),
              propertyValuePairs = declaration.replace(/;$/, '').split(/\s*;\s*/);

          for (i = 0, len = propertyValuePairs.length; i < len; i++) {
            var pair = propertyValuePairs[i].split(/\s*:\s*/),
                property = pair[0],
                value = pair[1];
            ruleObj[property] = value;
          }
          rule = match[1];
          rule.split(',').forEach(function(_rule) {
            _rule = _rule.replace(/^svg/i, '').trim();
            if (_rule === '') {
              return;
            }
            if (allRules[_rule]) {
              fabric.util.object.extend(allRules[_rule], ruleObj);
            }
            else {
              allRules[_rule] = fabric.util.object.clone(ruleObj);
            }
          });
        });
      }
      return allRules;
    },

    /**
     * Takes url corresponding to an SVG document, and parses it into a set of fabric objects.
     * Note that SVG is fetched via XMLHttpRequest, so it needs to conform to SOP (Same Origin Policy)
     * @memberOf fabric
     * @param {String} url
     * @param {Function} callback
     * @param {Function} [reviver] Method for further parsing of SVG elements, called after each fabric object created.
     * @param {Object} [options] Object containing options for parsing
     * @param {String} [options.crossOrigin] crossOrigin crossOrigin setting to use for external resources
     */
    loadSVGFromURL: function(url, callback, reviver, options) {

      url = url.replace(/^\n\s*/, '').trim();
      new fabric.util.request(url, {
        method: 'get',
        onComplete: onComplete
      });

      function onComplete(r) {

        var xml = r.responseXML;
        if (xml && !xml.documentElement && fabric.window.ActiveXObject && r.responseText) {
          xml = new ActiveXObject('Microsoft.XMLDOM');
          xml.async = 'false';
          //IE chokes on DOCTYPE
          xml.loadXML(r.responseText.replace(/<!DOCTYPE[\s\S]*?(\[[\s\S]*\])*?>/i, ''));
        }
        if (!xml || !xml.documentElement) {
          callback && callback(null);
        }

        fabric.parseSVGDocument(xml.documentElement, function (results, _options, elements, allElements) {
          callback && callback(results, _options, elements, allElements);
        }, reviver, options);
      }
    },

    /**
     * Takes string corresponding to an SVG document, and parses it into a set of fabric objects
     * @memberOf fabric
     * @param {String} string
     * @param {Function} callback
     * @param {Function} [reviver] Method for further parsing of SVG elements, called after each fabric object created.
     * @param {Object} [options] Object containing options for parsing
     * @param {String} [options.crossOrigin] crossOrigin crossOrigin setting to use for external resources
     */
    loadSVGFromString: function(string, callback, reviver, options) {
      string = string.trim();
      var doc;
      if (typeof DOMParser !== 'undefined') {
        var parser = new DOMParser();
        if (parser && parser.parseFromString) {
          doc = parser.parseFromString(string, 'text/xml');
        }
      }
      else if (fabric.window.ActiveXObject) {
        doc = new ActiveXObject('Microsoft.XMLDOM');
        doc.async = 'false';
        // IE chokes on DOCTYPE
        doc.loadXML(string.replace(/<!DOCTYPE[\s\S]*?(\[[\s\S]*\])*?>/i, ''));
      }

      fabric.parseSVGDocument(doc.documentElement, function (results, _options, elements, allElements) {
        callback(results, _options, elements, allElements);
      }, reviver, options);
    }
  });

})(typeof exports !== 'undefined' ? exports : this);


fabric.ElementsParser = function(elements, callback, options, reviver, parsingOptions) {
  this.elements = elements;
  this.callback = callback;
  this.options = options;
  this.reviver = reviver;
  this.svgUid = (options && options.svgUid) || 0;
  this.parsingOptions = parsingOptions;
  this.regexUrl = /^url\(['"]?#([^'"]+)['"]?\)/g;
};

fabric.ElementsParser.prototype.parse = function() {
  this.instances = new Array(this.elements.length);
  this.numElements = this.elements.length;

  this.createObjects();
};

fabric.ElementsParser.prototype.createObjects = function() {
  for (var i = 0, len = this.elements.length; i < len; i++) {
    this.elements[i].setAttribute('svgUid', this.svgUid);
    (function(_obj, i) {
      setTimeout(function() {
        _obj.createObject(_obj.elements[i], i);
      }, 0);
    })(this, i);
  }
};

fabric.ElementsParser.prototype.createObject = function(el, index) {
  var klass = fabric[fabric.util.string.capitalize(el.tagName.replace('svg:', ''))];
  if (klass && klass.fromElement) {
    try {
      this._createObject(klass, el, index);
    }
    catch (err) {
      fabric.log(err);
    }
  }
  else {
    this.checkIfDone();
  }
};

fabric.ElementsParser.prototype._createObject = function(klass, el, index) {
  klass.fromElement(el, this.createCallback(index, el), this.options);
};

fabric.ElementsParser.prototype.createCallback = function(index, el) {
  var _this = this;
  return function(obj) {
    var _options;
    _this.resolveGradient(obj, 'fill');
    _this.resolveGradient(obj, 'stroke');
    if (obj instanceof fabric.Image) {
      _options = obj.parsePreserveAspectRatioAttribute(el);
    }
    obj._removeTransformMatrix(_options);
    _this.reviver && _this.reviver(el, obj);
    _this.instances[index] = obj;
    _this.checkIfDone();
  };
};

fabric.ElementsParser.prototype.resolveGradient = function(obj, property) {

  var instanceFillValue = obj[property];
  if (!(/^url\(/).test(instanceFillValue)) {
    return;
  }
  var gradientId = this.regexUrl.exec(instanceFillValue)[1];
  this.regexUrl.lastIndex = 0;
  if (fabric.gradientDefs[this.svgUid][gradientId]) {
    obj.set(property,
      fabric.Gradient.fromElement(fabric.gradientDefs[this.svgUid][gradientId], obj));
  }
};

fabric.ElementsParser.prototype.checkIfDone = function() {
  if (--this.numElements === 0) {
    this.instances = this.instances.filter(function(el) {
      // eslint-disable-next-line no-eq-null, eqeqeq
      return el != null;
    });
    this.callback(this.instances, this.elements);
  }
};


(function(global) {

  'use strict';

  /* Adaptation of work of Kevin Lindsey (kevin@kevlindev.com) */

  var fabric = global.fabric || (global.fabric = { });

  if (fabric.Point) {
    fabric.warn('fabric.Point is already defined');
    return;
  }

  fabric.Point = Point;

  /**
   * Point class
   * @class fabric.Point
   * @memberOf fabric
   * @constructor
   * @param {Number} x
   * @param {Number} y
   * @return {fabric.Point} thisArg
   */
  function Point(x, y) {
    this.x = x;
    this.y = y;
  }

  Point.prototype = /** @lends fabric.Point.prototype */ {

    type: 'point',

    constructor: Point,

    /**
     * Adds another point to this one and returns another one
     * @param {fabric.Point} that
     * @return {fabric.Point} new Point instance with added values
     */
    add: function (that) {
      return new Point(this.x + that.x, this.y + that.y);
    },

    /**
     * Adds another point to this one
     * @param {fabric.Point} that
     * @return {fabric.Point} thisArg
     * @chainable
     */
    addEquals: function (that) {
      this.x += that.x;
      this.y += that.y;
      return this;
    },

    /**
     * Adds value to this point and returns a new one
     * @param {Number} scalar
     * @return {fabric.Point} new Point with added value
     */
    scalarAdd: function (scalar) {
      return new Point(this.x + scalar, this.y + scalar);
    },

    /**
     * Adds value to this point
     * @param {Number} scalar
     * @return {fabric.Point} thisArg
     * @chainable
     */
    scalarAddEquals: function (scalar) {
      this.x += scalar;
      this.y += scalar;
      return this;
    },

    /**
     * Subtracts another point from this point and returns a new one
     * @param {fabric.Point} that
     * @return {fabric.Point} new Point object with subtracted values
     */
    subtract: function (that) {
      return new Point(this.x - that.x, this.y - that.y);
    },

    /**
     * Subtracts another point from this point
     * @param {fabric.Point} that
     * @return {fabric.Point} thisArg
     * @chainable
     */
    subtractEquals: function (that) {
      this.x -= that.x;
      this.y -= that.y;
      return this;
    },

    /**
     * Subtracts value from this point and returns a new one
     * @param {Number} scalar
     * @return {fabric.Point}
     */
    scalarSubtract: function (scalar) {
      return new Point(this.x - scalar, this.y - scalar);
    },

    /**
     * Subtracts value from this point
     * @param {Number} scalar
     * @return {fabric.Point} thisArg
     * @chainable
     */
    scalarSubtractEquals: function (scalar) {
      this.x -= scalar;
      this.y -= scalar;
      return this;
    },

    /**
     * Multiplies this point by a value and returns a new one
     * TODO: rename in scalarMultiply in 2.0
     * @param {Number} scalar
     * @return {fabric.Point}
     */
    multiply: function (scalar) {
      return new Point(this.x * scalar, this.y * scalar);
    },

    /**
     * Multiplies this point by a value
     * TODO: rename in scalarMultiplyEquals in 2.0
     * @param {Number} scalar
     * @return {fabric.Point} thisArg
     * @chainable
     */
    multiplyEquals: function (scalar) {
      this.x *= scalar;
      this.y *= scalar;
      return this;
    },

    /**
     * Divides this point by a value and returns a new one
     * TODO: rename in scalarDivide in 2.0
     * @param {Number} scalar
     * @return {fabric.Point}
     */
    divide: function (scalar) {
      return new Point(this.x / scalar, this.y / scalar);
    },

    /**
     * Divides this point by a value
     * TODO: rename in scalarDivideEquals in 2.0
     * @param {Number} scalar
     * @return {fabric.Point} thisArg
     * @chainable
     */
    divideEquals: function (scalar) {
      this.x /= scalar;
      this.y /= scalar;
      return this;
    },

    /**
     * Returns true if this point is equal to another one
     * @param {fabric.Point} that
     * @return {Boolean}
     */
    eq: function (that) {
      return (this.x === that.x && this.y === that.y);
    },

    /**
     * Returns true if this point is less than another one
     * @param {fabric.Point} that
     * @return {Boolean}
     */
    lt: function (that) {
      return (this.x < that.x && this.y < that.y);
    },

    /**
     * Returns true if this point is less than or equal to another one
     * @param {fabric.Point} that
     * @return {Boolean}
     */
    lte: function (that) {
      return (this.x <= that.x && this.y <= that.y);
    },

    /**

     * Returns true if this point is greater another one
     * @param {fabric.Point} that
     * @return {Boolean}
     */
    gt: function (that) {
      return (this.x > that.x && this.y > that.y);
    },

    /**
     * Returns true if this point is greater than or equal to another one
     * @param {fabric.Point} that
     * @return {Boolean}
     */
    gte: function (that) {
      return (this.x >= that.x && this.y >= that.y);
    },

    /**
     * Returns new point which is the result of linear interpolation with this one and another one
     * @param {fabric.Point} that
     * @param {Number} t , position of interpolation, between 0 and 1 default 0.5
     * @return {fabric.Point}
     */
    lerp: function (that, t) {
      if (typeof t === 'undefined') {
        t = 0.5;
      }
      t = Math.max(Math.min(1, t), 0);
      return new Point(this.x + (that.x - this.x) * t, this.y + (that.y - this.y) * t);
    },

    /**
     * Returns distance from this point and another one
     * @param {fabric.Point} that
     * @return {Number}
     */
    distanceFrom: function (that) {
      var dx = this.x - that.x,
          dy = this.y - that.y;
      return Math.sqrt(dx * dx + dy * dy);
    },

    /**
     * Returns the point between this point and another one
     * @param {fabric.Point} that
     * @return {fabric.Point}
     */
    midPointFrom: function (that) {
      return this.lerp(that);
    },

    /**
     * Returns a new point which is the min of this and another one
     * @param {fabric.Point} that
     * @return {fabric.Point}
     */
    min: function (that) {
      return new Point(Math.min(this.x, that.x), Math.min(this.y, that.y));
    },

    /**
     * Returns a new point which is the max of this and another one
     * @param {fabric.Point} that
     * @return {fabric.Point}
     */
    max: function (that) {
      return new Point(Math.max(this.x, that.x), Math.max(this.y, that.y));
    },

    /**
     * Returns string representation of this point
     * @return {String}
     */
    toString: function () {
      return this.x + ',' + this.y;
    },

    /**
     * Sets x/y of this point
     * @param {Number} x
     * @param {Number} y
     * @chainable
     */
    setXY: function (x, y) {
      this.x = x;
      this.y = y;
      return this;
    },

    /**
     * Sets x of this point
     * @param {Number} x
     * @chainable
     */
    setX: function (x) {
      this.x = x;
      return this;
    },

    /**
     * Sets y of this point
     * @param {Number} y
     * @chainable
     */
    setY: function (y) {
      this.y = y;
      return this;
    },

    /**
     * Sets x/y of this point from another point
     * @param {fabric.Point} that
     * @chainable
     */
    setFromPoint: function (that) {
      this.x = that.x;
      this.y = that.y;
      return this;
    },

    /**
     * Swaps x/y of this point and another point
     * @param {fabric.Point} that
     */
    swap: function (that) {
      var x = this.x,
          y = this.y;
      this.x = that.x;
      this.y = that.y;
      that.x = x;
      that.y = y;
    },

    /**
     * return a cloned instance of the point
     * @return {fabric.Point}
     */
    clone: function () {
      return new Point(this.x, this.y);
    }
  };

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  /* Adaptation of work of Kevin Lindsey (kevin@kevlindev.com) */
  var fabric = global.fabric || (global.fabric = { });

  if (fabric.Intersection) {
    fabric.warn('fabric.Intersection is already defined');
    return;
  }

  /**
   * Intersection class
   * @class fabric.Intersection
   * @memberOf fabric
   * @constructor
   */
  function Intersection(status) {
    this.status = status;
    this.points = [];
  }

  fabric.Intersection = Intersection;

  fabric.Intersection.prototype = /** @lends fabric.Intersection.prototype */ {

    constructor: Intersection,

    /**
     * Appends a point to intersection
     * @param {fabric.Point} point
     * @return {fabric.Intersection} thisArg
     * @chainable
     */
    appendPoint: function (point) {
      this.points.push(point);
      return this;
    },

    /**
     * Appends points to intersection
     * @param {Array} points
     * @return {fabric.Intersection} thisArg
     * @chainable
     */
    appendPoints: function (points) {
      this.points = this.points.concat(points);
      return this;
    }
  };

  /**
   * Checks if one line intersects another
   * TODO: rename in intersectSegmentSegment
   * @static
   * @param {fabric.Point} a1
   * @param {fabric.Point} a2
   * @param {fabric.Point} b1
   * @param {fabric.Point} b2
   * @return {fabric.Intersection}
   */
  fabric.Intersection.intersectLineLine = function (a1, a2, b1, b2) {
    var result,
        uaT = (b2.x - b1.x) * (a1.y - b1.y) - (b2.y - b1.y) * (a1.x - b1.x),
        ubT = (a2.x - a1.x) * (a1.y - b1.y) - (a2.y - a1.y) * (a1.x - b1.x),
        uB = (b2.y - b1.y) * (a2.x - a1.x) - (b2.x - b1.x) * (a2.y - a1.y);
    if (uB !== 0) {
      var ua = uaT / uB,
          ub = ubT / uB;
      if (0 <= ua && ua <= 1 && 0 <= ub && ub <= 1) {
        result = new Intersection('Intersection');
        result.appendPoint(new fabric.Point(a1.x + ua * (a2.x - a1.x), a1.y + ua * (a2.y - a1.y)));
      }
      else {
        result = new Intersection();
      }
    }
    else {
      if (uaT === 0 || ubT === 0) {
        result = new Intersection('Coincident');
      }
      else {
        result = new Intersection('Parallel');
      }
    }
    return result;
  };

  /**
   * Checks if line intersects polygon
   * TODO: rename in intersectSegmentPolygon
   * fix detection of coincident
   * @static
   * @param {fabric.Point} a1
   * @param {fabric.Point} a2
   * @param {Array} points
   * @return {fabric.Intersection}
   */
  fabric.Intersection.intersectLinePolygon = function(a1, a2, points) {
    var result = new Intersection(),
        length = points.length,
        b1, b2, inter, i;

    for (i = 0; i < length; i++) {
      b1 = points[i];
      b2 = points[(i + 1) % length];
      inter = Intersection.intersectLineLine(a1, a2, b1, b2);

      result.appendPoints(inter.points);
    }
    if (result.points.length > 0) {
      result.status = 'Intersection';
    }
    return result;
  };

  /**
   * Checks if polygon intersects another polygon
   * @static
   * @param {Array} points1
   * @param {Array} points2
   * @return {fabric.Intersection}
   */
  fabric.Intersection.intersectPolygonPolygon = function (points1, points2) {
    var result = new Intersection(),
        length = points1.length, i;

    for (i = 0; i < length; i++) {
      var a1 = points1[i],
          a2 = points1[(i + 1) % length],
          inter = Intersection.intersectLinePolygon(a1, a2, points2);

      result.appendPoints(inter.points);
    }
    if (result.points.length > 0) {
      result.status = 'Intersection';
    }
    return result;
  };

  /**
   * Checks if polygon intersects rectangle
   * @static
   * @param {Array} points
   * @param {fabric.Point} r1
   * @param {fabric.Point} r2
   * @return {fabric.Intersection}
   */
  fabric.Intersection.intersectPolygonRectangle = function (points, r1, r2) {
    var min = r1.min(r2),
        max = r1.max(r2),
        topRight = new fabric.Point(max.x, min.y),
        bottomLeft = new fabric.Point(min.x, max.y),
        inter1 = Intersection.intersectLinePolygon(min, topRight, points),
        inter2 = Intersection.intersectLinePolygon(topRight, max, points),
        inter3 = Intersection.intersectLinePolygon(max, bottomLeft, points),
        inter4 = Intersection.intersectLinePolygon(bottomLeft, min, points),
        result = new Intersection();

    result.appendPoints(inter1.points);
    result.appendPoints(inter2.points);
    result.appendPoints(inter3.points);
    result.appendPoints(inter4.points);

    if (result.points.length > 0) {
      result.status = 'Intersection';
    }
    return result;
  };

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { });

  if (fabric.Color) {
    fabric.warn('fabric.Color is already defined.');
    return;
  }

  /**
   * Color class
   * The purpose of {@link fabric.Color} is to abstract and encapsulate common color operations;
   * {@link fabric.Color} is a constructor and creates instances of {@link fabric.Color} objects.
   *
   * @class fabric.Color
   * @param {String} color optional in hex or rgb(a) or hsl format or from known color list
   * @return {fabric.Color} thisArg
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-2/#colors}
   */
  function Color(color) {
    if (!color) {
      this.setSource([0, 0, 0, 1]);
    }
    else {
      this._tryParsingColor(color);
    }
  }

  fabric.Color = Color;

  fabric.Color.prototype = /** @lends fabric.Color.prototype */ {

    /**
     * @private
     * @param {String|Array} color Color value to parse
     */
    _tryParsingColor: function(color) {
      var source;

      if (color in Color.colorNameMap) {
        color = Color.colorNameMap[color];
      }

      if (color === 'transparent') {
        source = [255, 255, 255, 0];
      }

      if (!source) {
        source = Color.sourceFromHex(color);
      }
      if (!source) {
        source = Color.sourceFromRgb(color);
      }
      if (!source) {
        source = Color.sourceFromHsl(color);
      }
      if (!source) {
        //if color is not recognize let's make black as canvas does
        source = [0, 0, 0, 1];
      }
      if (source) {
        this.setSource(source);
      }
    },

    /**
     * Adapted from <a href="https://rawgithub.com/mjijackson/mjijackson.github.com/master/2008/02/rgb-to-hsl-and-rgb-to-hsv-color-model-conversion-algorithms-in-javascript.html">https://github.com/mjijackson</a>
     * @private
     * @param {Number} r Red color value
     * @param {Number} g Green color value
     * @param {Number} b Blue color value
     * @return {Array} Hsl color
     */
    _rgbToHsl: function(r, g, b) {
      r /= 255; g /= 255; b /= 255;

      var h, s, l,
          max = fabric.util.array.max([r, g, b]),
          min = fabric.util.array.min([r, g, b]);

      l = (max + min) / 2;

      if (max === min) {
        h = s = 0; // achromatic
      }
      else {
        var d = max - min;
        s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
        switch (max) {
          case r:
            h = (g - b) / d + (g < b ? 6 : 0);
            break;
          case g:
            h = (b - r) / d + 2;
            break;
          case b:
            h = (r - g) / d + 4;
            break;
        }
        h /= 6;
      }

      return [
        Math.round(h * 360),
        Math.round(s * 100),
        Math.round(l * 100)
      ];
    },

    /**
     * Returns source of this color (where source is an array representation; ex: [200, 200, 100, 1])
     * @return {Array}
     */
    getSource: function() {
      return this._source;
    },

    /**
     * Sets source of this color (where source is an array representation; ex: [200, 200, 100, 1])
     * @param {Array} source
     */
    setSource: function(source) {
      this._source = source;
    },

    /**
     * Returns color representation in RGB format
     * @return {String} ex: rgb(0-255,0-255,0-255)
     */
    toRgb: function() {
      var source = this.getSource();
      return 'rgb(' + source[0] + ',' + source[1] + ',' + source[2] + ')';
    },

    /**
     * Returns color representation in RGBA format
     * @return {String} ex: rgba(0-255,0-255,0-255,0-1)
     */
    toRgba: function() {
      var source = this.getSource();
      return 'rgba(' + source[0] + ',' + source[1] + ',' + source[2] + ',' + source[3] + ')';
    },

    /**
     * Returns color representation in HSL format
     * @return {String} ex: hsl(0-360,0%-100%,0%-100%)
     */
    toHsl: function() {
      var source = this.getSource(),
          hsl = this._rgbToHsl(source[0], source[1], source[2]);

      return 'hsl(' + hsl[0] + ',' + hsl[1] + '%,' + hsl[2] + '%)';
    },

    /**
     * Returns color representation in HSLA format
     * @return {String} ex: hsla(0-360,0%-100%,0%-100%,0-1)
     */
    toHsla: function() {
      var source = this.getSource(),
          hsl = this._rgbToHsl(source[0], source[1], source[2]);

      return 'hsla(' + hsl[0] + ',' + hsl[1] + '%,' + hsl[2] + '%,' + source[3] + ')';
    },

    /**
     * Returns color representation in HEX format
     * @return {String} ex: FF5555
     */
    toHex: function() {
      var source = this.getSource(), r, g, b;

      r = source[0].toString(16);
      r = (r.length === 1) ? ('0' + r) : r;

      g = source[1].toString(16);
      g = (g.length === 1) ? ('0' + g) : g;

      b = source[2].toString(16);
      b = (b.length === 1) ? ('0' + b) : b;

      return r.toUpperCase() + g.toUpperCase() + b.toUpperCase();
    },

    /**
     * Returns color representation in HEXA format
     * @return {String} ex: FF5555CC
     */
    toHexa: function() {
      var source = this.getSource(), a;

      a = Math.round(source[3] * 255);
      a = a.toString(16);
      a = (a.length === 1) ? ('0' + a) : a;

      return this.toHex() + a.toUpperCase();
    },

    /**
     * Gets value of alpha channel for this color
     * @return {Number} 0-1
     */
    getAlpha: function() {
      return this.getSource()[3];
    },

    /**
     * Sets value of alpha channel for this color
     * @param {Number} alpha Alpha value 0-1
     * @return {fabric.Color} thisArg
     */
    setAlpha: function(alpha) {
      var source = this.getSource();
      source[3] = alpha;
      this.setSource(source);
      return this;
    },

    /**
     * Transforms color to its grayscale representation
     * @return {fabric.Color} thisArg
     */
    toGrayscale: function() {
      var source = this.getSource(),
          average = parseInt((source[0] * 0.3 + source[1] * 0.59 + source[2] * 0.11).toFixed(0), 10),
          currentAlpha = source[3];
      this.setSource([average, average, average, currentAlpha]);
      return this;
    },

    /**
     * Transforms color to its black and white representation
     * @param {Number} threshold
     * @return {fabric.Color} thisArg
     */
    toBlackWhite: function(threshold) {
      var source = this.getSource(),
          average = (source[0] * 0.3 + source[1] * 0.59 + source[2] * 0.11).toFixed(0),
          currentAlpha = source[3];

      threshold = threshold || 127;

      average = (Number(average) < Number(threshold)) ? 0 : 255;
      this.setSource([average, average, average, currentAlpha]);
      return this;
    },

    /**
     * Overlays color with another color
     * @param {String|fabric.Color} otherColor
     * @return {fabric.Color} thisArg
     */
    overlayWith: function(otherColor) {
      if (!(otherColor instanceof Color)) {
        otherColor = new Color(otherColor);
      }

      var result = [],
          alpha = this.getAlpha(),
          otherAlpha = 0.5,
          source = this.getSource(),
          otherSource = otherColor.getSource(), i;

      for (i = 0; i < 3; i++) {
        result.push(Math.round((source[i] * (1 - otherAlpha)) + (otherSource[i] * otherAlpha)));
      }

      result[3] = alpha;
      this.setSource(result);
      return this;
    }
  };

  /**
   * Regex matching color in RGB or RGBA formats (ex: rgb(0, 0, 0), rgba(255, 100, 10, 0.5), rgba( 255 , 100 , 10 , 0.5 ), rgb(1,1,1), rgba(100%, 60%, 10%, 0.5))
   * @static
   * @field
   * @memberOf fabric.Color
   */
  // eslint-disable-next-line max-len
  fabric.Color.reRGBa = /^rgba?\(\s*(\d{1,3}(?:\.\d+)?\%?)\s*,\s*(\d{1,3}(?:\.\d+)?\%?)\s*,\s*(\d{1,3}(?:\.\d+)?\%?)\s*(?:\s*,\s*((?:\d*\.?\d+)?)\s*)?\)$/i;

  /**
   * Regex matching color in HSL or HSLA formats (ex: hsl(200, 80%, 10%), hsla(300, 50%, 80%, 0.5), hsla( 300 , 50% , 80% , 0.5 ))
   * @static
   * @field
   * @memberOf fabric.Color
   */
  fabric.Color.reHSLa = /^hsla?\(\s*(\d{1,3})\s*,\s*(\d{1,3}\%)\s*,\s*(\d{1,3}\%)\s*(?:\s*,\s*(\d+(?:\.\d+)?)\s*)?\)$/i;

  /**
   * Regex matching color in HEX format (ex: #FF5544CC, #FF5555, 010155, aff)
   * @static
   * @field
   * @memberOf fabric.Color
   */
  fabric.Color.reHex = /^#?([0-9a-f]{8}|[0-9a-f]{6}|[0-9a-f]{4}|[0-9a-f]{3})$/i;

  /**
   * Map of the 148 color names with HEX code
   * @static
   * @field
   * @memberOf fabric.Color
   * @see: https://www.w3.org/TR/css3-color/#svg-color
   */
  fabric.Color.colorNameMap = {
    aliceblue:            '#F0F8FF',
    antiquewhite:         '#FAEBD7',
    aqua:                 '#00FFFF',
    aquamarine:           '#7FFFD4',
    azure:                '#F0FFFF',
    beige:                '#F5F5DC',
    bisque:               '#FFE4C4',
    black:                '#000000',
    blanchedalmond:       '#FFEBCD',
    blue:                 '#0000FF',
    blueviolet:           '#8A2BE2',
    brown:                '#A52A2A',
    burlywood:            '#DEB887',
    cadetblue:            '#5F9EA0',
    chartreuse:           '#7FFF00',
    chocolate:            '#D2691E',
    coral:                '#FF7F50',
    cornflowerblue:       '#6495ED',
    cornsilk:             '#FFF8DC',
    crimson:              '#DC143C',
    cyan:                 '#00FFFF',
    darkblue:             '#00008B',
    darkcyan:             '#008B8B',
    darkgoldenrod:        '#B8860B',
    darkgray:             '#A9A9A9',
    darkgrey:             '#A9A9A9',
    darkgreen:            '#006400',
    darkkhaki:            '#BDB76B',
    darkmagenta:          '#8B008B',
    darkolivegreen:       '#556B2F',
    darkorange:           '#FF8C00',
    darkorchid:           '#9932CC',
    darkred:              '#8B0000',
    darksalmon:           '#E9967A',
    darkseagreen:         '#8FBC8F',
    darkslateblue:        '#483D8B',
    darkslategray:        '#2F4F4F',
    darkslategrey:        '#2F4F4F',
    darkturquoise:        '#00CED1',
    darkviolet:           '#9400D3',
    deeppink:             '#FF1493',
    deepskyblue:          '#00BFFF',
    dimgray:              '#696969',
    dimgrey:              '#696969',
    dodgerblue:           '#1E90FF',
    firebrick:            '#B22222',
    floralwhite:          '#FFFAF0',
    forestgreen:          '#228B22',
    fuchsia:              '#FF00FF',
    gainsboro:            '#DCDCDC',
    ghostwhite:           '#F8F8FF',
    gold:                 '#FFD700',
    goldenrod:            '#DAA520',
    gray:                 '#808080',
    grey:                 '#808080',
    green:                '#008000',
    greenyellow:          '#ADFF2F',
    honeydew:             '#F0FFF0',
    hotpink:              '#FF69B4',
    indianred:            '#CD5C5C',
    indigo:               '#4B0082',
    ivory:                '#FFFFF0',
    khaki:                '#F0E68C',
    lavender:             '#E6E6FA',
    lavenderblush:        '#FFF0F5',
    lawngreen:            '#7CFC00',
    lemonchiffon:         '#FFFACD',
    lightblue:            '#ADD8E6',
    lightcoral:           '#F08080',
    lightcyan:            '#E0FFFF',
    lightgoldenrodyellow: '#FAFAD2',
    lightgray:            '#D3D3D3',
    lightgrey:            '#D3D3D3',
    lightgreen:           '#90EE90',
    lightpink:            '#FFB6C1',
    lightsalmon:          '#FFA07A',
    lightseagreen:        '#20B2AA',
    lightskyblue:         '#87CEFA',
    lightslategray:       '#778899',
    lightslategrey:       '#778899',
    lightsteelblue:       '#B0C4DE',
    lightyellow:          '#FFFFE0',
    lime:                 '#00FF00',
    limegreen:            '#32CD32',
    linen:                '#FAF0E6',
    magenta:              '#FF00FF',
    maroon:               '#800000',
    mediumaquamarine:     '#66CDAA',
    mediumblue:           '#0000CD',
    mediumorchid:         '#BA55D3',
    mediumpurple:         '#9370DB',
    mediumseagreen:       '#3CB371',
    mediumslateblue:      '#7B68EE',
    mediumspringgreen:    '#00FA9A',
    mediumturquoise:      '#48D1CC',
    mediumvioletred:      '#C71585',
    midnightblue:         '#191970',
    mintcream:            '#F5FFFA',
    mistyrose:            '#FFE4E1',
    moccasin:             '#FFE4B5',
    navajowhite:          '#FFDEAD',
    navy:                 '#000080',
    oldlace:              '#FDF5E6',
    olive:                '#808000',
    olivedrab:            '#6B8E23',
    orange:               '#FFA500',
    orangered:            '#FF4500',
    orchid:               '#DA70D6',
    palegoldenrod:        '#EEE8AA',
    palegreen:            '#98FB98',
    paleturquoise:        '#AFEEEE',
    palevioletred:        '#DB7093',
    papayawhip:           '#FFEFD5',
    peachpuff:            '#FFDAB9',
    peru:                 '#CD853F',
    pink:                 '#FFC0CB',
    plum:                 '#DDA0DD',
    powderblue:           '#B0E0E6',
    purple:               '#800080',
    rebeccapurple:        '#663399',
    red:                  '#FF0000',
    rosybrown:            '#BC8F8F',
    royalblue:            '#4169E1',
    saddlebrown:          '#8B4513',
    salmon:               '#FA8072',
    sandybrown:           '#F4A460',
    seagreen:             '#2E8B57',
    seashell:             '#FFF5EE',
    sienna:               '#A0522D',
    silver:               '#C0C0C0',
    skyblue:              '#87CEEB',
    slateblue:            '#6A5ACD',
    slategray:            '#708090',
    slategrey:            '#708090',
    snow:                 '#FFFAFA',
    springgreen:          '#00FF7F',
    steelblue:            '#4682B4',
    tan:                  '#D2B48C',
    teal:                 '#008080',
    thistle:              '#D8BFD8',
    tomato:               '#FF6347',
    turquoise:            '#40E0D0',
    violet:               '#EE82EE',
    wheat:                '#F5DEB3',
    white:                '#FFFFFF',
    whitesmoke:           '#F5F5F5',
    yellow:               '#FFFF00',
    yellowgreen:          '#9ACD32'
  };

  /**
   * @private
   * @param {Number} p
   * @param {Number} q
   * @param {Number} t
   * @return {Number}
   */
  function hue2rgb(p, q, t) {
    if (t < 0) {
      t += 1;
    }
    if (t > 1) {
      t -= 1;
    }
    if (t < 1 / 6) {
      return p + (q - p) * 6 * t;
    }
    if (t < 1 / 2) {
      return q;
    }
    if (t < 2 / 3) {
      return p + (q - p) * (2 / 3 - t) * 6;
    }
    return p;
  }

  /**
   * Returns new color object, when given a color in RGB format
   * @memberOf fabric.Color
   * @param {String} color Color value ex: rgb(0-255,0-255,0-255)
   * @return {fabric.Color}
   */
  fabric.Color.fromRgb = function(color) {
    return Color.fromSource(Color.sourceFromRgb(color));
  };

  /**
   * Returns array representation (ex: [100, 100, 200, 1]) of a color that's in RGB or RGBA format
   * @memberOf fabric.Color
   * @param {String} color Color value ex: rgb(0-255,0-255,0-255), rgb(0%-100%,0%-100%,0%-100%)
   * @return {Array} source
   */
  fabric.Color.sourceFromRgb = function(color) {
    var match = color.match(Color.reRGBa);
    if (match) {
      var r = parseInt(match[1], 10) / (/%$/.test(match[1]) ? 100 : 1) * (/%$/.test(match[1]) ? 255 : 1),
          g = parseInt(match[2], 10) / (/%$/.test(match[2]) ? 100 : 1) * (/%$/.test(match[2]) ? 255 : 1),
          b = parseInt(match[3], 10) / (/%$/.test(match[3]) ? 100 : 1) * (/%$/.test(match[3]) ? 255 : 1);

      return [
        parseInt(r, 10),
        parseInt(g, 10),
        parseInt(b, 10),
        match[4] ? parseFloat(match[4]) : 1
      ];
    }
  };

  /**
   * Returns new color object, when given a color in RGBA format
   * @static
   * @function
   * @memberOf fabric.Color
   * @param {String} color
   * @return {fabric.Color}
   */
  fabric.Color.fromRgba = Color.fromRgb;

  /**
   * Returns new color object, when given a color in HSL format
   * @param {String} color Color value ex: hsl(0-260,0%-100%,0%-100%)
   * @memberOf fabric.Color
   * @return {fabric.Color}
   */
  fabric.Color.fromHsl = function(color) {
    return Color.fromSource(Color.sourceFromHsl(color));
  };

  /**
   * Returns array representation (ex: [100, 100, 200, 1]) of a color that's in HSL or HSLA format.
   * Adapted from <a href="https://rawgithub.com/mjijackson/mjijackson.github.com/master/2008/02/rgb-to-hsl-and-rgb-to-hsv-color-model-conversion-algorithms-in-javascript.html">https://github.com/mjijackson</a>
   * @memberOf fabric.Color
   * @param {String} color Color value ex: hsl(0-360,0%-100%,0%-100%) or hsla(0-360,0%-100%,0%-100%, 0-1)
   * @return {Array} source
   * @see http://http://www.w3.org/TR/css3-color/#hsl-color
   */
  fabric.Color.sourceFromHsl = function(color) {
    var match = color.match(Color.reHSLa);
    if (!match) {
      return;
    }

    var h = (((parseFloat(match[1]) % 360) + 360) % 360) / 360,
        s = parseFloat(match[2]) / (/%$/.test(match[2]) ? 100 : 1),
        l = parseFloat(match[3]) / (/%$/.test(match[3]) ? 100 : 1),
        r, g, b;

    if (s === 0) {
      r = g = b = l;
    }
    else {
      var q = l <= 0.5 ? l * (s + 1) : l + s - l * s,
          p = l * 2 - q;

      r = hue2rgb(p, q, h + 1 / 3);
      g = hue2rgb(p, q, h);
      b = hue2rgb(p, q, h - 1 / 3);
    }

    return [
      Math.round(r * 255),
      Math.round(g * 255),
      Math.round(b * 255),
      match[4] ? parseFloat(match[4]) : 1
    ];
  };

  /**
   * Returns new color object, when given a color in HSLA format
   * @static
   * @function
   * @memberOf fabric.Color
   * @param {String} color
   * @return {fabric.Color}
   */
  fabric.Color.fromHsla = Color.fromHsl;

  /**
   * Returns new color object, when given a color in HEX format
   * @static
   * @memberOf fabric.Color
   * @param {String} color Color value ex: FF5555
   * @return {fabric.Color}
   */
  fabric.Color.fromHex = function(color) {
    return Color.fromSource(Color.sourceFromHex(color));
  };

  /**
   * Returns array representation (ex: [100, 100, 200, 1]) of a color that's in HEX format
   * @static
   * @memberOf fabric.Color
   * @param {String} color ex: FF5555 or FF5544CC (RGBa)
   * @return {Array} source
   */
  fabric.Color.sourceFromHex = function(color) {
    if (color.match(Color.reHex)) {
      var value = color.slice(color.indexOf('#') + 1),
          isShortNotation = (value.length === 3 || value.length === 4),
          isRGBa = (value.length === 8 || value.length === 4),
          r = isShortNotation ? (value.charAt(0) + value.charAt(0)) : value.substring(0, 2),
          g = isShortNotation ? (value.charAt(1) + value.charAt(1)) : value.substring(2, 4),
          b = isShortNotation ? (value.charAt(2) + value.charAt(2)) : value.substring(4, 6),
          a = isRGBa ? (isShortNotation ? (value.charAt(3) + value.charAt(3)) : value.substring(6, 8)) : 'FF';

      return [
        parseInt(r, 16),
        parseInt(g, 16),
        parseInt(b, 16),
        parseFloat((parseInt(a, 16) / 255).toFixed(2))
      ];
    }
  };

  /**
   * Returns new color object, when given color in array representation (ex: [200, 100, 100, 0.5])
   * @static
   * @memberOf fabric.Color
   * @param {Array} source
   * @return {fabric.Color}
   */
  fabric.Color.fromSource = function(source) {
    var oColor = new Color();
    oColor.setSource(source);
    return oColor;
  };

})(typeof exports !== 'undefined' ? exports : this);


(function() {

  /* _FROM_SVG_START_ */
  function getColorStop(el) {
    var style = el.getAttribute('style'),
        offset = el.getAttribute('offset') || 0,
        color, colorAlpha, opacity, i;

    // convert percents to absolute values
    offset = parseFloat(offset) / (/%$/.test(offset) ? 100 : 1);
    offset = offset < 0 ? 0 : offset > 1 ? 1 : offset;
    if (style) {
      var keyValuePairs = style.split(/\s*;\s*/);

      if (keyValuePairs[keyValuePairs.length - 1] === '') {
        keyValuePairs.pop();
      }

      for (i = keyValuePairs.length; i--; ) {

        var split = keyValuePairs[i].split(/\s*:\s*/),
            key = split[0].trim(),
            value = split[1].trim();

        if (key === 'stop-color') {
          color = value;
        }
        else if (key === 'stop-opacity') {
          opacity = value;
        }
      }
    }

    if (!color) {
      color = el.getAttribute('stop-color') || 'rgb(0,0,0)';
    }
    if (!opacity) {
      opacity = el.getAttribute('stop-opacity');
    }

    color = new fabric.Color(color);
    colorAlpha = color.getAlpha();
    opacity = isNaN(parseFloat(opacity)) ? 1 : parseFloat(opacity);
    opacity *= colorAlpha;

    return {
      offset: offset,
      color: color.toRgb(),
      opacity: opacity
    };
  }

  function getLinearCoords(el) {
    return {
      x1: el.getAttribute('x1') || 0,
      y1: el.getAttribute('y1') || 0,
      x2: el.getAttribute('x2') || '100%',
      y2: el.getAttribute('y2') || 0
    };
  }

  function getRadialCoords(el) {
    return {
      x1: el.getAttribute('fx') || el.getAttribute('cx') || '50%',
      y1: el.getAttribute('fy') || el.getAttribute('cy') || '50%',
      r1: 0,
      x2: el.getAttribute('cx') || '50%',
      y2: el.getAttribute('cy') || '50%',
      r2: el.getAttribute('r') || '50%'
    };
  }
  /* _FROM_SVG_END_ */

  var clone = fabric.util.object.clone;

  /**
   * Gradient class
   * @class fabric.Gradient
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-2#gradients}
   * @see {@link fabric.Gradient#initialize} for constructor definition
   */
  fabric.Gradient = fabric.util.createClass(/** @lends fabric.Gradient.prototype */ {

    /**
     * Horizontal offset for aligning gradients coming from SVG when outside pathgroups
     * @type Number
     * @default 0
     */
    offsetX: 0,

    /**
     * Vertical offset for aligning gradients coming from SVG when outside pathgroups
     * @type Number
     * @default 0
     */
    offsetY: 0,

    /**
     * Constructor
     * @param {Object} [options] Options object with type, coords, gradientUnits and colorStops
     * @return {fabric.Gradient} thisArg
     */
    initialize: function(options) {
      options || (options = { });

      var coords = { };

      this.id = fabric.Object.__uid++;
      this.type = options.type || 'linear';

      coords = {
        x1: options.coords.x1 || 0,
        y1: options.coords.y1 || 0,
        x2: options.coords.x2 || 0,
        y2: options.coords.y2 || 0
      };

      if (this.type === 'radial') {
        coords.r1 = options.coords.r1 || 0;
        coords.r2 = options.coords.r2 || 0;
      }
      this.coords = coords;
      this.colorStops = options.colorStops.slice();
      if (options.gradientTransform) {
        this.gradientTransform = options.gradientTransform;
      }
      this.offsetX = options.offsetX || this.offsetX;
      this.offsetY = options.offsetY || this.offsetY;
    },

    /**
     * Adds another colorStop
     * @param {Object} colorStop Object with offset and color
     * @return {fabric.Gradient} thisArg
     */
    addColorStop: function(colorStops) {
      for (var position in colorStops) {
        var color = new fabric.Color(colorStops[position]);
        this.colorStops.push({
          offset: parseFloat(position),
          color: color.toRgb(),
          opacity: color.getAlpha()
        });
      }
      return this;
    },

    /**
     * Returns object representation of a gradient
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object}
     */
    toObject: function(propertiesToInclude) {
      var object = {
        type: this.type,
        coords: this.coords,
        colorStops: this.colorStops,
        offsetX: this.offsetX,
        offsetY: this.offsetY,
        gradientTransform: this.gradientTransform ? this.gradientTransform.concat() : this.gradientTransform
      };
      fabric.util.populateWithProperties(this, object, propertiesToInclude);

      return object;
    },

    /* _TO_SVG_START_ */
    /**
     * Returns SVG representation of an gradient
     * @param {Object} object Object to create a gradient for
     * @return {String} SVG representation of an gradient (linear/radial)
     */
    toSVG: function(object) {
      var coords = clone(this.coords, true), i, len,
          markup, commonAttributes, colorStops = clone(this.colorStops, true),
          needsSwap = coords.r1 > coords.r2,
          offsetX = object.width / 2, offsetY = object.height / 2;
      // colorStops must be sorted ascending
      colorStops.sort(function(a, b) {
        return a.offset - b.offset;
      });
      if (object.type === 'path') {
        offsetX -= object.pathOffset.x;
        offsetY -= object.pathOffset.y;
      }
      for (var prop in coords) {
        if (prop === 'x1' || prop === 'x2') {
          coords[prop] += this.offsetX - offsetX;
        }
        else if (prop === 'y1' || prop === 'y2') {
          coords[prop] += this.offsetY - offsetY;
        }
      }

      commonAttributes = 'id="SVGID_' + this.id +
                     '" gradientUnits="userSpaceOnUse"';
      if (this.gradientTransform) {
        commonAttributes += ' gradientTransform="matrix(' + this.gradientTransform.join(' ') + ')" ';
      }
      if (this.type === 'linear') {
        markup = [
          '<linearGradient ',
          commonAttributes,
          ' x1="', coords.x1,
          '" y1="', coords.y1,
          '" x2="', coords.x2,
          '" y2="', coords.y2,
          '">\n'
        ];
      }
      else if (this.type === 'radial') {
        // svg radial gradient has just 1 radius. the biggest.
        markup = [
          '<radialGradient ',
          commonAttributes,
          ' cx="', needsSwap ? coords.x1 : coords.x2,
          '" cy="', needsSwap ? coords.y1 : coords.y2,
          '" r="', needsSwap ? coords.r1 : coords.r2,
          '" fx="', needsSwap ? coords.x2 : coords.x1,
          '" fy="', needsSwap ? coords.y2 : coords.y1,
          '">\n'
        ];
      }

      if (this.type === 'radial') {
        if (needsSwap) {
          // svg goes from internal to external radius. if radius are inverted, swap color stops.
          colorStops = colorStops.concat();
          colorStops.reverse();
          for (i = 0, len = colorStops.length; i < len; i++) {
            colorStops[i].offset = 1 - colorStops[i].offset;
          }
        }
        var minRadius = Math.min(coords.r1, coords.r2);
        if (minRadius > 0) {
          // i have to shift all colorStops and add new one in 0.
          var maxRadius = Math.max(coords.r1, coords.r2),
              percentageShift = minRadius / maxRadius;
          for (i = 0, len = colorStops.length; i < len; i++) {
            colorStops[i].offset += percentageShift * (1 - colorStops[i].offset);
          }
        }
      }

      for (i = 0, len = colorStops.length; i < len; i++) {
        var colorStop = colorStops[i];
        markup.push(
          '<stop ',
          'offset="', (colorStop.offset * 100) + '%',
          '" style="stop-color:', colorStop.color,
          (typeof colorStop.opacity !== 'undefined' ? ';stop-opacity: ' + colorStop.opacity : ';'),
          '"/>\n'
        );
      }

      markup.push((this.type === 'linear' ? '</linearGradient>\n' : '</radialGradient>\n'));

      return markup.join('');
    },
    /* _TO_SVG_END_ */

    /**
     * Returns an instance of CanvasGradient
     * @param {CanvasRenderingContext2D} ctx Context to render on
     * @return {CanvasGradient}
     */
    toLive: function(ctx) {
      var gradient, coords = fabric.util.object.clone(this.coords), i, len;

      if (!this.type) {
        return;
      }

      if (this.type === 'linear') {
        gradient = ctx.createLinearGradient(
          coords.x1, coords.y1, coords.x2, coords.y2);
      }
      else if (this.type === 'radial') {
        gradient = ctx.createRadialGradient(
          coords.x1, coords.y1, coords.r1, coords.x2, coords.y2, coords.r2);
      }

      for (i = 0, len = this.colorStops.length; i < len; i++) {
        var color = this.colorStops[i].color,
            opacity = this.colorStops[i].opacity,
            offset = this.colorStops[i].offset;

        if (typeof opacity !== 'undefined') {
          color = new fabric.Color(color).setAlpha(opacity).toRgba();
        }
        gradient.addColorStop(offset, color);
      }

      return gradient;
    }
  });

  fabric.util.object.extend(fabric.Gradient, {

    /* _FROM_SVG_START_ */
    /**
     * Returns {@link fabric.Gradient} instance from an SVG element
     * @static
     * @memberOf fabric.Gradient
     * @param {SVGGradientElement} el SVG gradient element
     * @param {fabric.Object} instance
     * @return {fabric.Gradient} Gradient instance
     * @see http://www.w3.org/TR/SVG/pservers.html#LinearGradientElement
     * @see http://www.w3.org/TR/SVG/pservers.html#RadialGradientElement
     */
    fromElement: function(el, instance) {
      /**
       *  @example:
       *
       *  <linearGradient id="linearGrad1">
       *    <stop offset="0%" stop-color="white"/>
       *    <stop offset="100%" stop-color="black"/>
       *  </linearGradient>
       *
       *  OR
       *
       *  <linearGradient id="linearGrad2">
       *    <stop offset="0" style="stop-color:rgb(255,255,255)"/>
       *    <stop offset="1" style="stop-color:rgb(0,0,0)"/>
       *  </linearGradient>
       *
       *  OR
       *
       *  <radialGradient id="radialGrad1">
       *    <stop offset="0%" stop-color="white" stop-opacity="1" />
       *    <stop offset="50%" stop-color="black" stop-opacity="0.5" />
       *    <stop offset="100%" stop-color="white" stop-opacity="1" />
       *  </radialGradient>
       *
       *  OR
       *
       *  <radialGradient id="radialGrad2">
       *    <stop offset="0" stop-color="rgb(255,255,255)" />
       *    <stop offset="0.5" stop-color="rgb(0,0,0)" />
       *    <stop offset="1" stop-color="rgb(255,255,255)" />
       *  </radialGradient>
       *
       */

      var colorStopEls = el.getElementsByTagName('stop'),
          type,
          gradientUnits = el.getAttribute('gradientUnits') || 'objectBoundingBox',
          gradientTransform = el.getAttribute('gradientTransform'),
          colorStops = [],
          coords, ellipseMatrix, i;

      if (el.nodeName === 'linearGradient' || el.nodeName === 'LINEARGRADIENT') {
        type = 'linear';
      }
      else {
        type = 'radial';
      }

      if (type === 'linear') {
        coords = getLinearCoords(el);
      }
      else if (type === 'radial') {
        coords = getRadialCoords(el);
      }

      for (i = colorStopEls.length; i--; ) {
        colorStops.push(getColorStop(colorStopEls[i]));
      }

      ellipseMatrix = _convertPercentUnitsToValues(instance, coords, gradientUnits);

      var gradient = new fabric.Gradient({
        type: type,
        coords: coords,
        colorStops: colorStops,
        offsetX: -instance.left,
        offsetY: -instance.top
      });

      if (gradientTransform || ellipseMatrix !== '') {
        gradient.gradientTransform = fabric.parseTransformAttribute((gradientTransform || '') + ellipseMatrix);
      }

      return gradient;
    },
    /* _FROM_SVG_END_ */

    /**
     * Returns {@link fabric.Gradient} instance from its object representation
     * @static
     * @memberOf fabric.Gradient
     * @param {Object} obj
     * @param {Object} [options] Options object
     */
    forObject: function(obj, options) {
      options || (options = { });
      _convertPercentUnitsToValues(obj, options.coords, 'userSpaceOnUse');
      return new fabric.Gradient(options);
    }
  });

  /**
   * @private
   */
  function _convertPercentUnitsToValues(object, options, gradientUnits) {
    var propValue, addFactor = 0, multFactor = 1, ellipseMatrix = '';
    for (var prop in options) {
      if (options[prop] === 'Infinity') {
        options[prop] = 1;
      }
      else if (options[prop] === '-Infinity') {
        options[prop] = 0;
      }
      propValue = parseFloat(options[prop], 10);
      if (typeof options[prop] === 'string' && /^(\d+\.\d+)%|(\d+)%$/.test(options[prop])) {
        multFactor = 0.01;
      }
      else {
        multFactor = 1;
      }
      if (prop === 'x1' || prop === 'x2' || prop === 'r2') {
        multFactor *= gradientUnits === 'objectBoundingBox' ? object.width : 1;
        addFactor = gradientUnits === 'objectBoundingBox' ? object.left || 0 : 0;
      }
      else if (prop === 'y1' || prop === 'y2') {
        multFactor *= gradientUnits === 'objectBoundingBox' ? object.height : 1;
        addFactor = gradientUnits === 'objectBoundingBox' ? object.top || 0 : 0;
      }
      options[prop] = propValue * multFactor + addFactor;
    }
    if (object.type === 'ellipse' &&
        options.r2 !== null &&
        gradientUnits === 'objectBoundingBox' &&
        object.rx !== object.ry) {

      var scaleFactor = object.ry / object.rx;
      ellipseMatrix = ' scale(1, ' + scaleFactor + ')';
      if (options.y1) {
        options.y1 /= scaleFactor;
      }
      if (options.y2) {
        options.y2 /= scaleFactor;
      }
    }
    return ellipseMatrix;
  }
})();


(function() {

  'use strict';

  var toFixed = fabric.util.toFixed;

  /**
   * Pattern class
   * @class fabric.Pattern
   * @see {@link http://fabricjs.com/patterns|Pattern demo}
   * @see {@link http://fabricjs.com/dynamic-patterns|DynamicPattern demo}
   * @see {@link fabric.Pattern#initialize} for constructor definition
   */


  fabric.Pattern = fabric.util.createClass(/** @lends fabric.Pattern.prototype */ {

    /**
     * Repeat property of a pattern (one of repeat, repeat-x, repeat-y or no-repeat)
     * @type String
     * @default
     */
    repeat: 'repeat',

    /**
     * Pattern horizontal offset from object's left/top corner
     * @type Number
     * @default
     */
    offsetX: 0,

    /**
     * Pattern vertical offset from object's left/top corner
     * @type Number
     * @default
     */
    offsetY: 0,

    /**
     * crossOrigin value (one of "", "anonymous", "use-credentials")
     * @see https://developer.mozilla.org/en-US/docs/HTML/CORS_settings_attributes
     * @type String
     * @default
     */
    crossOrigin: '',

    /**
     * transform matrix to change the pattern, imported from svgs.
     * @type Array
     * @default
     */
    patternTransform: null,

    /**
     * Constructor
     * @param {Object} [options] Options object
     * @param {Function} [callback] function to invoke after callback init.
     * @return {fabric.Pattern} thisArg
     */
    initialize: function(options, callback) {
      options || (options = { });

      this.id = fabric.Object.__uid++;
      this.setOptions(options);
      if (!options.source || (options.source && typeof options.source !== 'string')) {
        callback && callback(this);
        return;
      }
      // function string
      if (typeof fabric.util.getFunctionBody(options.source) !== 'undefined') {
        this.source = new Function(fabric.util.getFunctionBody(options.source));
        callback && callback(this);
      }
      else {
        // img src string
        var _this = this;
        this.source = fabric.util.createImage();
        fabric.util.loadImage(options.source, function(img) {
          _this.source = img;
          callback && callback(_this);
        }, null, this.crossOrigin);
      }
    },

    /**
     * Returns object representation of a pattern
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} Object representation of a pattern instance
     */
    toObject: function(propertiesToInclude) {
      var NUM_FRACTION_DIGITS = fabric.Object.NUM_FRACTION_DIGITS,
          source, object;

      // callback
      if (typeof this.source === 'function') {
        source = String(this.source);
      }
      // <img> element
      else if (typeof this.source.src === 'string') {
        source = this.source.src;
      }
      // <canvas> element
      else if (typeof this.source === 'object' && this.source.toDataURL) {
        source = this.source.toDataURL();
      }

      object = {
        type: 'pattern',
        source: source,
        repeat: this.repeat,
        crossOrigin: this.crossOrigin,
        offsetX: toFixed(this.offsetX, NUM_FRACTION_DIGITS),
        offsetY: toFixed(this.offsetY, NUM_FRACTION_DIGITS),
        patternTransform: this.patternTransform ? this.patternTransform.concat() : null
      };
      fabric.util.populateWithProperties(this, object, propertiesToInclude);

      return object;
    },

    /* _TO_SVG_START_ */
    /**
     * Returns SVG representation of a pattern
     * @param {fabric.Object} object
     * @return {String} SVG representation of a pattern
     */
    toSVG: function(object) {
      var patternSource = typeof this.source === 'function' ? this.source() : this.source,
          patternWidth = patternSource.width / object.width,
          patternHeight = patternSource.height / object.height,
          patternOffsetX = this.offsetX / object.width,
          patternOffsetY = this.offsetY / object.height,
          patternImgSrc = '';
      if (this.repeat === 'repeat-x' || this.repeat === 'no-repeat') {
        patternHeight = 1;
      }
      if (this.repeat === 'repeat-y' || this.repeat === 'no-repeat') {
        patternWidth = 1;
      }
      if (patternSource.src) {
        patternImgSrc = patternSource.src;
      }
      else if (patternSource.toDataURL) {
        patternImgSrc = patternSource.toDataURL();
      }

      return '<pattern id="SVGID_' + this.id +
                    '" x="' + patternOffsetX +
                    '" y="' + patternOffsetY +
                    '" width="' + patternWidth +
                    '" height="' + patternHeight + '">\n' +
               '<image x="0" y="0"' +
                      ' width="' + patternSource.width +
                      '" height="' + patternSource.height +
                      '" xlink:href="' + patternImgSrc +
               '"></image>\n' +
             '</pattern>\n';
    },
    /* _TO_SVG_END_ */

    setOptions: function(options) {
      for (var prop in options) {
        this[prop] = options[prop];
      }
    },

    /**
     * Returns an instance of CanvasPattern
     * @param {CanvasRenderingContext2D} ctx Context to create pattern
     * @return {CanvasPattern}
     */
    toLive: function(ctx) {
      var source = typeof this.source === 'function' ? this.source() : this.source;

      // if the image failed to load, return, and allow rest to continue loading
      if (!source) {
        return '';
      }

      // if an image
      if (typeof source.src !== 'undefined') {
        if (!source.complete) {
          return '';
        }
        if (source.naturalWidth === 0 || source.naturalHeight === 0) {
          return '';
        }
      }
      return ctx.createPattern(source, this.repeat);
    }
  });
})();


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { }),
      toFixed = fabric.util.toFixed;

  if (fabric.Shadow) {
    fabric.warn('fabric.Shadow is already defined.');
    return;
  }

  /**
   * Shadow class
   * @class fabric.Shadow
   * @see {@link http://fabricjs.com/shadows|Shadow demo}
   * @see {@link fabric.Shadow#initialize} for constructor definition
   */
  fabric.Shadow = fabric.util.createClass(/** @lends fabric.Shadow.prototype */ {

    /**
     * Shadow color
     * @type String
     * @default
     */
    color: 'rgb(0,0,0)',

    /**
     * Shadow blur
     * @type Number
     */
    blur: 0,

    /**
     * Shadow horizontal offset
     * @type Number
     * @default
     */
    offsetX: 0,

    /**
     * Shadow vertical offset
     * @type Number
     * @default
     */
    offsetY: 0,

    /**
     * Whether the shadow should affect stroke operations
     * @type Boolean
     * @default
     */
    affectStroke: false,

    /**
     * Indicates whether toObject should include default values
     * @type Boolean
     * @default
     */
    includeDefaultValues: true,

    /**
     * Constructor
     * @param {Object|String} [options] Options object with any of color, blur, offsetX, offsetY properties or string (e.g. "rgba(0,0,0,0.2) 2px 2px 10px")
     * @return {fabric.Shadow} thisArg
     */
    initialize: function(options) {

      if (typeof options === 'string') {
        options = this._parseShadow(options);
      }

      for (var prop in options) {
        this[prop] = options[prop];
      }

      this.id = fabric.Object.__uid++;
    },

    /**
     * @private
     * @param {String} shadow Shadow value to parse
     * @return {Object} Shadow object with color, offsetX, offsetY and blur
     */
    _parseShadow: function(shadow) {
      var shadowStr = shadow.trim(),
          offsetsAndBlur = fabric.Shadow.reOffsetsAndBlur.exec(shadowStr) || [],
          color = shadowStr.replace(fabric.Shadow.reOffsetsAndBlur, '') || 'rgb(0,0,0)';

      return {
        color: color.trim(),
        offsetX: parseInt(offsetsAndBlur[1], 10) || 0,
        offsetY: parseInt(offsetsAndBlur[2], 10) || 0,
        blur: parseInt(offsetsAndBlur[3], 10) || 0
      };
    },

    /**
     * Returns a string representation of an instance
     * @see http://www.w3.org/TR/css-text-decor-3/#text-shadow
     * @return {String} Returns CSS3 text-shadow declaration
     */
    toString: function() {
      return [this.offsetX, this.offsetY, this.blur, this.color].join('px ');
    },

    /* _TO_SVG_START_ */
    /**
     * Returns SVG representation of a shadow
     * @param {fabric.Object} object
     * @return {String} SVG representation of a shadow
     */
    toSVG: function(object) {
      var fBoxX = 40, fBoxY = 40, NUM_FRACTION_DIGITS = fabric.Object.NUM_FRACTION_DIGITS,
          offset = fabric.util.rotateVector(
            { x: this.offsetX, y: this.offsetY },
            fabric.util.degreesToRadians(-object.angle)),
          BLUR_BOX = 20, color = new fabric.Color(this.color);

      if (object.width && object.height) {
        //http://www.w3.org/TR/SVG/filters.html#FilterEffectsRegion
        // we add some extra space to filter box to contain the blur ( 20 )
        fBoxX = toFixed((Math.abs(offset.x) + this.blur) / object.width, NUM_FRACTION_DIGITS) * 100 + BLUR_BOX;
        fBoxY = toFixed((Math.abs(offset.y) + this.blur) / object.height, NUM_FRACTION_DIGITS) * 100 + BLUR_BOX;
      }
      if (object.flipX) {
        offset.x *= -1;
      }
      if (object.flipY) {
        offset.y *= -1;
      }

      return (
        '<filter id="SVGID_' + this.id + '" y="-' + fBoxY + '%" height="' + (100 + 2 * fBoxY) + '%" ' +
          'x="-' + fBoxX + '%" width="' + (100 + 2 * fBoxX) + '%" ' + '>\n' +
          '\t<feGaussianBlur in="SourceAlpha" stdDeviation="' +
            toFixed(this.blur ? this.blur / 2 : 0, NUM_FRACTION_DIGITS) + '"></feGaussianBlur>\n' +
          '\t<feOffset dx="' + toFixed(offset.x, NUM_FRACTION_DIGITS) +
          '" dy="' + toFixed(offset.y, NUM_FRACTION_DIGITS) + '" result="oBlur" ></feOffset>\n' +
          '\t<feFlood flood-color="' + color.toRgb() + '" flood-opacity="' + color.getAlpha() + '"/>\n' +
          '\t<feComposite in2="oBlur" operator="in" />\n' +
          '\t<feMerge>\n' +
            '\t\t<feMergeNode></feMergeNode>\n' +
            '\t\t<feMergeNode in="SourceGraphic"></feMergeNode>\n' +
          '\t</feMerge>\n' +
        '</filter>\n');
    },
    /* _TO_SVG_END_ */

    /**
     * Returns object representation of a shadow
     * @return {Object} Object representation of a shadow instance
     */
    toObject: function() {
      if (this.includeDefaultValues) {
        return {
          color: this.color,
          blur: this.blur,
          offsetX: this.offsetX,
          offsetY: this.offsetY,
          affectStroke: this.affectStroke
        };
      }
      var obj = { }, proto = fabric.Shadow.prototype;

      ['color', 'blur', 'offsetX', 'offsetY', 'affectStroke'].forEach(function(prop) {
        if (this[prop] !== proto[prop]) {
          obj[prop] = this[prop];
        }
      }, this);

      return obj;
    }
  });

  /**
   * Regex matching shadow offsetX, offsetY and blur (ex: "2px 2px 10px rgba(0,0,0,0.2)", "rgb(0,255,0) 2px 2px")
   * @static
   * @field
   * @memberOf fabric.Shadow
   */
  // eslint-disable-next-line max-len
  fabric.Shadow.reOffsetsAndBlur = /(?:\s|^)(-?\d+(?:px)?(?:\s?|$))?(-?\d+(?:px)?(?:\s?|$))?(\d+(?:px)?)?(?:\s?|$)(?:$|\s)/;

})(typeof exports !== 'undefined' ? exports : this);


(function () {

  'use strict';

  if (fabric.StaticCanvas) {
    fabric.warn('fabric.StaticCanvas is already defined.');
    return;
  }

  // aliases for faster resolution
  var extend = fabric.util.object.extend,
      getElementOffset = fabric.util.getElementOffset,
      removeFromArray = fabric.util.removeFromArray,
      toFixed = fabric.util.toFixed,
      transformPoint = fabric.util.transformPoint,
      invertTransform = fabric.util.invertTransform,

      CANVAS_INIT_ERROR = new Error('Could not initialize `canvas` element');

  /**
   * Static canvas class
   * @class fabric.StaticCanvas
   * @mixes fabric.Collection
   * @mixes fabric.Observable
   * @see {@link http://fabricjs.com/static_canvas|StaticCanvas demo}
   * @see {@link fabric.StaticCanvas#initialize} for constructor definition
   * @fires before:render
   * @fires after:render
   * @fires canvas:cleared
   * @fires object:added
   * @fires object:removed
   */
  fabric.StaticCanvas = fabric.util.createClass(fabric.CommonMethods, /** @lends fabric.StaticCanvas.prototype */ {

    /**
     * Constructor
     * @param {HTMLElement | String} el &lt;canvas> element to initialize instance on
     * @param {Object} [options] Options object
     * @return {Object} thisArg
     */
    initialize: function(el, options) {
      options || (options = { });
      this.renderAndResetBound = this.renderAndReset.bind(this);
      this.requestRenderAllBound = this.requestRenderAll.bind(this);
      this._initStatic(el, options);
    },

    /**
     * Background color of canvas instance.
     * Should be set via {@link fabric.StaticCanvas#setBackgroundColor}.
     * @type {(String|fabric.Pattern)}
     * @default
     */
    backgroundColor: '',

    /**
     * Background image of canvas instance.
     * Should be set via {@link fabric.StaticCanvas#setBackgroundImage}.
     * <b>Backwards incompatibility note:</b> The "backgroundImageOpacity"
     * and "backgroundImageStretch" properties are deprecated since 1.3.9.
     * Use {@link fabric.Image#opacity}, {@link fabric.Image#width} and {@link fabric.Image#height}.
     * @type fabric.Image
     * @default
     */
    backgroundImage: null,

    /**
     * Overlay color of canvas instance.
     * Should be set via {@link fabric.StaticCanvas#setOverlayColor}
     * @since 1.3.9
     * @type {(String|fabric.Pattern)}
     * @default
     */
    overlayColor: '',

    /**
     * Overlay image of canvas instance.
     * Should be set via {@link fabric.StaticCanvas#setOverlayImage}.
     * <b>Backwards incompatibility note:</b> The "overlayImageLeft"
     * and "overlayImageTop" properties are deprecated since 1.3.9.
     * Use {@link fabric.Image#left} and {@link fabric.Image#top}.
     * @type fabric.Image
     * @default
     */
    overlayImage: null,

    /**
     * Indicates whether toObject/toDatalessObject should include default values
     * @type Boolean
     * @default
     */
    includeDefaultValues: true,

    /**
     * Indicates whether objects' state should be saved
     * @type Boolean
     * @default
     */
    stateful: false,

    /**
     * Indicates whether {@link fabric.Collection.add}, {@link fabric.Collection.insertAt} and {@link fabric.Collection.remove},
     * {@link fabric.StaticCanvas.moveTo}, {@link fabric.StaticCanvas.clear} and many more, should also re-render canvas.
     * Disabling this option will not give a performance boost when adding/removing a lot of objects to/from canvas at once
     * since the renders are quequed and executed one per frame.
     * Disabling is suggested anyway and managing the renders of the app manually is not a big effort ( canvas.requestRenderAll() )
     * Left default to true to do not break documentation and old app, fiddles.
     * @type Boolean
     * @default
     */
    renderOnAddRemove: true,

    /**
     * Function that determines clipping of entire canvas area
     * Being passed context as first argument. See clipping canvas area in {@link https://github.com/kangax/fabric.js/wiki/FAQ}
     * @deprecated since 2.0.0
     * @type Function
     * @default
     */
    clipTo: null,

    /**
     * Indicates whether object controls (borders/controls) are rendered above overlay image
     * @type Boolean
     * @default
     */
    controlsAboveOverlay: false,

    /**
     * Indicates whether the browser can be scrolled when using a touchscreen and dragging on the canvas
     * @type Boolean
     * @default
     */
    allowTouchScrolling: false,

    /**
     * Indicates whether this canvas will use image smoothing, this is on by default in browsers
     * @type Boolean
     * @default
     */
    imageSmoothingEnabled: true,

    /**
     * The transformation (in the format of Canvas transform) which focuses the viewport
     * @type Array
     * @default
     */
    viewportTransform: fabric.iMatrix.concat(),

    /**
     * if set to false background image is not affected by viewport transform
     * @since 1.6.3
     * @type Boolean
     * @default
     */
    backgroundVpt: true,

    /**
     * if set to false overlya image is not affected by viewport transform
     * @since 1.6.3
     * @type Boolean
     * @default
     */
    overlayVpt: true,

    /**
     * Callback; invoked right before object is about to be scaled/rotated
     * @deprecated since 2.3.0
     * Use before:transform event
     */
    onBeforeScaleRotate: function () {
      /* NOOP */
    },

    /**
     * When true, canvas is scaled by devicePixelRatio for better rendering on retina screens
     * @type Boolean
     * @default
     */
    enableRetinaScaling: true,

    /**
     * Describe canvas element extension over design
     * properties are tl,tr,bl,br.
     * if canvas is not zoomed/panned those points are the four corner of canvas
     * if canvas is viewportTransformed you those points indicate the extension
     * of canvas element in plain untrasformed coordinates
     * The coordinates get updated with @method calcViewportBoundaries.
     * @memberOf fabric.StaticCanvas.prototype
     */
    vptCoords: { },

    /**
     * Based on vptCoords and object.aCoords, skip rendering of objects that
     * are not included in current viewport.
     * May greatly help in applications with crowded canvas and use of zoom/pan
     * If One of the corner of the bounding box of the object is on the canvas
     * the objects get rendered.
     * @memberOf fabric.StaticCanvas.prototype
     * @type Boolean
     * @default
     */
    skipOffscreen: true,

    /**
     * @private
     * @param {HTMLElement | String} el &lt;canvas> element to initialize instance on
     * @param {Object} [options] Options object
     */
    _initStatic: function(el, options) {
      var cb = this.requestRenderAllBound;
      this._objects = [];
      this._createLowerCanvas(el);
      this._initOptions(options);
      this._setImageSmoothing();
      // only initialize retina scaling once
      if (!this.interactive) {
        this._initRetinaScaling();
      }

      if (options.overlayImage) {
        this.setOverlayImage(options.overlayImage, cb);
      }
      if (options.backgroundImage) {
        this.setBackgroundImage(options.backgroundImage, cb);
      }
      if (options.backgroundColor) {
        this.setBackgroundColor(options.backgroundColor, cb);
      }
      if (options.overlayColor) {
        this.setOverlayColor(options.overlayColor, cb);
      }
      this.calcOffset();
    },

    /**
     * @private
     */
    _isRetinaScaling: function() {
      return (fabric.devicePixelRatio !== 1 && this.enableRetinaScaling);
    },

    /**
     * @private
     * @return {Number} retinaScaling if applied, otherwise 1;
     */
    getRetinaScaling: function() {
      return this._isRetinaScaling() ? fabric.devicePixelRatio : 1;
    },

    /**
     * @private
     */
    _initRetinaScaling: function() {
      if (!this._isRetinaScaling()) {
        return;
      }
      this.lowerCanvasEl.setAttribute('width', this.width * fabric.devicePixelRatio);
      this.lowerCanvasEl.setAttribute('height', this.height * fabric.devicePixelRatio);

      this.contextContainer.scale(fabric.devicePixelRatio, fabric.devicePixelRatio);
    },

    /**
     * Calculates canvas element offset relative to the document
     * This method is also attached as "resize" event handler of window
     * @return {fabric.Canvas} instance
     * @chainable
     */
    calcOffset: function () {
      this._offset = getElementOffset(this.lowerCanvasEl);
      return this;
    },

    /**
     * Sets {@link fabric.StaticCanvas#overlayImage|overlay image} for this canvas
     * @param {(fabric.Image|String)} image fabric.Image instance or URL of an image to set overlay to
     * @param {Function} callback callback to invoke when image is loaded and set as an overlay
     * @param {Object} [options] Optional options to set for the {@link fabric.Image|overlay image}.
     * @return {fabric.Canvas} thisArg
     * @chainable
     * @see {@link http://jsfiddle.net/fabricjs/MnzHT/|jsFiddle demo}
     * @example <caption>Normal overlayImage with left/top = 0</caption>
     * canvas.setOverlayImage('http://fabricjs.com/assets/jail_cell_bars.png', canvas.renderAll.bind(canvas), {
     *   // Needed to position overlayImage at 0/0
     *   originX: 'left',
     *   originY: 'top'
     * });
     * @example <caption>overlayImage with different properties</caption>
     * canvas.setOverlayImage('http://fabricjs.com/assets/jail_cell_bars.png', canvas.renderAll.bind(canvas), {
     *   opacity: 0.5,
     *   angle: 45,
     *   left: 400,
     *   top: 400,
     *   originX: 'left',
     *   originY: 'top'
     * });
     * @example <caption>Stretched overlayImage #1 - width/height correspond to canvas width/height</caption>
     * fabric.Image.fromURL('http://fabricjs.com/assets/jail_cell_bars.png', function(img) {
     *    img.set({width: canvas.width, height: canvas.height, originX: 'left', originY: 'top'});
     *    canvas.setOverlayImage(img, canvas.renderAll.bind(canvas));
     * });
     * @example <caption>Stretched overlayImage #2 - width/height correspond to canvas width/height</caption>
     * canvas.setOverlayImage('http://fabricjs.com/assets/jail_cell_bars.png', canvas.renderAll.bind(canvas), {
     *   width: canvas.width,
     *   height: canvas.height,
     *   // Needed to position overlayImage at 0/0
     *   originX: 'left',
     *   originY: 'top'
     * });
     * @example <caption>overlayImage loaded from cross-origin</caption>
     * canvas.setOverlayImage('http://fabricjs.com/assets/jail_cell_bars.png', canvas.renderAll.bind(canvas), {
     *   opacity: 0.5,
     *   angle: 45,
     *   left: 400,
     *   top: 400,
     *   originX: 'left',
     *   originY: 'top',
     *   crossOrigin: 'anonymous'
     * });
     */
    setOverlayImage: function (image, callback, options) {
      return this.__setBgOverlayImage('overlayImage', image, callback, options);
    },

    /**
     * Sets {@link fabric.StaticCanvas#backgroundImage|background image} for this canvas
     * @param {(fabric.Image|String)} image fabric.Image instance or URL of an image to set background to
     * @param {Function} callback Callback to invoke when image is loaded and set as background
     * @param {Object} [options] Optional options to set for the {@link fabric.Image|background image}.
     * @return {fabric.Canvas} thisArg
     * @chainable
     * @see {@link http://jsfiddle.net/djnr8o7a/28/|jsFiddle demo}
     * @example <caption>Normal backgroundImage with left/top = 0</caption>
     * canvas.setBackgroundImage('http://fabricjs.com/assets/honey_im_subtle.png', canvas.renderAll.bind(canvas), {
     *   // Needed to position backgroundImage at 0/0
     *   originX: 'left',
     *   originY: 'top'
     * });
     * @example <caption>backgroundImage with different properties</caption>
     * canvas.setBackgroundImage('http://fabricjs.com/assets/honey_im_subtle.png', canvas.renderAll.bind(canvas), {
     *   opacity: 0.5,
     *   angle: 45,
     *   left: 400,
     *   top: 400,
     *   originX: 'left',
     *   originY: 'top'
     * });
     * @example <caption>Stretched backgroundImage #1 - width/height correspond to canvas width/height</caption>
     * fabric.Image.fromURL('http://fabricjs.com/assets/honey_im_subtle.png', function(img) {
     *    img.set({width: canvas.width, height: canvas.height, originX: 'left', originY: 'top'});
     *    canvas.setBackgroundImage(img, canvas.renderAll.bind(canvas));
     * });
     * @example <caption>Stretched backgroundImage #2 - width/height correspond to canvas width/height</caption>
     * canvas.setBackgroundImage('http://fabricjs.com/assets/honey_im_subtle.png', canvas.renderAll.bind(canvas), {
     *   width: canvas.width,
     *   height: canvas.height,
     *   // Needed to position backgroundImage at 0/0
     *   originX: 'left',
     *   originY: 'top'
     * });
     * @example <caption>backgroundImage loaded from cross-origin</caption>
     * canvas.setBackgroundImage('http://fabricjs.com/assets/honey_im_subtle.png', canvas.renderAll.bind(canvas), {
     *   opacity: 0.5,
     *   angle: 45,
     *   left: 400,
     *   top: 400,
     *   originX: 'left',
     *   originY: 'top',
     *   crossOrigin: 'anonymous'
     * });
     */
    setBackgroundImage: function (image, callback, options) {
      return this.__setBgOverlayImage('backgroundImage', image, callback, options);
    },

    /**
     * Sets {@link fabric.StaticCanvas#overlayColor|foreground color} for this canvas
     * @param {(String|fabric.Pattern)} overlayColor Color or pattern to set foreground color to
     * @param {Function} callback Callback to invoke when foreground color is set
     * @return {fabric.Canvas} thisArg
     * @chainable
     * @see {@link http://jsfiddle.net/fabricjs/pB55h/|jsFiddle demo}
     * @example <caption>Normal overlayColor - color value</caption>
     * canvas.setOverlayColor('rgba(255, 73, 64, 0.6)', canvas.renderAll.bind(canvas));
     * @example <caption>fabric.Pattern used as overlayColor</caption>
     * canvas.setOverlayColor({
     *   source: 'http://fabricjs.com/assets/escheresque_ste.png'
     * }, canvas.renderAll.bind(canvas));
     * @example <caption>fabric.Pattern used as overlayColor with repeat and offset</caption>
     * canvas.setOverlayColor({
     *   source: 'http://fabricjs.com/assets/escheresque_ste.png',
     *   repeat: 'repeat',
     *   offsetX: 200,
     *   offsetY: 100
     * }, canvas.renderAll.bind(canvas));
     */
    setOverlayColor: function(overlayColor, callback) {
      return this.__setBgOverlayColor('overlayColor', overlayColor, callback);
    },

    /**
     * Sets {@link fabric.StaticCanvas#backgroundColor|background color} for this canvas
     * @param {(String|fabric.Pattern)} backgroundColor Color or pattern to set background color to
     * @param {Function} callback Callback to invoke when background color is set
     * @return {fabric.Canvas} thisArg
     * @chainable
     * @see {@link http://jsfiddle.net/fabricjs/hXzvk/|jsFiddle demo}
     * @example <caption>Normal backgroundColor - color value</caption>
     * canvas.setBackgroundColor('rgba(255, 73, 64, 0.6)', canvas.renderAll.bind(canvas));
     * @example <caption>fabric.Pattern used as backgroundColor</caption>
     * canvas.setBackgroundColor({
     *   source: 'http://fabricjs.com/assets/escheresque_ste.png'
     * }, canvas.renderAll.bind(canvas));
     * @example <caption>fabric.Pattern used as backgroundColor with repeat and offset</caption>
     * canvas.setBackgroundColor({
     *   source: 'http://fabricjs.com/assets/escheresque_ste.png',
     *   repeat: 'repeat',
     *   offsetX: 200,
     *   offsetY: 100
     * }, canvas.renderAll.bind(canvas));
     */
    setBackgroundColor: function(backgroundColor, callback) {
      return this.__setBgOverlayColor('backgroundColor', backgroundColor, callback);
    },

    /**
     * @private
     * @see {@link http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#dom-context-2d-imagesmoothingenabled|WhatWG Canvas Standard}
     */
    _setImageSmoothing: function() {
      var ctx = this.getContext();

      ctx.imageSmoothingEnabled = ctx.imageSmoothingEnabled || ctx.webkitImageSmoothingEnabled
        || ctx.mozImageSmoothingEnabled || ctx.msImageSmoothingEnabled || ctx.oImageSmoothingEnabled;
      ctx.imageSmoothingEnabled = this.imageSmoothingEnabled;
    },

    /**
     * @private
     * @param {String} property Property to set ({@link fabric.StaticCanvas#backgroundImage|backgroundImage}
     * or {@link fabric.StaticCanvas#overlayImage|overlayImage})
     * @param {(fabric.Image|String|null)} image fabric.Image instance, URL of an image or null to set background or overlay to
     * @param {Function} callback Callback to invoke when image is loaded and set as background or overlay
     * @param {Object} [options] Optional options to set for the {@link fabric.Image|image}.
     */
    __setBgOverlayImage: function(property, image, callback, options) {
      if (typeof image === 'string') {
        fabric.util.loadImage(image, function(img) {
          img && (this[property] = new fabric.Image(img, options));
          callback && callback(img);
        }, this, options && options.crossOrigin);
      }
      else {
        options && image.setOptions(options);
        this[property] = image;
        callback && callback(image);
      }

      return this;
    },

    /**
     * @private
     * @param {String} property Property to set ({@link fabric.StaticCanvas#backgroundColor|backgroundColor}
     * or {@link fabric.StaticCanvas#overlayColor|overlayColor})
     * @param {(Object|String|null)} color Object with pattern information, color value or null
     * @param {Function} [callback] Callback is invoked when color is set
     */
    __setBgOverlayColor: function(property, color, callback) {
      this[property] = color;
      this._initGradient(color, property);
      this._initPattern(color, property, callback);
      return this;
    },

    /**
     * @private
     */
    _createCanvasElement: function() {
      var element = fabric.util.createCanvasElement();
      if (!element) {
        throw CANVAS_INIT_ERROR;
      }
      if (!element.style) {
        element.style = { };
      }
      if (typeof element.getContext === 'undefined') {
        throw CANVAS_INIT_ERROR;
      }
      return element;
    },

    /**
     * @private
     * @param {Object} [options] Options object
     */
    _initOptions: function (options) {
      this._setOptions(options);

      this.width = this.width || parseInt(this.lowerCanvasEl.width, 10) || 0;
      this.height = this.height || parseInt(this.lowerCanvasEl.height, 10) || 0;

      if (!this.lowerCanvasEl.style) {
        return;
      }

      this.lowerCanvasEl.width = this.width;
      this.lowerCanvasEl.height = this.height;

      this.lowerCanvasEl.style.width = this.width + 'px';
      this.lowerCanvasEl.style.height = this.height + 'px';

      this.viewportTransform = this.viewportTransform.slice();
    },

    /**
     * Creates a bottom canvas
     * @private
     * @param {HTMLElement} [canvasEl]
     */
    _createLowerCanvas: function (canvasEl) {
      // canvasEl === 'HTMLCanvasElement' does not work on jsdom/node
      if (canvasEl && canvasEl.getContext) {
        this.lowerCanvasEl = canvasEl;
      }
      else {
        this.lowerCanvasEl = fabric.util.getById(canvasEl) || this._createCanvasElement();
      }

      fabric.util.addClass(this.lowerCanvasEl, 'lower-canvas');

      if (this.interactive) {
        this._applyCanvasStyle(this.lowerCanvasEl);
      }

      this.contextContainer = this.lowerCanvasEl.getContext('2d');
    },

    /**
     * Returns canvas width (in px)
     * @return {Number}
     */
    getWidth: function () {
      return this.width;
    },

    /**
     * Returns canvas height (in px)
     * @return {Number}
     */
    getHeight: function () {
      return this.height;
    },

    /**
     * Sets width of this canvas instance
     * @param {Number|String} value                         Value to set width to
     * @param {Object}        [options]                     Options object
     * @param {Boolean}       [options.backstoreOnly=false] Set the given dimensions only as canvas backstore dimensions
     * @param {Boolean}       [options.cssOnly=false]       Set the given dimensions only as css dimensions
     * @return {fabric.Canvas} instance
     * @chainable true
     */
    setWidth: function (value, options) {
      return this.setDimensions({ width: value }, options);
    },

    /**
     * Sets height of this canvas instance
     * @param {Number|String} value                         Value to set height to
     * @param {Object}        [options]                     Options object
     * @param {Boolean}       [options.backstoreOnly=false] Set the given dimensions only as canvas backstore dimensions
     * @param {Boolean}       [options.cssOnly=false]       Set the given dimensions only as css dimensions
     * @return {fabric.Canvas} instance
     * @chainable true
     */
    setHeight: function (value, options) {
      return this.setDimensions({ height: value }, options);
    },

    /**
     * Sets dimensions (width, height) of this canvas instance. when options.cssOnly flag active you should also supply the unit of measure (px/%/em)
     * @param {Object}        dimensions                    Object with width/height properties
     * @param {Number|String} [dimensions.width]            Width of canvas element
     * @param {Number|String} [dimensions.height]           Height of canvas element
     * @param {Object}        [options]                     Options object
     * @param {Boolean}       [options.backstoreOnly=false] Set the given dimensions only as canvas backstore dimensions
     * @param {Boolean}       [options.cssOnly=false]       Set the given dimensions only as css dimensions
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    setDimensions: function (dimensions, options) {
      var cssValue;

      options = options || {};

      for (var prop in dimensions) {
        cssValue = dimensions[prop];

        if (!options.cssOnly) {
          this._setBackstoreDimension(prop, dimensions[prop]);
          cssValue += 'px';
          this.hasLostContext = true;
        }

        if (!options.backstoreOnly) {
          this._setCssDimension(prop, cssValue);
        }
      }
      if (this._isCurrentlyDrawing) {
        this.freeDrawingBrush && this.freeDrawingBrush._setBrushStyles();
      }
      this._initRetinaScaling();
      this._setImageSmoothing();
      this.calcOffset();

      if (!options.cssOnly) {
        this.requestRenderAll();
      }

      return this;
    },

    /**
     * Helper for setting width/height
     * @private
     * @param {String} prop property (width|height)
     * @param {Number} value value to set property to
     * @return {fabric.Canvas} instance
     * @chainable true
     */
    _setBackstoreDimension: function (prop, value) {
      this.lowerCanvasEl[prop] = value;

      if (this.upperCanvasEl) {
        this.upperCanvasEl[prop] = value;
      }

      if (this.cacheCanvasEl) {
        this.cacheCanvasEl[prop] = value;
      }

      this[prop] = value;

      return this;
    },

    /**
     * Helper for setting css width/height
     * @private
     * @param {String} prop property (width|height)
     * @param {String} value value to set property to
     * @return {fabric.Canvas} instance
     * @chainable true
     */
    _setCssDimension: function (prop, value) {
      this.lowerCanvasEl.style[prop] = value;

      if (this.upperCanvasEl) {
        this.upperCanvasEl.style[prop] = value;
      }

      if (this.wrapperEl) {
        this.wrapperEl.style[prop] = value;
      }

      return this;
    },

    /**
     * Returns canvas zoom level
     * @return {Number}
     */
    getZoom: function () {
      return this.viewportTransform[0];
    },

    /**
     * Sets viewport transform of this canvas instance
     * @param {Array} vpt the transform in the form of context.transform
     * @return {fabric.Canvas} instance
     * @chainable true
     */
    setViewportTransform: function (vpt) {
      var activeObject = this._activeObject, object, ignoreVpt = false, skipAbsolute = true, i, len;
      this.viewportTransform = vpt;
      for (i = 0, len = this._objects.length; i < len; i++) {
        object = this._objects[i];
        object.group || object.setCoords(ignoreVpt, skipAbsolute);
      }
      if (activeObject && activeObject.type === 'activeSelection') {
        activeObject.setCoords(ignoreVpt, skipAbsolute);
      }
      this.calcViewportBoundaries();
      this.renderOnAddRemove && this.requestRenderAll();
      return this;
    },

    /**
     * Sets zoom level of this canvas instance, zoom centered around point
     * @param {fabric.Point} point to zoom with respect to
     * @param {Number} value to set zoom to, less than 1 zooms out
     * @return {fabric.Canvas} instance
     * @chainable true
     */
    zoomToPoint: function (point, value) {
      // TODO: just change the scale, preserve other transformations
      var before = point, vpt = this.viewportTransform.slice(0);
      point = transformPoint(point, invertTransform(this.viewportTransform));
      vpt[0] = value;
      vpt[3] = value;
      var after = transformPoint(point, vpt);
      vpt[4] += before.x - after.x;
      vpt[5] += before.y - after.y;
      return this.setViewportTransform(vpt);
    },

    /**
     * Sets zoom level of this canvas instance
     * @param {Number} value to set zoom to, less than 1 zooms out
     * @return {fabric.Canvas} instance
     * @chainable true
     */
    setZoom: function (value) {
      this.zoomToPoint(new fabric.Point(0, 0), value);
      return this;
    },

    /**
     * Pan viewport so as to place point at top left corner of canvas
     * @param {fabric.Point} point to move to
     * @return {fabric.Canvas} instance
     * @chainable true
     */
    absolutePan: function (point) {
      var vpt = this.viewportTransform.slice(0);
      vpt[4] = -point.x;
      vpt[5] = -point.y;
      return this.setViewportTransform(vpt);
    },

    /**
     * Pans viewpoint relatively
     * @param {fabric.Point} point (position vector) to move by
     * @return {fabric.Canvas} instance
     * @chainable true
     */
    relativePan: function (point) {
      return this.absolutePan(new fabric.Point(
        -point.x - this.viewportTransform[4],
        -point.y - this.viewportTransform[5]
      ));
    },

    /**
     * Returns &lt;canvas> element corresponding to this instance
     * @return {HTMLCanvasElement}
     */
    getElement: function () {
      return this.lowerCanvasEl;
    },

    /**
     * @private
     * @param {fabric.Object} obj Object that was added
     */
    _onObjectAdded: function(obj) {
      this.stateful && obj.setupState();
      obj._set('canvas', this);
      obj.setCoords();
      this.fire('object:added', { target: obj });
      obj.fire('added');
    },

    /**
     * @private
     * @param {fabric.Object} obj Object that was removed
     */
    _onObjectRemoved: function(obj) {
      this.fire('object:removed', { target: obj });
      obj.fire('removed');
      delete obj.canvas;
    },

    /**
     * Clears specified context of canvas element
     * @param {CanvasRenderingContext2D} ctx Context to clear
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    clearContext: function(ctx) {
      ctx.clearRect(0, 0, this.width, this.height);
      return this;
    },

    /**
     * Returns context of canvas where objects are drawn
     * @return {CanvasRenderingContext2D}
     */
    getContext: function () {
      return this.contextContainer;
    },

    /**
     * Clears all contexts (background, main, top) of an instance
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    clear: function () {
      this._objects.length = 0;
      this.backgroundImage = null;
      this.overlayImage = null;
      this.backgroundColor = '';
      this.overlayColor = '';
      if (this._hasITextHandlers) {
        this.off('mouse:up', this._mouseUpITextHandler);
        this._iTextInstances = null;
        this._hasITextHandlers = false;
      }
      this.clearContext(this.contextContainer);
      this.fire('canvas:cleared');
      this.renderOnAddRemove && this.requestRenderAll();
      return this;
    },

    /**
     * Renders the canvas
     * @return {fabric.Canvas} instance
     * @chainable
     */
    renderAll: function () {
      var canvasToDrawOn = this.contextContainer;
      this.renderCanvas(canvasToDrawOn, this._objects);
      return this;
    },

    /**
     * Function created to be instance bound at initialization
     * used in requestAnimationFrame rendering
     * @return {fabric.Canvas} instance
     * @chainable
     */
    renderAndReset: function() {
      this.isRendering = 0;
      this.renderAll();
    },

    /**
     * Append a renderAll request to next animation frame.
     * a boolean flag will avoid appending more.
     * @return {fabric.Canvas} instance
     * @chainable
     */
    requestRenderAll: function () {
      if (!this.isRendering) {
        this.isRendering = fabric.util.requestAnimFrame(this.renderAndResetBound);
      }
      return this;
    },

    /**
     * Calculate the position of the 4 corner of canvas with current viewportTransform.
     * helps to determinate when an object is in the current rendering viewport using
     * object absolute coordinates ( aCoords )
     * @return {Object} points.tl
     * @chainable
     */
    calcViewportBoundaries: function() {
      var points = { }, width = this.width, height = this.height,
          iVpt = invertTransform(this.viewportTransform);
      points.tl = transformPoint({ x: 0, y: 0 }, iVpt);
      points.br = transformPoint({ x: width, y: height }, iVpt);
      points.tr = new fabric.Point(points.br.x, points.tl.y);
      points.bl = new fabric.Point(points.tl.x, points.br.y);
      this.vptCoords = points;
      return points;
    },

    /**
     * Renders background, objects, overlay and controls.
     * @param {CanvasRenderingContext2D} ctx
     * @param {Array} objects to render
     * @return {fabric.Canvas} instance
     * @chainable
     */
    renderCanvas: function(ctx, objects) {
      var v = this.viewportTransform;
      if (this.isRendering) {
        fabric.util.cancelAnimFrame(this.isRendering);
        this.isRendering = 0;
      }
      this.calcViewportBoundaries();
      this.clearContext(ctx);
      this.fire('before:render');
      if (this.clipTo) {
        fabric.util.clipContext(this, ctx);
      }
      this._renderBackground(ctx);

      ctx.save();
      //apply viewport transform once for all rendering process
      ctx.transform(v[0], v[1], v[2], v[3], v[4], v[5]);
      this._renderObjects(ctx, objects);
      ctx.restore();
      if (!this.controlsAboveOverlay && this.interactive) {
        this.drawControls(ctx);
      }
      if (this.clipTo) {
        ctx.restore();
      }
      this._renderOverlay(ctx);
      if (this.controlsAboveOverlay && this.interactive) {
        this.drawControls(ctx);
      }
      this.fire('after:render');
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     * @param {Array} objects to render
     */
    _renderObjects: function(ctx, objects) {
      var i, len;
      for (i = 0, len = objects.length; i < len; ++i) {
        objects[i] && objects[i].render(ctx);
      }
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     * @param {string} property 'background' or 'overlay'
     */
    _renderBackgroundOrOverlay: function(ctx, property) {
      var object = this[property + 'Color'], v;
      if (object) {
        ctx.fillStyle = object.toLive
          ? object.toLive(ctx, this)
          : object;

        ctx.fillRect(
          object.offsetX || 0,
          object.offsetY || 0,
          this.width,
          this.height);
      }
      object = this[property + 'Image'];
      if (object) {
        if (this[property + 'Vpt']) {
          v = this.viewportTransform;
          ctx.save();
          ctx.transform(v[0], v[1], v[2], v[3], v[4], v[5]);
        }
        object.render(ctx);
        this[property + 'Vpt'] && ctx.restore();
      }
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderBackground: function(ctx) {
      this._renderBackgroundOrOverlay(ctx, 'background');
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderOverlay: function(ctx) {
      this._renderBackgroundOrOverlay(ctx, 'overlay');
    },

    /**
     * Returns coordinates of a center of canvas.
     * Returned value is an object with top and left properties
     * @return {Object} object with "top" and "left" number values
     */
    getCenter: function () {
      return {
        top: this.height / 2,
        left: this.width / 2
      };
    },

    /**
     * Centers object horizontally in the canvas
     * @param {fabric.Object} object Object to center horizontally
     * @return {fabric.Canvas} thisArg
     */
    centerObjectH: function (object) {
      return this._centerObject(object, new fabric.Point(this.getCenter().left, object.getCenterPoint().y));
    },

    /**
     * Centers object vertically in the canvas
     * @param {fabric.Object} object Object to center vertically
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    centerObjectV: function (object) {
      return this._centerObject(object, new fabric.Point(object.getCenterPoint().x, this.getCenter().top));
    },

    /**
     * Centers object vertically and horizontally in the canvas
     * @param {fabric.Object} object Object to center vertically and horizontally
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    centerObject: function(object) {
      var center = this.getCenter();

      return this._centerObject(object, new fabric.Point(center.left, center.top));
    },

    /**
     * Centers object vertically and horizontally in the viewport
     * @param {fabric.Object} object Object to center vertically and horizontally
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    viewportCenterObject: function(object) {
      var vpCenter = this.getVpCenter();

      return this._centerObject(object, vpCenter);
    },

    /**
     * Centers object horizontally in the viewport, object.top is unchanged
     * @param {fabric.Object} object Object to center vertically and horizontally
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    viewportCenterObjectH: function(object) {
      var vpCenter = this.getVpCenter();
      this._centerObject(object, new fabric.Point(vpCenter.x, object.getCenterPoint().y));
      return this;
    },

    /**
     * Centers object Vertically in the viewport, object.top is unchanged
     * @param {fabric.Object} object Object to center vertically and horizontally
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    viewportCenterObjectV: function(object) {
      var vpCenter = this.getVpCenter();

      return this._centerObject(object, new fabric.Point(object.getCenterPoint().x, vpCenter.y));
    },

    /**
     * Calculate the point in canvas that correspond to the center of actual viewport.
     * @return {fabric.Point} vpCenter, viewport center
     * @chainable
     */
    getVpCenter: function() {
      var center = this.getCenter(),
          iVpt = invertTransform(this.viewportTransform);
      return transformPoint({ x: center.left, y: center.top }, iVpt);
    },

    /**
     * @private
     * @param {fabric.Object} object Object to center
     * @param {fabric.Point} center Center point
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    _centerObject: function(object, center) {
      object.setPositionByOrigin(center, 'center', 'center');
      object.setCoords();
      this.renderOnAddRemove && this.requestRenderAll();
      return this;
    },

    /**
     * Returs dataless JSON representation of canvas
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {String} json string
     */
    toDatalessJSON: function (propertiesToInclude) {
      return this.toDatalessObject(propertiesToInclude);
    },

    /**
     * Returns object representation of canvas
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} object representation of an instance
     */
    toObject: function (propertiesToInclude) {
      return this._toObjectMethod('toObject', propertiesToInclude);
    },

    /**
     * Returns dataless object representation of canvas
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} object representation of an instance
     */
    toDatalessObject: function (propertiesToInclude) {
      return this._toObjectMethod('toDatalessObject', propertiesToInclude);
    },

    /**
     * @private
     */
    _toObjectMethod: function (methodName, propertiesToInclude) {

      var data = {
        version: fabric.version,
        objects: this._toObjects(methodName, propertiesToInclude)
      };

      extend(data, this.__serializeBgOverlay(methodName, propertiesToInclude));

      fabric.util.populateWithProperties(this, data, propertiesToInclude);

      return data;
    },

    /**
     * @private
     */
    _toObjects: function(methodName, propertiesToInclude) {
      return this.getObjects().filter(function(object) {
        return !object.excludeFromExport;
      }).map(function(instance) {
        return this._toObject(instance, methodName, propertiesToInclude);
      }, this);
    },

    /**
     * @private
     */
    _toObject: function(instance, methodName, propertiesToInclude) {
      var originalValue;

      if (!this.includeDefaultValues) {
        originalValue = instance.includeDefaultValues;
        instance.includeDefaultValues = false;
      }

      var object = instance[methodName](propertiesToInclude);
      if (!this.includeDefaultValues) {
        instance.includeDefaultValues = originalValue;
      }
      return object;
    },

    /**
     * @private
     */
    __serializeBgOverlay: function(methodName, propertiesToInclude) {
      var data = { }, bgImage = this.backgroundImage, overlay = this.overlayImage;

      if (this.backgroundColor) {
        data.background = this.backgroundColor.toObject
          ? this.backgroundColor.toObject(propertiesToInclude)
          : this.backgroundColor;
      }

      if (this.overlayColor) {
        data.overlay = this.overlayColor.toObject
          ? this.overlayColor.toObject(propertiesToInclude)
          : this.overlayColor;
      }
      if (bgImage && !bgImage.excludeFromExport) {
        data.backgroundImage = this._toObject(bgImage, methodName, propertiesToInclude);
      }
      if (overlay && !overlay.excludeFromExport) {
        data.overlayImage = this._toObject(overlay, methodName, propertiesToInclude);
      }

      return data;
    },

    /* _TO_SVG_START_ */
    /**
     * When true, getSvgTransform() will apply the StaticCanvas.viewportTransform to the SVG transformation. When true,
     * a zoomed canvas will then produce zoomed SVG output.
     * @type Boolean
     * @default
     */
    svgViewportTransformation: true,

    /**
     * Returns SVG representation of canvas
     * @function
     * @param {Object} [options] Options object for SVG output
     * @param {Boolean} [options.suppressPreamble=false] If true xml tag is not included
     * @param {Object} [options.viewBox] SVG viewbox object
     * @param {Number} [options.viewBox.x] x-cooridnate of viewbox
     * @param {Number} [options.viewBox.y] y-coordinate of viewbox
     * @param {Number} [options.viewBox.width] Width of viewbox
     * @param {Number} [options.viewBox.height] Height of viewbox
     * @param {String} [options.encoding=UTF-8] Encoding of SVG output
     * @param {String} [options.width] desired width of svg with or without units
     * @param {String} [options.height] desired height of svg with or without units
     * @param {Function} [reviver] Method for further parsing of svg elements, called after each fabric object converted into svg representation.
     * @return {String} SVG string
     * @tutorial {@link http://fabricjs.com/fabric-intro-part-3#serialization}
     * @see {@link http://jsfiddle.net/fabricjs/jQ3ZZ/|jsFiddle demo}
     * @example <caption>Normal SVG output</caption>
     * var svg = canvas.toSVG();
     * @example <caption>SVG output without preamble (without &lt;?xml ../>)</caption>
     * var svg = canvas.toSVG({suppressPreamble: true});
     * @example <caption>SVG output with viewBox attribute</caption>
     * var svg = canvas.toSVG({
     *   viewBox: {
     *     x: 100,
     *     y: 100,
     *     width: 200,
     *     height: 300
     *   }
     * });
     * @example <caption>SVG output with different encoding (default: UTF-8)</caption>
     * var svg = canvas.toSVG({encoding: 'ISO-8859-1'});
     * @example <caption>Modify SVG output with reviver function</caption>
     * var svg = canvas.toSVG(null, function(svg) {
     *   return svg.replace('stroke-dasharray: ; stroke-linecap: butt; stroke-linejoin: miter; stroke-miterlimit: 10; ', '');
     * });
     */
    toSVG: function(options, reviver) {
      options || (options = { });

      var markup = [];

      this._setSVGPreamble(markup, options);
      this._setSVGHeader(markup, options);

      this._setSVGBgOverlayColor(markup, 'backgroundColor');
      this._setSVGBgOverlayImage(markup, 'backgroundImage', reviver);

      this._setSVGObjects(markup, reviver);

      this._setSVGBgOverlayColor(markup, 'overlayColor');
      this._setSVGBgOverlayImage(markup, 'overlayImage', reviver);

      markup.push('</svg>');

      return markup.join('');
    },

    /**
     * @private
     */
    _setSVGPreamble: function(markup, options) {
      if (options.suppressPreamble) {
        return;
      }
      markup.push(
        '<?xml version="1.0" encoding="', (options.encoding || 'UTF-8'), '" standalone="no" ?>\n',
        '<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" ',
        '"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">\n'
      );
    },

    /**
     * @private
     */
    _setSVGHeader: function(markup, options) {
      var width = options.width || this.width,
          height = options.height || this.height,
          vpt, viewBox = 'viewBox="0 0 ' + this.width + ' ' + this.height + '" ',
          NUM_FRACTION_DIGITS = fabric.Object.NUM_FRACTION_DIGITS;

      if (options.viewBox) {
        viewBox = 'viewBox="' +
                options.viewBox.x + ' ' +
                options.viewBox.y + ' ' +
                options.viewBox.width + ' ' +
                options.viewBox.height + '" ';
      }
      else {
        if (this.svgViewportTransformation) {
          vpt = this.viewportTransform;
          viewBox = 'viewBox="' +
                  toFixed(-vpt[4] / vpt[0], NUM_FRACTION_DIGITS) + ' ' +
                  toFixed(-vpt[5] / vpt[3], NUM_FRACTION_DIGITS) + ' ' +
                  toFixed(this.width / vpt[0], NUM_FRACTION_DIGITS) + ' ' +
                  toFixed(this.height / vpt[3], NUM_FRACTION_DIGITS) + '" ';
        }
      }

      markup.push(
        '<svg ',
        'xmlns="http://www.w3.org/2000/svg" ',
        'xmlns:xlink="http://www.w3.org/1999/xlink" ',
        'version="1.1" ',
        'width="', width, '" ',
        'height="', height, '" ',
        viewBox,
        'xml:space="preserve">\n',
        '<desc>Created with Fabric.js ', fabric.version, '</desc>\n',
        '<defs>\n',
        this.createSVGFontFacesMarkup(),
        this.createSVGRefElementsMarkup(),
        '</defs>\n'
      );
    },

    /**
     * Creates markup containing SVG referenced elements like patterns, gradients etc.
     * @return {String}
     */
    createSVGRefElementsMarkup: function() {
      var _this = this,
          markup = ['backgroundColor', 'overlayColor'].map(function(prop) {
            var fill = _this[prop];
            if (fill && fill.toLive) {
              return fill.toSVG(_this, false);
            }
          });
      return markup.join('');
    },

    /**
     * Creates markup containing SVG font faces,
     * font URLs for font faces must be collected by developers
     * and are not extracted from the DOM by fabricjs
     * @param {Array} objects Array of fabric objects
     * @return {String}
     */
    createSVGFontFacesMarkup: function() {
      var markup = '', fontList = { }, obj, fontFamily,
          style, row, rowIndex, _char, charIndex, i, len,
          fontPaths = fabric.fontPaths, objects = this.getObjects();

      for (i = 0, len = objects.length; i < len; i++) {
        obj = objects[i];
        fontFamily = obj.fontFamily;
        if (obj.type.indexOf('text') === -1 || fontList[fontFamily] || !fontPaths[fontFamily]) {
          continue;
        }
        fontList[fontFamily] = true;
        if (!obj.styles) {
          continue;
        }
        style = obj.styles;
        for (rowIndex in style) {
          row = style[rowIndex];
          for (charIndex in row) {
            _char = row[charIndex];
            fontFamily = _char.fontFamily;
            if (!fontList[fontFamily] && fontPaths[fontFamily]) {
              fontList[fontFamily] = true;
            }
          }
        }
      }

      for (var j in fontList) {
        markup += [
          '\t\t@font-face {\n',
          '\t\t\tfont-family: \'', j, '\';\n',
          '\t\t\tsrc: url(\'', fontPaths[j], '\');\n',
          '\t\t}\n'
        ].join('');
      }

      if (markup) {
        markup = [
          '\t<style type="text/css">',
          '<![CDATA[\n',
          markup,
          ']]>',
          '</style>\n'
        ].join('');
      }

      return markup;
    },

    /**
     * @private
     */
    _setSVGObjects: function(markup, reviver) {
      var instance, i, len, objects = this.getObjects();
      for (i = 0, len = objects.length; i < len; i++) {
        instance = objects[i];
        if (instance.excludeFromExport) {
          continue;
        }
        this._setSVGObject(markup, instance, reviver);
      }
    },

    /**
     * @private
     */
    _setSVGObject: function(markup, instance, reviver) {
      markup.push(instance.toSVG(reviver));
    },

    /**
     * @private
     */
    _setSVGBgOverlayImage: function(markup, property, reviver) {
      if (this[property] && this[property].toSVG) {
        markup.push(this[property].toSVG(reviver));
      }
    },

    /**
     * @private
     */
    _setSVGBgOverlayColor: function(markup, property) {
      var filler = this[property], vpt = this.viewportTransform, finalWidth = this.width / vpt[0],
          finalHeight = this.height / vpt[3];
      if (!filler) {
        return;
      }
      if (filler.toLive) {
        var repeat = filler.repeat;
        markup.push(
          '<rect transform="translate(', finalWidth / 2, ',', finalHeight / 2, ')"',
          ' x="', filler.offsetX - finalWidth / 2, '" y="', filler.offsetY - finalHeight / 2, '" ',
          'width="',
          (repeat === 'repeat-y' || repeat === 'no-repeat'
            ? filler.source.width
            : finalWidth ),
          '" height="',
          (repeat === 'repeat-x' || repeat === 'no-repeat'
            ? filler.source.height
            : finalHeight),
          '" fill="url(#SVGID_' + filler.id + ')"',
          '></rect>\n'
        );
      }
      else {
        markup.push(
          '<rect x="0" y="0" width="100%" height="100%" ',
          'fill="', this[property], '"',
          '></rect>\n'
        );
      }
    },
    /* _TO_SVG_END_ */

    /**
     * Moves an object or the objects of a multiple selection
     * to the bottom of the stack of drawn objects
     * @param {fabric.Object} object Object to send to back
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    sendToBack: function (object) {
      if (!object) {
        return this;
      }
      var activeSelection = this._activeObject,
          i, obj, objs;
      if (object === activeSelection && object.type === 'activeSelection') {
        objs = activeSelection._objects;
        for (i = objs.length; i--;) {
          obj = objs[i];
          removeFromArray(this._objects, obj);
          this._objects.unshift(obj);
        }
      }
      else {
        removeFromArray(this._objects, object);
        this._objects.unshift(object);
      }
      this.renderOnAddRemove && this.requestRenderAll();
      return this;
    },

    /**
     * Moves an object or the objects of a multiple selection
     * to the top of the stack of drawn objects
     * @param {fabric.Object} object Object to send
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    bringToFront: function (object) {
      if (!object) {
        return this;
      }
      var activeSelection = this._activeObject,
          i, obj, objs;
      if (object === activeSelection && object.type === 'activeSelection') {
        objs = activeSelection._objects;
        for (i = 0; i < objs.length; i++) {
          obj = objs[i];
          removeFromArray(this._objects, obj);
          this._objects.push(obj);
        }
      }
      else {
        removeFromArray(this._objects, object);
        this._objects.push(object);
      }
      this.renderOnAddRemove && this.requestRenderAll();
      return this;
    },

    /**
     * Moves an object or a selection down in stack of drawn objects
     * An optional paramter, intersecting allowes to move the object in behind
     * the first intersecting object. Where intersection is calculated with
     * bounding box. If no intersection is found, there will not be change in the
     * stack.
     * @param {fabric.Object} object Object to send
     * @param {Boolean} [intersecting] If `true`, send object behind next lower intersecting object
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    sendBackwards: function (object, intersecting) {
      if (!object) {
        return this;
      }
      var activeSelection = this._activeObject,
          i, obj, idx, newIdx, objs, objsMoved = 0;

      if (object === activeSelection && object.type === 'activeSelection') {
        objs = activeSelection._objects;
        for (i = 0; i < objs.length; i++) {
          obj = objs[i];
          idx = this._objects.indexOf(obj);
          if (idx > 0 + objsMoved) {
            newIdx = idx - 1;
            removeFromArray(this._objects, obj);
            this._objects.splice(newIdx, 0, obj);
          }
          objsMoved++;
        }
      }
      else {
        idx = this._objects.indexOf(object);
        if (idx !== 0) {
          // if object is not on the bottom of stack
          newIdx = this._findNewLowerIndex(object, idx, intersecting);
          removeFromArray(this._objects, object);
          this._objects.splice(newIdx, 0, object);
        }
      }
      this.renderOnAddRemove && this.requestRenderAll();
      return this;
    },

    /**
     * @private
     */
    _findNewLowerIndex: function(object, idx, intersecting) {
      var newIdx, i;

      if (intersecting) {
        newIdx = idx;

        // traverse down the stack looking for the nearest intersecting object
        for (i = idx - 1; i >= 0; --i) {

          var isIntersecting = object.intersectsWithObject(this._objects[i]) ||
                               object.isContainedWithinObject(this._objects[i]) ||
                               this._objects[i].isContainedWithinObject(object);

          if (isIntersecting) {
            newIdx = i;
            break;
          }
        }
      }
      else {
        newIdx = idx - 1;
      }

      return newIdx;
    },

    /**
     * Moves an object or a selection up in stack of drawn objects
     * An optional paramter, intersecting allowes to move the object in front
     * of the first intersecting object. Where intersection is calculated with
     * bounding box. If no intersection is found, there will not be change in the
     * stack.
     * @param {fabric.Object} object Object to send
     * @param {Boolean} [intersecting] If `true`, send object in front of next upper intersecting object
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    bringForward: function (object, intersecting) {
      if (!object) {
        return this;
      }
      var activeSelection = this._activeObject,
          i, obj, idx, newIdx, objs, objsMoved = 0;

      if (object === activeSelection && object.type === 'activeSelection') {
        objs = activeSelection._objects;
        for (i = objs.length; i--;) {
          obj = objs[i];
          idx = this._objects.indexOf(obj);
          if (idx < this._objects.length - 1 - objsMoved) {
            newIdx = idx + 1;
            removeFromArray(this._objects, obj);
            this._objects.splice(newIdx, 0, obj);
          }
          objsMoved++;
        }
      }
      else {
        idx = this._objects.indexOf(object);
        if (idx !== this._objects.length - 1) {
          // if object is not on top of stack (last item in an array)
          newIdx = this._findNewUpperIndex(object, idx, intersecting);
          removeFromArray(this._objects, object);
          this._objects.splice(newIdx, 0, object);
        }
      }
      this.renderOnAddRemove && this.requestRenderAll();
      return this;
    },

    /**
     * @private
     */
    _findNewUpperIndex: function(object, idx, intersecting) {
      var newIdx, i, len;

      if (intersecting) {
        newIdx = idx;

        // traverse up the stack looking for the nearest intersecting object
        for (i = idx + 1, len = this._objects.length; i < len; ++i) {

          var isIntersecting = object.intersectsWithObject(this._objects[i]) ||
                               object.isContainedWithinObject(this._objects[i]) ||
                               this._objects[i].isContainedWithinObject(object);

          if (isIntersecting) {
            newIdx = i;
            break;
          }
        }
      }
      else {
        newIdx = idx + 1;
      }

      return newIdx;
    },

    /**
     * Moves an object to specified level in stack of drawn objects
     * @param {fabric.Object} object Object to send
     * @param {Number} index Position to move to
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    moveTo: function (object, index) {
      removeFromArray(this._objects, object);
      this._objects.splice(index, 0, object);
      return this.renderOnAddRemove && this.requestRenderAll();
    },

    /**
     * Clears a canvas element and dispose objects
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    dispose: function () {
      // cancel eventually ongoing renders
      if (this.isRendering) {
        fabric.util.cancelAnimFrame(this.isRendering);
        this.isRendering = 0;
      }
      this.forEachObject(function(object) {
        object.dispose && object.dispose();
      });
      this._objects = [];
      this.backgroundImage = null;
      this.overlayImage = null;
      this._iTextInstances = null;
      this.lowerCanvasEl = null;
      this.contextContainer = null;
      return this;
    },

    /**
     * Returns a string representation of an instance
     * @return {String} string representation of an instance
     */
    toString: function () {
      return '#<fabric.Canvas (' + this.complexity() + '): ' +
               '{ objects: ' + this.getObjects().length + ' }>';
    }
  });

  extend(fabric.StaticCanvas.prototype, fabric.Observable);
  extend(fabric.StaticCanvas.prototype, fabric.Collection);
  extend(fabric.StaticCanvas.prototype, fabric.DataURLExporter);

  extend(fabric.StaticCanvas, /** @lends fabric.StaticCanvas */ {

    /**
     * @static
     * @type String
     * @default
     */
    EMPTY_JSON: '{"objects": [], "background": "white"}',

    /**
     * Provides a way to check support of some of the canvas methods
     * (either those of HTMLCanvasElement itself, or rendering context)
     *
     * @param {String} methodName Method to check support for;
     *                            Could be one of "getImageData", "toDataURL", "toDataURLWithQuality" or "setLineDash"
     * @return {Boolean | null} `true` if method is supported (or at least exists),
     *                          `null` if canvas element or context can not be initialized
     */
    supports: function (methodName) {
      var el = fabric.util.createCanvasElement();

      if (!el || !el.getContext) {
        return null;
      }

      var ctx = el.getContext('2d');
      if (!ctx) {
        return null;
      }

      switch (methodName) {

        case 'getImageData':
          return typeof ctx.getImageData !== 'undefined';

        case 'setLineDash':
          return typeof ctx.setLineDash !== 'undefined';

        case 'toDataURL':
          return typeof el.toDataURL !== 'undefined';

        case 'toDataURLWithQuality':
          try {
            el.toDataURL('image/jpeg', 0);
            return true;
          }
          catch (e) { }
          return false;

        default:
          return null;
      }
    }
  });

  /**
   * Returns JSON representation of canvas
   * @function
   * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
   * @return {String} JSON string
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-3#serialization}
   * @see {@link http://jsfiddle.net/fabricjs/pec86/|jsFiddle demo}
   * @example <caption>JSON without additional properties</caption>
   * var json = canvas.toJSON();
   * @example <caption>JSON with additional properties included</caption>
   * var json = canvas.toJSON(['lockMovementX', 'lockMovementY', 'lockRotation', 'lockScalingX', 'lockScalingY', 'lockUniScaling']);
   * @example <caption>JSON without default values</caption>
   * canvas.includeDefaultValues = false;
   * var json = canvas.toJSON();
   */
  fabric.StaticCanvas.prototype.toJSON = fabric.StaticCanvas.prototype.toObject;

  if (fabric.isLikelyNode) {
    fabric.StaticCanvas.prototype.createPNGStream = function() {
      var impl = fabric.util.getNodeCanvas(this.lowerCanvasEl);
      return impl && impl.createPNGStream();
    };
    fabric.StaticCanvas.prototype.createJPEGStream = function(opts) {
      var impl = fabric.util.getNodeCanvas(this.lowerCanvasEl);
      return impl && impl.createJPEGStream(opts);
    };
  }
})();


/**
 * BaseBrush class
 * @class fabric.BaseBrush
 * @see {@link http://fabricjs.com/freedrawing|Freedrawing demo}
 */
fabric.BaseBrush = fabric.util.createClass(/** @lends fabric.BaseBrush.prototype */ {

  /**
   * Color of a brush
   * @type String
   * @default
   */
  color: 'rgb(0, 0, 0)',

  /**
   * Width of a brush, has to be a Number, no string literals
   * @type Number
   * @default
   */
  width: 1,

  /**
   * Shadow object representing shadow of this shape.
   * <b>Backwards incompatibility note:</b> This property replaces "shadowColor" (String), "shadowOffsetX" (Number),
   * "shadowOffsetY" (Number) and "shadowBlur" (Number) since v1.2.12
   * @type fabric.Shadow
   * @default
   */
  shadow: null,

  /**
   * Line endings style of a brush (one of "butt", "round", "square")
   * @type String
   * @default
   */
  strokeLineCap: 'round',

  /**
   * Corner style of a brush (one of "bevel", "round", "miter")
   * @type String
   * @default
   */
  strokeLineJoin: 'round',

  /**
   * Maximum miter length (used for strokeLineJoin = "miter") of a brush's
   * @type Number
   * @default
   */
  strokeMiterLimit:         10,

  /**
   * Stroke Dash Array.
   * @type Array
   * @default
   */
  strokeDashArray: null,

  /**
   * Sets shadow of an object
   * @param {Object|String} [options] Options object or string (e.g. "2px 2px 10px rgba(0,0,0,0.2)")
   * @return {fabric.Object} thisArg
   * @chainable
   */
  setShadow: function(options) {
    this.shadow = new fabric.Shadow(options);
    return this;
  },

  /**
   * Sets brush styles
   * @private
   */
  _setBrushStyles: function() {
    var ctx = this.canvas.contextTop;
    ctx.strokeStyle = this.color;
    ctx.lineWidth = this.width;
    ctx.lineCap = this.strokeLineCap;
    ctx.miterLimit = this.strokeMiterLimit;
    ctx.lineJoin = this.strokeLineJoin;
    if (fabric.StaticCanvas.supports('setLineDash')) {
      ctx.setLineDash(this.strokeDashArray || []);
    }
  },

  /**
   * Sets the transformation on given context
   * @param {RenderingContext2d} ctx context to render on
   * @private
   */
  _saveAndTransform: function(ctx) {
    var v = this.canvas.viewportTransform;
    ctx.save();
    ctx.transform(v[0], v[1], v[2], v[3], v[4], v[5]);
  },

  /**
   * Sets brush shadow styles
   * @private
   */
  _setShadow: function() {
    if (!this.shadow) {
      return;
    }

    var ctx = this.canvas.contextTop,
        zoom = this.canvas.getZoom();

    ctx.shadowColor = this.shadow.color;
    ctx.shadowBlur = this.shadow.blur * zoom;
    ctx.shadowOffsetX = this.shadow.offsetX * zoom;
    ctx.shadowOffsetY = this.shadow.offsetY * zoom;
  },

  /**
   * Removes brush shadow styles
   * @private
   */
  _resetShadow: function() {
    var ctx = this.canvas.contextTop;

    ctx.shadowColor = '';
    ctx.shadowBlur = ctx.shadowOffsetX = ctx.shadowOffsetY = 0;
  }
});


(function() {

  /**
   * PencilBrush class
   * @class fabric.PencilBrush
   * @extends fabric.BaseBrush
   */
  fabric.PencilBrush = fabric.util.createClass(fabric.BaseBrush, /** @lends fabric.PencilBrush.prototype */ {

    /**
     * Constructor
     * @param {fabric.Canvas} canvas
     * @return {fabric.PencilBrush} Instance of a pencil brush
     */
    initialize: function(canvas) {
      this.canvas = canvas;
      this._points = [];
    },

    /**
     * Invoked inside on mouse down and mouse move
     * @param {Object} pointer
     */
    _drawSegment: function (ctx, p1, p2) {
      var midPoint = p1.midPointFrom(p2);
      ctx.quadraticCurveTo(p1.x, p1.y, midPoint.x, midPoint.y);
      return midPoint;
    },

    /**
     * Inovoked on mouse down
     * @param {Object} pointer
     */
    onMouseDown: function(pointer) {
      this._prepareForDrawing(pointer);
      // capture coordinates immediately
      // this allows to draw dots (when movement never occurs)
      this._captureDrawingPath(pointer);
      this._render();
    },

    /**
     * Inovoked on mouse move
     * @param {Object} pointer
     */
    onMouseMove: function(pointer) {
      if (this._captureDrawingPath(pointer) && this._points.length > 1) {
        if (this.needsFullRender) {
          // redraw curve
          // clear top canvas
          this.canvas.clearContext(this.canvas.contextTop);
          this._render();
        }
        else {
          var points = this._points, length = points.length, ctx = this.canvas.contextTop;
          // draw the curve update
          this._saveAndTransform(ctx);
          if (this.oldEnd) {
            ctx.beginPath();
            ctx.moveTo(this.oldEnd.x, this.oldEnd.y);
          }
          this.oldEnd = this._drawSegment(ctx, points[length - 2], points[length - 1], true);
          ctx.stroke();
          ctx.restore();
        }
      }
    },

    /**
     * Invoked on mouse up
     */
    onMouseUp: function() {
      this.oldEnd = undefined;
      this._finalizeAndAddPath();
    },

    /**
     * @private
     * @param {Object} pointer Actual mouse position related to the canvas.
     */
    _prepareForDrawing: function(pointer) {

      var p = new fabric.Point(pointer.x, pointer.y);

      this._reset();
      this._addPoint(p);
      this.canvas.contextTop.moveTo(p.x, p.y);
    },

    /**
     * @private
     * @param {fabric.Point} point Point to be added to points array
     */
    _addPoint: function(point) {
      if (this._points.length > 1 && point.eq(this._points[this._points.length - 1])) {
        return false;
      }
      this._points.push(point);
      return true;
    },

    /**
     * Clear points array and set contextTop canvas style.
     * @private
     */
    _reset: function() {
      this._points.length = 0;
      this._setBrushStyles();
      var color = new fabric.Color(this.color);
      this.needsFullRender = (color.getAlpha() < 1);
      this._setShadow();
    },

    /**
     * @private
     * @param {Object} pointer Actual mouse position related to the canvas.
     */
    _captureDrawingPath: function(pointer) {
      var pointerPoint = new fabric.Point(pointer.x, pointer.y);
      return this._addPoint(pointerPoint);
    },

    /**
     * Draw a smooth path on the topCanvas using quadraticCurveTo
     * @private
     */
    _render: function() {
      var ctx  = this.canvas.contextTop, i, len,
          p1 = this._points[0],
          p2 = this._points[1];

      this._saveAndTransform(ctx);
      ctx.beginPath();
      //if we only have 2 points in the path and they are the same
      //it means that the user only clicked the canvas without moving the mouse
      //then we should be drawing a dot. A path isn't drawn between two identical dots
      //that's why we set them apart a bit
      if (this._points.length === 2 && p1.x === p2.x && p1.y === p2.y) {
        var width = this.width / 1000;
        p1 = new fabric.Point(p1.x, p1.y);
        p2 = new fabric.Point(p2.x, p2.y);
        p1.x -= width;
        p2.x += width;
      }
      ctx.moveTo(p1.x, p1.y);

      for (i = 1, len = this._points.length; i < len; i++) {
        // we pick the point between pi + 1 & pi + 2 as the
        // end point and p1 as our control point.
        this._drawSegment(ctx, p1, p2);
        p1 = this._points[i];
        p2 = this._points[i + 1];
      }
      // Draw last line as a straight line while
      // we wait for the next point to be able to calculate
      // the bezier control point
      ctx.lineTo(p1.x, p1.y);
      ctx.stroke();
      ctx.restore();
    },

    /**
     * Converts points to SVG path
     * @param {Array} points Array of points
     * @return {String} SVG path
     */
    convertPointsToSVGPath: function(points) {
      var path = [], i, width = this.width / 1000,
          p1 = new fabric.Point(points[0].x, points[0].y),
          p2 = new fabric.Point(points[1].x, points[1].y),
          len = points.length, multSignX = 1, multSignY = 1, manyPoints = len > 2;

      if (manyPoints) {
        multSignX = points[2].x < p2.x ? -1 : points[2].x === p2.x ? 0 : 1;
        multSignY = points[2].y < p2.y ? -1 : points[2].y === p2.y ? 0 : 1;
      }
      path.push('M ', p1.x - multSignX * width, ' ', p1.y - multSignY * width, ' ');
      for (i = 1; i < len; i++) {
        if (!p1.eq(p2)) {
          var midPoint = p1.midPointFrom(p2);
          // p1 is our bezier control point
          // midpoint is our endpoint
          // start point is p(i-1) value.
          path.push('Q ', p1.x, ' ', p1.y, ' ', midPoint.x, ' ', midPoint.y, ' ');
        }
        p1 = points[i];
        if ((i + 1) < points.length) {
          p2 = points[i + 1];
        }
      }
      if (manyPoints) {
        multSignX = p1.x > points[i - 2].x ? 1 : p1.x === points[i - 2].x ? 0 : -1;
        multSignY = p1.y > points[i - 2].y ? 1 : p1.y === points[i - 2].y ? 0 : -1;
      }
      path.push('L ', p1.x + multSignX * width, ' ', p1.y + multSignY * width);
      return path;
    },

    /**
     * Creates fabric.Path object to add on canvas
     * @param {String} pathData Path data
     * @return {fabric.Path} Path to add on canvas
     */
    createPath: function(pathData) {
      var path = new fabric.Path(pathData, {
        fill: null,
        stroke: this.color,
        strokeWidth: this.width,
        strokeLineCap: this.strokeLineCap,
        strokeMiterLimit: this.strokeMiterLimit,
        strokeLineJoin: this.strokeLineJoin,
        strokeDashArray: this.strokeDashArray,
      });
      var position = new fabric.Point(path.left + path.width / 2, path.top + path.height / 2);
      position = path.translateToGivenOrigin(position, 'center', 'center', path.originX, path.originY);
      path.top = position.y;
      path.left = position.x;
      if (this.shadow) {
        this.shadow.affectStroke = true;
        path.setShadow(this.shadow);
      }

      return path;
    },

    /**
     * On mouseup after drawing the path on contextTop canvas
     * we use the points captured to create an new fabric path object
     * and add it to the fabric canvas.
     */
    _finalizeAndAddPath: function() {
      var ctx = this.canvas.contextTop;
      ctx.closePath();

      var pathData = this.convertPointsToSVGPath(this._points).join('');
      if (pathData === 'M 0 0 Q 0 0 0 0 L 0 0') {
        // do not create 0 width/height paths, as they are
        // rendered inconsistently across browsers
        // Firefox 4, for example, renders a dot,
        // whereas Chrome 10 renders nothing
        this.canvas.requestRenderAll();
        return;
      }

      var path = this.createPath(pathData);
      this.canvas.clearContext(this.canvas.contextTop);
      this.canvas.add(path);
      this.canvas.renderAll();
      path.setCoords();
      this._resetShadow();


      // fire event 'path' created
      this.canvas.fire('path:created', { path: path });
    }
  });
})();


/**
 * CircleBrush class
 * @class fabric.CircleBrush
 */
fabric.CircleBrush = fabric.util.createClass(fabric.BaseBrush, /** @lends fabric.CircleBrush.prototype */ {

  /**
   * Width of a brush
   * @type Number
   * @default
   */
  width: 10,

  /**
   * Constructor
   * @param {fabric.Canvas} canvas
   * @return {fabric.CircleBrush} Instance of a circle brush
   */
  initialize: function(canvas) {
    this.canvas = canvas;
    this.points = [];
  },

  /**
   * Invoked inside on mouse down and mouse move
   * @param {Object} pointer
   */
  drawDot: function(pointer) {
    var point = this.addPoint(pointer),
        ctx = this.canvas.contextTop;
    this._saveAndTransform(ctx);
    ctx.fillStyle = point.fill;
    ctx.beginPath();
    ctx.arc(point.x, point.y, point.radius, 0, Math.PI * 2, false);
    ctx.closePath();
    ctx.fill();

    ctx.restore();
  },

  /**
   * Invoked on mouse down
   */
  onMouseDown: function(pointer) {
    this.points.length = 0;
    this.canvas.clearContext(this.canvas.contextTop);
    this._setShadow();
    this.drawDot(pointer);
  },

  /**
   * Render the full state of the brush
   * @private
   */
  _render: function() {
    var ctx  = this.canvas.contextTop, i, len,
        points = this.points, point;
    this._saveAndTransform(ctx);
    for (i = 0, len = points.length; i < len; i++) {
      point = points[i];
      ctx.fillStyle = point.fill;
      ctx.beginPath();
      ctx.arc(point.x, point.y, point.radius, 0, Math.PI * 2, false);
      ctx.closePath();
      ctx.fill();
    }
    ctx.restore();
  },

  /**
   * Invoked on mouse move
   * @param {Object} pointer
   */
  onMouseMove: function(pointer) {
    this.drawDot(pointer);
  },

  /**
   * Invoked on mouse up
   */
  onMouseUp: function() {
    var originalRenderOnAddRemove = this.canvas.renderOnAddRemove, i, len;
    this.canvas.renderOnAddRemove = false;

    var circles = [];

    for (i = 0, len = this.points.length; i < len; i++) {
      var point = this.points[i],
          circle = new fabric.Circle({
            radius: point.radius,
            left: point.x,
            top: point.y,
            originX: 'center',
            originY: 'center',
            fill: point.fill
          });

      this.shadow && circle.setShadow(this.shadow);

      circles.push(circle);
    }
    var group = new fabric.Group(circles, { originX: 'center', originY: 'center' });
    group.canvas = this.canvas;

    this.canvas.add(group);
    this.canvas.fire('path:created', { path: group });

    this.canvas.clearContext(this.canvas.contextTop);
    this._resetShadow();
    this.canvas.renderOnAddRemove = originalRenderOnAddRemove;
    this.canvas.requestRenderAll();
  },

  /**
   * @param {Object} pointer
   * @return {fabric.Point} Just added pointer point
   */
  addPoint: function(pointer) {
    var pointerPoint = new fabric.Point(pointer.x, pointer.y),

        circleRadius = fabric.util.getRandomInt(
          Math.max(0, this.width - 20), this.width + 20) / 2,

        circleColor = new fabric.Color(this.color)
          .setAlpha(fabric.util.getRandomInt(0, 100) / 100)
          .toRgba();

    pointerPoint.radius = circleRadius;
    pointerPoint.fill = circleColor;

    this.points.push(pointerPoint);

    return pointerPoint;
  }
});


/**
 * SprayBrush class
 * @class fabric.SprayBrush
 */
fabric.SprayBrush = fabric.util.createClass( fabric.BaseBrush, /** @lends fabric.SprayBrush.prototype */ {

  /**
   * Width of a spray
   * @type Number
   * @default
   */
  width:              10,

  /**
   * Density of a spray (number of dots per chunk)
   * @type Number
   * @default
   */
  density:            20,

  /**
   * Width of spray dots
   * @type Number
   * @default
   */
  dotWidth:           1,

  /**
   * Width variance of spray dots
   * @type Number
   * @default
   */
  dotWidthVariance:   1,

  /**
   * Whether opacity of a dot should be random
   * @type Boolean
   * @default
   */
  randomOpacity:        false,

  /**
   * Whether overlapping dots (rectangles) should be removed (for performance reasons)
   * @type Boolean
   * @default
   */
  optimizeOverlapping:  true,

  /**
   * Constructor
   * @param {fabric.Canvas} canvas
   * @return {fabric.SprayBrush} Instance of a spray brush
   */
  initialize: function(canvas) {
    this.canvas = canvas;
    this.sprayChunks = [];
  },

  /**
   * Invoked on mouse down
   * @param {Object} pointer
   */
  onMouseDown: function(pointer) {
    this.sprayChunks.length = 0;
    this.canvas.clearContext(this.canvas.contextTop);
    this._setShadow();

    this.addSprayChunk(pointer);
    this.render(this.sprayChunkPoints);
  },

  /**
   * Invoked on mouse move
   * @param {Object} pointer
   */
  onMouseMove: function(pointer) {
    this.addSprayChunk(pointer);
    this.render(this.sprayChunkPoints);
  },

  /**
   * Invoked on mouse up
   */
  onMouseUp: function() {
    var originalRenderOnAddRemove = this.canvas.renderOnAddRemove;
    this.canvas.renderOnAddRemove = false;

    var rects = [];

    for (var i = 0, ilen = this.sprayChunks.length; i < ilen; i++) {
      var sprayChunk = this.sprayChunks[i];

      for (var j = 0, jlen = sprayChunk.length; j < jlen; j++) {

        var rect = new fabric.Rect({
          width: sprayChunk[j].width,
          height: sprayChunk[j].width,
          left: sprayChunk[j].x + 1,
          top: sprayChunk[j].y + 1,
          originX: 'center',
          originY: 'center',
          fill: this.color
        });
        rects.push(rect);
      }
    }

    if (this.optimizeOverlapping) {
      rects = this._getOptimizedRects(rects);
    }

    var group = new fabric.Group(rects, { originX: 'center', originY: 'center' });
    this.shadow && group.setShadow(this.shadow);
    this.canvas.add(group);
    this.canvas.fire('path:created', { path: group });

    this.canvas.clearContext(this.canvas.contextTop);
    this._resetShadow();
    this.canvas.renderOnAddRemove = originalRenderOnAddRemove;
    this.canvas.requestRenderAll();
  },

  /**
   * @private
   * @param {Array} rects
   */
  _getOptimizedRects: function(rects) {

    // avoid creating duplicate rects at the same coordinates
    var uniqueRects = { }, key, i, len;

    for (i = 0, len = rects.length; i < len; i++) {
      key = rects[i].left + '' + rects[i].top;
      if (!uniqueRects[key]) {
        uniqueRects[key] = rects[i];
      }
    }
    var uniqueRectsArray = [];
    for (key in uniqueRects) {
      uniqueRectsArray.push(uniqueRects[key]);
    }

    return uniqueRectsArray;
  },

  /**
   * Render new chunk of spray brush
   */
  render: function(sprayChunk) {
    var ctx = this.canvas.contextTop, i, len;
    ctx.fillStyle = this.color;

    this._saveAndTransform(ctx);

    for (i = 0, len = sprayChunk.length; i < len; i++) {
      var point = sprayChunk[i];
      if (typeof point.opacity !== 'undefined') {
        ctx.globalAlpha = point.opacity;
      }
      ctx.fillRect(point.x, point.y, point.width, point.width);
    }
    ctx.restore();
  },

  /**
   * Render all spray chunks
   */
  _render: function() {
    var ctx = this.canvas.contextTop, i, ilen;
    ctx.fillStyle = this.color;

    this._saveAndTransform(ctx);

    for (i = 0, ilen = this.sprayChunks.length; i < ilen; i++) {
      this.render(this.sprayChunks[i]);
    }
    ctx.restore();
  },

  /**
   * @param {Object} pointer
   */
  addSprayChunk: function(pointer) {
    this.sprayChunkPoints = [];

    var x, y, width, radius = this.width / 2, i;

    for (i = 0; i < this.density; i++) {

      x = fabric.util.getRandomInt(pointer.x - radius, pointer.x + radius);
      y = fabric.util.getRandomInt(pointer.y - radius, pointer.y + radius);

      if (this.dotWidthVariance) {
        width = fabric.util.getRandomInt(
          // bottom clamp width to 1
          Math.max(1, this.dotWidth - this.dotWidthVariance),
          this.dotWidth + this.dotWidthVariance);
      }
      else {
        width = this.dotWidth;
      }

      var point = new fabric.Point(x, y);
      point.width = width;

      if (this.randomOpacity) {
        point.opacity = fabric.util.getRandomInt(0, 100) / 100;
      }

      this.sprayChunkPoints.push(point);
    }

    this.sprayChunks.push(this.sprayChunkPoints);
  }
});


/**
 * PatternBrush class
 * @class fabric.PatternBrush
 * @extends fabric.BaseBrush
 */
fabric.PatternBrush = fabric.util.createClass(fabric.PencilBrush, /** @lends fabric.PatternBrush.prototype */ {

  getPatternSrc: function() {

    var dotWidth = 20,
        dotDistance = 5,
        patternCanvas = fabric.document.createElement('canvas'),
        patternCtx = patternCanvas.getContext('2d');

    patternCanvas.width = patternCanvas.height = dotWidth + dotDistance;

    patternCtx.fillStyle = this.color;
    patternCtx.beginPath();
    patternCtx.arc(dotWidth / 2, dotWidth / 2, dotWidth / 2, 0, Math.PI * 2, false);
    patternCtx.closePath();
    patternCtx.fill();

    return patternCanvas;
  },

  getPatternSrcFunction: function() {
    return String(this.getPatternSrc).replace('this.color', '"' + this.color + '"');
  },

  /**
   * Creates "pattern" instance property
   */
  getPattern: function() {
    return this.canvas.contextTop.createPattern(this.source || this.getPatternSrc(), 'repeat');
  },

  /**
   * Sets brush styles
   */
  _setBrushStyles: function() {
    this.callSuper('_setBrushStyles');
    this.canvas.contextTop.strokeStyle = this.getPattern();
  },

  /**
   * Creates path
   */
  createPath: function(pathData) {
    var path = this.callSuper('createPath', pathData),
        topLeft = path._getLeftTopCoords().scalarAdd(path.strokeWidth / 2);

    path.stroke = new fabric.Pattern({
      source: this.source || this.getPatternSrcFunction(),
      offsetX: -topLeft.x,
      offsetY: -topLeft.y
    });
    return path;
  }
});


(function() {

  var getPointer = fabric.util.getPointer,
      degreesToRadians = fabric.util.degreesToRadians,
      radiansToDegrees = fabric.util.radiansToDegrees,
      atan2 = Math.atan2,
      abs = Math.abs,
      supportLineDash = fabric.StaticCanvas.supports('setLineDash'),

      STROKE_OFFSET = 0.5;

  /**
   * Canvas class
   * @class fabric.Canvas
   * @extends fabric.StaticCanvas
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-1#canvas}
   * @see {@link fabric.Canvas#initialize} for constructor definition
   *
   * @fires object:modified
   * @fires object:rotated
   * @fires object:scaled
   * @fires object:moved
   * @fires object:skewed
   * @fires object:rotating
   * @fires object:scaling
   * @fires object:moving
   * @fires object:skewing
   * @fires object:selected this event is deprecated. use selection:created
   *
   * @fires before:transform
   * @fires before:selection:cleared
   * @fires selection:cleared
   * @fires selection:updated
   * @fires selection:created
   *
   * @fires path:created
   * @fires mouse:down
   * @fires mouse:move
   * @fires mouse:up
   * @fires mouse:down:before
   * @fires mouse:move:before
   * @fires mouse:up:before
   * @fires mouse:over
   * @fires mouse:out
   * @fires mouse:dblclick
   *
   * @fires dragover
   * @fires dragenter
   * @fires dragleave
   * @fires drop
   *
   */
  fabric.Canvas = fabric.util.createClass(fabric.StaticCanvas, /** @lends fabric.Canvas.prototype */ {

    /**
     * Constructor
     * @param {HTMLElement | String} el &lt;canvas> element to initialize instance on
     * @param {Object} [options] Options object
     * @return {Object} thisArg
     */
    initialize: function(el, options) {
      options || (options = { });
      this.renderAndResetBound = this.renderAndReset.bind(this);
      this._initStatic(el, options);
      this._initInteractive();
      this._createCacheCanvas();
    },

    /**
     * When true, objects can be transformed by one side (unproportionally)
     * @type Boolean
     * @default
     */
    uniScaleTransform:      false,

    /**
     * Indicates which key enable unproportional scaling
     * values: 'altKey', 'shiftKey', 'ctrlKey'.
     * If `null` or 'none' or any other string that is not a modifier key
     * feature is disabled feature disabled.
     * @since 1.6.2
     * @type String
     * @default
     */
    uniScaleKey:           'shiftKey',

    /**
     * When true, objects use center point as the origin of scale transformation.
     * <b>Backwards incompatibility note:</b> This property replaces "centerTransform" (Boolean).
     * @since 1.3.4
     * @type Boolean
     * @default
     */
    centeredScaling:        false,

    /**
     * When true, objects use center point as the origin of rotate transformation.
     * <b>Backwards incompatibility note:</b> This property replaces "centerTransform" (Boolean).
     * @since 1.3.4
     * @type Boolean
     * @default
     */
    centeredRotation:       false,

    /**
     * Indicates which key enable centered Transform
     * values: 'altKey', 'shiftKey', 'ctrlKey'.
     * If `null` or 'none' or any other string that is not a modifier key
     * feature is disabled feature disabled.
     * @since 1.6.2
     * @type String
     * @default
     */
    centeredKey:           'altKey',

    /**
     * Indicates which key enable alternate action on corner
     * values: 'altKey', 'shiftKey', 'ctrlKey'.
     * If `null` or 'none' or any other string that is not a modifier key
     * feature is disabled feature disabled.
     * @since 1.6.2
     * @type String
     * @default
     */
    altActionKey:           'shiftKey',

    /**
     * Indicates that canvas is interactive. This property should not be changed.
     * @type Boolean
     * @default
     */
    interactive:            true,

    /**
     * Indicates whether group selection should be enabled
     * @type Boolean
     * @default
     */
    selection:              true,

    /**
     * Indicates which key or keys enable multiple click selection
     * Pass value as a string or array of strings
     * values: 'altKey', 'shiftKey', 'ctrlKey'.
     * If `null` or empty or containing any other string that is not a modifier key
     * feature is disabled.
     * @since 1.6.2
     * @type String|Array
     * @default
     */
    selectionKey:           'shiftKey',

    /**
     * Indicates which key enable alternative selection
     * in case of target overlapping with active object
     * values: 'altKey', 'shiftKey', 'ctrlKey'.
     * For a series of reason that come from the general expectations on how
     * things should work, this feature works only for preserveObjectStacking true.
     * If `null` or 'none' or any other string that is not a modifier key
     * feature is disabled.
     * @since 1.6.5
     * @type null|String
     * @default
     */
    altSelectionKey:           null,

    /**
     * Color of selection
     * @type String
     * @default
     */
    selectionColor:         'rgba(100, 100, 255, 0.3)', // blue

    /**
     * Default dash array pattern
     * If not empty the selection border is dashed
     * @type Array
     */
    selectionDashArray:     [],

    /**
     * Color of the border of selection (usually slightly darker than color of selection itself)
     * @type String
     * @default
     */
    selectionBorderColor:   'rgba(255, 255, 255, 0.3)',

    /**
     * Width of a line used in object/group selection
     * @type Number
     * @default
     */
    selectionLineWidth:     1,

    /**
     * Select only shapes that are fully contained in the dragged selection rectangle.
     * @type Boolean
     * @default
     */
    selectionFullyContained: false,

    /**
     * Default cursor value used when hovering over an object on canvas
     * @type String
     * @default
     */
    hoverCursor:            'move',

    /**
     * Default cursor value used when moving an object on canvas
     * @type String
     * @default
     */
    moveCursor:             'move',

    /**
     * Default cursor value used for the entire canvas
     * @type String
     * @default
     */
    defaultCursor:          'default',

    /**
     * Cursor value used during free drawing
     * @type String
     * @default
     */
    freeDrawingCursor:      'crosshair',

    /**
     * Cursor value used for rotation point
     * @type String
     * @default
     */
    rotationCursor:         'crosshair',

    /**
     * Cursor value used for disabled elements ( corners with disabled action )
     * @type String
     * @since 2.0.0
     * @default
     */
    notAllowedCursor:         'not-allowed',

    /**
     * Default element class that's given to wrapper (div) element of canvas
     * @type String
     * @default
     */
    containerClass:         'canvas-container',

    /**
     * When true, object detection happens on per-pixel basis rather than on per-bounding-box
     * @type Boolean
     * @default
     */
    perPixelTargetFind:     false,

    /**
     * Number of pixels around target pixel to tolerate (consider active) during object detection
     * @type Number
     * @default
     */
    targetFindTolerance:    0,

    /**
     * When true, target detection is skipped when hovering over canvas. This can be used to improve performance.
     * @type Boolean
     * @default
     */
    skipTargetFind:         false,

    /**
     * When true, mouse events on canvas (mousedown/mousemove/mouseup) result in free drawing.
     * After mousedown, mousemove creates a shape,
     * and then mouseup finalizes it and adds an instance of `fabric.Path` onto canvas.
     * @tutorial {@link http://fabricjs.com/fabric-intro-part-4#free_drawing}
     * @type Boolean
     * @default
     */
    isDrawingMode:          false,

    /**
     * Indicates whether objects should remain in current stack position when selected.
     * When false objects are brought to top and rendered as part of the selection group
     * @type Boolean
     * @default
     */
    preserveObjectStacking: false,

    /**
     * Indicates the angle that an object will lock to while rotating.
     * @type Number
     * @since 1.6.7
     * @default
     */
    snapAngle: 0,

    /**
     * Indicates the distance from the snapAngle the rotation will lock to the snapAngle.
     * When `null`, the snapThreshold will default to the snapAngle.
     * @type null|Number
     * @since 1.6.7
     * @default
     */
    snapThreshold: null,

    /**
     * Indicates if the right click on canvas can output the context menu or not
     * @type Boolean
     * @since 1.6.5
     * @default
     */
    stopContextMenu: false,

    /**
     * Indicates if the canvas can fire right click events
     * @type Boolean
     * @since 1.6.5
     * @default
     */
    fireRightClick: false,

    /**
     * Indicates if the canvas can fire middle click events
     * @type Boolean
     * @since 1.7.8
     * @default
     */
    fireMiddleClick: false,

    /**
     * @private
     */
    _initInteractive: function() {
      this._currentTransform = null;
      this._groupSelector = null;
      this._initWrapperElement();
      this._createUpperCanvas();
      this._initEventListeners();

      this._initRetinaScaling();

      this.freeDrawingBrush = fabric.PencilBrush && new fabric.PencilBrush(this);

      this.calcOffset();
    },

    /**
     * Divides objects in two groups, one to render immediately
     * and one to render as activeGroup.
     * @return {Array} objects to render immediately and pushes the other in the activeGroup.
     */
    _chooseObjectsToRender: function() {
      var activeObjects = this.getActiveObjects(),
          object, objsToRender, activeGroupObjects;

      if (activeObjects.length > 0 && !this.preserveObjectStacking) {
        objsToRender = [];
        activeGroupObjects = [];
        for (var i = 0, length = this._objects.length; i < length; i++) {
          object = this._objects[i];
          if (activeObjects.indexOf(object) === -1 ) {
            objsToRender.push(object);
          }
          else {
            activeGroupObjects.push(object);
          }
        }
        if (activeObjects.length > 1) {
          this._activeObject._objects = activeGroupObjects;
        }
        objsToRender.push.apply(objsToRender, activeGroupObjects);
      }
      else {
        objsToRender = this._objects;
      }
      return objsToRender;
    },

    /**
     * Renders both the top canvas and the secondary container canvas.
     * @return {fabric.Canvas} instance
     * @chainable
     */
    renderAll: function () {
      if (this.contextTopDirty && !this._groupSelector && !this.isDrawingMode) {
        this.clearContext(this.contextTop);
        this.contextTopDirty = false;
      }
      if (this.hasLostContext) {
        this.renderTopLayer(this.contextTop);
      }
      var canvasToDrawOn = this.contextContainer;
      this.renderCanvas(canvasToDrawOn, this._chooseObjectsToRender());
      return this;
    },

    renderTopLayer: function(ctx) {
      if (this.isDrawingMode && this._isCurrentlyDrawing) {
        this.freeDrawingBrush && this.freeDrawingBrush._render();
      }
      // we render the top context - last object
      if (this.selection && this._groupSelector) {
        this._drawSelection(ctx);
      }
    },

    /**
     * Method to render only the top canvas.
     * Also used to render the group selection box.
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    renderTop: function () {
      var ctx = this.contextTop;
      this.clearContext(ctx);
      this.renderTopLayer(ctx);
      this.fire('after:render');
      this.contextTopDirty = true;
      return this;
    },

    /**
     * Resets the current transform to its original values and chooses the type of resizing based on the event
     * @private
     */
    _resetCurrentTransform: function() {
      var t = this._currentTransform;

      t.target.set({
        scaleX: t.original.scaleX,
        scaleY: t.original.scaleY,
        skewX: t.original.skewX,
        skewY: t.original.skewY,
        left: t.original.left,
        top: t.original.top
      });

      if (this._shouldCenterTransform(t.target)) {
        if (t.originX !== 'center') {
          if (t.originX === 'right') {
            t.mouseXSign = -1;
          }
          else {
            t.mouseXSign = 1;
          }
        }
        if (t.originY !== 'center') {
          if (t.originY === 'bottom') {
            t.mouseYSign = -1;
          }
          else {
            t.mouseYSign = 1;
          }
        }

        t.originX = 'center';
        t.originY = 'center';
      }
      else {
        t.originX = t.original.originX;
        t.originY = t.original.originY;
      }
    },

    /**
     * Checks if point is contained within an area of given object
     * @param {Event} e Event object
     * @param {fabric.Object} target Object to test against
     * @param {Object} [point] x,y object of point coordinates we want to check.
     * @return {Boolean} true if point is contained within an area of given object
     */
    containsPoint: function (e, target, point) {
      var ignoreZoom = true,
          pointer = point || this.getPointer(e, ignoreZoom),
          xy;

      if (target.group && target.group === this._activeObject && target.group.type === 'activeSelection') {
        xy = this._normalizePointer(target.group, pointer);
      }
      else {
        xy = { x: pointer.x, y: pointer.y };
      }
      // http://www.geog.ubc.ca/courses/klink/gis.notes/ncgia/u32.html
      // http://idav.ucdavis.edu/~okreylos/TAship/Spring2000/PointInPolygon.html
      return (target.containsPoint(xy) || target._findTargetCorner(pointer));
    },

    /**
     * @private
     */
    _normalizePointer: function (object, pointer) {
      var m = object.calcTransformMatrix(),
          invertedM = fabric.util.invertTransform(m),
          vptPointer = this.restorePointerVpt(pointer);
      return fabric.util.transformPoint(vptPointer, invertedM);
    },

    /**
     * Returns true if object is transparent at a certain location
     * @param {fabric.Object} target Object to check
     * @param {Number} x Left coordinate
     * @param {Number} y Top coordinate
     * @return {Boolean}
     */
    isTargetTransparent: function (target, x, y) {
      if (target.shouldCache() && target._cacheCanvas) {
        var normalizedPointer = this._normalizePointer(target, {x: x, y: y}),
            targetRelativeX = target.cacheTranslationX + (normalizedPointer.x * target.zoomX),
            targetRelativeY = target.cacheTranslationY + (normalizedPointer.y * target.zoomY);

        var isTransparent = fabric.util.isTransparent(
          target._cacheContext, targetRelativeX, targetRelativeY, this.targetFindTolerance);

        return isTransparent;
      }

      var ctx = this.contextCache,
          originalColor = target.selectionBackgroundColor, v = this.viewportTransform;

      target.selectionBackgroundColor = '';

      this.clearContext(ctx);

      ctx.save();
      ctx.transform(v[0], v[1], v[2], v[3], v[4], v[5]);
      target.render(ctx);
      ctx.restore();

      target === this._activeObject && target._renderControls(ctx, {
        hasBorders: false,
        transparentCorners: false
      }, {
        hasBorders: false,
      });

      target.selectionBackgroundColor = originalColor;

      var isTransparent = fabric.util.isTransparent(
        ctx, x, y, this.targetFindTolerance);

      return isTransparent;
    },

    /**
     * takes an event and determins if selection key has been pressed
     * @private
     * @param {Event} e Event object
     */
    _isSelectionKeyPressed: function(e) {
      var selectionKeyPressed = false;

      if (Object.prototype.toString.call(this.selectionKey) === '[object Array]') {
        selectionKeyPressed = !!this.selectionKey.find(function(key) { return e[key] === true; });
      }
      else {
        selectionKeyPressed = e[this.selectionKey];
      }

      return selectionKeyPressed;
    },

    /**
     * @private
     * @param {Event} e Event object
     * @param {fabric.Object} target
     */
    _shouldClearSelection: function (e, target) {
      var activeObjects = this.getActiveObjects(),
          activeObject = this._activeObject;

      return (
        !target
        ||
        (target &&
          activeObject &&
          activeObjects.length > 1 &&
          activeObjects.indexOf(target) === -1 &&
          activeObject !== target &&
          !this._isSelectionKeyPressed(e))
        ||
        (target && !target.evented)
        ||
        (target &&
          !target.selectable &&
          activeObject &&
          activeObject !== target)
      );
    },

    /**
     * centeredScaling from object can't override centeredScaling from canvas.
     * this should be fixed, since object setting should take precedence over canvas.
     * @private
     * @param {fabric.Object} target
     */
    _shouldCenterTransform: function (target) {
      if (!target) {
        return;
      }

      var t = this._currentTransform,
          centerTransform;

      if (t.action === 'scale' || t.action === 'scaleX' || t.action === 'scaleY') {
        centerTransform = this.centeredScaling || target.centeredScaling;
      }
      else if (t.action === 'rotate') {
        centerTransform = this.centeredRotation || target.centeredRotation;
      }

      return centerTransform ? !t.altKey : t.altKey;
    },

    /**
     * @private
     */
    _getOriginFromCorner: function(target, corner) {
      var origin = {
        x: target.originX,
        y: target.originY
      };

      if (corner === 'ml' || corner === 'tl' || corner === 'bl') {
        origin.x = 'right';
      }
      else if (corner === 'mr' || corner === 'tr' || corner === 'br') {
        origin.x = 'left';
      }

      if (corner === 'tl' || corner === 'mt' || corner === 'tr') {
        origin.y = 'bottom';
      }
      else if (corner === 'bl' || corner === 'mb' || corner === 'br') {
        origin.y = 'top';
      }

      return origin;
    },

    /**
     * @private
     */
    _getActionFromCorner: function(target, corner, e) {
      if (!corner) {
        return 'drag';
      }

      switch (corner) {
        case 'mtr':
          return 'rotate';
        case 'ml':
        case 'mr':
          return e[this.altActionKey] ? 'skewY' : 'scaleX';
        case 'mt':
        case 'mb':
          return e[this.altActionKey] ? 'skewX' : 'scaleY';
        default:
          return 'scale';
      }
    },

    /**
     * @private
     * @param {Event} e Event object
     * @param {fabric.Object} target
     */
    _setupCurrentTransform: function (e, target) {
      if (!target) {
        return;
      }

      var pointer = this.getPointer(e),
          corner = target._findTargetCorner(this.getPointer(e, true)),
          action = this._getActionFromCorner(target, corner, e),
          origin = this._getOriginFromCorner(target, corner);

      this._currentTransform = {
        target: target,
        action: action,
        corner: corner,
        scaleX: target.scaleX,
        scaleY: target.scaleY,
        skewX: target.skewX,
        skewY: target.skewY,
        // used by transation
        offsetX: pointer.x - target.left,
        offsetY: pointer.y - target.top,
        originX: origin.x,
        originY: origin.y,
        ex: pointer.x,
        ey: pointer.y,
        lastX: pointer.x,
        lastY: pointer.y,
        // unsure they are usefull anymore.
        // left: target.left,
        // top: target.top,
        theta: degreesToRadians(target.angle),
        // end of unsure
        width: target.width * target.scaleX,
        mouseXSign: 1,
        mouseYSign: 1,
        shiftKey: e.shiftKey,
        altKey: e[this.centeredKey]
      };

      this._currentTransform.original = {
        left: target.left,
        top: target.top,
        scaleX: target.scaleX,
        scaleY: target.scaleY,
        skewX: target.skewX,
        skewY: target.skewY,
        originX: origin.x,
        originY: origin.y
      };

      this._resetCurrentTransform();
      this._beforeTransform(e);
    },

    /**
     * Translates object by "setting" its left/top
     * @private
     * @param {Number} x pointer's x coordinate
     * @param {Number} y pointer's y coordinate
     * @return {Boolean} true if the translation occurred
     */
    _translateObject: function (x, y) {
      var transform = this._currentTransform,
          target = transform.target,
          newLeft = x - transform.offsetX,
          newTop = y - transform.offsetY,
          moveX = !target.get('lockMovementX') && target.left !== newLeft,
          moveY = !target.get('lockMovementY') && target.top !== newTop;

      moveX && target.set('left', newLeft);
      moveY && target.set('top', newTop);
      return moveX || moveY;
    },

    /**
     * Check if we are increasing a positive skew or lower it,
     * checking mouse direction and pressed corner.
     * @private
     */
    _changeSkewTransformOrigin: function(mouseMove, t, by) {
      var property = 'originX', origins = { 0: 'center' },
          skew = t.target.skewX, originA = 'left', originB = 'right',
          corner = t.corner === 'mt' || t.corner === 'ml' ? 1 : -1,
          flipSign = 1;

      mouseMove = mouseMove > 0 ? 1 : -1;
      if (by === 'y') {
        skew = t.target.skewY;
        originA = 'top';
        originB = 'bottom';
        property = 'originY';
      }
      origins[-1] = originA;
      origins[1] = originB;

      t.target.flipX && (flipSign *= -1);
      t.target.flipY && (flipSign *= -1);

      if (skew === 0) {
        t.skewSign = -corner * mouseMove * flipSign;
        t[property] = origins[-mouseMove];
      }
      else {
        skew = skew > 0 ? 1 : -1;
        t.skewSign = skew;
        t[property] = origins[skew * corner * flipSign];
      }
    },

    /**
     * Skew object by mouse events
     * @private
     * @param {Number} x pointer's x coordinate
     * @param {Number} y pointer's y coordinate
     * @param {String} by Either 'x' or 'y'
     * @return {Boolean} true if the skewing occurred
     */
    _skewObject: function (x, y, by) {
      var t = this._currentTransform,
          target = t.target, skewed = false,
          lockSkewingX = target.get('lockSkewingX'),
          lockSkewingY = target.get('lockSkewingY');

      if ((lockSkewingX && by === 'x') || (lockSkewingY && by === 'y')) {
        return false;
      }

      // Get the constraint point
      var center = target.getCenterPoint(),
          actualMouseByCenter = target.toLocalPoint(new fabric.Point(x, y), 'center', 'center')[by],
          lastMouseByCenter = target.toLocalPoint(new fabric.Point(t.lastX, t.lastY), 'center', 'center')[by],
          actualMouseByOrigin, constraintPosition, dim = target._getTransformedDimensions();

      this._changeSkewTransformOrigin(actualMouseByCenter - lastMouseByCenter, t, by);
      actualMouseByOrigin = target.toLocalPoint(new fabric.Point(x, y), t.originX, t.originY)[by];
      constraintPosition = target.translateToOriginPoint(center, t.originX, t.originY);
      // Actually skew the object
      skewed = this._setObjectSkew(actualMouseByOrigin, t, by, dim);
      t.lastX = x;
      t.lastY = y;
      // Make sure the constraints apply
      target.setPositionByOrigin(constraintPosition, t.originX, t.originY);
      return skewed;
    },

    /**
     * Set object skew
     * @private
     * @return {Boolean} true if the skewing occurred
     */
    _setObjectSkew: function(localMouse, transform, by, _dim) {
      var target = transform.target, newValue, skewed = false,
          skewSign = transform.skewSign, newDim, dimNoSkew,
          otherBy, _otherBy, _by, newDimMouse, skewX, skewY;

      if (by === 'x') {
        otherBy = 'y';
        _otherBy = 'Y';
        _by = 'X';
        skewX = 0;
        skewY = target.skewY;
      }
      else {
        otherBy = 'x';
        _otherBy = 'X';
        _by = 'Y';
        skewX = target.skewX;
        skewY = 0;
      }

      dimNoSkew = target._getTransformedDimensions(skewX, skewY);
      newDimMouse = 2 * Math.abs(localMouse) - dimNoSkew[by];
      if (newDimMouse <= 2) {
        newValue = 0;
      }
      else {
        newValue = skewSign * Math.atan((newDimMouse / target['scale' + _by]) /
                                        (dimNoSkew[otherBy] / target['scale' + _otherBy]));
        newValue = fabric.util.radiansToDegrees(newValue);
      }
      skewed = target['skew' + _by] !== newValue;
      target.set('skew' + _by, newValue);
      if (target['skew' + _otherBy] !== 0) {
        newDim = target._getTransformedDimensions();
        newValue = (_dim[otherBy] / newDim[otherBy]) * target['scale' + _otherBy];
        target.set('scale' + _otherBy, newValue);
      }
      return skewed;
    },

    /**
     * Scales object by invoking its scaleX/scaleY methods
     * @private
     * @param {Number} x pointer's x coordinate
     * @param {Number} y pointer's y coordinate
     * @param {String} by Either 'x' or 'y' - specifies dimension constraint by which to scale an object.
     *                    When not provided, an object is scaled by both dimensions equally
     * @return {Boolean} true if the scaling occurred
     */
    _scaleObject: function (x, y, by) {
      var t = this._currentTransform,
          target = t.target,
          lockScalingX = target.lockScalingX,
          lockScalingY = target.lockScalingY,
          lockScalingFlip = target.lockScalingFlip;

      if (lockScalingX && lockScalingY) {
        return false;
      }

      // Get the constraint point
      var constraintPosition = target.translateToOriginPoint(target.getCenterPoint(), t.originX, t.originY),
          localMouse = target.toLocalPoint(new fabric.Point(x, y), t.originX, t.originY),
          dim = target._getTransformedDimensions(), scaled = false;

      this._setLocalMouse(localMouse, t);

      // Actually scale the object
      scaled = this._setObjectScale(localMouse, t, lockScalingX, lockScalingY, by, lockScalingFlip, dim);

      // Make sure the constraints apply
      target.setPositionByOrigin(constraintPosition, t.originX, t.originY);
      return scaled;
    },

    /**
     * @private
     * @return {Boolean} true if the scaling occurred
     */
    _setObjectScale: function(localMouse, transform, lockScalingX, lockScalingY, by, lockScalingFlip, _dim) {
      var target = transform.target, forbidScalingX = false, forbidScalingY = false, scaled = false,
          changeX, changeY, scaleX, scaleY;

      scaleX = localMouse.x * target.scaleX / _dim.x;
      scaleY = localMouse.y * target.scaleY / _dim.y;
      changeX = target.scaleX !== scaleX;
      changeY = target.scaleY !== scaleY;

      if (lockScalingFlip && scaleX <= 0 && scaleX < target.scaleX) {
        forbidScalingX = true;
        localMouse.x = 0;
      }

      if (lockScalingFlip && scaleY <= 0 && scaleY < target.scaleY) {
        forbidScalingY = true;
        localMouse.y = 0;
      }

      if (by === 'equally' && !lockScalingX && !lockScalingY) {
        scaled = this._scaleObjectEqually(localMouse, target, transform, _dim);
      }
      else if (!by) {
        forbidScalingX || lockScalingX || (target.set('scaleX', scaleX) && (scaled = scaled || changeX));
        forbidScalingY || lockScalingY || (target.set('scaleY', scaleY) && (scaled = scaled || changeY));
      }
      else if (by === 'x' && !target.get('lockUniScaling')) {
        forbidScalingX || lockScalingX || (target.set('scaleX', scaleX) && (scaled = scaled || changeX));
      }
      else if (by === 'y' && !target.get('lockUniScaling')) {
        forbidScalingY || lockScalingY || (target.set('scaleY', scaleY) && (scaled = scaled || changeY));
      }
      transform.newScaleX = scaleX;
      transform.newScaleY = scaleY;
      forbidScalingX || forbidScalingY || this._flipObject(transform, by);
      return scaled;
    },

    /**
     * @private
     * @return {Boolean} true if the scaling occurred
     */
    _scaleObjectEqually: function(localMouse, target, transform, _dim) {

      var dist = localMouse.y + localMouse.x,
          lastDist = _dim.y * transform.original.scaleY / target.scaleY +
                     _dim.x * transform.original.scaleX / target.scaleX,
          scaled, signX = localMouse.x < 0 ? -1 : 1,
          signY = localMouse.y < 0 ? -1 : 1;

      // We use transform.scaleX/Y instead of target.scaleX/Y
      // because the object may have a min scale and we'll loose the proportions
      transform.newScaleX = signX * Math.abs(transform.original.scaleX * dist / lastDist);
      transform.newScaleY = signY * Math.abs(transform.original.scaleY * dist / lastDist);
      scaled = transform.newScaleX !== target.scaleX || transform.newScaleY !== target.scaleY;
      target.set('scaleX', transform.newScaleX);
      target.set('scaleY', transform.newScaleY);
      return scaled;
    },

    /**
     * @private
     */
    _flipObject: function(transform, by) {
      if (transform.newScaleX < 0 && by !== 'y') {
        if (transform.originX === 'left') {
          transform.originX = 'right';
        }
        else if (transform.originX === 'right') {
          transform.originX = 'left';
        }
      }

      if (transform.newScaleY < 0 && by !== 'x') {
        if (transform.originY === 'top') {
          transform.originY = 'bottom';
        }
        else if (transform.originY === 'bottom') {
          transform.originY = 'top';
        }
      }
    },

    /**
     * @private
     */
    _setLocalMouse: function(localMouse, t) {
      var target = t.target, zoom = this.getZoom(),
          padding = target.padding / zoom;

      if (t.originX === 'right') {
        localMouse.x *= -1;
      }
      else if (t.originX === 'center') {
        localMouse.x *= t.mouseXSign * 2;
        if (localMouse.x < 0) {
          t.mouseXSign = -t.mouseXSign;
        }
      }

      if (t.originY === 'bottom') {
        localMouse.y *= -1;
      }
      else if (t.originY === 'center') {
        localMouse.y *= t.mouseYSign * 2;
        if (localMouse.y < 0) {
          t.mouseYSign = -t.mouseYSign;
        }
      }

      // adjust the mouse coordinates when dealing with padding
      if (abs(localMouse.x) > padding) {
        if (localMouse.x < 0) {
          localMouse.x += padding;
        }
        else {
          localMouse.x -= padding;
        }
      }
      else { // mouse is within the padding, set to 0
        localMouse.x = 0;
      }

      if (abs(localMouse.y) > padding) {
        if (localMouse.y < 0) {
          localMouse.y += padding;
        }
        else {
          localMouse.y -= padding;
        }
      }
      else {
        localMouse.y = 0;
      }
    },

    /**
     * Rotates object by invoking its rotate method
     * @private
     * @param {Number} x pointer's x coordinate
     * @param {Number} y pointer's y coordinate
     * @return {Boolean} true if the rotation occurred
     */
    _rotateObject: function (x, y) {

      var t = this._currentTransform,
          target = t.target, constraintPosition,
          constraintPosition = target.translateToOriginPoint(target.getCenterPoint(), t.originX, t.originY);

      if (target.lockRotation) {
        return false;
      }

      var lastAngle = atan2(t.ey - constraintPosition.y, t.ex - constraintPosition.x),
          curAngle = atan2(y - constraintPosition.y, x - constraintPosition.x),
          angle = radiansToDegrees(curAngle - lastAngle + t.theta),
          hasRotated = true;

      if (target.snapAngle > 0) {
        var snapAngle  = target.snapAngle,
            snapThreshold  = target.snapThreshold || snapAngle,
            rightAngleLocked = Math.ceil(angle / snapAngle) * snapAngle,
            leftAngleLocked = Math.floor(angle / snapAngle) * snapAngle;

        if (Math.abs(angle - leftAngleLocked) < snapThreshold) {
          angle = leftAngleLocked;
        }
        else if (Math.abs(angle - rightAngleLocked) < snapThreshold) {
          angle = rightAngleLocked;
        }
      }

      // normalize angle to positive value
      if (angle < 0) {
        angle = 360 + angle;
      }
      angle %= 360;

      if (target.angle === angle) {
        hasRotated = false;
      }
      else {
        // rotation only happen here
        target.angle = angle;
        // Make sure the constraints apply
        target.setPositionByOrigin(constraintPosition, t.originX, t.originY);
      }

      return hasRotated;
    },

    /**
     * Set the cursor type of the canvas element
     * @param {String} value Cursor type of the canvas element.
     * @see http://www.w3.org/TR/css3-ui/#cursor
     */
    setCursor: function (value) {
      this.upperCanvasEl.style.cursor = value;
    },

    /**
     * @param {fabric.Object} target to reset transform
     * @private
     */
    _resetObjectTransform: function (target) {
      target.scaleX = 1;
      target.scaleY = 1;
      target.skewX = 0;
      target.skewY = 0;
      target.rotate(0);
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx to draw the selection on
     */
    _drawSelection: function (ctx) {
      var groupSelector = this._groupSelector,
          left = groupSelector.left,
          top = groupSelector.top,
          aleft = abs(left),
          atop = abs(top);

      if (this.selectionColor) {
        ctx.fillStyle = this.selectionColor;

        ctx.fillRect(
          groupSelector.ex - ((left > 0) ? 0 : -left),
          groupSelector.ey - ((top > 0) ? 0 : -top),
          aleft,
          atop
        );
      }

      if (!this.selectionLineWidth || !this.selectionBorderColor) {
        return;
      }
      ctx.lineWidth = this.selectionLineWidth;
      ctx.strokeStyle = this.selectionBorderColor;

      // selection border
      if (this.selectionDashArray.length > 1 && !supportLineDash) {

        var px = groupSelector.ex + STROKE_OFFSET - ((left > 0) ? 0 : aleft),
            py = groupSelector.ey + STROKE_OFFSET - ((top > 0) ? 0 : atop);

        ctx.beginPath();

        fabric.util.drawDashedLine(ctx, px, py, px + aleft, py, this.selectionDashArray);
        fabric.util.drawDashedLine(ctx, px, py + atop - 1, px + aleft, py + atop - 1, this.selectionDashArray);
        fabric.util.drawDashedLine(ctx, px, py, px, py + atop, this.selectionDashArray);
        fabric.util.drawDashedLine(ctx, px + aleft - 1, py, px + aleft - 1, py + atop, this.selectionDashArray);

        ctx.closePath();
        ctx.stroke();
      }
      else {
        fabric.Object.prototype._setLineDash.call(this, ctx, this.selectionDashArray);
        ctx.strokeRect(
          groupSelector.ex + STROKE_OFFSET - ((left > 0) ? 0 : aleft),
          groupSelector.ey + STROKE_OFFSET - ((top > 0) ? 0 : atop),
          aleft,
          atop
        );
      }
    },

    /**
     * Method that determines what object we are clicking on
     * the skipGroup parameter is for internal use, is needed for shift+click action
     * @param {Event} e mouse event
     * @param {Boolean} skipGroup when true, activeGroup is skipped and only objects are traversed through
     */
    findTarget: function (e, skipGroup) {
      if (this.skipTargetFind) {
        return;
      }

      var ignoreZoom = true,
          pointer = this.getPointer(e, ignoreZoom),
          activeObject = this._activeObject,
          aObjects = this.getActiveObjects(),
          activeTarget, activeTargetSubs;

      // first check current group (if one exists)
      // active group does not check sub targets like normal groups.
      // if active group just exits.
      this.targets = [];

      if (aObjects.length > 1 && !skipGroup && activeObject === this._searchPossibleTargets([activeObject], pointer)) {
        return activeObject;
      }
      // if we hit the corner of an activeObject, let's return that.
      if (aObjects.length === 1 && activeObject._findTargetCorner(pointer)) {
        return activeObject;
      }
      if (aObjects.length === 1 &&
        activeObject === this._searchPossibleTargets([activeObject], pointer)) {
        if (!this.preserveObjectStacking) {
          return activeObject;
        }
        else {
          activeTarget = activeObject;
          activeTargetSubs = this.targets;
          this.targets = [];
        }
      }
      var target = this._searchPossibleTargets(this._objects, pointer);
      if (e[this.altSelectionKey] && target && activeTarget && target !== activeTarget) {
        target = activeTarget;
        this.targets = activeTargetSubs;
      }
      return target;
    },

    /**
     * @private
     */
    _checkTarget: function(pointer, obj) {
      if (obj &&
          obj.visible &&
          obj.evented &&
          this.containsPoint(null, obj, pointer)){
        if ((this.perPixelTargetFind || obj.perPixelTargetFind) && !obj.isEditing) {
          var isTransparent = this.isTargetTransparent(obj, pointer.x, pointer.y);
          if (!isTransparent) {
            return true;
          }
        }
        else {
          return true;
        }
      }
    },

    /**
     * @private
     */
    _searchPossibleTargets: function(objects, pointer) {

      // Cache all targets where their bounding box contains point.
      var target, i = objects.length, normalizedPointer, subTarget;
      // Do not check for currently grouped objects, since we check the parent group itself.
      // until we call this function specifically to search inside the activeGroup
      while (i--) {
        if (this._checkTarget(pointer, objects[i])) {
          target = objects[i];
          if (target.subTargetCheck && target instanceof fabric.Group) {
            normalizedPointer = this._normalizePointer(target, pointer);
            subTarget = this._searchPossibleTargets(target._objects, normalizedPointer);
            subTarget && this.targets.push(subTarget);
          }
          break;
        }
      }
      return target;
    },

    /**
     * Returns pointer coordinates without the effect of the viewport
     * @param {Object} pointer with "x" and "y" number values
     * @return {Object} object with "x" and "y" number values
     */
    restorePointerVpt: function(pointer) {
      return fabric.util.transformPoint(
        pointer,
        fabric.util.invertTransform(this.viewportTransform)
      );
    },

    /**
     * Returns pointer coordinates relative to canvas.
     * Can return coordinates with or without viewportTransform.
     * ignoreZoom false gives back coordinates that represent
     * the point clicked on canvas element.
     * ignoreZoom true gives back coordinates after being processed
     * by the viewportTransform ( sort of coordinates of what is displayed
     * on the canvas where you are clicking.
     * ignoreZoom true = HTMLElement coordinates relative to top,left
     * ignoreZoom false, default = fabric space coordinates, the same used for shape position
     * To interact with your shapes top and left you want to use ignoreZoom true
     * most of the time, while ignoreZoom false will give you coordinates
     * compatible with the object.oCoords system.
     * of the time.
     * @param {Event} e
     * @param {Boolean} ignoreZoom
     * @return {Object} object with "x" and "y" number values
     */
    getPointer: function (e, ignoreZoom) {
      // return cached values if we are in the event processing chain
      if (this._absolutePointer && !ignoreZoom) {
        return this._absolutePointer;
      }
      if (this._pointer && ignoreZoom) {
        return this._pointer;
      }

      var pointer = getPointer(e),
          upperCanvasEl = this.upperCanvasEl,
          bounds = upperCanvasEl.getBoundingClientRect(),
          boundsWidth = bounds.width || 0,
          boundsHeight = bounds.height || 0,
          cssScale;

      if (!boundsWidth || !boundsHeight ) {
        if ('top' in bounds && 'bottom' in bounds) {
          boundsHeight = Math.abs( bounds.top - bounds.bottom );
        }
        if ('right' in bounds && 'left' in bounds) {
          boundsWidth = Math.abs( bounds.right - bounds.left );
        }
      }

      this.calcOffset();
      pointer.x = pointer.x - this._offset.left;
      pointer.y = pointer.y - this._offset.top;
      if (!ignoreZoom) {
        pointer = this.restorePointerVpt(pointer);
      }

      if (boundsWidth === 0 || boundsHeight === 0) {
        // If bounds are not available (i.e. not visible), do not apply scale.
        cssScale = { width: 1, height: 1 };
      }
      else {
        cssScale = {
          width: upperCanvasEl.width / boundsWidth,
          height: upperCanvasEl.height / boundsHeight
        };
      }

      return {
        x: pointer.x * cssScale.width,
        y: pointer.y * cssScale.height
      };
    },

    /**
     * @private
     * @throws {CANVAS_INIT_ERROR} If canvas can not be initialized
     */
    _createUpperCanvas: function () {
      var lowerCanvasClass = this.lowerCanvasEl.className.replace(/\s*lower-canvas\s*/, '');

      // there is no need to create a new upperCanvas element if we have already one.
      if (this.upperCanvasEl) {
        this.upperCanvasEl.className = '';
      }
      else {
        this.upperCanvasEl = this._createCanvasElement();
      }
      fabric.util.addClass(this.upperCanvasEl, 'upper-canvas ' + lowerCanvasClass);

      this.wrapperEl.appendChild(this.upperCanvasEl);

      this._copyCanvasStyle(this.lowerCanvasEl, this.upperCanvasEl);
      this._applyCanvasStyle(this.upperCanvasEl);
      this.contextTop = this.upperCanvasEl.getContext('2d');
    },

    /**
     * @private
     */
    _createCacheCanvas: function () {
      this.cacheCanvasEl = this._createCanvasElement();
      this.cacheCanvasEl.setAttribute('width', this.width);
      this.cacheCanvasEl.setAttribute('height', this.height);
      this.contextCache = this.cacheCanvasEl.getContext('2d');
    },

    /**
     * @private
     */
    _initWrapperElement: function () {
      this.wrapperEl = fabric.util.wrapElement(this.lowerCanvasEl, 'div', {
        'class': this.containerClass
      });
      fabric.util.setStyle(this.wrapperEl, {
        width: this.width + 'px',
        height: this.height + 'px',
        position: 'relative'
      });
      fabric.util.makeElementUnselectable(this.wrapperEl);
    },

    /**
     * @private
     * @param {HTMLElement} element canvas element to apply styles on
     */
    _applyCanvasStyle: function (element) {
      var width = this.width || element.width,
          height = this.height || element.height;

      fabric.util.setStyle(element, {
        position: 'absolute',
        width: width + 'px',
        height: height + 'px',
        left: 0,
        top: 0,
        'touch-action': this.allowTouchScrolling ? 'manipulation' : 'none'
      });
      element.width = width;
      element.height = height;
      fabric.util.makeElementUnselectable(element);
    },

    /**
     * Copy the entire inline style from one element (fromEl) to another (toEl)
     * @private
     * @param {Element} fromEl Element style is copied from
     * @param {Element} toEl Element copied style is applied to
     */
    _copyCanvasStyle: function (fromEl, toEl) {
      toEl.style.cssText = fromEl.style.cssText;
    },

    /**
     * Returns context of canvas where object selection is drawn
     * @return {CanvasRenderingContext2D}
     */
    getSelectionContext: function() {
      return this.contextTop;
    },

    /**
     * Returns &lt;canvas> element on which object selection is drawn
     * @return {HTMLCanvasElement}
     */
    getSelectionElement: function () {
      return this.upperCanvasEl;
    },

    /**
     * Returns currently active object
     * @return {fabric.Object} active object
     */
    getActiveObject: function () {
      return this._activeObject;
    },

    /**
     * Returns an array with the current selected objects
     * @return {fabric.Object} active object
     */
    getActiveObjects: function () {
      var active = this._activeObject;
      if (active) {
        if (active.type === 'activeSelection' && active._objects) {
          return active._objects.slice(0);
        }
        else {
          return [active];
        }
      }
      return [];
    },

    /**
     * @private
     * @param {fabric.Object} obj Object that was removed
     */
    _onObjectRemoved: function(obj) {
      // removing active object should fire "selection:cleared" events
      if (obj === this._activeObject) {
        this.fire('before:selection:cleared', { target: obj });
        this._discardActiveObject();
        this.fire('selection:cleared', { target: obj });
        obj.fire('deselected');
      }
      if (this._hoveredTarget === obj) {
        this._hoveredTarget = null;
      }
      this.callSuper('_onObjectRemoved', obj);
    },

    /**
     * @private
     * Compares the old activeObject with the current one and fires correct events
     * @param {fabric.Object} obj old activeObject
     */
    _fireSelectionEvents: function(oldObjects, e) {
      var somethingChanged = false, objects = this.getActiveObjects(),
          added = [], removed = [], opt = { e: e };
      oldObjects.forEach(function(oldObject) {
        if (objects.indexOf(oldObject) === -1) {
          somethingChanged = true;
          oldObject.fire('deselected', opt);
          removed.push(oldObject);
        }
      });
      objects.forEach(function(object) {
        if (oldObjects.indexOf(object) === -1) {
          somethingChanged = true;
          object.fire('selected', opt);
          added.push(object);
        }
      });
      if (oldObjects.length > 0 && objects.length > 0) {
        opt.selected = added;
        opt.deselected = removed;
        // added for backward compatibility
        opt.updated = added[0] || removed[0];
        opt.target = this._activeObject;
        somethingChanged && this.fire('selection:updated', opt);
      }
      else if (objects.length > 0) {
        // deprecated event
        if (objects.length === 1) {
          opt.target = added[0];
          this.fire('object:selected', opt);
        }
        opt.selected = added;
        // added for backward compatibility
        opt.target = this._activeObject;
        this.fire('selection:created', opt);
      }
      else if (oldObjects.length > 0) {
        opt.deselected = removed;
        this.fire('selection:cleared', opt);
      }
    },

    /**
     * Sets given object as the only active object on canvas
     * @param {fabric.Object} object Object to set as an active one
     * @param {Event} [e] Event (passed along when firing "object:selected")
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    setActiveObject: function (object, e) {
      var currentActives = this.getActiveObjects();
      this._setActiveObject(object, e);
      this._fireSelectionEvents(currentActives, e);
      return this;
    },

    /**
     * @private
     * @param {Object} object to set as active
     * @param {Event} [e] Event (passed along when firing "object:selected")
     * @return {Boolean} true if the selection happened
     */
    _setActiveObject: function(object, e) {
      if (this._activeObject === object) {
        return false;
      }
      if (!this._discardActiveObject(e, object)) {
        return false;
      }
      if (object.onSelect({ e: e })) {
        return false;
      }
      this._activeObject = object;
      return true;
    },

    /**
     * @private
     */
    _discardActiveObject: function(e, object) {
      var obj = this._activeObject;
      if (obj) {
        // onDeselect return TRUE to cancel selection;
        if (obj.onDeselect({ e: e, object: object })) {
          return false;
        }
        this._activeObject = null;
      }
      return true;
    },

    /**
     * Discards currently active object and fire events. If the function is called by fabric
     * as a consequence of a mouse event, the event is passed as a parameter and
     * sent to the fire function for the custom events. When used as a method the
     * e param does not have any application.
     * @param {event} e
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    discardActiveObject: function (e) {
      var currentActives = this.getActiveObjects();
      if (currentActives.length) {
        this.fire('before:selection:cleared', { target: currentActives[0], e: e });
      }
      this._discardActiveObject(e);
      this._fireSelectionEvents(currentActives, e);
      return this;
    },

    /**
     * Clears a canvas element and removes all event listeners
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    dispose: function () {
      var wrapper = this.wrapperEl;
      this.removeListeners();
      wrapper.removeChild(this.upperCanvasEl);
      wrapper.removeChild(this.lowerCanvasEl);
      this.upperCanvasEl = null;
      this.cacheCanvasEl = null;
      this.contextCache = null;
      this.contextTop = null;
      if (wrapper.parentNode) {
        wrapper.parentNode.replaceChild(this.lowerCanvasEl, this.wrapperEl);
      }
      delete this.wrapperEl;
      fabric.StaticCanvas.prototype.dispose.call(this);
      return this;
    },

    /**
     * Clears all contexts (background, main, top) of an instance
     * @return {fabric.Canvas} thisArg
     * @chainable
     */
    clear: function () {
      // this.discardActiveGroup();
      this.discardActiveObject();
      this.clearContext(this.contextTop);
      return this.callSuper('clear');
    },

    /**
     * Draws objects' controls (borders/controls)
     * @param {CanvasRenderingContext2D} ctx Context to render controls on
     */
    drawControls: function(ctx) {
      var activeObject = this._activeObject;

      if (activeObject) {
        activeObject._renderControls(ctx);
      }
    },

    /**
     * @private
     */
    _toObject: function(instance, methodName, propertiesToInclude) {
      //If the object is part of the current selection group, it should
      //be transformed appropriately
      //i.e. it should be serialised as it would appear if the selection group
      //were to be destroyed.
      var originalProperties = this._realizeGroupTransformOnObject(instance),
          object = this.callSuper('_toObject', instance, methodName, propertiesToInclude);
      //Undo the damage we did by changing all of its properties
      this._unwindGroupTransformOnObject(instance, originalProperties);
      return object;
    },

    /**
     * Realises an object's group transformation on it
     * @private
     * @param {fabric.Object} [instance] the object to transform (gets mutated)
     * @returns the original values of instance which were changed
     */
    _realizeGroupTransformOnObject: function(instance) {
      if (instance.group && instance.group.type === 'activeSelection' && this._activeObject === instance.group) {
        var layoutProps = ['angle', 'flipX', 'flipY', 'left', 'scaleX', 'scaleY', 'skewX', 'skewY', 'top'];
        //Copy all the positionally relevant properties across now
        var originalValues = {};
        layoutProps.forEach(function(prop) {
          originalValues[prop] = instance[prop];
        });
        this._activeObject.realizeTransform(instance);
        return originalValues;
      }
      else {
        return null;
      }
    },

    /**
     * Restores the changed properties of instance
     * @private
     * @param {fabric.Object} [instance] the object to un-transform (gets mutated)
     * @param {Object} [originalValues] the original values of instance, as returned by _realizeGroupTransformOnObject
     */
    _unwindGroupTransformOnObject: function(instance, originalValues) {
      if (originalValues) {
        instance.set(originalValues);
      }
    },

    /**
     * @private
     */
    _setSVGObject: function(markup, instance, reviver) {
      //If the object is in a selection group, simulate what would happen to that
      //object when the group is deselected
      var originalProperties = this._realizeGroupTransformOnObject(instance);
      this.callSuper('_setSVGObject', markup, instance, reviver);
      this._unwindGroupTransformOnObject(instance, originalProperties);
    },
  });

  // copying static properties manually to work around Opera's bug,
  // where "prototype" property is enumerable and overrides existing prototype
  for (var prop in fabric.StaticCanvas) {
    if (prop !== 'prototype') {
      fabric.Canvas[prop] = fabric.StaticCanvas[prop];
    }
  }

  if (fabric.isTouchSupported) {
    /** @ignore */
    fabric.Canvas.prototype._setCursorFromEvent = function() { };
  }
})();


(function() {

  var cursorOffset = {
        mt: 0, // n
        tr: 1, // ne
        mr: 2, // e
        br: 3, // se
        mb: 4, // s
        bl: 5, // sw
        ml: 6, // w
        tl: 7 // nw
      },
      addListener = fabric.util.addListener,
      removeListener = fabric.util.removeListener,
      RIGHT_CLICK = 3, MIDDLE_CLICK = 2, LEFT_CLICK = 1,
      addEventOptions = { passive: false };

  function checkClick(e, value) {
    return 'which' in e ? e.which === value : e.button === value - 1;
  }

  fabric.util.object.extend(fabric.Canvas.prototype, /** @lends fabric.Canvas.prototype */ {

    /**
     * Map of cursor style values for each of the object controls
     * @private
     */
    cursorMap: [
      'n-resize',
      'ne-resize',
      'e-resize',
      'se-resize',
      's-resize',
      'sw-resize',
      'w-resize',
      'nw-resize'
    ],

    /**
     * Adds mouse listeners to canvas
     * @private
     */
    _initEventListeners: function () {
      // in case we initialized the class twice. This should not happen normally
      // but in some kind of applications where the canvas element may be changed
      // this is a workaround to having double listeners.
      this.removeListeners();
      this._bindEvents();
      this.addOrRemove(addListener, 'add');
    },

    addOrRemove: function(functor, eventjsFunctor) {
      functor(fabric.window, 'resize', this._onResize);
      functor(this.upperCanvasEl, 'mousedown', this._onMouseDown);
      functor(this.upperCanvasEl, 'mousemove', this._onMouseMove, addEventOptions);
      functor(this.upperCanvasEl, 'mouseout', this._onMouseOut);
      functor(this.upperCanvasEl, 'mouseenter', this._onMouseEnter);
      functor(this.upperCanvasEl, 'wheel', this._onMouseWheel);
      functor(this.upperCanvasEl, 'contextmenu', this._onContextMenu);
      functor(this.upperCanvasEl, 'dblclick', this._onDoubleClick);
      functor(this.upperCanvasEl, 'touchstart', this._onMouseDown, addEventOptions);
      functor(this.upperCanvasEl, 'touchmove', this._onMouseMove, addEventOptions);
      functor(this.upperCanvasEl, 'dragover', this._onDragOver);
      functor(this.upperCanvasEl, 'dragenter', this._onDragEnter);
      functor(this.upperCanvasEl, 'dragleave', this._onDragLeave);
      functor(this.upperCanvasEl, 'drop', this._onDrop);
      if (typeof eventjs !== 'undefined' && eventjsFunctor in eventjs) {
        eventjs[eventjsFunctor](this.upperCanvasEl, 'gesture', this._onGesture);
        eventjs[eventjsFunctor](this.upperCanvasEl, 'drag', this._onDrag);
        eventjs[eventjsFunctor](this.upperCanvasEl, 'orientation', this._onOrientationChange);
        eventjs[eventjsFunctor](this.upperCanvasEl, 'shake', this._onShake);
        eventjs[eventjsFunctor](this.upperCanvasEl, 'longpress', this._onLongPress);
      }
    },

    /**
     * Removes all event listeners
     */
    removeListeners: function() {
      this.addOrRemove(removeListener, 'remove');
      // if you dispose on a mouseDown, before mouse up, you need to clean document to...
      removeListener(fabric.document, 'mouseup', this._onMouseUp);
      removeListener(fabric.document, 'touchend', this._onMouseUp, addEventOptions);
      removeListener(fabric.document, 'mousemove', this._onMouseMove, addEventOptions);
      removeListener(fabric.document, 'touchmove', this._onMouseMove, addEventOptions);
    },

    /**
     * @private
     */
    _bindEvents: function() {
      if (this.eventsBound) {
        // for any reason we pass here twice we do not want to bind events twice.
        return;
      }
      this._onMouseDown = this._onMouseDown.bind(this);
      this._onMouseMove = this._onMouseMove.bind(this);
      this._onMouseUp = this._onMouseUp.bind(this);
      this._onResize = this._onResize.bind(this);
      this._onGesture = this._onGesture.bind(this);
      this._onDrag = this._onDrag.bind(this);
      this._onShake = this._onShake.bind(this);
      this._onLongPress = this._onLongPress.bind(this);
      this._onOrientationChange = this._onOrientationChange.bind(this);
      this._onMouseWheel = this._onMouseWheel.bind(this);
      this._onMouseOut = this._onMouseOut.bind(this);
      this._onMouseEnter = this._onMouseEnter.bind(this);
      this._onContextMenu = this._onContextMenu.bind(this);
      this._onDoubleClick = this._onDoubleClick.bind(this);
      this._onDragOver = this._onDragOver.bind(this);
      this._onDragEnter = this._simpleEventHandler.bind(this, 'dragenter');
      this._onDragLeave = this._simpleEventHandler.bind(this, 'dragleave');
      this._onDrop = this._simpleEventHandler.bind(this, 'drop');
      this.eventsBound = true;
    },

    /**
     * @private
     * @param {Event} [e] Event object fired on Event.js gesture
     * @param {Event} [self] Inner Event object
     */
    _onGesture: function(e, self) {
      this.__onTransformGesture && this.__onTransformGesture(e, self);
    },

    /**
     * @private
     * @param {Event} [e] Event object fired on Event.js drag
     * @param {Event} [self] Inner Event object
     */
    _onDrag: function(e, self) {
      this.__onDrag && this.__onDrag(e, self);
    },

    /**
     * @private
     * @param {Event} [e] Event object fired on wheel event
     */
    _onMouseWheel: function(e) {
      this.__onMouseWheel(e);
    },

    /**
     * @private
     * @param {Event} e Event object fired on mousedown
     */
    _onMouseOut: function(e) {
      var target = this._hoveredTarget;
      this.fire('mouse:out', { target: target, e: e });
      this._hoveredTarget = null;
      target && target.fire('mouseout', { e: e });
      if (this._iTextInstances) {
        this._iTextInstances.forEach(function(obj) {
          if (obj.isEditing) {
            obj.hiddenTextarea.focus();
          }
        });
      }
    },

    /**
     * @private
     * @param {Event} e Event object fired on mouseenter
     */
    _onMouseEnter: function(e) {
      if (!this.findTarget(e)) {
        this.fire('mouse:over', { target: null, e: e });
        this._hoveredTarget = null;
      }
    },

    /**
     * @private
     * @param {Event} [e] Event object fired on Event.js orientation change
     * @param {Event} [self] Inner Event object
     */
    _onOrientationChange: function(e, self) {
      this.__onOrientationChange && this.__onOrientationChange(e, self);
    },

    /**
     * @private
     * @param {Event} [e] Event object fired on Event.js shake
     * @param {Event} [self] Inner Event object
     */
    _onShake: function(e, self) {
      this.__onShake && this.__onShake(e, self);
    },

    /**
     * @private
     * @param {Event} [e] Event object fired on Event.js shake
     * @param {Event} [self] Inner Event object
     */
    _onLongPress: function(e, self) {
      this.__onLongPress && this.__onLongPress(e, self);
    },

    /**
     * prevent default to allow drop event to be fired
     * @private
     * @param {Event} [e] Event object fired on Event.js shake
     */
    _onDragOver: function(e) {
      e.preventDefault();
      var target = this._simpleEventHandler('dragover', e);
      this._fireEnterLeaveEvents(target, e);
    },

    /**
     * @private
     * @param {Event} e Event object fired on mousedown
     */
    _onContextMenu: function (e) {
      if (this.stopContextMenu) {
        e.stopPropagation();
        e.preventDefault();
      }
      return false;
    },

    /**
     * @private
     * @param {Event} e Event object fired on mousedown
     */
    _onDoubleClick: function (e) {
      this._cacheTransformEventData(e);
      this._handleEvent(e, 'dblclick');
      this._resetTransformEventData(e);
    },

    /**
     * @private
     * @param {Event} e Event object fired on mousedown
     */
    _onMouseDown: function (e) {
      this.__onMouseDown(e);
      this._resetTransformEventData();
      addListener(fabric.document, 'touchend', this._onMouseUp, addEventOptions);
      addListener(fabric.document, 'touchmove', this._onMouseMove, addEventOptions);

      removeListener(this.upperCanvasEl, 'mousemove', this._onMouseMove, addEventOptions);
      removeListener(this.upperCanvasEl, 'touchmove', this._onMouseMove, addEventOptions);

      if (e.type === 'touchstart') {
        // Unbind mousedown to prevent double triggers from touch devices
        removeListener(this.upperCanvasEl, 'mousedown', this._onMouseDown);
      }
      else {
        addListener(fabric.document, 'mouseup', this._onMouseUp);
        addListener(fabric.document, 'mousemove', this._onMouseMove, addEventOptions);
      }
    },

    /**
     * @private
     * @param {Event} e Event object fired on mouseup
     */
    _onMouseUp: function (e) {
      this.__onMouseUp(e);
      this._resetTransformEventData();
      removeListener(fabric.document, 'mouseup', this._onMouseUp);
      removeListener(fabric.document, 'touchend', this._onMouseUp, addEventOptions);

      removeListener(fabric.document, 'mousemove', this._onMouseMove, addEventOptions);
      removeListener(fabric.document, 'touchmove', this._onMouseMove, addEventOptions);

      addListener(this.upperCanvasEl, 'mousemove', this._onMouseMove, addEventOptions);
      addListener(this.upperCanvasEl, 'touchmove', this._onMouseMove, addEventOptions);

      if (e.type === 'touchend') {
        // Wait 400ms before rebinding mousedown to prevent double triggers
        // from touch devices
        var _this = this;
        setTimeout(function() {
          addListener(_this.upperCanvasEl, 'mousedown', _this._onMouseDown);
        }, 400);
      }
    },

    /**
     * @private
     * @param {Event} e Event object fired on mousemove
     */
    _onMouseMove: function (e) {
      !this.allowTouchScrolling && e.preventDefault && e.preventDefault();
      this.__onMouseMove(e);
    },

    /**
     * @private
     */
    _onResize: function () {
      this.calcOffset();
    },

    /**
     * Decides whether the canvas should be redrawn in mouseup and mousedown events.
     * @private
     * @param {Object} target
     * @param {Object} pointer
     */
    _shouldRender: function(target, pointer) {
      var activeObject = this._activeObject;

      if (activeObject && activeObject.isEditing && target === activeObject) {
        // if we mouse up/down over a editing textbox a cursor change,
        // there is no need to re render
        return false;
      }
      return !!(
        (target && (
          target.isMoving ||
          target !== activeObject))
        ||
        (!target && !!activeObject)
        ||
        (!target && !activeObject && !this._groupSelector)
        ||
        (pointer &&
          this._previousPointer &&
          this.selection && (
            pointer.x !== this._previousPointer.x ||
          pointer.y !== this._previousPointer.y))
      );
    },

    /**
     * Method that defines the actions when mouse is released on canvas.
     * The method resets the currentTransform parameters, store the image corner
     * position in the image object and render the canvas on top.
     * @private
     * @param {Event} e Event object fired on mouseup
     */
    __onMouseUp: function (e) {
      var target, transform = this._currentTransform,
          groupSelector = this._groupSelector,
          isClick = (!groupSelector || (groupSelector.left === 0 && groupSelector.top === 0));
      this._cacheTransformEventData(e);
      target = this._target;
      this._handleEvent(e, 'up:before');
      // if right/middle click just fire events and return
      // target undefined will make the _handleEvent search the target
      if (checkClick(e, RIGHT_CLICK)) {
        if (this.fireRightClick) {
          this._handleEvent(e, 'up', RIGHT_CLICK, isClick);
        }
        return;
      }

      if (checkClick(e, MIDDLE_CLICK)) {
        if (this.fireMiddleClick) {
          this._handleEvent(e, 'up', MIDDLE_CLICK, isClick);
        }
        this._resetTransformEventData();
        return;
      }

      if (this.isDrawingMode && this._isCurrentlyDrawing) {
        this._onMouseUpInDrawingMode(e);
        return;
      }

      if (transform) {
        this._finalizeCurrentTransform(e);
      }

      var shouldRender = this._shouldRender(target, this._absolutePointer);

      if (target || !isClick) {
        this._maybeGroupObjects(e);
      }
      if (target) {
        target.isMoving = false;
      }
      this._setCursorFromEvent(e, target);
      this._handleEvent(e, 'up', LEFT_CLICK, isClick);
      this._groupSelector = null;
      this._currentTransform = null;
      target && (target.__corner = 0);
      shouldRender && this.requestRenderAll();
    },

    /**
     * @private
     * Handle event firing for target and subtargets
     * @param {Event} e event from mouse
     * @param {String} eventType event to fire (up, down or move)
     * @return {Fabric.Object} target return the the target found, for internal reasons.
     */
    _simpleEventHandler: function(eventType, e) {
      var target = this.findTarget(e),
          targets = this.targets,
          options = {
            e: e,
            target: target,
            subTargets: targets,
          };
      this.fire(eventType, options);
      target && target.fire(eventType, options);
      if (!targets) {
        return target;
      }
      for (var i = 0; i < targets.length; i++) {
        targets[i].fire(eventType, options);
      }
      return target;
    },

    /**
     * @private
     * Handle event firing for target and subtargets
     * @param {Event} e event from mouse
     * @param {String} eventType event to fire (up, down or move)
     * @param {fabric.Object} targetObj receiving event
     * @param {Number} [button] button used in the event 1 = left, 2 = middle, 3 = right
     * @param {Boolean} isClick for left button only, indicates that the mouse up happened without move.
     */
    _handleEvent: function(e, eventType, button, isClick) {
      var target = this._target,
          targets = this.targets || [],
          options = {
            e: e,
            target: target,
            subTargets: targets,
            button: button || LEFT_CLICK,
            isClick: isClick || false,
            pointer: this._pointer,
            absolutePointer: this._absolutePointer,
            transform: this._currentTransform
          };
      this.fire('mouse:' + eventType, options);
      target && target.fire('mouse' + eventType, options);
      for (var i = 0; i < targets.length; i++) {
        targets[i].fire('mouse' + eventType, options);
      }
    },

    /**
     * @private
     * @param {Event} e send the mouse event that generate the finalize down, so it can be used in the event
     */
    _finalizeCurrentTransform: function(e) {

      var transform = this._currentTransform,
          target = transform.target,
          eventName,
          options = {
            e: e,
            target: target,
            transform: transform,
          };

      if (target._scaling) {
        target._scaling = false;
      }

      target.setCoords();

      if (transform.actionPerformed || (this.stateful && target.hasStateChanged())) {
        if (transform.actionPerformed) {
          eventName = this._addEventOptions(options, transform);
          this._fire(eventName, options);
        }
        this._fire('modified', options);
      }
    },

    /**
     * Mutate option object in order to add by property and give back the event name.
     * @private
     * @param {Object} options to mutate
     * @param {Object} transform to inspect action from
     */
    _addEventOptions: function(options, transform) {
      // we can probably add more details at low cost
      // scale change, rotation changes, translation changes
      var eventName, by;
      switch (transform.action) {
        case 'scaleX':
          eventName = 'scaled';
          by = 'x';
          break;
        case 'scaleY':
          eventName = 'scaled';
          by = 'y';
          break;
        case 'skewX':
          eventName = 'skewed';
          by = 'x';
          break;
        case 'skewY':
          eventName = 'skewed';
          by = 'y';
          break;
        case 'scale':
          eventName = 'scaled';
          by = 'equally';
          break;
        case 'rotate':
          eventName = 'rotated';
          break;
        case 'drag':
          eventName = 'moved';
          break;
      }
      options.by = by;
      return eventName;
    },

    /**
     * @private
     * @param {Event} e Event object fired on mousedown
     */
    _onMouseDownInDrawingMode: function(e) {
      this._isCurrentlyDrawing = true;
      if (this.getActiveObject()) {
        this.discardActiveObject(e).requestRenderAll();
      }
      if (this.clipTo) {
        fabric.util.clipContext(this, this.contextTop);
      }
      var pointer = this.getPointer(e);
      this.freeDrawingBrush.onMouseDown(pointer);
      this._handleEvent(e, 'down');
    },

    /**
     * @private
     * @param {Event} e Event object fired on mousemove
     */
    _onMouseMoveInDrawingMode: function(e) {
      if (this._isCurrentlyDrawing) {
        var pointer = this.getPointer(e);
        this.freeDrawingBrush.onMouseMove(pointer);
      }
      this.setCursor(this.freeDrawingCursor);
      this._handleEvent(e, 'move');
    },

    /**
     * @private
     * @param {Event} e Event object fired on mouseup
     */
    _onMouseUpInDrawingMode: function(e) {
      this._isCurrentlyDrawing = false;
      if (this.clipTo) {
        this.contextTop.restore();
      }
      this.freeDrawingBrush.onMouseUp();
      this._handleEvent(e, 'up');
    },

    /**
     * Method that defines the actions when mouse is clicked on canvas.
     * The method inits the currentTransform parameters and renders all the
     * canvas so the current image can be placed on the top canvas and the rest
     * in on the container one.
     * @private
     * @param {Event} e Event object fired on mousedown
     */
    __onMouseDown: function (e) {
      this._cacheTransformEventData(e);
      this._handleEvent(e, 'down:before');
      var target = this._target;
      // if right click just fire events
      if (checkClick(e, RIGHT_CLICK)) {
        if (this.fireRightClick) {
          this._handleEvent(e, 'down', RIGHT_CLICK);
        }
        return;
      }

      if (checkClick(e, MIDDLE_CLICK)) {
        if (this.fireMiddleClick) {
          this._handleEvent(e, 'down', MIDDLE_CLICK);
        }
        return;
      }

      if (this.isDrawingMode) {
        this._onMouseDownInDrawingMode(e);
        return;
      }

      // ignore if some object is being transformed at this moment
      if (this._currentTransform) {
        return;
      }

      var pointer = this._pointer;
      // save pointer for check in __onMouseUp event
      this._previousPointer = pointer;
      var shouldRender = this._shouldRender(target, pointer),
          shouldGroup = this._shouldGroup(e, target);
      if (this._shouldClearSelection(e, target)) {
        this.discardActiveObject(e);
      }
      else if (shouldGroup) {
        this._handleGrouping(e, target);
        target = this._activeObject;
      }

      if (this.selection && (!target ||
        (!target.selectable && !target.isEditing && target !== this._activeObject))) {
        this._groupSelector = {
          ex: pointer.x,
          ey: pointer.y,
          top: 0,
          left: 0
        };
      }

      if (target) {
        if (target.selectable) {
          this.setActiveObject(target, e);
        }
        if (target === this._activeObject && (target.__corner || !shouldGroup)) {
          this._setupCurrentTransform(e, target);
        }
      }
      this._handleEvent(e, 'down');
      // we must renderAll so that we update the visuals
      shouldRender && this.requestRenderAll();
    },

    /**
     * reset cache form common information needed during event processing
     * @private
     */
    _resetTransformEventData: function() {
      this._target = null;
      this._pointer = null;
      this._absolutePointer = null;
    },

    /**
     * Cache common information needed during event processing
     * @private
     * @param {Event} e Event object fired on event
     */
    _cacheTransformEventData: function(e) {
      // reset in order to avoid stale caching
      this._resetTransformEventData();
      this._pointer = this.getPointer(e, true);
      this._absolutePointer = this.restorePointerVpt(this._pointer);
      this._target = this._currentTransform ? this._currentTransform.target : this.findTarget(e) || null;
    },

    /**
     * @private
     */
    _beforeTransform: function(e) {
      var t = this._currentTransform;
      this.stateful && t.target.saveState();
      this.fire('before:transform', {
        e: e,
        transform: t,
      });
      // determine if it's a drag or rotate case
      if (t.corner) {
        this.onBeforeScaleRotate(t.target);
      }
    },

    /**
     * Method that defines the actions when mouse is hovering the canvas.
     * The currentTransform parameter will definde whether the user is rotating/scaling/translating
     * an image or neither of them (only hovering). A group selection is also possible and would cancel
     * all any other type of action.
     * In case of an image transformation only the top canvas will be rendered.
     * @private
     * @param {Event} e Event object fired on mousemove
     */
    __onMouseMove: function (e) {
      this._handleEvent(e, 'move:before');
      this._cacheTransformEventData(e);
      var target, pointer;

      if (this.isDrawingMode) {
        this._onMouseMoveInDrawingMode(e);
        return;
      }
      if (typeof e.touches !== 'undefined' && e.touches.length > 1) {
        return;
      }

      var groupSelector = this._groupSelector;

      // We initially clicked in an empty area, so we draw a box for multiple selection
      if (groupSelector) {
        pointer = this._pointer;

        groupSelector.left = pointer.x - groupSelector.ex;
        groupSelector.top = pointer.y - groupSelector.ey;

        this.renderTop();
      }
      else if (!this._currentTransform) {
        target = this.findTarget(e) || null;
        this._setCursorFromEvent(e, target);
        this._fireOverOutEvents(target, e);
      }
      else {
        this._transformObject(e);
      }
      this._handleEvent(e, 'move');
      this._resetTransformEventData();
    },

    /**
     * Manage the mouseout, mouseover events for the fabric object on the canvas
     * @param {Fabric.Object} target the target where the target from the mousemove event
     * @param {Event} e Event object fired on mousemove
     * @private
     */
    _fireOverOutEvents: function(target, e) {
      this.fireSynteticInOutEvents(target, e, {
        targetName: '_hoveredTarget',
        canvasEvtOut: 'mouse:out',
        evtOut: 'mouseout',
        canvasEvtIn: 'mouse:over',
        evtIn: 'mouseover',
      });
    },

    /**
     * Manage the dragEnter, dragLeave events for the fabric objects on the canvas
     * @param {Fabric.Object} target the target where the target from the onDrag event
     * @param {Event} e Event object fired on ondrag
     * @private
     */
    _fireEnterLeaveEvents: function(target, e) {
      this.fireSynteticInOutEvents(target, e, {
        targetName: '_draggedoverTarget',
        evtOut: 'dragleave',
        evtIn: 'dragenter',
      });
    },

    /**
     * Manage the syntetic in/out events for the fabric objects on the canvas
     * @param {Fabric.Object} target the target where the target from the supported events
     * @param {Event} e Event object fired
     * @param {Object} config configuration for the function to work
     * @param {String} config.targetName property on the canvas where the old target is stored
     * @param {String} [config.canvasEvtOut] name of the event to fire at canvas level for out
     * @param {String} config.evtOut name of the event to fire for out
     * @param {String} [config.canvasEvtIn] name of the event to fire at canvas level for in
     * @param {String} config.evtIn name of the event to fire for in
     * @private
     */
    fireSynteticInOutEvents: function(target, e, config) {
      var inOpt, outOpt, oldTarget = this[config.targetName], outFires, inFires,
          targetChanged = oldTarget !== target, canvasEvtIn = config.canvasEvtIn, canvasEvtOut = config.canvasEvtOut;
      if (targetChanged) {
        inOpt = { e: e, target: target, previousTarget: oldTarget };
        outOpt = { e: e, target: oldTarget, nextTarget: target };
        this[config.targetName] = target;
      }
      inFires = target && targetChanged;
      outFires = oldTarget && targetChanged;
      if (outFires) {
        canvasEvtOut && this.fire(canvasEvtOut, outOpt);
        oldTarget.fire(config.evtOut, outOpt);
      }
      if (inFires) {
        canvasEvtIn && this.fire(canvasEvtIn, inOpt);
        target.fire(config.evtIn, inOpt);
      }
    },

    /**
     * Method that defines actions when an Event Mouse Wheel
     * @param {Event} e Event object fired on mouseup
     */
    __onMouseWheel: function(e) {
      this._cacheTransformEventData(e);
      this._handleEvent(e, 'wheel');
      this._resetTransformEventData();
    },

    /**
     * @private
     * @param {Event} e Event fired on mousemove
     */
    _transformObject: function(e) {
      var pointer = this.getPointer(e),
          transform = this._currentTransform;

      transform.reset = false;
      transform.target.isMoving = true;
      transform.shiftKey = e.shiftKey;
      transform.altKey = e[this.centeredKey];

      this._beforeScaleTransform(e, transform);
      this._performTransformAction(e, transform, pointer);

      transform.actionPerformed && this.requestRenderAll();
    },

    /**
     * @private
     */
    _performTransformAction: function(e, transform, pointer) {
      var x = pointer.x,
          y = pointer.y,
          action = transform.action,
          actionPerformed = false,
          options = {
            target: transform.target,
            e: e,
            transform: transform,
            pointer: pointer
          };

      if (action === 'rotate') {
        (actionPerformed = this._rotateObject(x, y)) && this._fire('rotating', options);
      }
      else if (action === 'scale') {
        (actionPerformed = this._onScale(e, transform, x, y)) && this._fire('scaling', options);
      }
      else if (action === 'scaleX') {
        (actionPerformed = this._scaleObject(x, y, 'x')) && this._fire('scaling', options);
      }
      else if (action === 'scaleY') {
        (actionPerformed = this._scaleObject(x, y, 'y')) && this._fire('scaling', options);
      }
      else if (action === 'skewX') {
        (actionPerformed = this._skewObject(x, y, 'x')) && this._fire('skewing', options);
      }
      else if (action === 'skewY') {
        (actionPerformed = this._skewObject(x, y, 'y')) && this._fire('skewing', options);
      }
      else {
        actionPerformed = this._translateObject(x, y);
        if (actionPerformed) {
          this._fire('moving', options);
          this.setCursor(options.target.moveCursor || this.moveCursor);
        }
      }
      transform.actionPerformed = transform.actionPerformed || actionPerformed;
    },

    /**
     * @private
     */
    _fire: function(eventName, options) {
      this.fire('object:' + eventName, options);
      options.target.fire(eventName, options);
    },

    /**
     * @private
     */
    _beforeScaleTransform: function(e, transform) {
      if (transform.action === 'scale' || transform.action === 'scaleX' || transform.action === 'scaleY') {
        var centerTransform = this._shouldCenterTransform(transform.target);

        // Switch from a normal resize to center-based
        if ((centerTransform && (transform.originX !== 'center' || transform.originY !== 'center')) ||
           // Switch from center-based resize to normal one
           (!centerTransform && transform.originX === 'center' && transform.originY === 'center')
        ) {
          this._resetCurrentTransform();
          transform.reset = true;
        }
      }
    },

    /**
     * @private
     * @param {Event} e Event object
     * @param {Object} transform current tranform
     * @param {Number} x mouse position x from origin
     * @param {Number} y mouse poistion y from origin
     * @return {Boolean} true if the scaling occurred
     */
    _onScale: function(e, transform, x, y) {
      if (this._isUniscalePossible(e, transform.target)) {
        transform.currentAction = 'scale';
        return this._scaleObject(x, y);
      }
      else {
        // Switch from a normal resize to proportional
        if (!transform.reset && transform.currentAction === 'scale') {
          this._resetCurrentTransform();
        }

        transform.currentAction = 'scaleEqually';
        return this._scaleObject(x, y, 'equally');
      }
    },

    /**
     * @private
     * @param {Event} e Event object
     * @param {fabric.Object} target current target
     * @return {Boolean} true if unproportional scaling is possible
     */
    _isUniscalePossible: function(e, target) {
      return (e[this.uniScaleKey] || this.uniScaleTransform) && !target.get('lockUniScaling');
    },

    /**
     * Sets the cursor depending on where the canvas is being hovered.
     * Note: very buggy in Opera
     * @param {Event} e Event object
     * @param {Object} target Object that the mouse is hovering, if so.
     */
    _setCursorFromEvent: function (e, target) {

      if (!target) {
        this.setCursor(this.defaultCursor);
        return false;
      }

      var hoverCursor = target.hoverCursor || this.hoverCursor,
          activeSelection = this._activeObject && this._activeObject.type === 'activeSelection' ?
            this._activeObject : null,
          // only show proper corner when group selection is not active
          corner = (!activeSelection || !activeSelection.contains(target))
                    && target._findTargetCorner(this.getPointer(e, true));
      if (!corner) {
        this.setCursor(hoverCursor);
      }
      else {
        this.setCursor(this.getCornerCursor(corner, target, e));
      }
    },

    /**
     * @private
     */
    getCornerCursor: function(corner, target, e) {
      if (this.actionIsDisabled(corner, target, e)) {
        return this.notAllowedCursor;
      }
      else if (corner in cursorOffset) {
        return this._getRotatedCornerCursor(corner, target, e);
      }
      else if (corner === 'mtr' && target.hasRotatingPoint) {
        return this.rotationCursor;
      }
      else {
        return this.defaultCursor;
      }
    },

    actionIsDisabled: function(corner, target, e) {
      if (corner === 'mt' || corner === 'mb') {
        return e[this.altActionKey] ? target.lockSkewingX : target.lockScalingY;
      }
      else if (corner === 'ml' || corner === 'mr') {
        return e[this.altActionKey] ? target.lockSkewingY : target.lockScalingX;
      }
      else if (corner === 'mtr') {
        return target.lockRotation;
      }
      else {
        return this._isUniscalePossible(e, target) ?
          target.lockScalingX && target.lockScalingY : target.lockScalingX || target.lockScalingY;
      }
    },

    /**
     * @private
     */
    _getRotatedCornerCursor: function(corner, target, e) {
      var n = Math.round((target.angle % 360) / 45);

      if (n < 0) {
        n += 8; // full circle ahead
      }
      n += cursorOffset[corner];
      if (e[this.altActionKey] && cursorOffset[corner] % 2 === 0) {
        //if we are holding shift and we are on a mx corner...
        n += 2;
      }
      // normalize n to be from 0 to 7
      n %= 8;

      return this.cursorMap[n];
    }
  });
})();


(function() {

  var min = Math.min,
      max = Math.max;

  fabric.util.object.extend(fabric.Canvas.prototype, /** @lends fabric.Canvas.prototype */ {

    /**
     * @private
     * @param {Event} e Event object
     * @param {fabric.Object} target
     * @return {Boolean}
     */
    _shouldGroup: function(e, target) {
      var activeObject = this._activeObject;

      return activeObject && this._isSelectionKeyPressed(e) && target && target.selectable && this.selection &&
            (activeObject !== target || activeObject.type === 'activeSelection');
    },

    /**
     * @private
     * @param {Event} e Event object
     * @param {fabric.Object} target
     */
    _handleGrouping: function (e, target) {
      var activeObject = this._activeObject;
      if (activeObject.__corner) {
        return;
      }
      if (target === activeObject) {
        // if it's a group, find target again, using activeGroup objects
        target = this.findTarget(e, true);
        // if even object is not found or we are on activeObjectCorner, bail out
        if (!target) {
          return;
        }
      }
      if (activeObject && activeObject.type === 'activeSelection') {
        this._updateActiveSelection(target, e);
      }
      else {
        this._createActiveSelection(target, e);
      }
    },

    /**
     * @private
     */
    _updateActiveSelection: function(target, e) {
      var activeSelection = this._activeObject,
          currentActiveObjects = activeSelection._objects.slice(0);
      if (activeSelection.contains(target)) {
        activeSelection.removeWithUpdate(target);
        this._hoveredTarget = target;
        if (activeSelection.size() === 1) {
          // activate last remaining object
          this._setActiveObject(activeSelection.item(0), e);
        }
      }
      else {
        activeSelection.addWithUpdate(target);
        this._hoveredTarget = activeSelection;
      }
      this._fireSelectionEvents(currentActiveObjects, e);
    },

    /**
     * @private
     */
    _createActiveSelection: function(target, e) {
      var currentActives = this.getActiveObjects(), group = this._createGroup(target);
      this._hoveredTarget = group;
      this._setActiveObject(group, e);
      this._fireSelectionEvents(currentActives, e);
    },

    /**
     * @private
     * @param {Object} target
     */
    _createGroup: function(target) {
      var objects = this.getObjects(),
          isActiveLower = objects.indexOf(this._activeObject) < objects.indexOf(target),
          groupObjects = isActiveLower
            ? [this._activeObject, target]
            : [target, this._activeObject];
      this._activeObject.isEditing && this._activeObject.exitEditing();
      return new fabric.ActiveSelection(groupObjects, {
        canvas: this
      });
    },

    /**
     * @private
     * @param {Event} e mouse event
     */
    _groupSelectedObjects: function (e) {

      var group = this._collectObjects(),
          aGroup;

      // do not create group for 1 element only
      if (group.length === 1) {
        this.setActiveObject(group[0], e);
      }
      else if (group.length > 1) {
        aGroup = new fabric.ActiveSelection(group.reverse(), {
          canvas: this
        });
        this.setActiveObject(aGroup, e);
      }
    },

    /**
     * @private
     */
    _collectObjects: function() {
      var group = [],
          currentObject,
          x1 = this._groupSelector.ex,
          y1 = this._groupSelector.ey,
          x2 = x1 + this._groupSelector.left,
          y2 = y1 + this._groupSelector.top,
          selectionX1Y1 = new fabric.Point(min(x1, x2), min(y1, y2)),
          selectionX2Y2 = new fabric.Point(max(x1, x2), max(y1, y2)),
          allowIntersect = !this.selectionFullyContained,
          isClick = x1 === x2 && y1 === y2;
      // we iterate reverse order to collect top first in case of click.
      for (var i = this._objects.length; i--; ) {
        currentObject = this._objects[i];

        if (!currentObject || !currentObject.selectable || !currentObject.visible) {
          continue;
        }

        if ((allowIntersect && currentObject.intersectsWithRect(selectionX1Y1, selectionX2Y2)) ||
            currentObject.isContainedWithinRect(selectionX1Y1, selectionX2Y2) ||
            (allowIntersect && currentObject.containsPoint(selectionX1Y1)) ||
            (allowIntersect && currentObject.containsPoint(selectionX2Y2))
        ) {
          group.push(currentObject);

          // only add one object if it's a click
          if (isClick) {
            break;
          }
        }
      }

      return group;
    },

    /**
     * @private
     */
    _maybeGroupObjects: function(e) {
      if (this.selection && this._groupSelector) {
        this._groupSelectedObjects(e);
      }
      this.setCursor(this.defaultCursor);
      // clear selection and current transformation
      this._groupSelector = null;
    }
  });

})();


(function () {

  var supportQuality = fabric.StaticCanvas.supports('toDataURLWithQuality');

  fabric.util.object.extend(fabric.StaticCanvas.prototype, /** @lends fabric.StaticCanvas.prototype */ {

    /**
     * Exports canvas element to a dataurl image. Note that when multiplier is used, cropping is scaled appropriately
     * @param {Object} [options] Options object
     * @param {String} [options.format=png] The format of the output image. Either "jpeg" or "png"
     * @param {Number} [options.quality=1] Quality level (0..1). Only used for jpeg.
     * @param {Number} [options.multiplier=1] Multiplier to scale by, to have consistent
     * @param {Number} [options.left] Cropping left offset. Introduced in v1.2.14
     * @param {Number} [options.top] Cropping top offset. Introduced in v1.2.14
     * @param {Number} [options.width] Cropping width. Introduced in v1.2.14
     * @param {Number} [options.height] Cropping height. Introduced in v1.2.14
     * @param {Boolean} [options.enableRetinaScaling] Enable retina scaling for clone image. Introduce in 2.0.0
     * @return {String} Returns a data: URL containing a representation of the object in the format specified by options.format
     * @see {@link http://jsfiddle.net/fabricjs/NfZVb/|jsFiddle demo}
     * @example <caption>Generate jpeg dataURL with lower quality</caption>
     * var dataURL = canvas.toDataURL({
     *   format: 'jpeg',
     *   quality: 0.8
     * });
     * @example <caption>Generate cropped png dataURL (clipping of canvas)</caption>
     * var dataURL = canvas.toDataURL({
     *   format: 'png',
     *   left: 100,
     *   top: 100,
     *   width: 200,
     *   height: 200
     * });
     * @example <caption>Generate double scaled png dataURL</caption>
     * var dataURL = canvas.toDataURL({
     *   format: 'png',
     *   multiplier: 2
     * });
     */
    toDataURL: function (options) {
      options || (options = { });

      var format = options.format || 'png',
          quality = options.quality || 1,
          multiplier = (options.multiplier || 1) * (options.enableRetinaScaling ? 1 : 1 / this.getRetinaScaling()),
          cropping = {
            left: options.left || 0,
            top: options.top || 0,
            width: options.width || 0,
            height: options.height || 0,
          };
      return this.__toDataURLWithMultiplier(format, quality, cropping, multiplier);
    },

    /**
     * @private
     */
    __toDataURLWithMultiplier: function(format, quality, cropping, multiplier) {

      var origWidth = this.width,
          origHeight = this.height,
          scaledWidth = (cropping.width || this.width) * multiplier,
          scaledHeight = (cropping.height || this.height) * multiplier,
          zoom = this.getZoom(),
          newZoom = zoom * multiplier,
          vp = this.viewportTransform,
          translateX = (vp[4] - cropping.left) * multiplier,
          translateY = (vp[5] - cropping.top) * multiplier,
          newVp = [newZoom, 0, 0, newZoom, translateX, translateY],
          originalInteractive = this.interactive,
          originalSkipOffScreen = this.skipOffscreen,
          needsResize = origWidth !== scaledWidth || origHeight !== scaledHeight;

      this.viewportTransform = newVp;
      this.skipOffscreen = false;
      // setting interactive to false avoid exporting controls
      this.interactive = false;
      if (needsResize) {
        this.setDimensions({ width: scaledWidth, height: scaledHeight }, { backstoreOnly: true });
      }
      // call a renderAll to force sync update. This will cancel the scheduled requestRenderAll
      // from setDimensions
      this.renderAll();
      var data = this.__toDataURL(format, quality, cropping);
      this.interactive = originalInteractive;
      this.skipOffscreen = originalSkipOffScreen;
      this.viewportTransform = vp;
      //setDimensions with no option object is taking care of:
      //this.width, this.height, this.requestRenderAll()
      if (needsResize) {
        this.setDimensions({ width: origWidth, height: origHeight }, { backstoreOnly: true });
      }
      this.renderAll();
      return data;
    },

    /**
     * @private
     */
    __toDataURL: function(format, quality) {

      var canvasEl = this.contextContainer.canvas;
      // to avoid common confusion https://github.com/kangax/fabric.js/issues/806
      if (format === 'jpg') {
        format = 'jpeg';
      }

      var data = supportQuality
        ? canvasEl.toDataURL('image/' + format, quality)
        : canvasEl.toDataURL('image/' + format);

      return data;
    },
  });

})();


fabric.util.object.extend(fabric.StaticCanvas.prototype, /** @lends fabric.StaticCanvas.prototype */ {

  /**
   * Populates canvas with data from the specified dataless JSON.
   * JSON format must conform to the one of {@link fabric.Canvas#toDatalessJSON}
   * @deprecated since 1.2.2
   * @param {String|Object} json JSON string or object
   * @param {Function} callback Callback, invoked when json is parsed
   *                            and corresponding objects (e.g: {@link fabric.Image})
   *                            are initialized
   * @param {Function} [reviver] Method for further parsing of JSON elements, called after each fabric object created.
   * @return {fabric.Canvas} instance
   * @chainable
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-3#deserialization}
   */
  loadFromDatalessJSON: function (json, callback, reviver) {
    return this.loadFromJSON(json, callback, reviver);
  },

  /**
   * Populates canvas with data from the specified JSON.
   * JSON format must conform to the one of {@link fabric.Canvas#toJSON}
   * @param {String|Object} json JSON string or object
   * @param {Function} callback Callback, invoked when json is parsed
   *                            and corresponding objects (e.g: {@link fabric.Image})
   *                            are initialized
   * @param {Function} [reviver] Method for further parsing of JSON elements, called after each fabric object created.
   * @return {fabric.Canvas} instance
   * @chainable
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-3#deserialization}
   * @see {@link http://jsfiddle.net/fabricjs/fmgXt/|jsFiddle demo}
   * @example <caption>loadFromJSON</caption>
   * canvas.loadFromJSON(json, canvas.renderAll.bind(canvas));
   * @example <caption>loadFromJSON with reviver</caption>
   * canvas.loadFromJSON(json, canvas.renderAll.bind(canvas), function(o, object) {
   *   // `o` = json object
   *   // `object` = fabric.Object instance
   *   // ... do some stuff ...
   * });
   */
  loadFromJSON: function (json, callback, reviver) {
    if (!json) {
      return;
    }

    // serialize if it wasn't already
    var serialized = (typeof json === 'string')
      ? JSON.parse(json)
      : fabric.util.object.clone(json);

    var _this = this,
        renderOnAddRemove = this.renderOnAddRemove;
    this.renderOnAddRemove = false;

    this._enlivenObjects(serialized.objects, function (enlivenedObjects) {
      _this.clear();
      _this._setBgOverlay(serialized, function () {
        enlivenedObjects.forEach(function(obj, index) {
          // we splice the array just in case some custom classes restored from JSON
          // will add more object to canvas at canvas init.
          _this.insertAt(obj, index);
        });
        _this.renderOnAddRemove = renderOnAddRemove;
        // remove parts i cannot set as options
        delete serialized.objects;
        delete serialized.backgroundImage;
        delete serialized.overlayImage;
        delete serialized.background;
        delete serialized.overlay;
        // this._initOptions does too many things to just
        // call it. Normally loading an Object from JSON
        // create the Object instance. Here the Canvas is
        // already an instance and we are just loading things over it
        _this._setOptions(serialized);
        _this.renderAll();
        callback && callback();
      });
    }, reviver);
    return this;
  },

  /**
   * @private
   * @param {Object} serialized Object with background and overlay information
   * @param {Function} callback Invoked after all background and overlay images/patterns loaded
   */
  _setBgOverlay: function(serialized, callback) {
    var loaded = {
      backgroundColor: false,
      overlayColor: false,
      backgroundImage: false,
      overlayImage: false
    };

    if (!serialized.backgroundImage && !serialized.overlayImage && !serialized.background && !serialized.overlay) {
      callback && callback();
      return;
    }

    var cbIfLoaded = function () {
      if (loaded.backgroundImage && loaded.overlayImage && loaded.backgroundColor && loaded.overlayColor) {
        callback && callback();
      }
    };

    this.__setBgOverlay('backgroundImage', serialized.backgroundImage, loaded, cbIfLoaded);
    this.__setBgOverlay('overlayImage', serialized.overlayImage, loaded, cbIfLoaded);
    this.__setBgOverlay('backgroundColor', serialized.background, loaded, cbIfLoaded);
    this.__setBgOverlay('overlayColor', serialized.overlay, loaded, cbIfLoaded);
  },

  /**
   * @private
   * @param {String} property Property to set (backgroundImage, overlayImage, backgroundColor, overlayColor)
   * @param {(Object|String)} value Value to set
   * @param {Object} loaded Set loaded property to true if property is set
   * @param {Object} callback Callback function to invoke after property is set
   */
  __setBgOverlay: function(property, value, loaded, callback) {
    var _this = this;

    if (!value) {
      loaded[property] = true;
      callback && callback();
      return;
    }

    if (property === 'backgroundImage' || property === 'overlayImage') {
      fabric.util.enlivenObjects([value], function(enlivedObject){
        _this[property] = enlivedObject[0];
        loaded[property] = true;
        callback && callback();
      });
    }
    else {
      this['set' + fabric.util.string.capitalize(property, true)](value, function() {
        loaded[property] = true;
        callback && callback();
      });
    }
  },

  /**
   * @private
   * @param {Array} objects
   * @param {Function} callback
   * @param {Function} [reviver]
   */
  _enlivenObjects: function (objects, callback, reviver) {
    if (!objects || objects.length === 0) {
      callback && callback([]);
      return;
    }

    fabric.util.enlivenObjects(objects, function(enlivenedObjects) {
      callback && callback(enlivenedObjects);
    }, null, reviver);
  },

  /**
   * @private
   * @param {String} format
   * @param {Function} callback
   */
  _toDataURL: function (format, callback) {
    this.clone(function (clone) {
      callback(clone.toDataURL(format));
    });
  },

  /**
   * @private
   * @param {String} format
   * @param {Number} multiplier
   * @param {Function} callback
   */
  _toDataURLWithMultiplier: function (format, multiplier, callback) {
    this.clone(function (clone) {
      callback(clone.toDataURLWithMultiplier(format, multiplier));
    });
  },

  /**
   * Clones canvas instance
   * @param {Object} [callback] Receives cloned instance as a first argument
   * @param {Array} [properties] Array of properties to include in the cloned canvas and children
   */
  clone: function (callback, properties) {
    var data = JSON.stringify(this.toJSON(properties));
    this.cloneWithoutData(function(clone) {
      clone.loadFromJSON(data, function() {
        callback && callback(clone);
      });
    });
  },

  /**
   * Clones canvas instance without cloning existing data.
   * This essentially copies canvas dimensions, clipping properties, etc.
   * but leaves data empty (so that you can populate it with your own)
   * @param {Object} [callback] Receives cloned instance as a first argument
   */
  cloneWithoutData: function(callback) {
    var el = fabric.document.createElement('canvas');

    el.width = this.width;
    el.height = this.height;

    var clone = new fabric.Canvas(el);
    clone.clipTo = this.clipTo;
    if (this.backgroundImage) {
      clone.setBackgroundImage(this.backgroundImage.src, function() {
        clone.renderAll();
        callback && callback(clone);
      });
      clone.backgroundImageOpacity = this.backgroundImageOpacity;
      clone.backgroundImageStretch = this.backgroundImageStretch;
    }
    else {
      callback && callback(clone);
    }
  }
});


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { }),
      extend = fabric.util.object.extend,
      clone = fabric.util.object.clone,
      toFixed = fabric.util.toFixed,
      capitalize = fabric.util.string.capitalize,
      degreesToRadians = fabric.util.degreesToRadians,
      supportsLineDash = fabric.StaticCanvas.supports('setLineDash'),
      objectCaching = !fabric.isLikelyNode,
      ALIASING_LIMIT = 2;

  if (fabric.Object) {
    return;
  }

  /**
   * Root object class from which all 2d shape classes inherit from
   * @class fabric.Object
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-1#objects}
   * @see {@link fabric.Object#initialize} for constructor definition
   *
   * @fires added
   * @fires removed
   *
   * @fires selected
   * @fires deselected
   * @fires modified
   * @fires modified
   * @fires moved
   * @fires scaled
   * @fires rotated
   * @fires skewed
   *
   * @fires rotating
   * @fires scaling
   * @fires moving
   * @fires skewing
   *
   * @fires mousedown
   * @fires mouseup
   * @fires mouseover
   * @fires mouseout
   * @fires mousewheel
   * @fires mousedblclick
   *
   * @fires dragover
   * @fires dragenter
   * @fires dragleave
   * @fires drop
   */
  fabric.Object = fabric.util.createClass(fabric.CommonMethods, /** @lends fabric.Object.prototype */ {

    /**
     * Type of an object (rect, circle, path, etc.).
     * Note that this property is meant to be read-only and not meant to be modified.
     * If you modify, certain parts of Fabric (such as JSON loading) won't work correctly.
     * @type String
     * @default
     */
    type:                     'object',

    /**
     * Horizontal origin of transformation of an object (one of "left", "right", "center")
     * See http://jsfiddle.net/1ow02gea/244/ on how originX/originY affect objects in groups
     * @type String
     * @default
     */
    originX:                  'left',

    /**
     * Vertical origin of transformation of an object (one of "top", "bottom", "center")
     * See http://jsfiddle.net/1ow02gea/244/ on how originX/originY affect objects in groups
     * @type String
     * @default
     */
    originY:                  'top',

    /**
     * Top position of an object. Note that by default it's relative to object top. You can change this by setting originY={top/center/bottom}
     * @type Number
     * @default
     */
    top:                      0,

    /**
     * Left position of an object. Note that by default it's relative to object left. You can change this by setting originX={left/center/right}
     * @type Number
     * @default
     */
    left:                     0,

    /**
     * Object width
     * @type Number
     * @default
     */
    width:                    0,

    /**
     * Object height
     * @type Number
     * @default
     */
    height:                   0,

    /**
     * Object scale factor (horizontal)
     * @type Number
     * @default
     */
    scaleX:                   1,

    /**
     * Object scale factor (vertical)
     * @type Number
     * @default
     */
    scaleY:                   1,

    /**
     * When true, an object is rendered as flipped horizontally
     * @type Boolean
     * @default
     */
    flipX:                    false,

    /**
     * When true, an object is rendered as flipped vertically
     * @type Boolean
     * @default
     */
    flipY:                    false,

    /**
     * Opacity of an object
     * @type Number
     * @default
     */
    opacity:                  1,

    /**
     * Angle of rotation of an object (in degrees)
     * @type Number
     * @default
     */
    angle:                    0,

    /**
     * Angle of skew on x axes of an object (in degrees)
     * @type Number
     * @default
     */
    skewX:                    0,

    /**
     * Angle of skew on y axes of an object (in degrees)
     * @type Number
     * @default
     */
    skewY:                    0,

    /**
     * Size of object's controlling corners (in pixels)
     * @type Number
     * @default
     */
    cornerSize:               13,

    /**
     * When true, object's controlling corners are rendered as transparent inside (i.e. stroke instead of fill)
     * @type Boolean
     * @default
     */
    transparentCorners:       true,

    /**
     * Default cursor value used when hovering over this object on canvas
     * @type String
     * @default
     */
    hoverCursor:              null,

    /**
     * Default cursor value used when moving this object on canvas
     * @type String
     * @default
     */
    moveCursor:               null,

    /**
     * Padding between object and its controlling borders (in pixels)
     * @type Number
     * @default
     */
    padding:                  0,

    /**
     * Color of controlling borders of an object (when it's active)
     * @type String
     * @default
     */
    borderColor:              'rgba(102,153,255,0.75)',

    /**
     * Array specifying dash pattern of an object's borders (hasBorder must be true)
     * @since 1.6.2
     * @type Array
     */
    borderDashArray:          null,

    /**
     * Color of controlling corners of an object (when it's active)
     * @type String
     * @default
     */
    cornerColor:              'rgba(102,153,255,0.5)',

    /**
     * Color of controlling corners of an object (when it's active and transparentCorners false)
     * @since 1.6.2
     * @type String
     * @default
     */
    cornerStrokeColor:        null,

    /**
     * Specify style of control, 'rect' or 'circle'
     * @since 1.6.2
     * @type String
     */
    cornerStyle:          'rect',

    /**
     * Array specifying dash pattern of an object's control (hasBorder must be true)
     * @since 1.6.2
     * @type Array
     */
    cornerDashArray:          null,

    /**
     * When true, this object will use center point as the origin of transformation
     * when being scaled via the controls.
     * <b>Backwards incompatibility note:</b> This property replaces "centerTransform" (Boolean).
     * @since 1.3.4
     * @type Boolean
     * @default
     */
    centeredScaling:          false,

    /**
     * When true, this object will use center point as the origin of transformation
     * when being rotated via the controls.
     * <b>Backwards incompatibility note:</b> This property replaces "centerTransform" (Boolean).
     * @since 1.3.4
     * @type Boolean
     * @default
     */
    centeredRotation:         true,

    /**
     * Color of object's fill
     * takes css colors https://www.w3.org/TR/css-color-3/
     * @type String
     * @default
     */
    fill:                     'rgb(0,0,0)',

    /**
     * Fill rule used to fill an object
     * accepted values are nonzero, evenodd
     * <b>Backwards incompatibility note:</b> This property was used for setting globalCompositeOperation until v1.4.12 (use `fabric.Object#globalCompositeOperation` instead)
     * @type String
     * @default
     */
    fillRule:                 'nonzero',

    /**
     * Composite rule used for canvas globalCompositeOperation
     * @type String
     * @default
     */
    globalCompositeOperation: 'source-over',

    /**
     * Background color of an object.
     * takes css colors https://www.w3.org/TR/css-color-3/
     * @type String
     * @default
     */
    backgroundColor:          '',

    /**
     * Selection Background color of an object. colored layer behind the object when it is active.
     * does not mix good with globalCompositeOperation methods.
     * @type String
     * @default
     */
    selectionBackgroundColor:          '',

    /**
     * When defined, an object is rendered via stroke and this property specifies its color
     * takes css colors https://www.w3.org/TR/css-color-3/
     * @type String
     * @default
     */
    stroke:                   null,

    /**
     * Width of a stroke used to render this object
     * @type Number
     * @default
     */
    strokeWidth:              1,

    /**
     * Array specifying dash pattern of an object's stroke (stroke must be defined)
     * @type Array
     */
    strokeDashArray:          null,

    /**
     * Line endings style of an object's stroke (one of "butt", "round", "square")
     * @type String
     * @default
     */
    strokeLineCap:            'butt',

    /**
     * Corner style of an object's stroke (one of "bevil", "round", "miter")
     * @type String
     * @default
     */
    strokeLineJoin:           'miter',

    /**
     * Maximum miter length (used for strokeLineJoin = "miter") of an object's stroke
     * @type Number
     * @default
     */
    strokeMiterLimit:         4,

    /**
     * Shadow object representing shadow of this shape
     * @type fabric.Shadow
     * @default
     */
    shadow:                   null,

    /**
     * Opacity of object's controlling borders when object is active and moving
     * @type Number
     * @default
     */
    borderOpacityWhenMoving:  0.4,

    /**
     * Scale factor of object's controlling borders
     * @type Number
     * @default
     */
    borderScaleFactor:        1,

    /**
     * Transform matrix (similar to SVG's transform matrix)
     * @type Array
     */
    transformMatrix:          null,

    /**
     * Minimum allowed scale value of an object
     * @type Number
     * @default
     */
    minScaleLimit:            0,

    /**
     * When set to `false`, an object can not be selected for modification (using either point-click-based or group-based selection).
     * But events still fire on it.
     * @type Boolean
     * @default
     */
    selectable:               true,

    /**
     * When set to `false`, an object can not be a target of events. All events propagate through it. Introduced in v1.3.4
     * @type Boolean
     * @default
     */
    evented:                  true,

    /**
     * When set to `false`, an object is not rendered on canvas
     * @type Boolean
     * @default
     */
    visible:                  true,

    /**
     * When set to `false`, object's controls are not displayed and can not be used to manipulate object
     * @type Boolean
     * @default
     */
    hasControls:              true,

    /**
     * When set to `false`, object's controlling borders are not rendered
     * @type Boolean
     * @default
     */
    hasBorders:               true,

    /**
     * When set to `false`, object's controlling rotating point will not be visible or selectable
     * @type Boolean
     * @default
     */
    hasRotatingPoint:         true,

    /**
     * Offset for object's controlling rotating point (when enabled via `hasRotatingPoint`)
     * @type Number
     * @default
     */
    rotatingPointOffset:      40,

    /**
     * When set to `true`, objects are "found" on canvas on per-pixel basis rather than according to bounding box
     * @type Boolean
     * @default
     */
    perPixelTargetFind:       false,

    /**
     * When `false`, default object's values are not included in its serialization
     * @type Boolean
     * @default
     */
    includeDefaultValues:     true,

    /**
     * Function that determines clipping of an object (context is passed as a first argument)
     * Note that context origin is at the object's center point (not left/top corner)
     * @deprecated since 2.0.0
     * @type Function
     */
    clipTo:                   null,

    /**
     * When `true`, object horizontal movement is locked
     * @type Boolean
     * @default
     */
    lockMovementX:            false,

    /**
     * When `true`, object vertical movement is locked
     * @type Boolean
     * @default
     */
    lockMovementY:            false,

    /**
     * When `true`, object rotation is locked
     * @type Boolean
     * @default
     */
    lockRotation:             false,

    /**
     * When `true`, object horizontal scaling is locked
     * @type Boolean
     * @default
     */
    lockScalingX:             false,

    /**
     * When `true`, object vertical scaling is locked
     * @type Boolean
     * @default
     */
    lockScalingY:             false,

    /**
     * When `true`, object non-uniform scaling is locked
     * @type Boolean
     * @default
     */
    lockUniScaling:           false,

    /**
     * When `true`, object horizontal skewing is locked
     * @type Boolean
     * @default
     */
    lockSkewingX:             false,

    /**
     * When `true`, object vertical skewing is locked
     * @type Boolean
     * @default
     */
    lockSkewingY:             false,

    /**
     * When `true`, object cannot be flipped by scaling into negative values
     * @type Boolean
     * @default
     */
    lockScalingFlip:          false,

    /**
     * When `true`, object is not exported in OBJECT/JSON
     * since 1.6.3
     * @type Boolean
     * @default
     */
    excludeFromExport:        false,

    /**
     * When `true`, object is cached on an additional canvas.
     * default to true
     * since 1.7.0
     * @type Boolean
     * @default true
     */
    objectCaching:            objectCaching,

    /**
     * When `true`, object properties are checked for cache invalidation. In some particular
     * situation you may want this to be disabled ( spray brush, very big, groups)
     * or if your application does not allow you to modify properties for groups child you want
     * to disable it for groups.
     * default to false
     * since 1.7.0
     * @type Boolean
     * @default false
     */
    statefullCache:            false,

    /**
     * When `true`, cache does not get updated during scaling. The picture will get blocky if scaled
     * too much and will be redrawn with correct details at the end of scaling.
     * this setting is performance and application dependant.
     * default to true
     * since 1.7.0
     * @type Boolean
     * @default true
     */
    noScaleCache:              true,

    /**
     * When set to `true`, object's cache will be rerendered next render call.
     * since 1.7.0
     * @type Boolean
     * @default true
     */
    dirty:                true,

    /**
     * keeps the value of the last hovered coner during mouse move.
     * 0 is no corner, or 'mt', 'ml', 'mtr' etc..
     * It should be private, but there is no harm in using it as
     * a read-only property.
     * @type number|string|any
     * @default 0
     */
    __corner: 0,

    /**
     * Determins if the fill or the stroke is drawn first (one of "fill" or "stroke")
     * @type String
     * @default
     */
    paintFirst:           'fill',

    /**
     * List of properties to consider when checking if state
     * of an object is changed (fabric.Object#hasStateChanged)
     * as well as for history (undo/redo) purposes
     * @type Array
     */
    stateProperties: (
      'top left width height scaleX scaleY flipX flipY originX originY transformMatrix ' +
      'stroke strokeWidth strokeDashArray strokeLineCap strokeLineJoin strokeMiterLimit ' +
      'angle opacity fill globalCompositeOperation shadow clipTo visible backgroundColor ' +
      'skewX skewY fillRule paintFirst'
    ).split(' '),

    /**
     * List of properties to consider when checking if cache needs refresh
     * @type Array
     */
    cacheProperties: (
      'fill stroke strokeWidth strokeDashArray width height paintFirst' +
      ' strokeLineCap strokeLineJoin strokeMiterLimit backgroundColor'
    ).split(' '),

    /**
     * Constructor
     * @param {Object} [options] Options object
     */
    initialize: function(options) {
      if (options) {
        this.setOptions(options);
      }
    },

    /**
     * Create a the canvas used to keep the cached copy of the object
     * @private
     */
    _createCacheCanvas: function() {
      this._cacheProperties = {};
      this._cacheCanvas = fabric.document.createElement('canvas');
      this._cacheContext = this._cacheCanvas.getContext('2d');
      this._updateCacheCanvas();
      // if canvas gets created, is empty, so dirty.
      this.dirty = true;
    },

    /**
     * Limit the cache dimensions so that X * Y do not cross fabric.perfLimitSizeTotal
     * and each side do not cross fabric.cacheSideLimit
     * those numbers are configurable so that you can get as much detail as you want
     * making bargain with performances.
     * @param {Object} dims
     * @param {Object} dims.width width of canvas
     * @param {Object} dims.height height of canvas
     * @param {Object} dims.zoomX zoomX zoom value to unscale the canvas before drawing cache
     * @param {Object} dims.zoomY zoomY zoom value to unscale the canvas before drawing cache
     * @return {Object}.width width of canvas
     * @return {Object}.height height of canvas
     * @return {Object}.zoomX zoomX zoom value to unscale the canvas before drawing cache
     * @return {Object}.zoomY zoomY zoom value to unscale the canvas before drawing cache
     */
    _limitCacheSize: function(dims) {
      var perfLimitSizeTotal = fabric.perfLimitSizeTotal,
          width = dims.width, height = dims.height,
          max = fabric.maxCacheSideLimit, min = fabric.minCacheSideLimit;
      if (width <= max && height <= max && width * height <= perfLimitSizeTotal) {
        if (width < min) {
          dims.width = min;
        }
        if (height < min) {
          dims.height = min;
        }
        return dims;
      }
      var ar = width / height, limitedDims = fabric.util.limitDimsByArea(ar, perfLimitSizeTotal),
          capValue = fabric.util.capValue,
          x = capValue(min, limitedDims.x, max),
          y = capValue(min, limitedDims.y, max);
      if (width > x) {
        dims.zoomX /= width / x;
        dims.width = x;
        dims.capped = true;
      }
      if (height > y) {
        dims.zoomY /= height / y;
        dims.height = y;
        dims.capped = true;
      }
      return dims;
    },

    /**
     * Return the dimension and the zoom level needed to create a cache canvas
     * big enough to host the object to be cached.
     * @private
     * @param {Object} dim.x width of object to be cached
     * @param {Object} dim.y height of object to be cached
     * @return {Object}.width width of canvas
     * @return {Object}.height height of canvas
     * @return {Object}.zoomX zoomX zoom value to unscale the canvas before drawing cache
     * @return {Object}.zoomY zoomY zoom value to unscale the canvas before drawing cache
     */
    _getCacheCanvasDimensions: function() {
      var zoom = this.canvas && this.canvas.getZoom() || 1,
          objectScale = this.getObjectScaling(),
          retina = this.canvas && this.canvas._isRetinaScaling() ? fabric.devicePixelRatio : 1,
          dim = this._getNonTransformedDimensions(),
          zoomX = objectScale.scaleX * zoom * retina,
          zoomY = objectScale.scaleY * zoom * retina,
          width = dim.x * zoomX,
          height = dim.y * zoomY;
      return {
        // for sure this ALIASING_LIMIT is slightly crating problem
        // in situation in wich the cache canvas gets an upper limit
        width: width + ALIASING_LIMIT,
        height: height + ALIASING_LIMIT,
        zoomX: zoomX,
        zoomY: zoomY,
        x: dim.x,
        y: dim.y
      };
    },

    /**
     * Update width and height of the canvas for cache
     * returns true or false if canvas needed resize.
     * @private
     * @return {Boolean} true if the canvas has been resized
     */
    _updateCacheCanvas: function() {
      if (this.noScaleCache && this.canvas && this.canvas._currentTransform) {
        var target = this.canvas._currentTransform.target,
            action = this.canvas._currentTransform.action;
        if (this === target && action.slice && action.slice(0, 5) === 'scale') {
          return false;
        }
      }
      var canvas = this._cacheCanvas,
          dims = this._limitCacheSize(this._getCacheCanvasDimensions()),
          minCacheSize = fabric.minCacheSideLimit,
          width = dims.width, height = dims.height, drawingWidth, drawingHeight,
          zoomX = dims.zoomX, zoomY = dims.zoomY,
          dimensionsChanged = width !== this.cacheWidth || height !== this.cacheHeight,
          zoomChanged = this.zoomX !== zoomX || this.zoomY !== zoomY,
          shouldRedraw = dimensionsChanged || zoomChanged,
          additionalWidth = 0, additionalHeight = 0, shouldResizeCanvas = false;
      if (dimensionsChanged) {
        var canvasWidth = this._cacheCanvas.width,
            canvasHeight = this._cacheCanvas.height,
            sizeGrowing = width > canvasWidth || height > canvasHeight,
            sizeShrinking = (width < canvasWidth * 0.9 || height < canvasHeight * 0.9) &&
              canvasWidth > minCacheSize && canvasHeight > minCacheSize;
        shouldResizeCanvas = sizeGrowing || sizeShrinking;
        if (sizeGrowing && !dims.capped && (width > minCacheSize || height > minCacheSize)) {
          additionalWidth = width * 0.1;
          additionalHeight = height * 0.1;
        }
      }
      if (shouldRedraw) {
        if (shouldResizeCanvas) {
          canvas.width = Math.ceil(width + additionalWidth);
          canvas.height = Math.ceil(height + additionalHeight);
        }
        else {
          this._cacheContext.setTransform(1, 0, 0, 1, 0, 0);
          this._cacheContext.clearRect(0, 0, canvas.width, canvas.height);
        }
        drawingWidth = dims.x * zoomX / 2;
        drawingHeight = dims.y * zoomY / 2;
        this.cacheTranslationX = Math.round(canvas.width / 2 - drawingWidth) + drawingWidth;
        this.cacheTranslationY = Math.round(canvas.height / 2 - drawingHeight) + drawingHeight;
        this.cacheWidth = width;
        this.cacheHeight = height;
        this._cacheContext.translate(this.cacheTranslationX, this.cacheTranslationY);
        this._cacheContext.scale(zoomX, zoomY);
        this.zoomX = zoomX;
        this.zoomY = zoomY;
        return true;
      }
      return false;
    },

    /**
     * Sets object's properties from options
     * @param {Object} [options] Options object
     */
    setOptions: function(options) {
      this._setOptions(options);
      this._initGradient(options.fill, 'fill');
      this._initGradient(options.stroke, 'stroke');
      this._initClipping(options);
      this._initPattern(options.fill, 'fill');
      this._initPattern(options.stroke, 'stroke');
    },

    /**
     * Transforms context when rendering an object
     * @param {CanvasRenderingContext2D} ctx Context
     */
    transform: function(ctx) {
      var m;
      if (this.group && !this.group._transformDone) {
        m = this.calcTransformMatrix();
      }
      else {
        m = this.calcOwnMatrix();
      }
      ctx.transform(m[0], m[1], m[2], m[3], m[4], m[5]);
    },

    /**
     * Returns an object representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} Object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      var NUM_FRACTION_DIGITS = fabric.Object.NUM_FRACTION_DIGITS,

          object = {
            type:                     this.type,
            version:                  fabric.version,
            originX:                  this.originX,
            originY:                  this.originY,
            left:                     toFixed(this.left, NUM_FRACTION_DIGITS),
            top:                      toFixed(this.top, NUM_FRACTION_DIGITS),
            width:                    toFixed(this.width, NUM_FRACTION_DIGITS),
            height:                   toFixed(this.height, NUM_FRACTION_DIGITS),
            fill:                     (this.fill && this.fill.toObject) ? this.fill.toObject() : this.fill,
            stroke:                   (this.stroke && this.stroke.toObject) ? this.stroke.toObject() : this.stroke,
            strokeWidth:              toFixed(this.strokeWidth, NUM_FRACTION_DIGITS),
            strokeDashArray:          this.strokeDashArray ? this.strokeDashArray.concat() : this.strokeDashArray,
            strokeLineCap:            this.strokeLineCap,
            strokeLineJoin:           this.strokeLineJoin,
            strokeMiterLimit:         toFixed(this.strokeMiterLimit, NUM_FRACTION_DIGITS),
            scaleX:                   toFixed(this.scaleX, NUM_FRACTION_DIGITS),
            scaleY:                   toFixed(this.scaleY, NUM_FRACTION_DIGITS),
            angle:                    toFixed(this.angle, NUM_FRACTION_DIGITS),
            flipX:                    this.flipX,
            flipY:                    this.flipY,
            opacity:                  toFixed(this.opacity, NUM_FRACTION_DIGITS),
            shadow:                   (this.shadow && this.shadow.toObject) ? this.shadow.toObject() : this.shadow,
            visible:                  this.visible,
            clipTo:                   this.clipTo && String(this.clipTo),
            backgroundColor:          this.backgroundColor,
            fillRule:                 this.fillRule,
            paintFirst:               this.paintFirst,
            globalCompositeOperation: this.globalCompositeOperation,
            transformMatrix:          this.transformMatrix ? this.transformMatrix.concat() : null,
            skewX:                    toFixed(this.skewX, NUM_FRACTION_DIGITS),
            skewY:                    toFixed(this.skewY, NUM_FRACTION_DIGITS)
          };

      fabric.util.populateWithProperties(this, object, propertiesToInclude);
      if (!this.includeDefaultValues) {
        object = this._removeDefaultValues(object);
      }

      return object;
    },

    /**
     * Returns (dataless) object representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} Object representation of an instance
     */
    toDatalessObject: function(propertiesToInclude) {
      // will be overwritten by subclasses
      return this.toObject(propertiesToInclude);
    },

    /**
     * @private
     * @param {Object} object
     */
    _removeDefaultValues: function(object) {
      var prototype = fabric.util.getKlass(object.type).prototype,
          stateProperties = prototype.stateProperties;
      stateProperties.forEach(function(prop) {
        if (object[prop] === prototype[prop]) {
          delete object[prop];
        }
        var isArray = Object.prototype.toString.call(object[prop]) === '[object Array]' &&
                      Object.prototype.toString.call(prototype[prop]) === '[object Array]';

        // basically a check for [] === []
        if (isArray && object[prop].length === 0 && prototype[prop].length === 0) {
          delete object[prop];
        }
      });

      return object;
    },

    /**
     * Returns a string representation of an instance
     * @return {String}
     */
    toString: function() {
      return '#<fabric.' + capitalize(this.type) + '>';
    },

    /**
     * Return the object scale factor counting also the group scaling
     * @return {Object} object with scaleX and scaleY properties
     */
    getObjectScaling: function() {
      var scaleX = this.scaleX, scaleY = this.scaleY;
      if (this.group) {
        var scaling = this.group.getObjectScaling();
        scaleX *= scaling.scaleX;
        scaleY *= scaling.scaleY;
      }
      return { scaleX: scaleX, scaleY: scaleY };
    },

    /**
     * Return the object opacity counting also the group property
     * @return {Number}
     */
    getObjectOpacity: function() {
      var opacity = this.opacity;
      if (this.group) {
        opacity *= this.group.getObjectOpacity();
      }
      return opacity;
    },

    /**
     * @private
     * @param {String} key
     * @param {*} value
     * @return {fabric.Object} thisArg
     */
    _set: function(key, value) {
      var shouldConstrainValue = (key === 'scaleX' || key === 'scaleY'),
          isChanged = this[key] !== value, groupNeedsUpdate = false;

      if (shouldConstrainValue) {
        value = this._constrainScale(value);
      }
      if (key === 'scaleX' && value < 0) {
        this.flipX = !this.flipX;
        value *= -1;
      }
      else if (key === 'scaleY' && value < 0) {
        this.flipY = !this.flipY;
        value *= -1;
      }
      else if (key === 'shadow' && value && !(value instanceof fabric.Shadow)) {
        value = new fabric.Shadow(value);
      }
      else if (key === 'dirty' && this.group) {
        this.group.set('dirty', value);
      }

      this[key] = value;

      if (isChanged) {
        groupNeedsUpdate = this.group && this.group.isOnACache();
        if (this.cacheProperties.indexOf(key) > -1) {
          this.dirty = true;
          groupNeedsUpdate && this.group.set('dirty', true);
        }
        else if (groupNeedsUpdate && this.stateProperties.indexOf(key) > -1) {
          this.group.set('dirty', true);
        }
      }

      return this;
    },

    /**
     * This callback function is called by the parent group of an object every
     * time a non-delegated property changes on the group. It is passed the key
     * and value as parameters. Not adding in this function's signature to avoid
     * Travis build error about unused variables.
     */
    setOnGroup: function() {
      // implemented by sub-classes, as needed.
    },

    /**
     * Retrieves viewportTransform from Object's canvas if possible
     * @method getViewportTransform
     * @memberOf fabric.Object.prototype
     * @return {Boolean}
     */
    getViewportTransform: function() {
      if (this.canvas && this.canvas.viewportTransform) {
        return this.canvas.viewportTransform;
      }
      return fabric.iMatrix.concat();
    },

    /*
     * @private
     * return if the object would be visible in rendering
     * @memberOf fabric.Object.prototype
     * @return {Boolean}
     */
    isNotVisible: function() {
      return this.opacity === 0 || (this.width === 0 && this.height === 0) || !this.visible;
    },

    /**
     * Renders an object on a specified context
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    render: function(ctx) {
      // do not render if width/height are zeros or object is not visible
      if (this.isNotVisible()) {
        return;
      }
      if (this.canvas && this.canvas.skipOffscreen && !this.group && !this.isOnScreen()) {
        return;
      }
      ctx.save();
      this._setupCompositeOperation(ctx);
      this.drawSelectionBackground(ctx);
      this.transform(ctx);
      this._setOpacity(ctx);
      this._setShadow(ctx, this);
      if (this.transformMatrix) {
        ctx.transform.apply(ctx, this.transformMatrix);
      }
      this.clipTo && fabric.util.clipContext(this, ctx);
      if (this.shouldCache()) {
        if (!this._cacheCanvas) {
          this._createCacheCanvas();

        }
        if (this.isCacheDirty()) {
          this.statefullCache && this.saveState({ propertySet: 'cacheProperties' });
          this.drawObject(this._cacheContext);
          this.dirty = false;
        }
        this.drawCacheOnCanvas(ctx);
      }
      else {
        this._removeCacheCanvas();
        this.dirty = false;
        this.drawObject(ctx);
        if (this.objectCaching && this.statefullCache) {
          this.saveState({ propertySet: 'cacheProperties' });
        }
      }
      this.clipTo && ctx.restore();
      ctx.restore();
    },

    /**
     * Remove cacheCanvas and its dimensions from the objects
     */
    _removeCacheCanvas: function() {
      this._cacheCanvas = null;
      this.cacheWidth = 0;
      this.cacheHeight = 0;
    },

    /**
     * When set to `true`, force the object to have its own cache, even if it is inside a group
     * it may be needed when your object behave in a particular way on the cache and always needs
     * its own isolated canvas to render correctly.
     * Created to be overridden
     * since 1.7.12
     * @returns false
     */
    needsItsOwnCache: function() {
      if (this.paintFirst === 'stroke' && typeof this.shadow === 'object') {
        return true;
      }
      return false;
    },

    /**
     * Decide if the object should cache or not. Create its own cache level
     * objectCaching is a global flag, wins over everything
     * needsItsOwnCache should be used when the object drawing method requires
     * a cache step. None of the fabric classes requires it.
     * Generally you do not cache objects in groups because the group outside is cached.
     * @return {Boolean}
     */
    shouldCache: function() {
      this.ownCaching = this.objectCaching &&
      (!this.group || this.needsItsOwnCache() || !this.group.isOnACache());
      return this.ownCaching;
    },

    /**
     * Check if this object or a child object will cast a shadow
     * used by Group.shouldCache to know if child has a shadow recursively
     * @return {Boolean}
     */
    willDrawShadow: function() {
      return !!this.shadow && (this.shadow.offsetX !== 0 || this.shadow.offsetY !== 0);
    },

    /**
     * Execute the drawing operation for an object on a specified context
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    drawObject: function(ctx) {
      this._renderBackground(ctx);
      this._setStrokeStyles(ctx, this);
      this._setFillStyles(ctx, this);
      this._render(ctx);
    },

    /**
     * Paint the cached copy of the object on the target context.
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    drawCacheOnCanvas: function(ctx) {
      ctx.scale(1 / this.zoomX, 1 / this.zoomY);
      ctx.drawImage(this._cacheCanvas, -this.cacheTranslationX, -this.cacheTranslationY);
    },

    /**
     * Check if cache is dirty
     * @param {Boolean} skipCanvas skip canvas checks because this object is painted
     * on parent canvas.
     */
    isCacheDirty: function(skipCanvas) {
      if (this.isNotVisible()) {
        return false;
      }
      if (this._cacheCanvas && !skipCanvas && this._updateCacheCanvas()) {
        // in this case the context is already cleared.
        return true;
      }
      else {
        if (this.dirty || (this.statefullCache && this.hasStateChanged('cacheProperties'))) {
          if (this._cacheCanvas && !skipCanvas) {
            var width = this.cacheWidth / this.zoomX;
            var height = this.cacheHeight / this.zoomY;
            this._cacheContext.clearRect(-width / 2, -height / 2, width, height);
          }
          return true;
        }
      }
      return false;
    },

    /**
     * Draws a background for the object big as its untrasformed dimensions
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderBackground: function(ctx) {
      if (!this.backgroundColor) {
        return;
      }
      var dim = this._getNonTransformedDimensions();
      ctx.fillStyle = this.backgroundColor;

      ctx.fillRect(
        -dim.x / 2,
        -dim.y / 2,
        dim.x,
        dim.y
      );
      // if there is background color no other shadows
      // should be casted
      this._removeShadow(ctx);
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _setOpacity: function(ctx) {
      if (this.group && !this.group._transformDone) {
        ctx.globalAlpha = this.getObjectOpacity();
      }
      else {
        ctx.globalAlpha *= this.opacity;
      }
    },

    _setStrokeStyles: function(ctx, decl) {
      if (decl.stroke) {
        ctx.lineWidth = decl.strokeWidth;
        ctx.lineCap = decl.strokeLineCap;
        ctx.lineJoin = decl.strokeLineJoin;
        ctx.miterLimit = decl.strokeMiterLimit;
        ctx.strokeStyle = decl.stroke.toLive
          ? decl.stroke.toLive(ctx, this)
          : decl.stroke;
      }
    },

    _setFillStyles: function(ctx, decl) {
      if (decl.fill) {
        ctx.fillStyle = decl.fill.toLive
          ? decl.fill.toLive(ctx, this)
          : decl.fill;
      }
    },

    /**
     * @private
     * Sets line dash
     * @param {CanvasRenderingContext2D} ctx Context to set the dash line on
     * @param {Array} dashArray array representing dashes
     * @param {Function} alternative function to call if browaser does not support lineDash
     */
    _setLineDash: function(ctx, dashArray, alternative) {
      if (!dashArray) {
        return;
      }
      // Spec requires the concatenation of two copies the dash list when the number of elements is odd
      if (1 & dashArray.length) {
        dashArray.push.apply(dashArray, dashArray);
      }
      if (supportsLineDash) {
        ctx.setLineDash(dashArray);
      }
      else {
        alternative && alternative(ctx);
      }
    },

    /**
     * Renders controls and borders for the object
     * @param {CanvasRenderingContext2D} ctx Context to render on
     * @param {Object} [styleOverride] properties to override the object style
     */
    _renderControls: function(ctx, styleOverride) {
      var vpt = this.getViewportTransform(),
          matrix = this.calcTransformMatrix(),
          options, drawBorders, drawControls;
      styleOverride = styleOverride || { };
      drawBorders = typeof styleOverride.hasBorders !== 'undefined' ? styleOverride.hasBorders : this.hasBorders;
      drawControls = typeof styleOverride.hasControls !== 'undefined' ? styleOverride.hasControls : this.hasControls;
      matrix = fabric.util.multiplyTransformMatrices(vpt, matrix);
      options = fabric.util.qrDecompose(matrix);
      ctx.save();
      ctx.translate(options.translateX, options.translateY);
      ctx.lineWidth = 1 * this.borderScaleFactor;
      if (!this.group) {
        ctx.globalAlpha = this.isMoving ? this.borderOpacityWhenMoving : 1;
      }
      if (styleOverride.forActiveSelection) {
        ctx.rotate(degreesToRadians(options.angle));
        drawBorders && this.drawBordersInGroup(ctx, options, styleOverride);
      }
      else {
        ctx.rotate(degreesToRadians(this.angle));
        drawBorders && this.drawBorders(ctx, styleOverride);
      }
      drawControls && this.drawControls(ctx, styleOverride);
      ctx.restore();
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _setShadow: function(ctx) {
      if (!this.shadow) {
        return;
      }

      var multX = (this.canvas && this.canvas.viewportTransform[0]) || 1,
          multY = (this.canvas && this.canvas.viewportTransform[3]) || 1,
          scaling = this.getObjectScaling();
      if (this.canvas && this.canvas._isRetinaScaling()) {
        multX *= fabric.devicePixelRatio;
        multY *= fabric.devicePixelRatio;
      }
      ctx.shadowColor = this.shadow.color;
      ctx.shadowBlur = this.shadow.blur * fabric.browserShadowBlurConstant *
        (multX + multY) * (scaling.scaleX + scaling.scaleY) / 4;
      ctx.shadowOffsetX = this.shadow.offsetX * multX * scaling.scaleX;
      ctx.shadowOffsetY = this.shadow.offsetY * multY * scaling.scaleY;
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _removeShadow: function(ctx) {
      if (!this.shadow) {
        return;
      }

      ctx.shadowColor = '';
      ctx.shadowBlur = ctx.shadowOffsetX = ctx.shadowOffsetY = 0;
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     * @param {Object} filler fabric.Pattern or fabric.Gradient
     */
    _applyPatternGradientTransform: function(ctx, filler) {
      if (!filler || !filler.toLive) {
        return { offsetX: 0, offsetY: 0 };
      }
      var t = filler.gradientTransform || filler.patternTransform;
      var offsetX = -this.width / 2 + filler.offsetX || 0,
          offsetY = -this.height / 2 + filler.offsetY || 0;
      ctx.translate(offsetX, offsetY);
      if (t) {
        ctx.transform(t[0], t[1], t[2], t[3], t[4], t[5]);
      }
      return { offsetX: offsetX, offsetY: offsetY };
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderPaintInOrder: function(ctx) {
      if (this.paintFirst === 'stroke') {
        this._renderStroke(ctx);
        this._renderFill(ctx);
      }
      else {
        this._renderFill(ctx);
        this._renderStroke(ctx);
      }
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderFill: function(ctx) {
      if (!this.fill) {
        return;
      }

      ctx.save();
      this._applyPatternGradientTransform(ctx, this.fill);
      if (this.fillRule === 'evenodd') {
        ctx.fill('evenodd');
      }
      else {
        ctx.fill();
      }
      ctx.restore();
    },

    _renderStroke: function(ctx) {
      if (!this.stroke || this.strokeWidth === 0) {
        return;
      }

      if (this.shadow && !this.shadow.affectStroke) {
        this._removeShadow(ctx);
      }

      ctx.save();
      this._setLineDash(ctx, this.strokeDashArray, this._renderDashedStroke);
      this._applyPatternGradientTransform(ctx, this.stroke);
      ctx.stroke();
      ctx.restore();
    },

    /**
     * This function is an helper for svg import. it returns the center of the object in the svg
     * untransformed coordinates
     * @private
     * @return {Object} center point from element coordinates
     */
    _findCenterFromElement: function() {
      return { x: this.left + this.width / 2, y: this.top + this.height / 2 };
    },

    /**
     * This function is an helper for svg import. it decoompose the transformMatrix
     * and assign properties to object.
     * untransformed coordinates
     * @private
     * @chainable
     */
    _assignTransformMatrixProps: function() {
      if (this.transformMatrix) {
        var options = fabric.util.qrDecompose(this.transformMatrix);
        this.flipX = false;
        this.flipY = false;
        this.set('scaleX', options.scaleX);
        this.set('scaleY', options.scaleY);
        this.angle = options.angle;
        this.skewX = options.skewX;
        this.skewY = 0;
      }
    },

    /**
     * This function is an helper for svg import. it removes the transform matrix
     * and set to object properties that fabricjs can handle
     * @private
     * @param {Object} preserveAspectRatioOptions
     * @return {thisArg}
     */
    _removeTransformMatrix: function(preserveAspectRatioOptions) {
      var center = this._findCenterFromElement();
      if (this.transformMatrix) {
        this._assignTransformMatrixProps();
        center = fabric.util.transformPoint(center, this.transformMatrix);
      }
      this.transformMatrix = null;
      if (preserveAspectRatioOptions) {
        this.scaleX *= preserveAspectRatioOptions.scaleX;
        this.scaleY *= preserveAspectRatioOptions.scaleY;
        this.cropX = preserveAspectRatioOptions.cropX;
        this.cropY = preserveAspectRatioOptions.cropY;
        center.x += preserveAspectRatioOptions.offsetLeft;
        center.y += preserveAspectRatioOptions.offsetTop;
        this.width = preserveAspectRatioOptions.width;
        this.height = preserveAspectRatioOptions.height;
      }
      this.setPositionByOrigin(center, 'center', 'center');
    },

    /**
     * Clones an instance, using a callback method will work for every object.
     * @param {Function} callback Callback is invoked with a clone as a first argument
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     */
    clone: function(callback, propertiesToInclude) {
      var objectForm = this.toObject(propertiesToInclude);
      if (this.constructor.fromObject) {
        this.constructor.fromObject(objectForm, callback);
      }
      else {
        fabric.Object._fromObject('Object', objectForm, callback);
      }
    },

    /**
     * Creates an instance of fabric.Image out of an object
     * @param {Function} callback callback, invoked with an instance as a first argument
     * @param {Object} [options] for clone as image, passed to toDataURL
     * @param {Boolean} [options.enableRetinaScaling] enable retina scaling for the cloned image
     * @return {fabric.Object} thisArg
     */
    cloneAsImage: function(callback, options) {
      var dataUrl = this.toDataURL(options);
      fabric.util.loadImage(dataUrl, function(img) {
        if (callback) {
          callback(new fabric.Image(img));
        }
      });
      return this;
    },

    /**
     * Converts an object into a data-url-like string
     * @param {Object} options Options object
     * @param {String} [options.format=png] The format of the output image. Either "jpeg" or "png"
     * @param {Number} [options.quality=1] Quality level (0..1). Only used for jpeg.
     * @param {Number} [options.multiplier=1] Multiplier to scale by
     * @param {Number} [options.left] Cropping left offset. Introduced in v1.2.14
     * @param {Number} [options.top] Cropping top offset. Introduced in v1.2.14
     * @param {Number} [options.width] Cropping width. Introduced in v1.2.14
     * @param {Number} [options.height] Cropping height. Introduced in v1.2.14
     * @param {Boolean} [options.enableRetinaScaling] Enable retina scaling for clone image. Introduce in 1.6.4
     * @return {String} Returns a data: URL containing a representation of the object in the format specified by options.format
     */
    toDataURL: function(options) {
      options || (options = { });

      var el = fabric.util.createCanvasElement(),
          boundingRect = this.getBoundingRect();

      el.width = boundingRect.width;
      el.height = boundingRect.height;
      fabric.util.wrapElement(el, 'div');
      var canvas = new fabric.StaticCanvas(el, {
        enableRetinaScaling: options.enableRetinaScaling,
        renderOnAddRemove: false,
        skipOffscreen: false,
      });
      // to avoid common confusion https://github.com/kangax/fabric.js/issues/806
      if (options.format === 'jpg') {
        options.format = 'jpeg';
      }

      if (options.format === 'jpeg') {
        canvas.backgroundColor = '#fff';
      }

      var origParams = {
        left: this.left,
        top: this.top
      };

      this.setPositionByOrigin(new fabric.Point(canvas.width / 2, canvas.height / 2), 'center', 'center');

      var originalCanvas = this.canvas;
      canvas.add(this);
      var data = canvas.toDataURL(options);
      this.set(origParams).setCoords();
      this.canvas = originalCanvas;
      // canvas.dispose will call image.dispose that will nullify the elements
      // since this canvas is a simple element for the process, we remove references
      // to objects in this way in order to avoid object trashing.
      canvas._objects = [];
      canvas.dispose();
      canvas = null;

      return data;
    },

    /**
     * Returns true if specified type is identical to the type of an instance
     * @param {String} type Type to check against
     * @return {Boolean}
     */
    isType: function(type) {
      return this.type === type;
    },

    /**
     * Returns complexity of an instance
     * @return {Number} complexity of this instance (is 1 unless subclassed)
     */
    complexity: function() {
      return 1;
    },

    /**
     * Returns a JSON representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} JSON
     */
    toJSON: function(propertiesToInclude) {
      // delegate, not alias
      return this.toObject(propertiesToInclude);
    },

    /**
     * Sets gradient (fill or stroke) of an object
     * <b>Backwards incompatibility note:</b> This method was named "setGradientFill" until v1.1.0
     * @param {String} property Property name 'stroke' or 'fill'
     * @param {Object} [options] Options object
     * @param {String} [options.type] Type of gradient 'radial' or 'linear'
     * @param {Number} [options.x1=0] x-coordinate of start point
     * @param {Number} [options.y1=0] y-coordinate of start point
     * @param {Number} [options.x2=0] x-coordinate of end point
     * @param {Number} [options.y2=0] y-coordinate of end point
     * @param {Number} [options.r1=0] Radius of start point (only for radial gradients)
     * @param {Number} [options.r2=0] Radius of end point (only for radial gradients)
     * @param {Object} [options.colorStops] Color stops object eg. {0: 'ff0000', 1: '000000'}
     * @param {Object} [options.gradientTransform] transforMatrix for gradient
     * @return {fabric.Object} thisArg
     * @chainable
     * @see {@link http://jsfiddle.net/fabricjs/58y8b/|jsFiddle demo}
     * @example <caption>Set linear gradient</caption>
     * object.setGradient('fill', {
     *   type: 'linear',
     *   x1: -object.width / 2,
     *   y1: 0,
     *   x2: object.width / 2,
     *   y2: 0,
     *   colorStops: {
     *     0: 'red',
     *     0.5: '#005555',
     *     1: 'rgba(0,0,255,0.5)'
     *   }
     * });
     * canvas.renderAll();
     * @example <caption>Set radial gradient</caption>
     * object.setGradient('fill', {
     *   type: 'radial',
     *   x1: 0,
     *   y1: 0,
     *   x2: 0,
     *   y2: 0,
     *   r1: object.width / 2,
     *   r2: 10,
     *   colorStops: {
     *     0: 'red',
     *     0.5: '#005555',
     *     1: 'rgba(0,0,255,0.5)'
     *   }
     * });
     * canvas.renderAll();
     */
    setGradient: function(property, options) {
      options || (options = { });

      var gradient = { colorStops: [] };

      gradient.type = options.type || (options.r1 || options.r2 ? 'radial' : 'linear');
      gradient.coords = {
        x1: options.x1,
        y1: options.y1,
        x2: options.x2,
        y2: options.y2
      };

      if (options.r1 || options.r2) {
        gradient.coords.r1 = options.r1;
        gradient.coords.r2 = options.r2;
      }

      gradient.gradientTransform = options.gradientTransform;
      fabric.Gradient.prototype.addColorStop.call(gradient, options.colorStops);

      return this.set(property, fabric.Gradient.forObject(this, gradient));
    },

    /**
     * Sets pattern fill of an object
     * @param {Object} options Options object
     * @param {(String|HTMLImageElement)} options.source Pattern source
     * @param {String} [options.repeat=repeat] Repeat property of a pattern (one of repeat, repeat-x, repeat-y or no-repeat)
     * @param {Number} [options.offsetX=0] Pattern horizontal offset from object's left/top corner
     * @param {Number} [options.offsetY=0] Pattern vertical offset from object's left/top corner
     * @return {fabric.Object} thisArg
     * @chainable
     * @see {@link http://jsfiddle.net/fabricjs/QT3pa/|jsFiddle demo}
     * @example <caption>Set pattern</caption>
     * fabric.util.loadImage('http://fabricjs.com/assets/escheresque_ste.png', function(img) {
     *   object.setPatternFill({
     *     source: img,
     *     repeat: 'repeat'
     *   });
     *   canvas.renderAll();
     * });
     */
    setPatternFill: function(options) {
      return this.set('fill', new fabric.Pattern(options));
    },

    /**
     * Sets {@link fabric.Object#shadow|shadow} of an object
     * @param {Object|String} [options] Options object or string (e.g. "2px 2px 10px rgba(0,0,0,0.2)")
     * @param {String} [options.color=rgb(0,0,0)] Shadow color
     * @param {Number} [options.blur=0] Shadow blur
     * @param {Number} [options.offsetX=0] Shadow horizontal offset
     * @param {Number} [options.offsetY=0] Shadow vertical offset
     * @return {fabric.Object} thisArg
     * @chainable
     * @see {@link http://jsfiddle.net/fabricjs/7gvJG/|jsFiddle demo}
     * @example <caption>Set shadow with string notation</caption>
     * object.setShadow('2px 2px 10px rgba(0,0,0,0.2)');
     * canvas.renderAll();
     * @example <caption>Set shadow with object notation</caption>
     * object.setShadow({
     *   color: 'red',
     *   blur: 10,
     *   offsetX: 20,
     *   offsetY: 20
     * });
     * canvas.renderAll();
     */
    setShadow: function(options) {
      return this.set('shadow', options ? new fabric.Shadow(options) : null);
    },

    /**
     * Sets "color" of an instance (alias of `set('fill', &hellip;)`)
     * @param {String} color Color value
     * @return {fabric.Object} thisArg
     * @chainable
     */
    setColor: function(color) {
      this.set('fill', color);
      return this;
    },

    /**
     * Sets "angle" of an instance with centered rotation
     * @param {Number} angle Angle value (in degrees)
     * @return {fabric.Object} thisArg
     * @chainable
     */
    rotate: function(angle) {
      var shouldCenterOrigin = (this.originX !== 'center' || this.originY !== 'center') && this.centeredRotation;

      if (shouldCenterOrigin) {
        this._setOriginToCenter();
      }

      this.set('angle', angle);

      if (shouldCenterOrigin) {
        this._resetOrigin();
      }

      return this;
    },

    /**
     * Centers object horizontally on canvas to which it was added last.
     * You might need to call `setCoords` on an object after centering, to update controls area.
     * @return {fabric.Object} thisArg
     * @chainable
     */
    centerH: function () {
      this.canvas && this.canvas.centerObjectH(this);
      return this;
    },

    /**
     * Centers object horizontally on current viewport of canvas to which it was added last.
     * You might need to call `setCoords` on an object after centering, to update controls area.
     * @return {fabric.Object} thisArg
     * @chainable
     */
    viewportCenterH: function () {
      this.canvas && this.canvas.viewportCenterObjectH(this);
      return this;
    },

    /**
     * Centers object vertically on canvas to which it was added last.
     * You might need to call `setCoords` on an object after centering, to update controls area.
     * @return {fabric.Object} thisArg
     * @chainable
     */
    centerV: function () {
      this.canvas && this.canvas.centerObjectV(this);
      return this;
    },

    /**
     * Centers object vertically on current viewport of canvas to which it was added last.
     * You might need to call `setCoords` on an object after centering, to update controls area.
     * @return {fabric.Object} thisArg
     * @chainable
     */
    viewportCenterV: function () {
      this.canvas && this.canvas.viewportCenterObjectV(this);
      return this;
    },

    /**
     * Centers object vertically and horizontally on canvas to which is was added last
     * You might need to call `setCoords` on an object after centering, to update controls area.
     * @return {fabric.Object} thisArg
     * @chainable
     */
    center: function () {
      this.canvas && this.canvas.centerObject(this);
      return this;
    },

    /**
     * Centers object on current viewport of canvas to which it was added last.
     * You might need to call `setCoords` on an object after centering, to update controls area.
     * @return {fabric.Object} thisArg
     * @chainable
     */
    viewportCenter: function () {
      this.canvas && this.canvas.viewportCenterObject(this);
      return this;
    },

    /**
     * Returns coordinates of a pointer relative to an object
     * @param {Event} e Event to operate upon
     * @param {Object} [pointer] Pointer to operate upon (instead of event)
     * @return {Object} Coordinates of a pointer (x, y)
     */
    getLocalPointer: function(e, pointer) {
      pointer = pointer || this.canvas.getPointer(e);
      var pClicked = new fabric.Point(pointer.x, pointer.y),
          objectLeftTop = this._getLeftTopCoords();
      if (this.angle) {
        pClicked = fabric.util.rotatePoint(
          pClicked, objectLeftTop, degreesToRadians(-this.angle));
      }
      return {
        x: pClicked.x - objectLeftTop.x,
        y: pClicked.y - objectLeftTop.y
      };
    },

    /**
     * Sets canvas globalCompositeOperation for specific object
     * custom composition operation for the particular object can be specifed using globalCompositeOperation property
     * @param {CanvasRenderingContext2D} ctx Rendering canvas context
     */
    _setupCompositeOperation: function (ctx) {
      if (this.globalCompositeOperation) {
        ctx.globalCompositeOperation = this.globalCompositeOperation;
      }
    }
  });

  fabric.util.createAccessors && fabric.util.createAccessors(fabric.Object);

  extend(fabric.Object.prototype, fabric.Observable);

  /**
   * Defines the number of fraction digits to use when serializing object values.
   * You can use it to increase/decrease precision of such values like left, top, scaleX, scaleY, etc.
   * @static
   * @memberOf fabric.Object
   * @constant
   * @type Number
   */
  fabric.Object.NUM_FRACTION_DIGITS = 2;

  fabric.Object._fromObject = function(className, object, callback, extraParam) {
    var klass = fabric[className];
    object = clone(object, true);
    fabric.util.enlivenPatterns([object.fill, object.stroke], function(patterns) {
      if (typeof patterns[0] !== 'undefined') {
        object.fill = patterns[0];
      }
      if (typeof patterns[1] !== 'undefined') {
        object.stroke = patterns[1];
      }
      var instance = extraParam ? new klass(object[extraParam], object) : new klass(object);
      callback && callback(instance);
    });
  };

  /**
   * Unique id used internally when creating SVG elements
   * @static
   * @memberOf fabric.Object
   * @type Number
   */
  fabric.Object.__uid = 0;

})(typeof exports !== 'undefined' ? exports : this);


(function() {

  var degreesToRadians = fabric.util.degreesToRadians,
      originXOffset = {
        left: -0.5,
        center: 0,
        right: 0.5
      },
      originYOffset = {
        top: -0.5,
        center: 0,
        bottom: 0.5
      };

  fabric.util.object.extend(fabric.Object.prototype, /** @lends fabric.Object.prototype */ {

    /**
     * Translates the coordinates from a set of origin to another (based on the object's dimensions)
     * @param {fabric.Point} point The point which corresponds to the originX and originY params
     * @param {String} fromOriginX Horizontal origin: 'left', 'center' or 'right'
     * @param {String} fromOriginY Vertical origin: 'top', 'center' or 'bottom'
     * @param {String} toOriginX Horizontal origin: 'left', 'center' or 'right'
     * @param {String} toOriginY Vertical origin: 'top', 'center' or 'bottom'
     * @return {fabric.Point}
     */
    translateToGivenOrigin: function(point, fromOriginX, fromOriginY, toOriginX, toOriginY) {
      var x = point.x,
          y = point.y,
          offsetX, offsetY, dim;

      if (typeof fromOriginX === 'string') {
        fromOriginX = originXOffset[fromOriginX];
      }
      else {
        fromOriginX -= 0.5;
      }

      if (typeof toOriginX === 'string') {
        toOriginX = originXOffset[toOriginX];
      }
      else {
        toOriginX -= 0.5;
      }

      offsetX = toOriginX - fromOriginX;

      if (typeof fromOriginY === 'string') {
        fromOriginY = originYOffset[fromOriginY];
      }
      else {
        fromOriginY -= 0.5;
      }

      if (typeof toOriginY === 'string') {
        toOriginY = originYOffset[toOriginY];
      }
      else {
        toOriginY -= 0.5;
      }

      offsetY = toOriginY - fromOriginY;

      if (offsetX || offsetY) {
        dim = this._getTransformedDimensions();
        x = point.x + offsetX * dim.x;
        y = point.y + offsetY * dim.y;
      }

      return new fabric.Point(x, y);
    },

    /**
     * Translates the coordinates from origin to center coordinates (based on the object's dimensions)
     * @param {fabric.Point} point The point which corresponds to the originX and originY params
     * @param {String} originX Horizontal origin: 'left', 'center' or 'right'
     * @param {String} originY Vertical origin: 'top', 'center' or 'bottom'
     * @return {fabric.Point}
     */
    translateToCenterPoint: function(point, originX, originY) {
      var p = this.translateToGivenOrigin(point, originX, originY, 'center', 'center');
      if (this.angle) {
        return fabric.util.rotatePoint(p, point, degreesToRadians(this.angle));
      }
      return p;
    },

    /**
     * Translates the coordinates from center to origin coordinates (based on the object's dimensions)
     * @param {fabric.Point} center The point which corresponds to center of the object
     * @param {String} originX Horizontal origin: 'left', 'center' or 'right'
     * @param {String} originY Vertical origin: 'top', 'center' or 'bottom'
     * @return {fabric.Point}
     */
    translateToOriginPoint: function(center, originX, originY) {
      var p = this.translateToGivenOrigin(center, 'center', 'center', originX, originY);
      if (this.angle) {
        return fabric.util.rotatePoint(p, center, degreesToRadians(this.angle));
      }
      return p;
    },

    /**
     * Returns the real center coordinates of the object
     * @return {fabric.Point}
     */
    getCenterPoint: function() {
      var leftTop = new fabric.Point(this.left, this.top);
      return this.translateToCenterPoint(leftTop, this.originX, this.originY);
    },

    /**
     * Returns the coordinates of the object based on center coordinates
     * @param {fabric.Point} point The point which corresponds to the originX and originY params
     * @return {fabric.Point}
     */
    // getOriginPoint: function(center) {
    //   return this.translateToOriginPoint(center, this.originX, this.originY);
    // },

    /**
     * Returns the coordinates of the object as if it has a different origin
     * @param {String} originX Horizontal origin: 'left', 'center' or 'right'
     * @param {String} originY Vertical origin: 'top', 'center' or 'bottom'
     * @return {fabric.Point}
     */
    getPointByOrigin: function(originX, originY) {
      var center = this.getCenterPoint();
      return this.translateToOriginPoint(center, originX, originY);
    },

    /**
     * Returns the point in local coordinates
     * @param {fabric.Point} point The point relative to the global coordinate system
     * @param {String} originX Horizontal origin: 'left', 'center' or 'right'
     * @param {String} originY Vertical origin: 'top', 'center' or 'bottom'
     * @return {fabric.Point}
     */
    toLocalPoint: function(point, originX, originY) {
      var center = this.getCenterPoint(),
          p, p2;

      if (typeof originX !== 'undefined' && typeof originY !== 'undefined' ) {
        p = this.translateToGivenOrigin(center, 'center', 'center', originX, originY);
      }
      else {
        p = new fabric.Point(this.left, this.top);
      }

      p2 = new fabric.Point(point.x, point.y);
      if (this.angle) {
        p2 = fabric.util.rotatePoint(p2, center, -degreesToRadians(this.angle));
      }
      return p2.subtractEquals(p);
    },

    /**
     * Returns the point in global coordinates
     * @param {fabric.Point} The point relative to the local coordinate system
     * @return {fabric.Point}
     */
    // toGlobalPoint: function(point) {
    //   return fabric.util.rotatePoint(point, this.getCenterPoint(), degreesToRadians(this.angle)).addEquals(new fabric.Point(this.left, this.top));
    // },

    /**
     * Sets the position of the object taking into consideration the object's origin
     * @param {fabric.Point} pos The new position of the object
     * @param {String} originX Horizontal origin: 'left', 'center' or 'right'
     * @param {String} originY Vertical origin: 'top', 'center' or 'bottom'
     * @return {void}
     */
    setPositionByOrigin: function(pos, originX, originY) {
      var center = this.translateToCenterPoint(pos, originX, originY),
          position = this.translateToOriginPoint(center, this.originX, this.originY);
      this.set('left', position.x);
      this.set('top', position.y);
    },

    /**
     * @param {String} to One of 'left', 'center', 'right'
     */
    adjustPosition: function(to) {
      var angle = degreesToRadians(this.angle),
          hypotFull = this.getScaledWidth(),
          xFull = fabric.util.cos(angle) * hypotFull,
          yFull = fabric.util.sin(angle) * hypotFull,
          offsetFrom, offsetTo;

      //TODO: this function does not consider mixed situation like top, center.
      if (typeof this.originX === 'string') {
        offsetFrom = originXOffset[this.originX];
      }
      else {
        offsetFrom = this.originX - 0.5;
      }
      if (typeof to === 'string') {
        offsetTo = originXOffset[to];
      }
      else {
        offsetTo = to - 0.5;
      }
      this.left += xFull * (offsetTo - offsetFrom);
      this.top += yFull * (offsetTo - offsetFrom);
      this.setCoords();
      this.originX = to;
    },

    /**
     * Sets the origin/position of the object to it's center point
     * @private
     * @return {void}
     */
    _setOriginToCenter: function() {
      this._originalOriginX = this.originX;
      this._originalOriginY = this.originY;

      var center = this.getCenterPoint();

      this.originX = 'center';
      this.originY = 'center';

      this.left = center.x;
      this.top = center.y;
    },

    /**
     * Resets the origin/position of the object to it's original origin
     * @private
     * @return {void}
     */
    _resetOrigin: function() {
      var originPoint = this.translateToOriginPoint(
        this.getCenterPoint(),
        this._originalOriginX,
        this._originalOriginY);

      this.originX = this._originalOriginX;
      this.originY = this._originalOriginY;

      this.left = originPoint.x;
      this.top = originPoint.y;

      this._originalOriginX = null;
      this._originalOriginY = null;
    },

    /**
     * @private
     */
    _getLeftTopCoords: function() {
      return this.translateToOriginPoint(this.getCenterPoint(), 'left', 'top');
    },
  });

})();


(function() {

  function getCoords(coords) {
    return [
      new fabric.Point(coords.tl.x, coords.tl.y),
      new fabric.Point(coords.tr.x, coords.tr.y),
      new fabric.Point(coords.br.x, coords.br.y),
      new fabric.Point(coords.bl.x, coords.bl.y)
    ];
  }

  var degreesToRadians = fabric.util.degreesToRadians,
      multiplyMatrices = fabric.util.multiplyTransformMatrices,
      transformPoint = fabric.util.transformPoint;

  fabric.util.object.extend(fabric.Object.prototype, /** @lends fabric.Object.prototype */ {

    /**
     * Describe object's corner position in canvas element coordinates.
     * properties are tl,mt,tr,ml,mr,bl,mb,br,mtr for the main controls.
     * each property is an object with x, y and corner.
     * The `corner` property contains in a similar manner the 4 points of the
     * interactive area of the corner.
     * The coordinates depends from this properties: width, height, scaleX, scaleY
     * skewX, skewY, angle, strokeWidth, viewportTransform, top, left, padding.
     * The coordinates get updated with @method setCoords.
     * You can calculate them without updating with @method calcCoords;
     * @memberOf fabric.Object.prototype
     */
    oCoords: null,

    /**
     * Describe object's corner position in canvas object absolute coordinates
     * properties are tl,tr,bl,br and describe the four main corner.
     * each property is an object with x, y, instance of Fabric.Point.
     * The coordinates depends from this properties: width, height, scaleX, scaleY
     * skewX, skewY, angle, strokeWidth, top, left.
     * Those coordinates are usefull to understand where an object is. They get updated
     * with oCoords but they do not need to be updated when zoom or panning change.
     * The coordinates get updated with @method setCoords.
     * You can calculate them without updating with @method calcCoords(true);
     * @memberOf fabric.Object.prototype
     */
    aCoords: null,

    /**
     * storage for object transform matrix
     */
    ownMatrixCache: null,

    /**
     * storage for object full transform matrix
     */
    matrixCache: null,

    /**
     * return correct set of coordinates for intersection
     */
    getCoords: function(absolute, calculate) {
      if (!this.oCoords) {
        this.setCoords();
      }
      var coords = absolute ? this.aCoords : this.oCoords;
      return getCoords(calculate ? this.calcCoords(absolute) : coords);
    },

    /**
     * Checks if object intersects with an area formed by 2 points
     * @param {Object} pointTL top-left point of area
     * @param {Object} pointBR bottom-right point of area
     * @param {Boolean} [absolute] use coordinates without viewportTransform
     * @param {Boolean} [calculate] use coordinates of current position instead of .oCoords
     * @return {Boolean} true if object intersects with an area formed by 2 points
     */
    intersectsWithRect: function(pointTL, pointBR, absolute, calculate) {
      var coords = this.getCoords(absolute, calculate),
          intersection = fabric.Intersection.intersectPolygonRectangle(
            coords,
            pointTL,
            pointBR
          );
      return intersection.status === 'Intersection';
    },

    /**
     * Checks if object intersects with another object
     * @param {Object} other Object to test
     * @param {Boolean} [absolute] use coordinates without viewportTransform
     * @param {Boolean} [calculate] use coordinates of current position instead of .oCoords
     * @return {Boolean} true if object intersects with another object
     */
    intersectsWithObject: function(other, absolute, calculate) {
      var intersection = fabric.Intersection.intersectPolygonPolygon(
        this.getCoords(absolute, calculate),
        other.getCoords(absolute, calculate)
      );

      return intersection.status === 'Intersection'
        || other.isContainedWithinObject(this, absolute, calculate)
        || this.isContainedWithinObject(other, absolute, calculate);
    },

    /**
     * Checks if object is fully contained within area of another object
     * @param {Object} other Object to test
     * @param {Boolean} [absolute] use coordinates without viewportTransform
     * @param {Boolean} [calculate] use coordinates of current position instead of .oCoords
     * @return {Boolean} true if object is fully contained within area of another object
     */
    isContainedWithinObject: function(other, absolute, calculate) {
      var points = this.getCoords(absolute, calculate),
          i = 0, lines = other._getImageLines(
            calculate ? other.calcCoords(absolute) : absolute ? other.aCoords : other.oCoords
          );
      for (; i < 4; i++) {
        if (!other.containsPoint(points[i], lines)) {
          return false;
        }
      }
      return true;
    },

    /**
     * Checks if object is fully contained within area formed by 2 points
     * @param {Object} pointTL top-left point of area
     * @param {Object} pointBR bottom-right point of area
     * @param {Boolean} [absolute] use coordinates without viewportTransform
     * @param {Boolean} [calculate] use coordinates of current position instead of .oCoords
     * @return {Boolean} true if object is fully contained within area formed by 2 points
     */
    isContainedWithinRect: function(pointTL, pointBR, absolute, calculate) {
      var boundingRect = this.getBoundingRect(absolute, calculate);

      return (
        boundingRect.left >= pointTL.x &&
        boundingRect.left + boundingRect.width <= pointBR.x &&
        boundingRect.top >= pointTL.y &&
        boundingRect.top + boundingRect.height <= pointBR.y
      );
    },

    /**
     * Checks if point is inside the object
     * @param {fabric.Point} point Point to check against
     * @param {Object} [lines] object returned from @method _getImageLines
     * @param {Boolean} [absolute] use coordinates without viewportTransform
     * @param {Boolean} [calculate] use coordinates of current position instead of .oCoords
     * @return {Boolean} true if point is inside the object
     */
    containsPoint: function(point, lines, absolute, calculate) {
      var lines = lines || this._getImageLines(
            calculate ? this.calcCoords(absolute) : absolute ? this.aCoords : this.oCoords
          ),
          xPoints = this._findCrossPoints(point, lines);

      // if xPoints is odd then point is inside the object
      return (xPoints !== 0 && xPoints % 2 === 1);
    },

    /**
     * Checks if object is contained within the canvas with current viewportTransform
     * the check is done stopping at first point that appears on screen
     * @param {Boolean} [calculate] use coordinates of current position instead of .oCoords
     * @return {Boolean} true if object is fully or partially contained within canvas
     */
    isOnScreen: function(calculate) {
      if (!this.canvas) {
        return false;
      }
      var pointTL = this.canvas.vptCoords.tl, pointBR = this.canvas.vptCoords.br;
      var points = this.getCoords(true, calculate), point;
      for (var i = 0; i < 4; i++) {
        point = points[i];
        if (point.x <= pointBR.x && point.x >= pointTL.x && point.y <= pointBR.y && point.y >= pointTL.y) {
          return true;
        }
      }
      // no points on screen, check intersection with absolute coordinates
      if (this.intersectsWithRect(pointTL, pointBR, true, calculate)) {
        return true;
      }
      return this._containsCenterOfCanvas(pointTL, pointBR, calculate);
    },

    /**
     * Checks if the object contains the midpoint between canvas extremities
     * Does not make sense outside the context of isOnScreen and isPartiallyOnScreen
     * @private
     * @param {Fabric.Point} pointTL Top Left point
     * @param {Fabric.Point} pointBR Top Right point
     * @param {Boolean} calculate use coordinates of current position instead of .oCoords
     * @return {Boolean} true if the objects containe the point
     */
    _containsCenterOfCanvas: function(pointTL, pointBR, calculate) {
      // worst case scenario the object is so big that contains the screen
      var centerPoint = { x: (pointTL.x + pointBR.x) / 2, y: (pointTL.y + pointBR.y) / 2 };
      if (this.containsPoint(centerPoint, null, true, calculate)) {
        return true;
      }
      return false;
    },

    /**
     * Checks if object is partially contained within the canvas with current viewportTransform
     * @param {Boolean} [calculate] use coordinates of current position instead of .oCoords
     * @return {Boolean} true if object is partially contained within canvas
     */
    isPartiallyOnScreen: function(calculate) {
      if (!this.canvas) {
        return false;
      }
      var pointTL = this.canvas.vptCoords.tl, pointBR = this.canvas.vptCoords.br;
      if (this.intersectsWithRect(pointTL, pointBR, true, calculate)) {
        return true;
      }
      return this._containsCenterOfCanvas(pointTL, pointBR, calculate);
    },

    /**
     * Method that returns an object with the object edges in it, given the coordinates of the corners
     * @private
     * @param {Object} oCoords Coordinates of the object corners
     */
    _getImageLines: function(oCoords) {
      return {
        topline: {
          o: oCoords.tl,
          d: oCoords.tr
        },
        rightline: {
          o: oCoords.tr,
          d: oCoords.br
        },
        bottomline: {
          o: oCoords.br,
          d: oCoords.bl
        },
        leftline: {
          o: oCoords.bl,
          d: oCoords.tl
        }
      };
    },

    /**
     * Helper method to determine how many cross points are between the 4 object edges
     * and the horizontal line determined by a point on canvas
     * @private
     * @param {fabric.Point} point Point to check
     * @param {Object} lines Coordinates of the object being evaluated
     */
    // remove yi, not used but left code here just in case.
    _findCrossPoints: function(point, lines) {
      var b1, b2, a1, a2, xi, // yi,
          xcount = 0,
          iLine;

      for (var lineKey in lines) {
        iLine = lines[lineKey];
        // optimisation 1: line below point. no cross
        if ((iLine.o.y < point.y) && (iLine.d.y < point.y)) {
          continue;
        }
        // optimisation 2: line above point. no cross
        if ((iLine.o.y >= point.y) && (iLine.d.y >= point.y)) {
          continue;
        }
        // optimisation 3: vertical line case
        if ((iLine.o.x === iLine.d.x) && (iLine.o.x >= point.x)) {
          xi = iLine.o.x;
          // yi = point.y;
        }
        // calculate the intersection point
        else {
          b1 = 0;
          b2 = (iLine.d.y - iLine.o.y) / (iLine.d.x - iLine.o.x);
          a1 = point.y - b1 * point.x;
          a2 = iLine.o.y - b2 * iLine.o.x;

          xi = -(a1 - a2) / (b1 - b2);
          // yi = a1 + b1 * xi;
        }
        // dont count xi < point.x cases
        if (xi >= point.x) {
          xcount += 1;
        }
        // optimisation 4: specific for square images
        if (xcount === 2) {
          break;
        }
      }
      return xcount;
    },

    /**
     * Returns coordinates of object's bounding rectangle (left, top, width, height)
     * the box is intented as aligned to axis of canvas.
     * @param {Boolean} [absolute] use coordinates without viewportTransform
     * @param {Boolean} [calculate] use coordinates of current position instead of .oCoords / .aCoords
     * @return {Object} Object with left, top, width, height properties
     */
    getBoundingRect: function(absolute, calculate) {
      var coords = this.getCoords(absolute, calculate);
      return fabric.util.makeBoundingBoxFromPoints(coords);
    },

    /**
     * Returns width of an object bounding box counting transformations
     * before 2.0 it was named getWidth();
     * @return {Number} width value
     */
    getScaledWidth: function() {
      return this._getTransformedDimensions().x;
    },

    /**
     * Returns height of an object bounding box counting transformations
     * before 2.0 it was named getHeight();
     * @return {Number} height value
     */
    getScaledHeight: function() {
      return this._getTransformedDimensions().y;
    },

    /**
     * Makes sure the scale is valid and modifies it if necessary
     * @private
     * @param {Number} value
     * @return {Number}
     */
    _constrainScale: function(value) {
      if (Math.abs(value) < this.minScaleLimit) {
        if (value < 0) {
          return -this.minScaleLimit;
        }
        else {
          return this.minScaleLimit;
        }
      }
      else if (value === 0) {
        return 0.0001;
      }
      return value;
    },

    /**
     * Scales an object (equally by x and y)
     * @param {Number} value Scale factor
     * @return {fabric.Object} thisArg
     * @chainable
     */
    scale: function(value) {
      this._set('scaleX', value);
      this._set('scaleY', value);
      return this.setCoords();
    },

    /**
     * Scales an object to a given width, with respect to bounding box (scaling by x/y equally)
     * @param {Number} value New width value
     * @param {Boolean} absolute ignore viewport
     * @return {fabric.Object} thisArg
     * @chainable
     */
    scaleToWidth: function(value, absolute) {
      // adjust to bounding rect factor so that rotated shapes would fit as well
      var boundingRectFactor = this.getBoundingRect(absolute).width / this.getScaledWidth();
      return this.scale(value / this.width / boundingRectFactor);
    },

    /**
     * Scales an object to a given height, with respect to bounding box (scaling by x/y equally)
     * @param {Number} value New height value
     * @param {Boolean} absolute ignore viewport
     * @return {fabric.Object} thisArg
     * @chainable
     */
    scaleToHeight: function(value, absolute) {
      // adjust to bounding rect factor so that rotated shapes would fit as well
      var boundingRectFactor = this.getBoundingRect(absolute).height / this.getScaledHeight();
      return this.scale(value / this.height / boundingRectFactor);
    },

    /**
     * Calculate and returns the .coords of an object.
     * @return {Object} Object with tl, tr, br, bl ....
     * @chainable
     */
    calcCoords: function(absolute) {
      var rotateMatrix = this._calcRotateMatrix(),
          translateMatrix = this._calcTranslateMatrix(),
          startMatrix = multiplyMatrices(translateMatrix, rotateMatrix),
          vpt = this.getViewportTransform(),
          finalMatrix = absolute ? startMatrix : multiplyMatrices(vpt, startMatrix),
          dim = this._getTransformedDimensions(),
          w = dim.x / 2, h = dim.y / 2,
          tl = transformPoint({ x: -w, y: -h }, finalMatrix),
          tr = transformPoint({ x: w, y: -h }, finalMatrix),
          bl = transformPoint({ x: -w, y: h }, finalMatrix),
          br = transformPoint({ x: w, y: h }, finalMatrix);
      if (!absolute) {
        var padding = this.padding, angle = degreesToRadians(this.angle),
            cos = fabric.util.cos(angle), sin = fabric.util.sin(angle),
            cosP = cos * padding, sinP = sin * padding, cosPSinP = cosP + sinP,
            cosPMinusSinP = cosP - sinP;
        if (padding) {
          tl.x -= cosPMinusSinP;
          tl.y -= cosPSinP;
          tr.x += cosPSinP;
          tr.y -= cosPMinusSinP;
          bl.x -= cosPSinP;
          bl.y += cosPMinusSinP;
          br.x += cosPMinusSinP;
          br.y += cosPSinP;
        }
        var ml  = new fabric.Point((tl.x + bl.x) / 2, (tl.y + bl.y) / 2),
            mt  = new fabric.Point((tr.x + tl.x) / 2, (tr.y + tl.y) / 2),
            mr  = new fabric.Point((br.x + tr.x) / 2, (br.y + tr.y) / 2),
            mb  = new fabric.Point((br.x + bl.x) / 2, (br.y + bl.y) / 2),
            mtr = new fabric.Point(mt.x + sin * this.rotatingPointOffset, mt.y - cos * this.rotatingPointOffset);
      }

      // if (!absolute) {
      //   var canvas = this.canvas;
      //   setTimeout(function() {
      //     canvas.contextTop.clearRect(0, 0, 700, 700);
      //     canvas.contextTop.fillStyle = 'green';
      //     canvas.contextTop.fillRect(mb.x, mb.y, 3, 3);
      //     canvas.contextTop.fillRect(bl.x, bl.y, 3, 3);
      //     canvas.contextTop.fillRect(br.x, br.y, 3, 3);
      //     canvas.contextTop.fillRect(tl.x, tl.y, 3, 3);
      //     canvas.contextTop.fillRect(tr.x, tr.y, 3, 3);
      //     canvas.contextTop.fillRect(ml.x, ml.y, 3, 3);
      //     canvas.contextTop.fillRect(mr.x, mr.y, 3, 3);
      //     canvas.contextTop.fillRect(mt.x, mt.y, 3, 3);
      //     canvas.contextTop.fillRect(mtr.x, mtr.y, 3, 3);
      //   }, 50);
      // }

      var coords = {
        // corners
        tl: tl, tr: tr, br: br, bl: bl,
      };
      if (!absolute) {
        // middle
        coords.ml = ml;
        coords.mt = mt;
        coords.mr = mr;
        coords.mb = mb;
        // rotating point
        coords.mtr = mtr;
      }
      return coords;
    },

    /**
     * Sets corner position coordinates based on current angle, width and height
     * See https://github.com/kangax/fabric.js/wiki/When-to-call-setCoords
     * @param {Boolean} [ignoreZoom] set oCoords with or without the viewport transform.
     * @param {Boolean} [skipAbsolute] skip calculation of aCoords, usefull in setViewportTransform
     * @return {fabric.Object} thisArg
     * @chainable
     */
    setCoords: function(ignoreZoom, skipAbsolute) {
      this.oCoords = this.calcCoords(ignoreZoom);
      if (!skipAbsolute) {
        this.aCoords = this.calcCoords(true);
      }

      // set coordinates of the draggable boxes in the corners used to scale/rotate the image
      ignoreZoom || (this._setCornerCoords && this._setCornerCoords());

      return this;
    },

    /**
     * calculate rotation matrix of an object
     * @return {Array} rotation matrix for the object
     */
    _calcRotateMatrix: function() {
      if (this.angle) {
        var theta = degreesToRadians(this.angle), cos = fabric.util.cos(theta), sin = fabric.util.sin(theta);
        return [cos, sin, -sin, cos, 0, 0];
      }
      return fabric.iMatrix.concat();
    },

    /**
     * calculate the translation matrix for an object transform
     * @return {Array} rotation matrix for the object
     */
    _calcTranslateMatrix: function() {
      var center = this.getCenterPoint();
      return [1, 0, 0, 1, center.x, center.y];
    },

    transformMatrixKey: function(skipGroup) {
      var sep = '_', prefix = '';
      if (!skipGroup && this.group) {
        prefix = this.group.transformMatrixKey(skipGroup) + sep;
      };
      return prefix + this.top + sep + this.left + sep + this.scaleX + sep + this.scaleY +
        sep + this.skewX + sep + this.skewY + sep + this.angle + sep + this.originX + sep + this.originY +
        sep + this.width + sep + this.height + sep + this.strokeWidth + this.flipX + this.flipY;
    },

    /**
     * calculate trasform Matrix that represent current transformation from
     * object properties.
     * @param {Boolean} [skipGroup] return transformMatrix for object and not go upward with parents
     * @return {Array} matrix Transform Matrix for the object
     */
    calcTransformMatrix: function(skipGroup) {
      if (skipGroup) {
        return this.calcOwnMatrix();
      }
      var key = this.transformMatrixKey(), cache = this.matrixCache || (this.matrixCache = {});
      if (cache.key === key) {
        return cache.value;
      }
      var matrix = this.calcOwnMatrix();
      if (this.group) {
        matrix = multiplyMatrices(this.group.calcTransformMatrix(), matrix);
      }
      cache.key = key;
      cache.value = matrix;
      return matrix;
    },

    calcOwnMatrix: function() {
      var key = this.transformMatrixKey(true), cache = this.ownMatrixCache || (this.ownMatrixCache = {});
      if (cache.key === key) {
        return cache.value;
      }
      var matrix = this._calcTranslateMatrix(),
          rotateMatrix,
          dimensionMatrix = this._calcDimensionsTransformMatrix(this.skewX, this.skewY, true);
      if (this.angle) {
        rotateMatrix = this._calcRotateMatrix();
        matrix = multiplyMatrices(matrix, rotateMatrix);
      }
      matrix = multiplyMatrices(matrix, dimensionMatrix);
      cache.key = key;
      cache.value = matrix;
      return matrix;
    },

    _calcDimensionsTransformMatrix: function(skewX, skewY, flipping) {
      var skewMatrix,
          scaleX = this.scaleX * (flipping && this.flipX ? -1 : 1),
          scaleY = this.scaleY * (flipping && this.flipY ? -1 : 1),
          scaleMatrix = [scaleX, 0, 0, scaleY, 0, 0];
      if (skewX) {
        skewMatrix = [1, 0, Math.tan(degreesToRadians(skewX)), 1];
        scaleMatrix = multiplyMatrices(scaleMatrix, skewMatrix, true);
      }
      if (skewY) {
        skewMatrix = [1, Math.tan(degreesToRadians(skewY)), 0, 1];
        scaleMatrix = multiplyMatrices(scaleMatrix, skewMatrix, true);
      }
      return scaleMatrix;
    },


    /*
     * Calculate object dimensions from its properties
     * @private
     * @return {Object} .x width dimension
     * @return {Object} .y height dimension
     */
    _getNonTransformedDimensions: function() {
      var strokeWidth = this.strokeWidth,
          w = this.width + strokeWidth,
          h = this.height + strokeWidth;
      return { x: w, y: h };
    },

    /*
     * Calculate object bounding boxdimensions from its properties scale, skew.
     * @private
     * @return {Object} .x width dimension
     * @return {Object} .y height dimension
     */
    _getTransformedDimensions: function(skewX, skewY) {
      if (typeof skewX === 'undefined') {
        skewX = this.skewX;
      }
      if (typeof skewY === 'undefined') {
        skewY = this.skewY;
      }
      var dimensions = this._getNonTransformedDimensions();
      if (skewX === 0 && skewY === 0) {
        return { x: dimensions.x * this.scaleX, y: dimensions.y * this.scaleY };
      }
      var dimX = dimensions.x / 2, dimY = dimensions.y / 2,
          points = [
            {
              x: -dimX,
              y: -dimY
            },
            {
              x: dimX,
              y: -dimY
            },
            {
              x: -dimX,
              y: dimY
            },
            {
              x: dimX,
              y: dimY
            }],
          i, transformMatrix = this._calcDimensionsTransformMatrix(skewX, skewY, false),
          bbox;
      for (i = 0; i < points.length; i++) {
        points[i] = fabric.util.transformPoint(points[i], transformMatrix);
      }
      bbox = fabric.util.makeBoundingBoxFromPoints(points);
      return { x: bbox.width, y: bbox.height };
    },

    /*
     * Calculate object dimensions for controls. include padding and canvas zoom
     * private
     */
    _calculateCurrentDimensions: function()  {
      var vpt = this.getViewportTransform(),
          dim = this._getTransformedDimensions(),
          p = fabric.util.transformPoint(dim, vpt, true);

      return p.scalarAdd(2 * this.padding);
    },
  });
})();


fabric.util.object.extend(fabric.Object.prototype, /** @lends fabric.Object.prototype */ {

  /**
   * Moves an object to the bottom of the stack of drawn objects
   * @return {fabric.Object} thisArg
   * @chainable
   */
  sendToBack: function() {
    if (this.group) {
      fabric.StaticCanvas.prototype.sendToBack.call(this.group, this);
    }
    else {
      this.canvas.sendToBack(this);
    }
    return this;
  },

  /**
   * Moves an object to the top of the stack of drawn objects
   * @return {fabric.Object} thisArg
   * @chainable
   */
  bringToFront: function() {
    if (this.group) {
      fabric.StaticCanvas.prototype.bringToFront.call(this.group, this);
    }
    else {
      this.canvas.bringToFront(this);
    }
    return this;
  },

  /**
   * Moves an object down in stack of drawn objects
   * @param {Boolean} [intersecting] If `true`, send object behind next lower intersecting object
   * @return {fabric.Object} thisArg
   * @chainable
   */
  sendBackwards: function(intersecting) {
    if (this.group) {
      fabric.StaticCanvas.prototype.sendBackwards.call(this.group, this, intersecting);
    }
    else {
      this.canvas.sendBackwards(this, intersecting);
    }
    return this;
  },

  /**
   * Moves an object up in stack of drawn objects
   * @param {Boolean} [intersecting] If `true`, send object in front of next upper intersecting object
   * @return {fabric.Object} thisArg
   * @chainable
   */
  bringForward: function(intersecting) {
    if (this.group) {
      fabric.StaticCanvas.prototype.bringForward.call(this.group, this, intersecting);
    }
    else {
      this.canvas.bringForward(this, intersecting);
    }
    return this;
  },

  /**
   * Moves an object to specified level in stack of drawn objects
   * @param {Number} index New position of object
   * @return {fabric.Object} thisArg
   * @chainable
   */
  moveTo: function(index) {
    if (this.group && this.group.type !== 'activeSelection') {
      fabric.StaticCanvas.prototype.moveTo.call(this.group, this, index);
    }
    else {
      this.canvas.moveTo(this, index);
    }
    return this;
  }
});


/* _TO_SVG_START_ */
(function() {
  function getSvgColorString(prop, value) {
    if (!value) {
      return prop + ': none; ';
    }
    else if (value.toLive) {
      return prop + ': url(#SVGID_' + value.id + '); ';
    }
    else {
      var color = new fabric.Color(value),
          str = prop + ': ' + color.toRgb() + '; ',
          opacity = color.getAlpha();
      if (opacity !== 1) {
        //change the color in rgb + opacity
        str += prop + '-opacity: ' + opacity.toString() + '; ';
      }
      return str;
    }
  }

  var toFixed = fabric.util.toFixed;

  fabric.util.object.extend(fabric.Object.prototype, /** @lends fabric.Object.prototype */ {
    /**
     * Returns styles-string for svg-export
     * @param {Boolean} skipShadow a boolean to skip shadow filter output
     * @return {String}
     */
    getSvgStyles: function(skipShadow) {

      var fillRule = this.fillRule,
          strokeWidth = this.strokeWidth ? this.strokeWidth : '0',
          strokeDashArray = this.strokeDashArray ? this.strokeDashArray.join(' ') : 'none',
          strokeLineCap = this.strokeLineCap ? this.strokeLineCap : 'butt',
          strokeLineJoin = this.strokeLineJoin ? this.strokeLineJoin : 'miter',
          strokeMiterLimit = this.strokeMiterLimit ? this.strokeMiterLimit : '4',
          opacity = typeof this.opacity !== 'undefined' ? this.opacity : '1',
          visibility = this.visible ? '' : ' visibility: hidden;',
          filter = skipShadow ? '' : this.getSvgFilter(),
          fill = getSvgColorString('fill', this.fill),
          stroke = getSvgColorString('stroke', this.stroke);

      return [
        stroke,
        'stroke-width: ', strokeWidth, '; ',
        'stroke-dasharray: ', strokeDashArray, '; ',
        'stroke-linecap: ', strokeLineCap, '; ',
        'stroke-linejoin: ', strokeLineJoin, '; ',
        'stroke-miterlimit: ', strokeMiterLimit, '; ',
        fill,
        'fill-rule: ', fillRule, '; ',
        'opacity: ', opacity, ';',
        filter,
        visibility
      ].join('');
    },

    /**
     * Returns styles-string for svg-export
     * @param {Object} style the object from which to retrieve style properties
     * @param {Boolean} useWhiteSpace a boolean to include an additional attribute in the style.
     * @return {String}
     */
    getSvgSpanStyles: function(style, useWhiteSpace) {
      var term = '; ';
      var fontFamily = style.fontFamily ?
        'font-family: ' + (((style.fontFamily.indexOf('\'') === -1 && style.fontFamily.indexOf('"') === -1) ?
          '\'' + style.fontFamily  + '\'' : style.fontFamily)) + term : '';
      var strokeWidth = style.strokeWidth ? 'stroke-width: ' + style.strokeWidth + term : '',
          fontFamily = fontFamily,
          fontSize = style.fontSize ? 'font-size: ' + style.fontSize + 'px' + term : '',
          fontStyle = style.fontStyle ? 'font-style: ' + style.fontStyle + term : '',
          fontWeight = style.fontWeight ? 'font-weight: ' + style.fontWeight + term : '',
          fill = style.fill ? getSvgColorString('fill', style.fill) : '',
          stroke = style.stroke ? getSvgColorString('stroke', style.stroke) : '',
          textDecoration = this.getSvgTextDecoration(style),
          deltaY = style.deltaY ? 'baseline-shift: ' + (-style.deltaY) + '; ' : '';
      if (textDecoration) {
        textDecoration = 'text-decoration: ' + textDecoration + term;
      }

      return [
        stroke,
        strokeWidth,
        fontFamily,
        fontSize,
        fontStyle,
        fontWeight,
        textDecoration,
        fill,
        deltaY,
        useWhiteSpace ? 'white-space: pre; ' : ''
      ].join('');
    },

    /**
     * Returns text-decoration property for svg-export
     * @param {Object} style the object from which to retrieve style properties
     * @return {String}
     */
    getSvgTextDecoration: function(style) {
      if ('overline' in style || 'underline' in style || 'linethrough' in style) {
        return (style.overline ? 'overline ' : '') +
          (style.underline ? 'underline ' : '') + (style.linethrough ? 'line-through ' : '');
      }
      return '';
    },

    /**
     * Returns filter for svg shadow
     * @return {String}
     */
    getSvgFilter: function() {
      return this.shadow ? 'filter: url(#SVGID_' + this.shadow.id + ');' : '';
    },

    /**
     * Returns id attribute for svg output
     * @return {String}
     */
    getSvgId: function() {
      return this.id ? 'id="' + this.id + '" ' : '';
    },

    /**
     * Returns transform-string for svg-export
     * @return {String}
     */
    getSvgTransform: function() {
      var angle = this.angle,
          skewX = (this.skewX % 360),
          skewY = (this.skewY % 360),
          center = this.getCenterPoint(),

          NUM_FRACTION_DIGITS = fabric.Object.NUM_FRACTION_DIGITS,

          translatePart = 'translate(' +
                            toFixed(center.x, NUM_FRACTION_DIGITS) +
                            ' ' +
                            toFixed(center.y, NUM_FRACTION_DIGITS) +
                          ')',

          anglePart = angle !== 0
            ? (' rotate(' + toFixed(angle, NUM_FRACTION_DIGITS) + ')')
            : '',

          scalePart = (this.scaleX === 1 && this.scaleY === 1)
            ? '' :
            (' scale(' +
              toFixed(this.scaleX, NUM_FRACTION_DIGITS) +
              ' ' +
              toFixed(this.scaleY, NUM_FRACTION_DIGITS) +
            ')'),

          skewXPart = skewX !== 0 ? ' skewX(' + toFixed(skewX, NUM_FRACTION_DIGITS) + ')' : '',

          skewYPart = skewY !== 0 ? ' skewY(' + toFixed(skewY, NUM_FRACTION_DIGITS) + ')' : '',

          flipXPart = this.flipX ? ' matrix(-1 0 0 1 0 0) ' : '',

          flipYPart = this.flipY ? ' matrix(1 0 0 -1 0 0)' : '';

      return [
        translatePart, anglePart, scalePart, flipXPart, flipYPart, skewXPart, skewYPart
      ].join('');
    },

    /**
     * Returns transform-string for svg-export from the transform matrix of single elements
     * @return {String}
     */
    getSvgTransformMatrix: function() {
      return this.transformMatrix ? ' matrix(' + this.transformMatrix.join(' ') + ') ' : '';
    },

    _setSVGBg: function(textBgRects) {
      if (this.backgroundColor) {
        var NUM_FRACTION_DIGITS = fabric.Object.NUM_FRACTION_DIGITS;
        textBgRects.push(
          '\t\t<rect ',
          this._getFillAttributes(this.backgroundColor),
          ' x="',
          toFixed(-this.width / 2, NUM_FRACTION_DIGITS),
          '" y="',
          toFixed(-this.height / 2, NUM_FRACTION_DIGITS),
          '" width="',
          toFixed(this.width, NUM_FRACTION_DIGITS),
          '" height="',
          toFixed(this.height, NUM_FRACTION_DIGITS),
          '"></rect>\n');
      }
    },

    /**
     * @private
     */
    _createBaseSVGMarkup: function() {
      var markup = [];

      if (this.fill && this.fill.toLive) {
        markup.push(this.fill.toSVG(this, false));
      }
      if (this.stroke && this.stroke.toLive) {
        markup.push(this.stroke.toSVG(this, false));
      }
      if (this.shadow) {
        markup.push(this.shadow.toSVG(this));
      }
      return markup;
    },

    addPaintOrder: function() {
      return this.paintFirst !== 'fill' ? ' paint-order="' + this.paintFirst + '" ' : '';
    }
  });
})();
/* _TO_SVG_END_ */


(function() {

  var extend = fabric.util.object.extend,
      originalSet = 'stateProperties';

  /*
    Depends on `stateProperties`
  */
  function saveProps(origin, destination, props) {
    var tmpObj = { }, deep = true;
    props.forEach(function(prop) {
      tmpObj[prop] = origin[prop];
    });
    extend(origin[destination], tmpObj, deep);
  }

  function _isEqual(origValue, currentValue, firstPass) {
    if (origValue === currentValue) {
      // if the objects are identical, return
      return true;
    }
    else if (Array.isArray(origValue)) {
      if (!Array.isArray(currentValue) || origValue.length !== currentValue.length) {
        return false;
      }
      for (var i = 0, len = origValue.length; i < len; i++) {
        if (!_isEqual(origValue[i], currentValue[i])) {
          return false;
        }
      }
      return true;
    }
    else if (origValue && typeof origValue === 'object') {
      var keys = Object.keys(origValue), key;
      if (!currentValue ||
          typeof currentValue !== 'object' ||
          (!firstPass && keys.length !== Object.keys(currentValue).length)
      ) {
        return false;
      }
      for (var i = 0, len = keys.length; i < len; i++) {
        key = keys[i];
        if (!_isEqual(origValue[key], currentValue[key])) {
          return false;
        }
      }
      return true;
    }
  }


  fabric.util.object.extend(fabric.Object.prototype, /** @lends fabric.Object.prototype */ {

    /**
     * Returns true if object state (one of its state properties) was changed
     * @param {String} [propertySet] optional name for the set of property we want to save
     * @return {Boolean} true if instance' state has changed since `{@link fabric.Object#saveState}` was called
     */
    hasStateChanged: function(propertySet) {
      propertySet = propertySet || originalSet;
      var dashedPropertySet = '_' + propertySet;
      if (Object.keys(this[dashedPropertySet]).length < this[propertySet].length) {
        return true;
      }
      return !_isEqual(this[dashedPropertySet], this, true);
    },

    /**
     * Saves state of an object
     * @param {Object} [options] Object with additional `stateProperties` array to include when saving state
     * @return {fabric.Object} thisArg
     */
    saveState: function(options) {
      var propertySet = options && options.propertySet || originalSet,
          destination = '_' + propertySet;
      if (!this[destination]) {
        return this.setupState(options);
      }
      saveProps(this, destination, this[propertySet]);
      if (options && options.stateProperties) {
        saveProps(this, destination, options.stateProperties);
      }
      return this;
    },

    /**
     * Setups state of an object
     * @param {Object} [options] Object with additional `stateProperties` array to include when saving state
     * @return {fabric.Object} thisArg
     */
    setupState: function(options) {
      options = options || { };
      var propertySet = options.propertySet || originalSet;
      options.propertySet = propertySet;
      this['_' + propertySet] = { };
      this.saveState(options);
      return this;
    }
  });
})();


(function() {

  var degreesToRadians = fabric.util.degreesToRadians;

  fabric.util.object.extend(fabric.Object.prototype, /** @lends fabric.Object.prototype */ {

    /**
     * The object interactivity controls.
     * @private
     */
    _controlsVisibility: null,

    /**
     * Determines which corner has been clicked
     * @private
     * @param {Object} pointer The pointer indicating the mouse position
     * @return {String|Boolean} corner code (tl, tr, bl, br, etc.), or false if nothing is found
     */
    _findTargetCorner: function(pointer) {
      // objects in group, anykind, are not self modificable,
      // must not return an hovered corner.
      if (!this.hasControls || this.group || (!this.canvas || this.canvas._activeObject !== this)) {
        return false;
      }

      var ex = pointer.x,
          ey = pointer.y,
          xPoints,
          lines;
      this.__corner = 0;
      for (var i in this.oCoords) {

        if (!this.isControlVisible(i)) {
          continue;
        }

        if (i === 'mtr' && !this.hasRotatingPoint) {
          continue;
        }

        if (this.get('lockUniScaling') &&
           (i === 'mt' || i === 'mr' || i === 'mb' || i === 'ml')) {
          continue;
        }

        lines = this._getImageLines(this.oCoords[i].corner);

        // debugging

        // canvas.contextTop.fillRect(lines.bottomline.d.x, lines.bottomline.d.y, 2, 2);
        // canvas.contextTop.fillRect(lines.bottomline.o.x, lines.bottomline.o.y, 2, 2);

        // canvas.contextTop.fillRect(lines.leftline.d.x, lines.leftline.d.y, 2, 2);
        // canvas.contextTop.fillRect(lines.leftline.o.x, lines.leftline.o.y, 2, 2);

        // canvas.contextTop.fillRect(lines.topline.d.x, lines.topline.d.y, 2, 2);
        // canvas.contextTop.fillRect(lines.topline.o.x, lines.topline.o.y, 2, 2);

        // canvas.contextTop.fillRect(lines.rightline.d.x, lines.rightline.d.y, 2, 2);
        // canvas.contextTop.fillRect(lines.rightline.o.x, lines.rightline.o.y, 2, 2);

        xPoints = this._findCrossPoints({ x: ex, y: ey }, lines);
        if (xPoints !== 0 && xPoints % 2 === 1) {
          this.__corner = i;
          return i;
        }
      }
      return false;
    },

    /**
     * Sets the coordinates of the draggable boxes in the corners of
     * the image used to scale/rotate it.
     * @private
     */
    _setCornerCoords: function() {
      var coords = this.oCoords,
          newTheta = degreesToRadians(45 - this.angle),
          /* Math.sqrt(2 * Math.pow(this.cornerSize, 2)) / 2, */
          /* 0.707106 stands for sqrt(2)/2 */
          cornerHypotenuse = this.cornerSize * 0.707106,
          cosHalfOffset = cornerHypotenuse * fabric.util.cos(newTheta),
          sinHalfOffset = cornerHypotenuse * fabric.util.sin(newTheta),
          x, y;

      for (var point in coords) {
        x = coords[point].x;
        y = coords[point].y;
        coords[point].corner = {
          tl: {
            x: x - sinHalfOffset,
            y: y - cosHalfOffset
          },
          tr: {
            x: x + cosHalfOffset,
            y: y - sinHalfOffset
          },
          bl: {
            x: x - cosHalfOffset,
            y: y + sinHalfOffset
          },
          br: {
            x: x + sinHalfOffset,
            y: y + cosHalfOffset
          }
        };
      }
    },

    /**
     * Draws a colored layer behind the object, inside its selection borders.
     * Requires public options: padding, selectionBackgroundColor
     * this function is called when the context is transformed
     * has checks to be skipped when the object is on a staticCanvas
     * @param {CanvasRenderingContext2D} ctx Context to draw on
     * @return {fabric.Object} thisArg
     * @chainable
     */
    drawSelectionBackground: function(ctx) {
      if (!this.selectionBackgroundColor ||
        (this.canvas && !this.canvas.interactive) ||
        (this.canvas && this.canvas._activeObject !== this)
      ) {
        return this;
      }
      ctx.save();
      var center = this.getCenterPoint(), wh = this._calculateCurrentDimensions(),
          vpt = this.canvas.viewportTransform;
      ctx.translate(center.x, center.y);
      ctx.scale(1 / vpt[0], 1 / vpt[3]);
      ctx.rotate(degreesToRadians(this.angle));
      ctx.fillStyle = this.selectionBackgroundColor;
      ctx.fillRect(-wh.x / 2, -wh.y / 2, wh.x, wh.y);
      ctx.restore();
      return this;
    },

    /**
     * Draws borders of an object's bounding box.
     * Requires public properties: width, height
     * Requires public options: padding, borderColor
     * @param {CanvasRenderingContext2D} ctx Context to draw on
     * @param {Object} styleOverride object to override the object style
     * @return {fabric.Object} thisArg
     * @chainable
     */
    drawBorders: function(ctx, styleOverride) {
      styleOverride = styleOverride || {};
      var wh = this._calculateCurrentDimensions(),
          strokeWidth = 1 / this.borderScaleFactor,
          width = wh.x + strokeWidth,
          height = wh.y + strokeWidth,
          drawRotatingPoint = typeof styleOverride.hasRotatingPoint !== 'undefined' ?
            styleOverride.hasRotatingPoint : this.hasRotatingPoint,
          hasControls = typeof styleOverride.hasControls !== 'undefined' ?
            styleOverride.hasControls : this.hasControls,
          rotatingPointOffset = typeof styleOverride.rotatingPointOffset !== 'undefined' ?
            styleOverride.rotatingPointOffset : this.rotatingPointOffset;

      ctx.save();
      ctx.strokeStyle = styleOverride.borderColor || this.borderColor;
      this._setLineDash(ctx, styleOverride.borderDashArray || this.borderDashArray, null);

      ctx.strokeRect(
        -width / 2,
        -height / 2,
        width,
        height
      );

      if (drawRotatingPoint && this.isControlVisible('mtr') && hasControls) {

        var rotateHeight = -height / 2;

        ctx.beginPath();
        ctx.moveTo(0, rotateHeight);
        ctx.lineTo(0, rotateHeight - rotatingPointOffset);
        ctx.stroke();
      }

      ctx.restore();
      return this;
    },

    /**
     * Draws borders of an object's bounding box when it is inside a group.
     * Requires public properties: width, height
     * Requires public options: padding, borderColor
     * @param {CanvasRenderingContext2D} ctx Context to draw on
     * @param {object} options object representing current object parameters
     * @param {Object} styleOverride object to override the object style
     * @return {fabric.Object} thisArg
     * @chainable
     */
    drawBordersInGroup: function(ctx, options, styleOverride) {
      styleOverride = styleOverride || {};
      var p = this._getNonTransformedDimensions(),
          matrix = fabric.util.customTransformMatrix(options.scaleX, options.scaleY, options.skewX),
          wh = fabric.util.transformPoint(p, matrix),
          strokeWidth = 1 / this.borderScaleFactor,
          width = wh.x + strokeWidth,
          height = wh.y + strokeWidth;

      ctx.save();
      this._setLineDash(ctx, styleOverride.borderDashArray || this.borderDashArray, null);
      ctx.strokeStyle = styleOverride.borderColor || this.borderColor;

      ctx.strokeRect(
        -width / 2,
        -height / 2,
        width,
        height
      );

      ctx.restore();
      return this;
    },

    /**
     * Draws corners of an object's bounding box.
     * Requires public properties: width, height
     * Requires public options: cornerSize, padding
     * @param {CanvasRenderingContext2D} ctx Context to draw on
     * @param {Object} styleOverride object to override the object style
     * @return {fabric.Object} thisArg
     * @chainable
     */
    drawControls: function(ctx, styleOverride) {
      styleOverride = styleOverride || {};
      var wh = this._calculateCurrentDimensions(),
          width = wh.x,
          height = wh.y,
          scaleOffset = styleOverride.cornerSize || this.cornerSize,
          left = -(width + scaleOffset) / 2,
          top = -(height + scaleOffset) / 2,
          transparentCorners = typeof styleOverride.transparentCorners !== 'undefined' ?
            styleOverride.transparentCorners : this.transparentCorners,
          hasRotatingPoint = typeof styleOverride.hasRotatingPoint !== 'undefined' ?
            styleOverride.hasRotatingPoint : this.hasRotatingPoint,
          methodName = transparentCorners ? 'stroke' : 'fill';

      ctx.save();
      ctx.strokeStyle = ctx.fillStyle = styleOverride.cornerColor || this.cornerColor;
      if (!this.transparentCorners) {
        ctx.strokeStyle = styleOverride.cornerStrokeColor || this.cornerStrokeColor;
      }
      this._setLineDash(ctx, styleOverride.cornerDashArray || this.cornerDashArray, null);

      // top-left
      this._drawControl('tl', ctx, methodName,
        left,
        top, styleOverride);

      // top-right
      this._drawControl('tr', ctx, methodName,
        left + width,
        top, styleOverride);

      // bottom-left
      this._drawControl('bl', ctx, methodName,
        left,
        top + height, styleOverride);

      // bottom-right
      this._drawControl('br', ctx, methodName,
        left + width,
        top + height, styleOverride);

      if (!this.get('lockUniScaling')) {

        // middle-top
        this._drawControl('mt', ctx, methodName,
          left + width / 2,
          top, styleOverride);

        // middle-bottom
        this._drawControl('mb', ctx, methodName,
          left + width / 2,
          top + height, styleOverride);

        // middle-right
        this._drawControl('mr', ctx, methodName,
          left + width,
          top + height / 2, styleOverride);

        // middle-left
        this._drawControl('ml', ctx, methodName,
          left,
          top + height / 2, styleOverride);
      }

      // middle-top-rotate
      if (hasRotatingPoint) {
        this._drawControl('mtr', ctx, methodName,
          left + width / 2,
          top - this.rotatingPointOffset, styleOverride);
      }

      ctx.restore();

      return this;
    },

    /**
     * @private
     */
    _drawControl: function(control, ctx, methodName, left, top, styleOverride) {
      styleOverride = styleOverride || {};
      if (!this.isControlVisible(control)) {
        return;
      }
      var size = this.cornerSize, stroke = !this.transparentCorners && this.cornerStrokeColor;
      switch (styleOverride.cornerStyle || this.cornerStyle) {
        case 'circle':
          ctx.beginPath();
          ctx.arc(left + size / 2, top + size / 2, size / 2, 0, 2 * Math.PI, false);
          ctx[methodName]();
          if (stroke) {
            ctx.stroke();
          }
          break;
        default:
          this.transparentCorners || ctx.clearRect(left, top, size, size);
          ctx[methodName + 'Rect'](left, top, size, size);
          if (stroke) {
            ctx.strokeRect(left, top, size, size);
          }
      }
    },

    /**
     * Returns true if the specified control is visible, false otherwise.
     * @param {String} controlName The name of the control. Possible values are 'tl', 'tr', 'br', 'bl', 'ml', 'mt', 'mr', 'mb', 'mtr'.
     * @returns {Boolean} true if the specified control is visible, false otherwise
     */
    isControlVisible: function(controlName) {
      return this._getControlsVisibility()[controlName];
    },

    /**
     * Sets the visibility of the specified control.
     * @param {String} controlName The name of the control. Possible values are 'tl', 'tr', 'br', 'bl', 'ml', 'mt', 'mr', 'mb', 'mtr'.
     * @param {Boolean} visible true to set the specified control visible, false otherwise
     * @return {fabric.Object} thisArg
     * @chainable
     */
    setControlVisible: function(controlName, visible) {
      this._getControlsVisibility()[controlName] = visible;
      return this;
    },

    /**
     * Sets the visibility state of object controls.
     * @param {Object} [options] Options object
     * @param {Boolean} [options.bl] true to enable the bottom-left control, false to disable it
     * @param {Boolean} [options.br] true to enable the bottom-right control, false to disable it
     * @param {Boolean} [options.mb] true to enable the middle-bottom control, false to disable it
     * @param {Boolean} [options.ml] true to enable the middle-left control, false to disable it
     * @param {Boolean} [options.mr] true to enable the middle-right control, false to disable it
     * @param {Boolean} [options.mt] true to enable the middle-top control, false to disable it
     * @param {Boolean} [options.tl] true to enable the top-left control, false to disable it
     * @param {Boolean} [options.tr] true to enable the top-right control, false to disable it
     * @param {Boolean} [options.mtr] true to enable the middle-top-rotate control, false to disable it
     * @return {fabric.Object} thisArg
     * @chainable
     */
    setControlsVisibility: function(options) {
      options || (options = { });

      for (var p in options) {
        this.setControlVisible(p, options[p]);
      }
      return this;
    },

    /**
     * Returns the instance of the control visibility set for this object.
     * @private
     * @returns {Object}
     */
    _getControlsVisibility: function() {
      if (!this._controlsVisibility) {
        this._controlsVisibility = {
          tl: true,
          tr: true,
          br: true,
          bl: true,
          ml: true,
          mt: true,
          mr: true,
          mb: true,
          mtr: true
        };
      }
      return this._controlsVisibility;
    },

    /**
     * This callback function is called every time _discardActiveObject or _setActiveObject
     * try to to deselect this object. If the function returns true, the process is cancelled
     * @param {Object} [options] options sent from the upper functions
     * @param {Event} [options.e] event if the process is generated by an event
     */
    onDeselect: function() {
      // implemented by sub-classes, as needed.
    },


    /**
     * This callback function is called every time _discardActiveObject or _setActiveObject
     * try to to select this object. If the function returns true, the process is cancelled
     * @param {Object} [options] options sent from the upper functions
     * @param {Event} [options.e] event if the process is generated by an event
     */
    onSelect: function() {
      // implemented by sub-classes, as needed.
    }
  });
})();


fabric.util.object.extend(fabric.StaticCanvas.prototype, /** @lends fabric.StaticCanvas.prototype */ {

  /**
   * Animation duration (in ms) for fx* methods
   * @type Number
   * @default
   */
  FX_DURATION: 500,

  /**
   * Centers object horizontally with animation.
   * @param {fabric.Object} object Object to center
   * @param {Object} [callbacks] Callbacks object with optional "onComplete" and/or "onChange" properties
   * @param {Function} [callbacks.onComplete] Invoked on completion
   * @param {Function} [callbacks.onChange] Invoked on every step of animation
   * @return {fabric.Canvas} thisArg
   * @chainable
   */
  fxCenterObjectH: function (object, callbacks) {
    callbacks = callbacks || { };

    var empty = function() { },
        onComplete = callbacks.onComplete || empty,
        onChange = callbacks.onChange || empty,
        _this = this;

    fabric.util.animate({
      startValue: object.left,
      endValue: this.getCenter().left,
      duration: this.FX_DURATION,
      onChange: function(value) {
        object.set('left', value);
        _this.requestRenderAll();
        onChange();
      },
      onComplete: function() {
        object.setCoords();
        onComplete();
      }
    });

    return this;
  },

  /**
   * Centers object vertically with animation.
   * @param {fabric.Object} object Object to center
   * @param {Object} [callbacks] Callbacks object with optional "onComplete" and/or "onChange" properties
   * @param {Function} [callbacks.onComplete] Invoked on completion
   * @param {Function} [callbacks.onChange] Invoked on every step of animation
   * @return {fabric.Canvas} thisArg
   * @chainable
   */
  fxCenterObjectV: function (object, callbacks) {
    callbacks = callbacks || { };

    var empty = function() { },
        onComplete = callbacks.onComplete || empty,
        onChange = callbacks.onChange || empty,
        _this = this;

    fabric.util.animate({
      startValue: object.top,
      endValue: this.getCenter().top,
      duration: this.FX_DURATION,
      onChange: function(value) {
        object.set('top', value);
        _this.requestRenderAll();
        onChange();
      },
      onComplete: function() {
        object.setCoords();
        onComplete();
      }
    });

    return this;
  },

  /**
   * Same as `fabric.Canvas#remove` but animated
   * @param {fabric.Object} object Object to remove
   * @param {Object} [callbacks] Callbacks object with optional "onComplete" and/or "onChange" properties
   * @param {Function} [callbacks.onComplete] Invoked on completion
   * @param {Function} [callbacks.onChange] Invoked on every step of animation
   * @return {fabric.Canvas} thisArg
   * @chainable
   */
  fxRemove: function (object, callbacks) {
    callbacks = callbacks || { };

    var empty = function() { },
        onComplete = callbacks.onComplete || empty,
        onChange = callbacks.onChange || empty,
        _this = this;

    fabric.util.animate({
      startValue: object.opacity,
      endValue: 0,
      duration: this.FX_DURATION,
      onChange: function(value) {
        object.set('opacity', value);
        _this.requestRenderAll();
        onChange();
      },
      onComplete: function () {
        _this.remove(object);
        onComplete();
      }
    });

    return this;
  }
});

fabric.util.object.extend(fabric.Object.prototype, /** @lends fabric.Object.prototype */ {
  /**
   * Animates object's properties
   * @param {String|Object} property Property to animate (if string) or properties to animate (if object)
   * @param {Number|Object} value Value to animate property to (if string was given first) or options object
   * @return {fabric.Object} thisArg
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-2#animation}
   * @chainable
   *
   * As object — multiple properties
   *
   * object.animate({ left: ..., top: ... });
   * object.animate({ left: ..., top: ... }, { duration: ... });
   *
   * As string — one property
   *
   * object.animate('left', ...);
   * object.animate('left', { duration: ... });
   *
   */
  animate: function() {
    if (arguments[0] && typeof arguments[0] === 'object') {
      var propsToAnimate = [], prop, skipCallbacks;
      for (prop in arguments[0]) {
        propsToAnimate.push(prop);
      }
      for (var i = 0, len = propsToAnimate.length; i < len; i++) {
        prop = propsToAnimate[i];
        skipCallbacks = i !== len - 1;
        this._animate(prop, arguments[0][prop], arguments[1], skipCallbacks);
      }
    }
    else {
      this._animate.apply(this, arguments);
    }
    return this;
  },

  /**
   * @private
   * @param {String} property Property to animate
   * @param {String} to Value to animate to
   * @param {Object} [options] Options object
   * @param {Boolean} [skipCallbacks] When true, callbacks like onchange and oncomplete are not invoked
   */
  _animate: function(property, to, options, skipCallbacks) {
    var _this = this, propPair;

    to = to.toString();

    if (!options) {
      options = { };
    }
    else {
      options = fabric.util.object.clone(options);
    }

    if (~property.indexOf('.')) {
      propPair = property.split('.');
    }

    var currentValue = propPair
      ? this.get(propPair[0])[propPair[1]]
      : this.get(property);

    if (!('from' in options)) {
      options.from = currentValue;
    }

    if (~to.indexOf('=')) {
      to = currentValue + parseFloat(to.replace('=', ''));
    }
    else {
      to = parseFloat(to);
    }

    fabric.util.animate({
      startValue: options.from,
      endValue: to,
      byValue: options.by,
      easing: options.easing,
      duration: options.duration,
      abort: options.abort && function() {
        return options.abort.call(_this);
      },
      onChange: function(value, valueProgress, timeProgress) {
        if (propPair) {
          _this[propPair[0]][propPair[1]] = value;
        }
        else {
          _this.set(property, value);
        }
        if (skipCallbacks) {
          return;
        }
        options.onChange && options.onChange(value, valueProgress, timeProgress);
      },
      onComplete: function(value, valueProgress, timeProgress) {
        if (skipCallbacks) {
          return;
        }

        _this.setCoords();
        options.onComplete && options.onComplete(value, valueProgress, timeProgress);
      }
    });
  }
});


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { }),
      extend = fabric.util.object.extend,
      clone = fabric.util.object.clone,
      coordProps = { x1: 1, x2: 1, y1: 1, y2: 1 },
      supportsLineDash = fabric.StaticCanvas.supports('setLineDash');

  if (fabric.Line) {
    fabric.warn('fabric.Line is already defined');
    return;
  }

  /**
   * Line class
   * @class fabric.Line
   * @extends fabric.Object
   * @see {@link fabric.Line#initialize} for constructor definition
   */
  fabric.Line = fabric.util.createClass(fabric.Object, /** @lends fabric.Line.prototype */ {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'line',

    /**
     * x value or first line edge
     * @type Number
     * @default
     */
    x1: 0,

    /**
     * y value or first line edge
     * @type Number
     * @default
     */
    y1: 0,

    /**
     * x value or second line edge
     * @type Number
     * @default
     */
    x2: 0,

    /**
     * y value or second line edge
     * @type Number
     * @default
     */
    y2: 0,

    cacheProperties: fabric.Object.prototype.cacheProperties.concat('x1', 'x2', 'y1', 'y2'),

    /**
     * Constructor
     * @param {Array} [points] Array of points
     * @param {Object} [options] Options object
     * @return {fabric.Line} thisArg
     */
    initialize: function(points, options) {
      if (!points) {
        points = [0, 0, 0, 0];
      }

      this.callSuper('initialize', options);

      this.set('x1', points[0]);
      this.set('y1', points[1]);
      this.set('x2', points[2]);
      this.set('y2', points[3]);

      this._setWidthHeight(options);
    },

    /**
     * @private
     * @param {Object} [options] Options
     */
    _setWidthHeight: function(options) {
      options || (options = { });

      this.width = Math.abs(this.x2 - this.x1);
      this.height = Math.abs(this.y2 - this.y1);

      this.left = 'left' in options
        ? options.left
        : this._getLeftToOriginX();

      this.top = 'top' in options
        ? options.top
        : this._getTopToOriginY();
    },

    /**
     * @private
     * @param {String} key
     * @param {*} value
     */
    _set: function(key, value) {
      this.callSuper('_set', key, value);
      if (typeof coordProps[key] !== 'undefined') {
        this._setWidthHeight();
      }
      return this;
    },

    /**
     * @private
     * @return {Number} leftToOriginX Distance from left edge of canvas to originX of Line.
     */
    _getLeftToOriginX: makeEdgeToOriginGetter(
      { // property names
        origin: 'originX',
        axis1: 'x1',
        axis2: 'x2',
        dimension: 'width'
      },
      { // possible values of origin
        nearest: 'left',
        center: 'center',
        farthest: 'right'
      }
    ),

    /**
     * @private
     * @return {Number} topToOriginY Distance from top edge of canvas to originY of Line.
     */
    _getTopToOriginY: makeEdgeToOriginGetter(
      { // property names
        origin: 'originY',
        axis1: 'y1',
        axis2: 'y2',
        dimension: 'height'
      },
      { // possible values of origin
        nearest: 'top',
        center: 'center',
        farthest: 'bottom'
      }
    ),

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _render: function(ctx) {
      ctx.beginPath();

      if (!this.strokeDashArray || this.strokeDashArray && supportsLineDash) {
        // move from center (of virtual box) to its left/top corner
        // we can't assume x1, y1 is top left and x2, y2 is bottom right
        var p = this.calcLinePoints();
        ctx.moveTo(p.x1, p.y1);
        ctx.lineTo(p.x2, p.y2);
      }

      ctx.lineWidth = this.strokeWidth;

      // TODO: test this
      // make sure setting "fill" changes color of a line
      // (by copying fillStyle to strokeStyle, since line is stroked, not filled)
      var origStrokeStyle = ctx.strokeStyle;
      ctx.strokeStyle = this.stroke || ctx.fillStyle;
      this.stroke && this._renderStroke(ctx);
      ctx.strokeStyle = origStrokeStyle;
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderDashedStroke: function(ctx) {
      var p = this.calcLinePoints();

      ctx.beginPath();
      fabric.util.drawDashedLine(ctx, p.x1, p.y1, p.x2, p.y2, this.strokeDashArray);
      ctx.closePath();
    },

    /**
     * This function is an helper for svg import. it returns the center of the object in the svg
     * untransformed coordinates
     * @private
     * @return {Object} center point from element coordinates
     */
    _findCenterFromElement: function() {
      return {
        x: (this.x1 + this.x2) / 2,
        y: (this.y1 + this.y2) / 2,
      };
    },

    /**
     * Returns object representation of an instance
     * @methd toObject
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      return extend(this.callSuper('toObject', propertiesToInclude), this.calcLinePoints());
    },

    /*
     * Calculate object dimensions from its properties
     * @private
     */
    _getNonTransformedDimensions: function() {
      var dim = this.callSuper('_getNonTransformedDimensions');
      if (this.strokeLineCap === 'butt') {
        if (this.width === 0) {
          dim.y -= this.strokeWidth;
        }
        if (this.height === 0) {
          dim.x -= this.strokeWidth;
        }
      }
      return dim;
    },

    /**
     * Recalculates line points given width and height
     * @private
     */
    calcLinePoints: function() {
      var xMult = this.x1 <= this.x2 ? -1 : 1,
          yMult = this.y1 <= this.y2 ? -1 : 1,
          x1 = (xMult * this.width * 0.5),
          y1 = (yMult * this.height * 0.5),
          x2 = (xMult * this.width * -0.5),
          y2 = (yMult * this.height * -0.5);

      return {
        x1: x1,
        x2: x2,
        y1: y1,
        y2: y2
      };
    },

    /* _TO_SVG_START_ */
    /**
     * Returns SVG representation of an instance
     * @param {Function} [reviver] Method for further parsing of svg representation.
     * @return {String} svg representation of an instance
     */
    toSVG: function(reviver) {
      var markup = this._createBaseSVGMarkup(),
          p = this.calcLinePoints();
      markup.push(
        '<line ', this.getSvgId(),
        'x1="', p.x1,
        '" y1="', p.y1,
        '" x2="', p.x2,
        '" y2="', p.y2,
        '" style="', this.getSvgStyles(),
        '" transform="', this.getSvgTransform(),
        this.getSvgTransformMatrix(),
        '"/>\n'
      );

      return reviver ? reviver(markup.join('')) : markup.join('');
    },
    /* _TO_SVG_END_ */
  });

  /* _FROM_SVG_START_ */
  /**
   * List of attribute names to account for when parsing SVG element (used by {@link fabric.Line.fromElement})
   * @static
   * @memberOf fabric.Line
   * @see http://www.w3.org/TR/SVG/shapes.html#LineElement
   */
  fabric.Line.ATTRIBUTE_NAMES = fabric.SHARED_ATTRIBUTES.concat('x1 y1 x2 y2'.split(' '));

  /**
   * Returns fabric.Line instance from an SVG element
   * @static
   * @memberOf fabric.Line
   * @param {SVGElement} element Element to parse
   * @param {Object} [options] Options object
   * @param {Function} [callback] callback function invoked after parsing
   */
  fabric.Line.fromElement = function(element, callback, options) {
    options = options || { };
    var parsedAttributes = fabric.parseAttributes(element, fabric.Line.ATTRIBUTE_NAMES),
        points = [
          parsedAttributes.x1 || 0,
          parsedAttributes.y1 || 0,
          parsedAttributes.x2 || 0,
          parsedAttributes.y2 || 0
        ];
    callback(new fabric.Line(points, extend(parsedAttributes, options)));
  };
  /* _FROM_SVG_END_ */

  /**
   * Returns fabric.Line instance from an object representation
   * @static
   * @memberOf fabric.Line
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] invoked with new instance as first argument
   */
  fabric.Line.fromObject = function(object, callback) {
    function _callback(instance) {
      delete instance.points;
      callback && callback(instance);
    };
    var options = clone(object, true);
    options.points = [object.x1, object.y1, object.x2, object.y2];
    fabric.Object._fromObject('Line', options, _callback, 'points');
  };

  /**
   * Produces a function that calculates distance from canvas edge to Line origin.
   */
  function makeEdgeToOriginGetter(propertyNames, originValues) {
    var origin = propertyNames.origin,
        axis1 = propertyNames.axis1,
        axis2 = propertyNames.axis2,
        dimension = propertyNames.dimension,
        nearest = originValues.nearest,
        center = originValues.center,
        farthest = originValues.farthest;

    return function() {
      switch (this.get(origin)) {
        case nearest:
          return Math.min(this.get(axis1), this.get(axis2));
        case center:
          return Math.min(this.get(axis1), this.get(axis2)) + (0.5 * this.get(dimension));
        case farthest:
          return Math.max(this.get(axis1), this.get(axis2));
      }
    };

  }

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { }),
      pi = Math.PI;

  if (fabric.Circle) {
    fabric.warn('fabric.Circle is already defined.');
    return;
  }

  /**
   * Circle class
   * @class fabric.Circle
   * @extends fabric.Object
   * @see {@link fabric.Circle#initialize} for constructor definition
   */
  fabric.Circle = fabric.util.createClass(fabric.Object, /** @lends fabric.Circle.prototype */ {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'circle',

    /**
     * Radius of this circle
     * @type Number
     * @default
     */
    radius: 0,

    /**
     * Start angle of the circle, moving clockwise
     * deprectated type, this should be in degree, this was an oversight.
     * probably will change to degrees in next major version
     * @type Number
     * @default 0
     */
    startAngle: 0,

    /**
     * End angle of the circle
     * deprectated type, this should be in degree, this was an oversight.
     * probably will change to degrees in next major version
     * @type Number
     * @default 2Pi
     */
    endAngle: pi * 2,

    cacheProperties: fabric.Object.prototype.cacheProperties.concat('radius', 'startAngle', 'endAngle'),

    /**
     * @private
     * @param {String} key
     * @param {*} value
     * @return {fabric.Circle} thisArg
     */
    _set: function(key, value) {
      this.callSuper('_set', key, value);

      if (key === 'radius') {
        this.setRadius(value);
      }

      return this;
    },

    /**
     * Returns object representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      return this.callSuper('toObject', ['radius', 'startAngle', 'endAngle'].concat(propertiesToInclude));
    },

    /* _TO_SVG_START_ */
    /**
     * Returns svg representation of an instance
     * @param {Function} [reviver] Method for further parsing of svg representation.
     * @return {String} svg representation of an instance
     */
    toSVG: function(reviver) {
      var markup = this._createBaseSVGMarkup(), x = 0, y = 0,
          angle = (this.endAngle - this.startAngle) % ( 2 * pi);

      if (angle === 0) {
        markup.push(
          '<circle ', this.getSvgId(),
          'cx="' + x + '" cy="' + y + '" ',
          'r="', this.radius,
          '" style="', this.getSvgStyles(),
          '" transform="', this.getSvgTransform(),
          ' ', this.getSvgTransformMatrix(), '"',
          this.addPaintOrder(),
          '/>\n'
        );
      }
      else {
        var startX = fabric.util.cos(this.startAngle) * this.radius,
            startY = fabric.util.sin(this.startAngle) * this.radius,
            endX = fabric.util.cos(this.endAngle) * this.radius,
            endY = fabric.util.sin(this.endAngle) * this.radius,
            largeFlag = angle > pi ? '1' : '0';

        markup.push(
          '<path d="M ' + startX + ' ' + startY,
          ' A ' + this.radius + ' ' + this.radius,
          ' 0 ', +largeFlag + ' 1', ' ' + endX + ' ' + endY,
          '" style="', this.getSvgStyles(),
          '" transform="', this.getSvgTransform(),
          ' ', this.getSvgTransformMatrix(), '"',
          this.addPaintOrder(),
          '"/>\n'
        );
      }

      return reviver ? reviver(markup.join('')) : markup.join('');
    },
    /* _TO_SVG_END_ */

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx context to render on
     */
    _render: function(ctx) {
      ctx.beginPath();
      ctx.arc(
        0,
        0,
        this.radius,
        this.startAngle,
        this.endAngle, false);
      this._renderPaintInOrder(ctx);
    },

    /**
     * Returns horizontal radius of an object (according to how an object is scaled)
     * @return {Number}
     */
    getRadiusX: function() {
      return this.get('radius') * this.get('scaleX');
    },

    /**
     * Returns vertical radius of an object (according to how an object is scaled)
     * @return {Number}
     */
    getRadiusY: function() {
      return this.get('radius') * this.get('scaleY');
    },

    /**
     * Sets radius of an object (and updates width accordingly)
     * @return {fabric.Circle} thisArg
     */
    setRadius: function(value) {
      this.radius = value;
      return this.set('width', value * 2).set('height', value * 2);
    },
  });

  /* _FROM_SVG_START_ */
  /**
   * List of attribute names to account for when parsing SVG element (used by {@link fabric.Circle.fromElement})
   * @static
   * @memberOf fabric.Circle
   * @see: http://www.w3.org/TR/SVG/shapes.html#CircleElement
   */
  fabric.Circle.ATTRIBUTE_NAMES = fabric.SHARED_ATTRIBUTES.concat('cx cy r'.split(' '));

  /**
   * Returns {@link fabric.Circle} instance from an SVG element
   * @static
   * @memberOf fabric.Circle
   * @param {SVGElement} element Element to parse
   * @param {Function} [callback] Options callback invoked after parsing is finished
   * @param {Object} [options] Options object
   * @throws {Error} If value of `r` attribute is missing or invalid
   */
  fabric.Circle.fromElement = function(element, callback) {
    var parsedAttributes = fabric.parseAttributes(element, fabric.Circle.ATTRIBUTE_NAMES);

    if (!isValidRadius(parsedAttributes)) {
      throw new Error('value of `r` attribute is required and can not be negative');
    }

    parsedAttributes.left = (parsedAttributes.left || 0) - parsedAttributes.radius;
    parsedAttributes.top = (parsedAttributes.top || 0) - parsedAttributes.radius;
    callback(new fabric.Circle(parsedAttributes));
  };

  /**
   * @private
   */
  function isValidRadius(attributes) {
    return (('radius' in attributes) && (attributes.radius >= 0));
  }
  /* _FROM_SVG_END_ */

  /**
   * Returns {@link fabric.Circle} instance from an object representation
   * @static
   * @memberOf fabric.Circle
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] invoked with new instance as first argument
   * @return {Object} Instance of fabric.Circle
   */
  fabric.Circle.fromObject = function(object, callback) {
    return fabric.Object._fromObject('Circle', object, callback);
  };

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { });

  if (fabric.Triangle) {
    fabric.warn('fabric.Triangle is already defined');
    return;
  }

  /**
   * Triangle class
   * @class fabric.Triangle
   * @extends fabric.Object
   * @return {fabric.Triangle} thisArg
   * @see {@link fabric.Triangle#initialize} for constructor definition
   */
  fabric.Triangle = fabric.util.createClass(fabric.Object, /** @lends fabric.Triangle.prototype */ {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'triangle',

    /**
     * Width is set to 100 to compensate the old initialize code that was setting it to 100
     * @type Number
     * @default
     */
    width: 100,

    /**
     * Height is set to 100 to compensate the old initialize code that was setting it to 100
     * @type Number
     * @default
     */
    height: 100,

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _render: function(ctx) {
      var widthBy2 = this.width / 2,
          heightBy2 = this.height / 2;

      ctx.beginPath();
      ctx.moveTo(-widthBy2, heightBy2);
      ctx.lineTo(0, -heightBy2);
      ctx.lineTo(widthBy2, heightBy2);
      ctx.closePath();

      this._renderPaintInOrder(ctx);
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderDashedStroke: function(ctx) {
      var widthBy2 = this.width / 2,
          heightBy2 = this.height / 2;

      ctx.beginPath();
      fabric.util.drawDashedLine(ctx, -widthBy2, heightBy2, 0, -heightBy2, this.strokeDashArray);
      fabric.util.drawDashedLine(ctx, 0, -heightBy2, widthBy2, heightBy2, this.strokeDashArray);
      fabric.util.drawDashedLine(ctx, widthBy2, heightBy2, -widthBy2, heightBy2, this.strokeDashArray);
      ctx.closePath();
    },

    /* _TO_SVG_START_ */
    /**
     * Returns SVG representation of an instance
     * @param {Function} [reviver] Method for further parsing of svg representation.
     * @return {String} svg representation of an instance
     */
    toSVG: function(reviver) {
      var markup = this._createBaseSVGMarkup(),
          widthBy2 = this.width / 2,
          heightBy2 = this.height / 2,
          points = [
            -widthBy2 + ' ' + heightBy2,
            '0 ' + -heightBy2,
            widthBy2 + ' ' + heightBy2
          ]
            .join(',');

      markup.push(
        '<polygon ', this.getSvgId(),
        'points="', points,
        '" style="', this.getSvgStyles(),
        '" transform="', this.getSvgTransform(), '"',
        this.addPaintOrder(),
        '/>'
      );

      return reviver ? reviver(markup.join('')) : markup.join('');
    },
    /* _TO_SVG_END_ */
  });

  /**
   * Returns {@link fabric.Triangle} instance from an object representation
   * @static
   * @memberOf fabric.Triangle
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] invoked with new instance as first argument
   */
  fabric.Triangle.fromObject = function(object, callback) {
    return fabric.Object._fromObject('Triangle', object, callback);
  };

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { }),
      piBy2   = Math.PI * 2;

  if (fabric.Ellipse) {
    fabric.warn('fabric.Ellipse is already defined.');
    return;
  }

  /**
   * Ellipse class
   * @class fabric.Ellipse
   * @extends fabric.Object
   * @return {fabric.Ellipse} thisArg
   * @see {@link fabric.Ellipse#initialize} for constructor definition
   */
  fabric.Ellipse = fabric.util.createClass(fabric.Object, /** @lends fabric.Ellipse.prototype */ {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'ellipse',

    /**
     * Horizontal radius
     * @type Number
     * @default
     */
    rx:   0,

    /**
     * Vertical radius
     * @type Number
     * @default
     */
    ry:   0,

    cacheProperties: fabric.Object.prototype.cacheProperties.concat('rx', 'ry'),

    /**
     * Constructor
     * @param {Object} [options] Options object
     * @return {fabric.Ellipse} thisArg
     */
    initialize: function(options) {
      this.callSuper('initialize', options);
      this.set('rx', options && options.rx || 0);
      this.set('ry', options && options.ry || 0);
    },

    /**
     * @private
     * @param {String} key
     * @param {*} value
     * @return {fabric.Ellipse} thisArg
     */
    _set: function(key, value) {
      this.callSuper('_set', key, value);
      switch (key) {

        case 'rx':
          this.rx = value;
          this.set('width', value * 2);
          break;

        case 'ry':
          this.ry = value;
          this.set('height', value * 2);
          break;

      }
      return this;
    },

    /**
     * Returns horizontal radius of an object (according to how an object is scaled)
     * @return {Number}
     */
    getRx: function() {
      return this.get('rx') * this.get('scaleX');
    },

    /**
     * Returns Vertical radius of an object (according to how an object is scaled)
     * @return {Number}
     */
    getRy: function() {
      return this.get('ry') * this.get('scaleY');
    },

    /**
     * Returns object representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      return this.callSuper('toObject', ['rx', 'ry'].concat(propertiesToInclude));
    },

    /* _TO_SVG_START_ */
    /**
     * Returns svg representation of an instance
     * @param {Function} [reviver] Method for further parsing of svg representation.
     * @return {String} svg representation of an instance
     */
    toSVG: function(reviver) {
      var markup = this._createBaseSVGMarkup();
      markup.push(
        '<ellipse ', this.getSvgId(),
        'cx="0" cy="0" ',
        'rx="', this.rx,
        '" ry="', this.ry,
        '" style="', this.getSvgStyles(),
        '" transform="', this.getSvgTransform(),
        this.getSvgTransformMatrix(), '"',
        this.addPaintOrder(),
        '/>\n'
      );

      return reviver ? reviver(markup.join('')) : markup.join('');
    },
    /* _TO_SVG_END_ */

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx context to render on
     */
    _render: function(ctx) {
      ctx.beginPath();
      ctx.save();
      ctx.transform(1, 0, 0, this.ry / this.rx, 0, 0);
      ctx.arc(
        0,
        0,
        this.rx,
        0,
        piBy2,
        false);
      ctx.restore();
      this._renderPaintInOrder(ctx);
    },
  });

  /* _FROM_SVG_START_ */
  /**
   * List of attribute names to account for when parsing SVG element (used by {@link fabric.Ellipse.fromElement})
   * @static
   * @memberOf fabric.Ellipse
   * @see http://www.w3.org/TR/SVG/shapes.html#EllipseElement
   */
  fabric.Ellipse.ATTRIBUTE_NAMES = fabric.SHARED_ATTRIBUTES.concat('cx cy rx ry'.split(' '));

  /**
   * Returns {@link fabric.Ellipse} instance from an SVG element
   * @static
   * @memberOf fabric.Ellipse
   * @param {SVGElement} element Element to parse
   * @param {Function} [callback] Options callback invoked after parsing is finished
   * @return {fabric.Ellipse}
   */
  fabric.Ellipse.fromElement = function(element, callback) {

    var parsedAttributes = fabric.parseAttributes(element, fabric.Ellipse.ATTRIBUTE_NAMES);

    parsedAttributes.left = (parsedAttributes.left || 0) - parsedAttributes.rx;
    parsedAttributes.top = (parsedAttributes.top || 0) - parsedAttributes.ry;
    callback(new fabric.Ellipse(parsedAttributes));
  };
  /* _FROM_SVG_END_ */

  /**
   * Returns {@link fabric.Ellipse} instance from an object representation
   * @static
   * @memberOf fabric.Ellipse
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] invoked with new instance as first argument
   * @return {fabric.Ellipse}
   */
  fabric.Ellipse.fromObject = function(object, callback) {
    return fabric.Object._fromObject('Ellipse', object, callback);
  };

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { }),
      extend = fabric.util.object.extend;

  if (fabric.Rect) {
    fabric.warn('fabric.Rect is already defined');
    return;
  }

  /**
   * Rectangle class
   * @class fabric.Rect
   * @extends fabric.Object
   * @return {fabric.Rect} thisArg
   * @see {@link fabric.Rect#initialize} for constructor definition
   */
  fabric.Rect = fabric.util.createClass(fabric.Object, /** @lends fabric.Rect.prototype */ {

    /**
     * List of properties to consider when checking if state of an object is changed ({@link fabric.Object#hasStateChanged})
     * as well as for history (undo/redo) purposes
     * @type Array
     */
    stateProperties: fabric.Object.prototype.stateProperties.concat('rx', 'ry'),

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'rect',

    /**
     * Horizontal border radius
     * @type Number
     * @default
     */
    rx:   0,

    /**
     * Vertical border radius
     * @type Number
     * @default
     */
    ry:   0,

    cacheProperties: fabric.Object.prototype.cacheProperties.concat('rx', 'ry'),

    /**
     * Constructor
     * @param {Object} [options] Options object
     * @return {Object} thisArg
     */
    initialize: function(options) {
      this.callSuper('initialize', options);
      this._initRxRy();
    },

    /**
     * Initializes rx/ry attributes
     * @private
     */
    _initRxRy: function() {
      if (this.rx && !this.ry) {
        this.ry = this.rx;
      }
      else if (this.ry && !this.rx) {
        this.rx = this.ry;
      }
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _render: function(ctx) {

      // optimize 1x1 case (used in spray brush)
      if (this.width === 1 && this.height === 1) {
        ctx.fillRect(-0.5, -0.5, 1, 1);
        return;
      }

      var rx = this.rx ? Math.min(this.rx, this.width / 2) : 0,
          ry = this.ry ? Math.min(this.ry, this.height / 2) : 0,
          w = this.width,
          h = this.height,
          x = -this.width / 2,
          y = -this.height / 2,
          isRounded = rx !== 0 || ry !== 0,
          /* "magic number" for bezier approximations of arcs (http://itc.ktu.lt/itc354/Riskus354.pdf) */
          k = 1 - 0.5522847498;
      ctx.beginPath();

      ctx.moveTo(x + rx, y);

      ctx.lineTo(x + w - rx, y);
      isRounded && ctx.bezierCurveTo(x + w - k * rx, y, x + w, y + k * ry, x + w, y + ry);

      ctx.lineTo(x + w, y + h - ry);
      isRounded && ctx.bezierCurveTo(x + w, y + h - k * ry, x + w - k * rx, y + h, x + w - rx, y + h);

      ctx.lineTo(x + rx, y + h);
      isRounded && ctx.bezierCurveTo(x + k * rx, y + h, x, y + h - k * ry, x, y + h - ry);

      ctx.lineTo(x, y + ry);
      isRounded && ctx.bezierCurveTo(x, y + k * ry, x + k * rx, y, x + rx, y);

      ctx.closePath();

      this._renderPaintInOrder(ctx);
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderDashedStroke: function(ctx) {
      var x = -this.width / 2,
          y = -this.height / 2,
          w = this.width,
          h = this.height;

      ctx.beginPath();
      fabric.util.drawDashedLine(ctx, x, y, x + w, y, this.strokeDashArray);
      fabric.util.drawDashedLine(ctx, x + w, y, x + w, y + h, this.strokeDashArray);
      fabric.util.drawDashedLine(ctx, x + w, y + h, x, y + h, this.strokeDashArray);
      fabric.util.drawDashedLine(ctx, x, y + h, x, y, this.strokeDashArray);
      ctx.closePath();
    },

    /**
     * Returns object representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      return this.callSuper('toObject', ['rx', 'ry'].concat(propertiesToInclude));
    },

    /* _TO_SVG_START_ */
    /**
     * Returns svg representation of an instance
     * @param {Function} [reviver] Method for further parsing of svg representation.
     * @return {String} svg representation of an instance
     */
    toSVG: function(reviver) {
      var markup = this._createBaseSVGMarkup(), x = -this.width / 2, y = -this.height / 2;
      markup.push(
        '<rect ', this.getSvgId(),
        'x="', x, '" y="', y,
        '" rx="', this.get('rx'), '" ry="', this.get('ry'),
        '" width="', this.width, '" height="', this.height,
        '" style="', this.getSvgStyles(),
        '" transform="', this.getSvgTransform(),
        this.getSvgTransformMatrix(), '"',
        this.addPaintOrder(),
        '/>\n');

      return reviver ? reviver(markup.join('')) : markup.join('');
    },
    /* _TO_SVG_END_ */
  });

  /* _FROM_SVG_START_ */
  /**
   * List of attribute names to account for when parsing SVG element (used by `fabric.Rect.fromElement`)
   * @static
   * @memberOf fabric.Rect
   * @see: http://www.w3.org/TR/SVG/shapes.html#RectElement
   */
  fabric.Rect.ATTRIBUTE_NAMES = fabric.SHARED_ATTRIBUTES.concat('x y rx ry width height'.split(' '));

  /**
   * Returns {@link fabric.Rect} instance from an SVG element
   * @static
   * @memberOf fabric.Rect
   * @param {SVGElement} element Element to parse
   * @param {Function} callback callback function invoked after parsing
   * @param {Object} [options] Options object
   */
  fabric.Rect.fromElement = function(element, callback, options) {
    if (!element) {
      return callback(null);
    }
    options = options || { };

    var parsedAttributes = fabric.parseAttributes(element, fabric.Rect.ATTRIBUTE_NAMES);

    parsedAttributes.left = parsedAttributes.left || 0;
    parsedAttributes.top  = parsedAttributes.top  || 0;
    var rect = new fabric.Rect(extend((options ? fabric.util.object.clone(options) : { }), parsedAttributes));
    rect.visible = rect.visible && rect.width > 0 && rect.height > 0;
    callback(rect);
  };
  /* _FROM_SVG_END_ */

  /**
   * Returns {@link fabric.Rect} instance from an object representation
   * @static
   * @memberOf fabric.Rect
   * @param {Object} object Object to create an instance from
   * @param {Function} [callback] Callback to invoke when an fabric.Rect instance is created
   */
  fabric.Rect.fromObject = function(object, callback) {
    return fabric.Object._fromObject('Rect', object, callback);
  };

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { }),
      extend = fabric.util.object.extend,
      min = fabric.util.array.min,
      max = fabric.util.array.max,
      toFixed = fabric.util.toFixed;

  if (fabric.Polyline) {
    fabric.warn('fabric.Polyline is already defined');
    return;
  }

  /**
   * Polyline class
   * @class fabric.Polyline
   * @extends fabric.Object
   * @see {@link fabric.Polyline#initialize} for constructor definition
   */
  fabric.Polyline = fabric.util.createClass(fabric.Object, /** @lends fabric.Polyline.prototype */ {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'polyline',

    /**
     * Points array
     * @type Array
     * @default
     */
    points: null,

    cacheProperties: fabric.Object.prototype.cacheProperties.concat('points'),

    /**
     * Constructor
     * @param {Array} points Array of points (where each point is an object with x and y)
     * @param {Object} [options] Options object
     * @return {fabric.Polyline} thisArg
     * @example
     * var poly = new fabric.Polyline([
     *     { x: 10, y: 10 },
     *     { x: 50, y: 30 },
     *     { x: 40, y: 70 },
     *     { x: 60, y: 50 },
     *     { x: 100, y: 150 },
     *     { x: 40, y: 100 }
     *   ], {
     *   stroke: 'red',
     *   left: 100,
     *   top: 100
     * });
     */
    initialize: function(points, options) {
      options = options || {};
      this.points = points || [];
      this.callSuper('initialize', options);
      var calcDim = this._calcDimensions();
      if (typeof options.left === 'undefined') {
        this.left = calcDim.left;
      }
      if (typeof options.top === 'undefined') {
        this.top = calcDim.top;
      }
      this.width = calcDim.width;
      this.height = calcDim.height;
      this.pathOffset = {
        x: calcDim.left + this.width / 2,
        y: calcDim.top + this.height / 2
      };
    },

    /**
     * Calculate the polygon min and max point from points array,
     * returning an object with left, top, widht, height to measure the
     * polygon size
     * @return {Object} object.left X coordinate of the polygon leftmost point
     * @return {Object} object.top Y coordinate of the polygon topmost point
     * @return {Object} object.width distance between X coordinates of the polygon leftmost and rightmost point
     * @return {Object} object.height distance between Y coordinates of the polygon topmost and bottommost point
     * @private
     */
    _calcDimensions: function() {

      var points = this.points,
          minX = min(points, 'x') || 0,
          minY = min(points, 'y') || 0,
          maxX = max(points, 'x') || 0,
          maxY = max(points, 'y') || 0,
          width = (maxX - minX),
          height = (maxY - minY);

      return {
        left: minX,
        top: minY,
        width: width,
        height: height
      };
    },

    /**
     * Returns object representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} Object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      return extend(this.callSuper('toObject', propertiesToInclude), {
        points: this.points.concat()
      });
    },

    /* _TO_SVG_START_ */
    /**
     * Returns svg representation of an instance
     * @param {Function} [reviver] Method for further parsing of svg representation.
     * @return {String} svg representation of an instance
     */
    toSVG: function(reviver) {
      var points = [], diffX = this.pathOffset.x, diffY = this.pathOffset.y,
          markup = this._createBaseSVGMarkup(),
          NUM_FRACTION_DIGITS = fabric.Object.NUM_FRACTION_DIGITS;

      for (var i = 0, len = this.points.length; i < len; i++) {
        points.push(
          toFixed(this.points[i].x - diffX, NUM_FRACTION_DIGITS), ',',
          toFixed(this.points[i].y - diffY, NUM_FRACTION_DIGITS), ' '
        );
      }
      markup.push(
        '<', this.type, ' ', this.getSvgId(),
        'points="', points.join(''),
        '" style="', this.getSvgStyles(),
        '" transform="', this.getSvgTransform(),
        ' ', this.getSvgTransformMatrix(), '"',
        this.addPaintOrder(),
        '/>\n'
      );

      return reviver ? reviver(markup.join('')) : markup.join('');
    },
    /* _TO_SVG_END_ */


    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    commonRender: function(ctx) {
      var point, len = this.points.length,
          x = this.pathOffset.x,
          y = this.pathOffset.y;

      if (!len || isNaN(this.points[len - 1].y)) {
        // do not draw if no points or odd points
        // NaN comes from parseFloat of a empty string in parser
        return false;
      }
      ctx.beginPath();
      ctx.moveTo(this.points[0].x - x, this.points[0].y - y);
      for (var i = 0; i < len; i++) {
        point = this.points[i];
        ctx.lineTo(point.x - x, point.y - y);
      }
      return true;
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _render: function(ctx) {
      if (!this.commonRender(ctx)) {
        return;
      }
      this._renderPaintInOrder(ctx);
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderDashedStroke: function(ctx) {
      var p1, p2;

      ctx.beginPath();
      for (var i = 0, len = this.points.length; i < len; i++) {
        p1 = this.points[i];
        p2 = this.points[i + 1] || p1;
        fabric.util.drawDashedLine(ctx, p1.x, p1.y, p2.x, p2.y, this.strokeDashArray);
      }
    },

    /**
     * Returns complexity of an instance
     * @return {Number} complexity of this instance
     */
    complexity: function() {
      return this.get('points').length;
    }
  });

  /* _FROM_SVG_START_ */
  /**
   * List of attribute names to account for when parsing SVG element (used by {@link fabric.Polyline.fromElement})
   * @static
   * @memberOf fabric.Polyline
   * @see: http://www.w3.org/TR/SVG/shapes.html#PolylineElement
   */
  fabric.Polyline.ATTRIBUTE_NAMES = fabric.SHARED_ATTRIBUTES.concat();

  /**
   * Returns fabric.Polyline instance from an SVG element
   * @static
   * @memberOf fabric.Polyline
   * @param {SVGElement} element Element to parser
   * @param {Function} callback callback function invoked after parsing
   * @param {Object} [options] Options object
   */
  fabric.Polyline.fromElement = function(element, callback, options) {
    if (!element) {
      return callback(null);
    }
    options || (options = { });

    var points = fabric.parsePointsAttribute(element.getAttribute('points')),
        parsedAttributes = fabric.parseAttributes(element, fabric.Polyline.ATTRIBUTE_NAMES);

    callback(new fabric.Polyline(points, fabric.util.object.extend(parsedAttributes, options)));
  };
  /* _FROM_SVG_END_ */

  /**
   * Returns fabric.Polyline instance from an object representation
   * @static
   * @memberOf fabric.Polyline
   * @param {Object} object Object to create an instance from
   * @param {Function} [callback] Callback to invoke when an fabric.Path instance is created
   */
  fabric.Polyline.fromObject = function(object, callback) {
    return fabric.Object._fromObject('Polyline', object, callback, 'points');
  };

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { }),
      extend = fabric.util.object.extend;

  if (fabric.Polygon) {
    fabric.warn('fabric.Polygon is already defined');
    return;
  }

  /**
   * Polygon class
   * @class fabric.Polygon
   * @extends fabric.Polyline
   * @see {@link fabric.Polygon#initialize} for constructor definition
   */
  fabric.Polygon = fabric.util.createClass(fabric.Polyline, /** @lends fabric.Polygon.prototype */ {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'polygon',

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _render: function(ctx) {
      if (!this.commonRender(ctx)) {
        return;
      }
      ctx.closePath();
      this._renderPaintInOrder(ctx);
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderDashedStroke: function(ctx) {
      this.callSuper('_renderDashedStroke', ctx);
      ctx.closePath();
    },
  });

  /* _FROM_SVG_START_ */
  /**
   * List of attribute names to account for when parsing SVG element (used by `fabric.Polygon.fromElement`)
   * @static
   * @memberOf fabric.Polygon
   * @see: http://www.w3.org/TR/SVG/shapes.html#PolygonElement
   */
  fabric.Polygon.ATTRIBUTE_NAMES = fabric.SHARED_ATTRIBUTES.concat();

  /**
   * Returns {@link fabric.Polygon} instance from an SVG element
   * @static
   * @memberOf fabric.Polygon
   * @param {SVGElement} element Element to parse
   * @param {Function} callback callback function invoked after parsing
   * @param {Object} [options] Options object
   */
  fabric.Polygon.fromElement = function(element, callback, options) {
    if (!element) {
      return callback(null);
    }

    options || (options = { });

    var points = fabric.parsePointsAttribute(element.getAttribute('points')),
        parsedAttributes = fabric.parseAttributes(element, fabric.Polygon.ATTRIBUTE_NAMES);

    callback(new fabric.Polygon(points, extend(parsedAttributes, options)));
  };
  /* _FROM_SVG_END_ */

  /**
   * Returns fabric.Polygon instance from an object representation
   * @static
   * @memberOf fabric.Polygon
   * @param {Object} object Object to create an instance from
   * @param {Function} [callback] Callback to invoke when an fabric.Path instance is created
   */
  fabric.Polygon.fromObject = function(object, callback) {
    return fabric.Object._fromObject('Polygon', object, callback, 'points');
  };

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { }),
      min = fabric.util.array.min,
      max = fabric.util.array.max,
      extend = fabric.util.object.extend,
      _toString = Object.prototype.toString,
      drawArc = fabric.util.drawArc,
      commandLengths = {
        m: 2,
        l: 2,
        h: 1,
        v: 1,
        c: 6,
        s: 4,
        q: 4,
        t: 2,
        a: 7
      },
      repeatedCommands = {
        m: 'l',
        M: 'L'
      };

  if (fabric.Path) {
    fabric.warn('fabric.Path is already defined');
    return;
  }

  /**
   * Path class
   * @class fabric.Path
   * @extends fabric.Object
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-1#path_and_pathgroup}
   * @see {@link fabric.Path#initialize} for constructor definition
   */
  fabric.Path = fabric.util.createClass(fabric.Object, /** @lends fabric.Path.prototype */ {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'path',

    /**
     * Array of path points
     * @type Array
     * @default
     */
    path: null,

    cacheProperties: fabric.Object.prototype.cacheProperties.concat('path', 'fillRule'),

    stateProperties: fabric.Object.prototype.stateProperties.concat('path'),

    /**
     * Constructor
     * @param {Array|String} path Path data (sequence of coordinates and corresponding "command" tokens)
     * @param {Object} [options] Options object
     * @return {fabric.Path} thisArg
     */
    initialize: function(path, options) {
      options = options || { };
      this.callSuper('initialize', options);

      if (!path) {
        path = [];
      }

      var fromArray = _toString.call(path) === '[object Array]';

      this.path = fromArray
        ? path
        // one of commands (m,M,l,L,q,Q,c,C,etc.) followed by non-command characters (i.e. command values)
        : path.match && path.match(/[mzlhvcsqta][^mzlhvcsqta]*/gi);

      if (!this.path) {
        return;
      }

      if (!fromArray) {
        this.path = this._parsePath();
      }

      this._setPositionDimensions(options);
    },

    /**
     * @private
     * @param {Object} options Options object
     */
    _setPositionDimensions: function(options) {
      var calcDim = this._parseDimensions();

      this.width = calcDim.width;
      this.height = calcDim.height;

      if (typeof options.left === 'undefined') {
        this.left = calcDim.left;
      }

      if (typeof options.top === 'undefined') {
        this.top = calcDim.top;
      }

      this.pathOffset = this.pathOffset || {
        x: calcDim.left + this.width / 2,
        y: calcDim.top + this.height / 2
      };
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx context to render path on
     */
    _renderPathCommands: function(ctx) {
      var current, // current instruction
          previous = null,
          subpathStartX = 0,
          subpathStartY = 0,
          x = 0, // current x
          y = 0, // current y
          controlX = 0, // current control point x
          controlY = 0, // current control point y
          tempX,
          tempY,
          l = -this.pathOffset.x,
          t = -this.pathOffset.y;

      ctx.beginPath();

      for (var i = 0, len = this.path.length; i < len; ++i) {

        current = this.path[i];

        switch (current[0]) { // first letter

          case 'l': // lineto, relative
            x += current[1];
            y += current[2];
            ctx.lineTo(x + l, y + t);
            break;

          case 'L': // lineto, absolute
            x = current[1];
            y = current[2];
            ctx.lineTo(x + l, y + t);
            break;

          case 'h': // horizontal lineto, relative
            x += current[1];
            ctx.lineTo(x + l, y + t);
            break;

          case 'H': // horizontal lineto, absolute
            x = current[1];
            ctx.lineTo(x + l, y + t);
            break;

          case 'v': // vertical lineto, relative
            y += current[1];
            ctx.lineTo(x + l, y + t);
            break;

          case 'V': // verical lineto, absolute
            y = current[1];
            ctx.lineTo(x + l, y + t);
            break;

          case 'm': // moveTo, relative
            x += current[1];
            y += current[2];
            subpathStartX = x;
            subpathStartY = y;
            ctx.moveTo(x + l, y + t);
            break;

          case 'M': // moveTo, absolute
            x = current[1];
            y = current[2];
            subpathStartX = x;
            subpathStartY = y;
            ctx.moveTo(x + l, y + t);
            break;

          case 'c': // bezierCurveTo, relative
            tempX = x + current[5];
            tempY = y + current[6];
            controlX = x + current[3];
            controlY = y + current[4];
            ctx.bezierCurveTo(
              x + current[1] + l, // x1
              y + current[2] + t, // y1
              controlX + l, // x2
              controlY + t, // y2
              tempX + l,
              tempY + t
            );
            x = tempX;
            y = tempY;
            break;

          case 'C': // bezierCurveTo, absolute
            x = current[5];
            y = current[6];
            controlX = current[3];
            controlY = current[4];
            ctx.bezierCurveTo(
              current[1] + l,
              current[2] + t,
              controlX + l,
              controlY + t,
              x + l,
              y + t
            );
            break;

          case 's': // shorthand cubic bezierCurveTo, relative

            // transform to absolute x,y
            tempX = x + current[3];
            tempY = y + current[4];

            if (previous[0].match(/[CcSs]/) === null) {
              // If there is no previous command or if the previous command was not a C, c, S, or s,
              // the control point is coincident with the current point
              controlX = x;
              controlY = y;
            }
            else {
              // calculate reflection of previous control points
              controlX = 2 * x - controlX;
              controlY = 2 * y - controlY;
            }

            ctx.bezierCurveTo(
              controlX + l,
              controlY + t,
              x + current[1] + l,
              y + current[2] + t,
              tempX + l,
              tempY + t
            );
            // set control point to 2nd one of this command
            // "... the first control point is assumed to be
            // the reflection of the second control point on
            // the previous command relative to the current point."
            controlX = x + current[1];
            controlY = y + current[2];

            x = tempX;
            y = tempY;
            break;

          case 'S': // shorthand cubic bezierCurveTo, absolute
            tempX = current[3];
            tempY = current[4];
            if (previous[0].match(/[CcSs]/) === null) {
              // If there is no previous command or if the previous command was not a C, c, S, or s,
              // the control point is coincident with the current point
              controlX = x;
              controlY = y;
            }
            else {
              // calculate reflection of previous control points
              controlX = 2 * x - controlX;
              controlY = 2 * y - controlY;
            }
            ctx.bezierCurveTo(
              controlX + l,
              controlY + t,
              current[1] + l,
              current[2] + t,
              tempX + l,
              tempY + t
            );
            x = tempX;
            y = tempY;

            // set control point to 2nd one of this command
            // "... the first control point is assumed to be
            // the reflection of the second control point on
            // the previous command relative to the current point."
            controlX = current[1];
            controlY = current[2];

            break;

          case 'q': // quadraticCurveTo, relative
            // transform to absolute x,y
            tempX = x + current[3];
            tempY = y + current[4];

            controlX = x + current[1];
            controlY = y + current[2];

            ctx.quadraticCurveTo(
              controlX + l,
              controlY + t,
              tempX + l,
              tempY + t
            );
            x = tempX;
            y = tempY;
            break;

          case 'Q': // quadraticCurveTo, absolute
            tempX = current[3];
            tempY = current[4];

            ctx.quadraticCurveTo(
              current[1] + l,
              current[2] + t,
              tempX + l,
              tempY + t
            );
            x = tempX;
            y = tempY;
            controlX = current[1];
            controlY = current[2];
            break;

          case 't': // shorthand quadraticCurveTo, relative

            // transform to absolute x,y
            tempX = x + current[1];
            tempY = y + current[2];

            if (previous[0].match(/[QqTt]/) === null) {
              // If there is no previous command or if the previous command was not a Q, q, T or t,
              // assume the control point is coincident with the current point
              controlX = x;
              controlY = y;
            }
            else {
              // calculate reflection of previous control point
              controlX = 2 * x - controlX;
              controlY = 2 * y - controlY;
            }

            ctx.quadraticCurveTo(
              controlX + l,
              controlY + t,
              tempX + l,
              tempY + t
            );
            x = tempX;
            y = tempY;

            break;

          case 'T':
            tempX = current[1];
            tempY = current[2];

            if (previous[0].match(/[QqTt]/) === null) {
              // If there is no previous command or if the previous command was not a Q, q, T or t,
              // assume the control point is coincident with the current point
              controlX = x;
              controlY = y;
            }
            else {
              // calculate reflection of previous control point
              controlX = 2 * x - controlX;
              controlY = 2 * y - controlY;
            }
            ctx.quadraticCurveTo(
              controlX + l,
              controlY + t,
              tempX + l,
              tempY + t
            );
            x = tempX;
            y = tempY;
            break;

          case 'a':
            // TODO: optimize this
            drawArc(ctx, x + l, y + t, [
              current[1],
              current[2],
              current[3],
              current[4],
              current[5],
              current[6] + x + l,
              current[7] + y + t
            ]);
            x += current[6];
            y += current[7];
            break;

          case 'A':
            // TODO: optimize this
            drawArc(ctx, x + l, y + t, [
              current[1],
              current[2],
              current[3],
              current[4],
              current[5],
              current[6] + l,
              current[7] + t
            ]);
            x = current[6];
            y = current[7];
            break;

          case 'z':
          case 'Z':
            x = subpathStartX;
            y = subpathStartY;
            ctx.closePath();
            break;
        }
        previous = current;
      }
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx context to render path on
     */
    _render: function(ctx) {
      this._renderPathCommands(ctx);
      this._renderPaintInOrder(ctx);
    },

    /**
     * Returns string representation of an instance
     * @return {String} string representation of an instance
     */
    toString: function() {
      return '#<fabric.Path (' + this.complexity() +
        '): { "top": ' + this.top + ', "left": ' + this.left + ' }>';
    },

    /**
     * Returns object representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      var o = extend(this.callSuper('toObject', propertiesToInclude), {
        path: this.path.map(function(item) { return item.slice(); }),
        top: this.top,
        left: this.left,
      });
      return o;
    },

    /**
     * Returns dataless object representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} object representation of an instance
     */
    toDatalessObject: function(propertiesToInclude) {
      var o = this.toObject(['sourcePath'].concat(propertiesToInclude));
      if (o.sourcePath) {
        delete o.path;
      }
      return o;
    },

    /* _TO_SVG_START_ */
    /**
     * Returns svg representation of an instance
     * @param {Function} [reviver] Method for further parsing of svg representation.
     * @return {String} svg representation of an instance
     */
    toSVG: function(reviver) {
      var chunks = [],
          markup = this._createBaseSVGMarkup(), addTransform = '';

      for (var i = 0, len = this.path.length; i < len; i++) {
        chunks.push(this.path[i].join(' '));
      }
      var path = chunks.join(' ');
      addTransform = ' translate(' + (-this.pathOffset.x) + ', ' + (-this.pathOffset.y) + ') ';
      markup.push(
        '<path ', this.getSvgId(),
        'd="', path,
        '" style="', this.getSvgStyles(),
        '" transform="', this.getSvgTransform(), addTransform,
        this.getSvgTransformMatrix(), '" stroke-linecap="round" ',
        this.addPaintOrder(),
        '/>\n'
      );

      return reviver ? reviver(markup.join('')) : markup.join('');
    },
    /* _TO_SVG_END_ */

    /**
     * Returns number representation of an instance complexity
     * @return {Number} complexity of this instance
     */
    complexity: function() {
      return this.path.length;
    },

    /**
     * @private
     */
    _parsePath: function() {
      var result = [],
          coords = [],
          currentPath,
          parsed,
          re = /([-+]?((\d+\.\d+)|((\d+)|(\.\d+)))(?:e[-+]?\d+)?)/ig,
          match,
          coordsStr;

      for (var i = 0, coordsParsed, len = this.path.length; i < len; i++) {
        currentPath = this.path[i];

        coordsStr = currentPath.slice(1).trim();
        coords.length = 0;

        while ((match = re.exec(coordsStr))) {
          coords.push(match[0]);
        }

        coordsParsed = [currentPath.charAt(0)];

        for (var j = 0, jlen = coords.length; j < jlen; j++) {
          parsed = parseFloat(coords[j]);
          if (!isNaN(parsed)) {
            coordsParsed.push(parsed);
          }
        }

        var command = coordsParsed[0],
            commandLength = commandLengths[command.toLowerCase()],
            repeatedCommand = repeatedCommands[command] || command;

        if (coordsParsed.length - 1 > commandLength) {
          for (var k = 1, klen = coordsParsed.length; k < klen; k += commandLength) {
            result.push([command].concat(coordsParsed.slice(k, k + commandLength)));
            command = repeatedCommand;
          }
        }
        else {
          result.push(coordsParsed);
        }
      }

      return result;
    },

    /**
     * @private
     */
    _parseDimensions: function() {

      var aX = [],
          aY = [],
          current, // current instruction
          previous = null,
          subpathStartX = 0,
          subpathStartY = 0,
          x = 0, // current x
          y = 0, // current y
          controlX = 0, // current control point x
          controlY = 0, // current control point y
          tempX,
          tempY,
          bounds;

      for (var i = 0, len = this.path.length; i < len; ++i) {

        current = this.path[i];

        switch (current[0]) { // first letter

          case 'l': // lineto, relative
            x += current[1];
            y += current[2];
            bounds = [];
            break;

          case 'L': // lineto, absolute
            x = current[1];
            y = current[2];
            bounds = [];
            break;

          case 'h': // horizontal lineto, relative
            x += current[1];
            bounds = [];
            break;

          case 'H': // horizontal lineto, absolute
            x = current[1];
            bounds = [];
            break;

          case 'v': // vertical lineto, relative
            y += current[1];
            bounds = [];
            break;

          case 'V': // verical lineto, absolute
            y = current[1];
            bounds = [];
            break;

          case 'm': // moveTo, relative
            x += current[1];
            y += current[2];
            subpathStartX = x;
            subpathStartY = y;
            bounds = [];
            break;

          case 'M': // moveTo, absolute
            x = current[1];
            y = current[2];
            subpathStartX = x;
            subpathStartY = y;
            bounds = [];
            break;

          case 'c': // bezierCurveTo, relative
            tempX = x + current[5];
            tempY = y + current[6];
            controlX = x + current[3];
            controlY = y + current[4];
            bounds = fabric.util.getBoundsOfCurve(x, y,
              x + current[1], // x1
              y + current[2], // y1
              controlX, // x2
              controlY, // y2
              tempX,
              tempY
            );
            x = tempX;
            y = tempY;
            break;

          case 'C': // bezierCurveTo, absolute
            controlX = current[3];
            controlY = current[4];
            bounds = fabric.util.getBoundsOfCurve(x, y,
              current[1],
              current[2],
              controlX,
              controlY,
              current[5],
              current[6]
            );
            x = current[5];
            y = current[6];
            break;

          case 's': // shorthand cubic bezierCurveTo, relative

            // transform to absolute x,y
            tempX = x + current[3];
            tempY = y + current[4];

            if (previous[0].match(/[CcSs]/) === null) {
              // If there is no previous command or if the previous command was not a C, c, S, or s,
              // the control point is coincident with the current point
              controlX = x;
              controlY = y;
            }
            else {
              // calculate reflection of previous control points
              controlX = 2 * x - controlX;
              controlY = 2 * y - controlY;
            }

            bounds = fabric.util.getBoundsOfCurve(x, y,
              controlX,
              controlY,
              x + current[1],
              y + current[2],
              tempX,
              tempY
            );
            // set control point to 2nd one of this command
            // "... the first control point is assumed to be
            // the reflection of the second control point on
            // the previous command relative to the current point."
            controlX = x + current[1];
            controlY = y + current[2];
            x = tempX;
            y = tempY;
            break;

          case 'S': // shorthand cubic bezierCurveTo, absolute
            tempX = current[3];
            tempY = current[4];
            if (previous[0].match(/[CcSs]/) === null) {
              // If there is no previous command or if the previous command was not a C, c, S, or s,
              // the control point is coincident with the current point
              controlX = x;
              controlY = y;
            }
            else {
              // calculate reflection of previous control points
              controlX = 2 * x - controlX;
              controlY = 2 * y - controlY;
            }
            bounds = fabric.util.getBoundsOfCurve(x, y,
              controlX,
              controlY,
              current[1],
              current[2],
              tempX,
              tempY
            );
            x = tempX;
            y = tempY;
            // set control point to 2nd one of this command
            // "... the first control point is assumed to be
            // the reflection of the second control point on
            // the previous command relative to the current point."
            controlX = current[1];
            controlY = current[2];
            break;

          case 'q': // quadraticCurveTo, relative
            // transform to absolute x,y
            tempX = x + current[3];
            tempY = y + current[4];
            controlX = x + current[1];
            controlY = y + current[2];
            bounds = fabric.util.getBoundsOfCurve(x, y,
              controlX,
              controlY,
              controlX,
              controlY,
              tempX,
              tempY
            );
            x = tempX;
            y = tempY;
            break;

          case 'Q': // quadraticCurveTo, absolute
            controlX = current[1];
            controlY = current[2];
            bounds = fabric.util.getBoundsOfCurve(x, y,
              controlX,
              controlY,
              controlX,
              controlY,
              current[3],
              current[4]
            );
            x = current[3];
            y = current[4];
            break;

          case 't': // shorthand quadraticCurveTo, relative
            // transform to absolute x,y
            tempX = x + current[1];
            tempY = y + current[2];
            if (previous[0].match(/[QqTt]/) === null) {
              // If there is no previous command or if the previous command was not a Q, q, T or t,
              // assume the control point is coincident with the current point
              controlX = x;
              controlY = y;
            }
            else {
              // calculate reflection of previous control point
              controlX = 2 * x - controlX;
              controlY = 2 * y - controlY;
            }

            bounds = fabric.util.getBoundsOfCurve(x, y,
              controlX,
              controlY,
              controlX,
              controlY,
              tempX,
              tempY
            );
            x = tempX;
            y = tempY;

            break;

          case 'T':
            tempX = current[1];
            tempY = current[2];

            if (previous[0].match(/[QqTt]/) === null) {
              // If there is no previous command or if the previous command was not a Q, q, T or t,
              // assume the control point is coincident with the current point
              controlX = x;
              controlY = y;
            }
            else {
              // calculate reflection of previous control point
              controlX = 2 * x - controlX;
              controlY = 2 * y - controlY;
            }
            bounds = fabric.util.getBoundsOfCurve(x, y,
              controlX,
              controlY,
              controlX,
              controlY,
              tempX,
              tempY
            );
            x = tempX;
            y = tempY;
            break;

          case 'a':
            // TODO: optimize this
            bounds = fabric.util.getBoundsOfArc(x, y,
              current[1],
              current[2],
              current[3],
              current[4],
              current[5],
              current[6] + x,
              current[7] + y
            );
            x += current[6];
            y += current[7];
            break;

          case 'A':
            // TODO: optimize this
            bounds = fabric.util.getBoundsOfArc(x, y,
              current[1],
              current[2],
              current[3],
              current[4],
              current[5],
              current[6],
              current[7]
            );
            x = current[6];
            y = current[7];
            break;

          case 'z':
          case 'Z':
            x = subpathStartX;
            y = subpathStartY;
            break;
        }
        previous = current;
        bounds.forEach(function (point) {
          aX.push(point.x);
          aY.push(point.y);
        });
        aX.push(x);
        aY.push(y);
      }

      var minX = min(aX) || 0,
          minY = min(aY) || 0,
          maxX = max(aX) || 0,
          maxY = max(aY) || 0,
          deltaX = maxX - minX,
          deltaY = maxY - minY,

          o = {
            left: minX,
            top: minY,
            width: deltaX,
            height: deltaY
          };

      return o;
    }
  });

  /**
   * Creates an instance of fabric.Path from an object
   * @static
   * @memberOf fabric.Path
   * @param {Object} object
   * @param {Function} [callback] Callback to invoke when an fabric.Path instance is created
   */
  fabric.Path.fromObject = function(object, callback) {
    if (typeof object.sourcePath === 'string') {
      var pathUrl = object.sourcePath;
      fabric.loadSVGFromURL(pathUrl, function (elements) {
        var path = elements[0];
        path.setOptions(object);
        callback && callback(path);
      });
    }
    else {
      fabric.Object._fromObject('Path', object, callback, 'path');
    }
  };

  /* _FROM_SVG_START_ */
  /**
   * List of attribute names to account for when parsing SVG element (used by `fabric.Path.fromElement`)
   * @static
   * @memberOf fabric.Path
   * @see http://www.w3.org/TR/SVG/paths.html#PathElement
   */
  fabric.Path.ATTRIBUTE_NAMES = fabric.SHARED_ATTRIBUTES.concat(['d']);

  /**
   * Creates an instance of fabric.Path from an SVG <path> element
   * @static
   * @memberOf fabric.Path
   * @param {SVGElement} element to parse
   * @param {Function} callback Callback to invoke when an fabric.Path instance is created
   * @param {Object} [options] Options object
   * @param {Function} [callback] Options callback invoked after parsing is finished
   */
  fabric.Path.fromElement = function(element, callback, options) {
    var parsedAttributes = fabric.parseAttributes(element, fabric.Path.ATTRIBUTE_NAMES);
    callback(new fabric.Path(parsedAttributes.d, extend(parsedAttributes, options)));
  };
  /* _FROM_SVG_END_ */

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { }),
      extend = fabric.util.object.extend,
      min = fabric.util.array.min,
      max = fabric.util.array.max;

  if (fabric.Group) {
    return;
  }

  /**
   * Group class
   * @class fabric.Group
   * @extends fabric.Object
   * @mixes fabric.Collection
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-3#groups}
   * @see {@link fabric.Group#initialize} for constructor definition
   */
  fabric.Group = fabric.util.createClass(fabric.Object, fabric.Collection, /** @lends fabric.Group.prototype */ {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'group',

    /**
     * Width of stroke
     * @type Number
     * @default
     */
    strokeWidth: 0,

    /**
     * Indicates if click events should also check for subtargets
     * @type Boolean
     * @default
     */
    subTargetCheck: false,

    /**
     * Groups are container, do not render anything on theyr own, ence no cache properties
     * @type Array
     * @default
     */
    cacheProperties: [],

    /**
     * setOnGroup is a method used for TextBox that is no more used since 2.0.0 The behavior is still
     * available setting this boolean to true.
     * @type Boolean
     * @since 2.0.0
     * @default
     */
    useSetOnGroup: false,

    /**
     * Constructor
     * @param {Object} objects Group objects
     * @param {Object} [options] Options object
     * @param {Boolean} [isAlreadyGrouped] if true, objects have been grouped already.
     * @return {Object} thisArg
     */
    initialize: function(objects, options, isAlreadyGrouped) {
      options = options || {};
      this._objects = [];
      // if objects enclosed in a group have been grouped already,
      // we cannot change properties of objects.
      // Thus we need to set options to group without objects,
      isAlreadyGrouped && this.callSuper('initialize', options);
      this._objects = objects || [];
      for (var i = this._objects.length; i--; ) {
        this._objects[i].group = this;
      }

      if (options.originX) {
        this.originX = options.originX;
      }
      if (options.originY) {
        this.originY = options.originY;
      }

      if (!isAlreadyGrouped) {
        var center = options && options.centerPoint;
        // if coming from svg i do not want to calc bounds.
        // i assume width and height are passed along options
        center || this._calcBounds();
        this._updateObjectsCoords(center);
        delete options.centerPoint;
        this.callSuper('initialize', options);
      }
      else {
        this._updateObjectsACoords();
      }

      this.setCoords();
    },

    /**
     * @private
     * @param {Boolean} [skipCoordsChange] if true, coordinates of objects enclosed in a group do not change
     */
    _updateObjectsACoords: function() {
      var ignoreZoom = true, skipAbsolute = true;
      for (var i = this._objects.length; i--; ){
        this._objects[i].setCoords(ignoreZoom, skipAbsolute);
      }
    },

    /**
     * @private
     * @param {Boolean} [skipCoordsChange] if true, coordinates of objects enclosed in a group do not change
     */
    _updateObjectsCoords: function(center) {
      var center = center || this.getCenterPoint();
      for (var i = this._objects.length; i--; ){
        this._updateObjectCoords(this._objects[i], center);
      }
    },

    /**
     * @private
     * @param {Object} object
     * @param {fabric.Point} center, current center of group.
     */
    _updateObjectCoords: function(object, center) {
      var objectLeft = object.left,
          objectTop = object.top,
          ignoreZoom = true, skipAbsolute = true;

      object.set({
        left: objectLeft - center.x,
        top: objectTop - center.y
      });
      object.group = this;
      object.setCoords(ignoreZoom, skipAbsolute);
    },

    /**
     * Returns string represenation of a group
     * @return {String}
     */
    toString: function() {
      return '#<fabric.Group: (' + this.complexity() + ')>';
    },

    /**
     * Adds an object to a group; Then recalculates group's dimension, position.
     * @param {Object} object
     * @return {fabric.Group} thisArg
     * @chainable
     */
    addWithUpdate: function(object) {
      this._restoreObjectsState();
      fabric.util.resetObjectTransform(this);
      if (object) {
        this._objects.push(object);
        object.group = this;
        object._set('canvas', this.canvas);
      }
      this._calcBounds();
      this._updateObjectsCoords();
      this.setCoords();
      this.dirty = true;
      return this;
    },

    /**
     * Removes an object from a group; Then recalculates group's dimension, position.
     * @param {Object} object
     * @return {fabric.Group} thisArg
     * @chainable
     */
    removeWithUpdate: function(object) {
      this._restoreObjectsState();
      fabric.util.resetObjectTransform(this);

      this.remove(object);
      this._calcBounds();
      this._updateObjectsCoords();
      this.setCoords();
      this.dirty = true;
      return this;
    },

    /**
     * @private
     */
    _onObjectAdded: function(object) {
      this.dirty = true;
      object.group = this;
      object._set('canvas', this.canvas);
    },

    /**
     * @private
     */
    _onObjectRemoved: function(object) {
      this.dirty = true;
      delete object.group;
    },

    /**
     * @private
     */
    _set: function(key, value) {
      var i = this._objects.length;
      if (this.useSetOnGroup) {
        while (i--) {
          this._objects[i].setOnGroup(key, value);
        }
      }
      if (key === 'canvas') {
        i = this._objects.length;
        while (i--) {
          this._objects[i]._set(key, value);
        }
      }
      this.callSuper('_set', key, value);
    },

    /**
     * Returns object representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      var objsToObject = this.getObjects().map(function(obj) {
        var originalDefaults = obj.includeDefaultValues;
        obj.includeDefaultValues = obj.group.includeDefaultValues;
        var _obj = obj.toObject(propertiesToInclude);
        obj.includeDefaultValues = originalDefaults;
        return _obj;
      });
      return extend(this.callSuper('toObject', propertiesToInclude), {
        objects: objsToObject
      });
    },

    /**
     * Returns object representation of an instance, in dataless mode.
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} object representation of an instance
     */
    toDatalessObject: function(propertiesToInclude) {
      var objsToObject, sourcePath = this.sourcePath;
      if (sourcePath) {
        objsToObject = sourcePath;
      }
      else {
        objsToObject = this.getObjects().map(function(obj) {
          var originalDefaults = obj.includeDefaultValues;
          obj.includeDefaultValues = obj.group.includeDefaultValues;
          var _obj = obj.toDatalessObject(propertiesToInclude);
          obj.includeDefaultValues = originalDefaults;
          return _obj;
        });
      }
      return extend(this.callSuper('toDatalessObject', propertiesToInclude), {
        objects: objsToObject
      });
    },

    /**
     * Renders instance on a given context
     * @param {CanvasRenderingContext2D} ctx context to render instance on
     */
    render: function(ctx) {
      this._transformDone = true;
      this.callSuper('render', ctx);
      this._transformDone = false;
    },

    /**
     * Decide if the object should cache or not. Create its own cache level
     * objectCaching is a global flag, wins over everything
     * needsItsOwnCache should be used when the object drawing method requires
     * a cache step. None of the fabric classes requires it.
     * Generally you do not cache objects in groups because the group outside is cached.
     * @return {Boolean}
     */
    shouldCache: function() {
      var ownCache = this.objectCaching && (!this.group || this.needsItsOwnCache() || !this.group.isOnACache());
      this.ownCaching = ownCache;
      if (ownCache) {
        for (var i = 0, len = this._objects.length; i < len; i++) {
          if (this._objects[i].willDrawShadow()) {
            this.ownCaching = false;
            return false;
          }
        }
      }
      return ownCache;
    },

    /**
     * Check if this object or a child object will cast a shadow
     * @return {Boolean}
     */
    willDrawShadow: function() {
      if (this.shadow) {
        return this.callSuper('willDrawShadow');
      }
      for (var i = 0, len = this._objects.length; i < len; i++) {
        if (this._objects[i].willDrawShadow()) {
          return true;
        }
      }
      return false;
    },

    /**
     * Check if this group or its parent group are caching, recursively up
     * @return {Boolean}
     */
    isOnACache: function() {
      return this.ownCaching || (this.group && this.group.isOnACache());
    },

    /**
     * Execute the drawing operation for an object on a specified context
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    drawObject: function(ctx) {
      for (var i = 0, len = this._objects.length; i < len; i++) {
        this._objects[i].render(ctx);
      }
    },

    /**
     * Check if cache is dirty
     */
    isCacheDirty: function() {
      if (this.callSuper('isCacheDirty')) {
        return true;
      }
      if (!this.statefullCache) {
        return false;
      }
      for (var i = 0, len = this._objects.length; i < len; i++) {
        if (this._objects[i].isCacheDirty(true)) {
          if (this._cacheCanvas) {
            // if this group has not a cache canvas there is nothing to clean
            var x = this.cacheWidth / this.zoomX, y = this.cacheHeight / this.zoomY;
            this._cacheContext.clearRect(-x / 2, -y / 2, x, y);
          }
          return true;
        }
      }
      return false;
    },

    /**
     * Retores original state of each of group objects (original state is that which was before group was created).
     * @private
     * @return {fabric.Group} thisArg
     * @chainable
     */
    _restoreObjectsState: function() {
      this._objects.forEach(this._restoreObjectState, this);
      return this;
    },

    /**
     * Realises the transform from this group onto the supplied object
     * i.e. it tells you what would happen if the supplied object was in
     * the group, and then the group was destroyed. It mutates the supplied
     * object.
     * @param {fabric.Object} object
     * @return {fabric.Object} transformedObject
     */
    realizeTransform: function(object) {
      var matrix = object.calcTransformMatrix(),
          options = fabric.util.qrDecompose(matrix),
          center = new fabric.Point(options.translateX, options.translateY);
      object.flipX = false;
      object.flipY = false;
      object.set('scaleX', options.scaleX);
      object.set('scaleY', options.scaleY);
      object.skewX = options.skewX;
      object.skewY = options.skewY;
      object.angle = options.angle;
      object.setPositionByOrigin(center, 'center', 'center');
      return object;
    },

    /**
     * Restores original state of a specified object in group
     * @private
     * @param {fabric.Object} object
     * @return {fabric.Group} thisArg
     */
    _restoreObjectState: function(object) {
      this.realizeTransform(object);
      object.setCoords();
      delete object.group;
      return this;
    },

    /**
     * Destroys a group (restoring state of its objects)
     * @return {fabric.Group} thisArg
     * @chainable
     */
    destroy: function() {
      // when group is destroyed objects needs to get a repaint to be eventually
      // displayed on canvas.
      this._objects.forEach(function(object) {
        object.set('dirty', true);
      });
      return this._restoreObjectsState();
    },

    /**
     * make a group an active selection, remove the group from canvas
     * the group has to be on canvas for this to work.
     * @return {fabric.ActiveSelection} thisArg
     * @chainable
     */
    toActiveSelection: function() {
      if (!this.canvas) {
        return;
      }
      var objects = this._objects, canvas = this.canvas;
      this._objects = [];
      var options = this.toObject();
      delete options.objects;
      var activeSelection = new fabric.ActiveSelection([]);
      activeSelection.set(options);
      activeSelection.type = 'activeSelection';
      canvas.remove(this);
      objects.forEach(function(object) {
        object.group = activeSelection;
        object.dirty = true;
        canvas.add(object);
      });
      activeSelection.canvas = canvas;
      activeSelection._objects = objects;
      canvas._activeObject = activeSelection;
      activeSelection.setCoords();
      return activeSelection;
    },

    /**
     * Destroys a group (restoring state of its objects)
     * @return {fabric.Group} thisArg
     * @chainable
     */
    ungroupOnCanvas: function() {
      return this._restoreObjectsState();
    },

    /**
     * Sets coordinates of all objects inside group
     * @return {fabric.Group} thisArg
     * @chainable
     */
    setObjectsCoords: function() {
      var ignoreZoom = true, skipAbsolute = true;
      this.forEachObject(function(object) {
        object.setCoords(ignoreZoom, skipAbsolute);
      });
      return this;
    },

    /**
     * @private
     */
    _calcBounds: function(onlyWidthHeight) {
      var aX = [],
          aY = [],
          o, prop,
          props = ['tr', 'br', 'bl', 'tl'],
          i = 0, iLen = this._objects.length,
          j, jLen = props.length,
          ignoreZoom = true;

      for ( ; i < iLen; ++i) {
        o = this._objects[i];
        o.setCoords(ignoreZoom);
        for (j = 0; j < jLen; j++) {
          prop = props[j];
          aX.push(o.oCoords[prop].x);
          aY.push(o.oCoords[prop].y);
        }
      }

      this.set(this._getBounds(aX, aY, onlyWidthHeight));
    },

    /**
     * @private
     */
    _getBounds: function(aX, aY, onlyWidthHeight) {
      var minXY = new fabric.Point(min(aX), min(aY)),
          maxXY = new fabric.Point(max(aX), max(aY)),
          obj = {
            width: (maxXY.x - minXY.x) || 0,
            height: (maxXY.y - minXY.y) || 0
          };

      if (!onlyWidthHeight) {
        obj.left = minXY.x || 0;
        obj.top = minXY.y || 0;
        if (this.originX === 'center') {
          obj.left += obj.width / 2;
        }
        if (this.originX === 'right') {
          obj.left += obj.width;
        }
        if (this.originY === 'center') {
          obj.top += obj.height / 2;
        }
        if (this.originY === 'bottom') {
          obj.top += obj.height;
        }
      }
      return obj;
    },

    /* _TO_SVG_START_ */
    /**
     * Returns svg representation of an instance
     * @param {Function} [reviver] Method for further parsing of svg representation.
     * @return {String} svg representation of an instance
     */
    toSVG: function(reviver) {
      var markup = this._createBaseSVGMarkup();
      markup.push(
        '<g ', this.getSvgId(), 'transform="',
        /* avoiding styles intentionally */
        this.getSvgTransform(),
        this.getSvgTransformMatrix(),
        '" style="',
        this.getSvgFilter(),
        '">\n'
      );

      for (var i = 0, len = this._objects.length; i < len; i++) {
        markup.push('\t', this._objects[i].toSVG(reviver));
      }

      markup.push('</g>\n');

      return reviver ? reviver(markup.join('')) : markup.join('');
    },
    /* _TO_SVG_END_ */
  });

  /**
   * Returns {@link fabric.Group} instance from an object representation
   * @static
   * @memberOf fabric.Group
   * @param {Object} object Object to create a group from
   * @param {Function} [callback] Callback to invoke when an group instance is created
   */
  fabric.Group.fromObject = function(object, callback) {
    fabric.util.enlivenObjects(object.objects, function(enlivenedObjects) {
      var options = fabric.util.object.clone(object, true);
      delete options.objects;
      callback && callback(new fabric.Group(enlivenedObjects, options, true));
    });
  };

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { });

  if (fabric.ActiveSelection) {
    return;
  }

  /**
   * Group class
   * @class fabric.ActiveSelection
   * @extends fabric.Group
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-3#groups}
   * @see {@link fabric.ActiveSelection#initialize} for constructor definition
   */
  fabric.ActiveSelection = fabric.util.createClass(fabric.Group, /** @lends fabric.ActiveSelection.prototype */ {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'activeSelection',

    /**
     * Constructor
     * @param {Object} objects ActiveSelection objects
     * @param {Object} [options] Options object
     * @return {Object} thisArg
     */
    initialize: function(objects, options) {
      options = options || {};
      this._objects = objects || [];
      for (var i = this._objects.length; i--; ) {
        this._objects[i].group = this;
      }

      if (options.originX) {
        this.originX = options.originX;
      }
      if (options.originY) {
        this.originY = options.originY;
      }
      this._calcBounds();
      this._updateObjectsCoords();
      fabric.Object.prototype.initialize.call(this, options);
      this.setCoords();
    },

    /**
     * Change te activeSelection to a normal group,
     * High level function that automatically adds it to canvas as
     * active object. no events fired.
     * @since 2.0.0
     * @return {fabric.Group}
     */
    toGroup: function() {
      var objects = this._objects;
      this._objects = [];
      var options = this.toObject();
      var newGroup = new fabric.Group([]);
      delete options.objects;
      newGroup.set(options);
      newGroup.type = 'group';
      objects.forEach(function(object) {
        object.group = newGroup;
        object.canvas.remove(object);
      });
      newGroup._objects = objects;
      if (!this.canvas) {
        return newGroup;
      }
      var canvas = this.canvas;
      canvas.add(newGroup);
      canvas._activeObject = newGroup;
      newGroup.setCoords();
      return newGroup;
    },

    /**
     * If returns true, deselection is cancelled.
     * @since 2.0.0
     * @return {Boolean} [cancel]
     */
    onDeselect: function() {
      this.destroy();
      return false;
    },

    /**
     * Returns string representation of a group
     * @return {String}
     */
    toString: function() {
      return '#<fabric.ActiveSelection: (' + this.complexity() + ')>';
    },

    /**
     * @private
     */
    _set: function(key, value) {
      var i = this._objects.length;
      if (key === 'canvas') {
        while (i--) {
          this._objects[i].set(key, value);
        }
      }
      if (this.useSetOnGroup) {
        while (i--) {
          this._objects[i].setOnGroup(key, value);
        }
      }
      fabric.Object.prototype._set.call(this, key, value);
    },

    /**
     * Decide if the object should cache or not. Create its own cache level
     * objectCaching is a global flag, wins over everything
     * needsItsOwnCache should be used when the object drawing method requires
     * a cache step. None of the fabric classes requires it.
     * Generally you do not cache objects in groups because the group outside is cached.
     * @return {Boolean}
     */
    shouldCache: function() {
      return false;
    },

    /**
     * Check if this object or a child object will cast a shadow
     * @return {Boolean}
     */
    willDrawShadow: function() {
      if (this.shadow) {
        return this.callSuper('willDrawShadow');
      }
      for (var i = 0, len = this._objects.length; i < len; i++) {
        if (this._objects[i].willDrawShadow()) {
          return true;
        }
      }
      return false;
    },

    /**
     * Check if this group or its parent group are caching, recursively up
     * @return {Boolean}
     */
    isOnACache: function() {
      return false;
    },

    /**
     * Renders controls and borders for the object
     * @param {CanvasRenderingContext2D} ctx Context to render on
     * @param {Object} [styleOverride] properties to override the object style
     * @param {Object} [childrenOverride] properties to override the children overrides
     */
    _renderControls: function(ctx, styleOverride, childrenOverride) {
      ctx.save();
      ctx.globalAlpha = this.isMoving ? this.borderOpacityWhenMoving : 1;
      this.callSuper('_renderControls', ctx, styleOverride);
      childrenOverride = childrenOverride || { };
      if (typeof childrenOverride.hasControls === 'undefined') {
        childrenOverride.hasControls = false;
      }
      if (typeof childrenOverride.hasRotatingPoint === 'undefined') {
        childrenOverride.hasRotatingPoint = false;
      }
      childrenOverride.forActiveSelection = true;
      for (var i = 0, len = this._objects.length; i < len; i++) {
        this._objects[i]._renderControls(ctx, childrenOverride);
      }
      ctx.restore();
    },
  });

  /**
   * Returns {@link fabric.ActiveSelection} instance from an object representation
   * @static
   * @memberOf fabric.ActiveSelection
   * @param {Object} object Object to create a group from
   * @param {Function} [callback] Callback to invoke when an ActiveSelection instance is created
   */
  fabric.ActiveSelection.fromObject = function(object, callback) {
    fabric.util.enlivenObjects(object.objects, function(enlivenedObjects) {
      delete object.objects;
      callback && callback(new fabric.ActiveSelection(enlivenedObjects, object, true));
    });
  };

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var extend = fabric.util.object.extend;

  if (!global.fabric) {
    global.fabric = { };
  }

  if (global.fabric.Image) {
    fabric.warn('fabric.Image is already defined.');
    return;
  }

  /**
   * Image class
   * @class fabric.Image
   * @extends fabric.Object
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-1#images}
   * @see {@link fabric.Image#initialize} for constructor definition
   */
  fabric.Image = fabric.util.createClass(fabric.Object, /** @lends fabric.Image.prototype */ {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'image',

    /**
     * crossOrigin value (one of "", "anonymous", "use-credentials")
     * @see https://developer.mozilla.org/en-US/docs/HTML/CORS_settings_attributes
     * @type String
     * @default
     */
    crossOrigin: '',

    /**
     * Width of a stroke.
     * For image quality a stroke multiple of 2 gives better results.
     * @type Number
     * @default
     */
    strokeWidth: 0,

    /**
     * private
     * contains last value of scaleX to detect
     * if the Image got resized after the last Render
     * @type Number
     */
    _lastScaleX: 1,

    /**
     * private
     * contains last value of scaleY to detect
     * if the Image got resized after the last Render
     * @type Number
     */
    _lastScaleY: 1,

    /**
     * private
     * contains last value of scaling applied by the apply filter chain
     * @type Number
     */
    _filterScalingX: 1,

    /**
     * private
     * contains last value of scaling applied by the apply filter chain
     * @type Number
     */
    _filterScalingY: 1,

    /**
     * minimum scale factor under which any resizeFilter is triggered to resize the image
     * 0 will disable the automatic resize. 1 will trigger automatically always.
     * number bigger than 1 are not implemented yet.
     * @type Number
     */
    minimumScaleTrigger: 0.5,

    /**
     * List of properties to consider when checking if
     * state of an object is changed ({@link fabric.Object#hasStateChanged})
     * as well as for history (undo/redo) purposes
     * @type Array
     */
    stateProperties: fabric.Object.prototype.stateProperties.concat('cropX', 'cropY'),

    /**
     * When `true`, object is cached on an additional canvas.
     * default to false for images
     * since 1.7.0
     * @type Boolean
     * @default
     */
    objectCaching: false,

    /**
     * key used to retrieve the texture representing this image
     * since 2.0.0
     * @type String
     * @default
     */
    cacheKey: '',

    /**
     * Image crop in pixels from original image size.
     * since 2.0.0
     * @type Number
     * @default
     */
    cropX: 0,

    /**
     * Image crop in pixels from original image size.
     * since 2.0.0
     * @type Number
     * @default
     */
    cropY: 0,

    /**
     * Constructor
     * @param {HTMLImageElement | String} element Image element
     * @param {Object} [options] Options object
     * @param {function} [callback] callback function to call after eventual filters applied.
     * @return {fabric.Image} thisArg
     */
    initialize: function(element, options) {
      options || (options = { });
      this.filters = [];
      this.cacheKey = 'texture' + fabric.Object.__uid++;
      this.callSuper('initialize', options);
      this._initElement(element, options);
    },

    /**
     * Returns image element which this instance if based on
     * @return {HTMLImageElement} Image element
     */
    getElement: function() {
      return this._element;
    },

    /**
     * Sets image element for this instance to a specified one.
     * If filters defined they are applied to new image.
     * You might need to call `canvas.renderAll` and `object.setCoords` after replacing, to render new image and update controls area.
     * @param {HTMLImageElement} element
     * @param {Object} [options] Options object
     * @return {fabric.Image} thisArg
     * @chainable
     */
    setElement: function(element, options) {
      var backend = fabric.filterBackend;
      if (backend && backend.evictCachesForKey) {
        backend.evictCachesForKey(this.cacheKey);
        backend.evictCachesForKey(this.cacheKey + '_filtered');
      }
      this._element = element;
      this._originalElement = element;
      this._initConfig(options);
      if (this.resizeFilter) {
        this.applyResizeFilters();
      }
      if (this.filters.length !== 0) {
        this.applyFilters();
      }
      return this;
    },

    /**
     * Delete cacheKey if we have a webGlBackend
     * delete reference to image elements
     */
    dispose: function() {
      var backend = fabric.filterBackend;
      if (backend && backend.evictCachesForKey) {
        backend.evictCachesForKey(this.cacheKey);
        backend.evictCachesForKey(this.cacheKey + '_filtered');
      }
      this._originalElement = undefined;
      this._element = undefined;
      this._filteredEl = undefined;
    },

    /**
     * Sets crossOrigin value (on an instance and corresponding image element)
     * @return {fabric.Image} thisArg
     * @chainable
     */
    setCrossOrigin: function(value) {
      this.crossOrigin = value;
      this._element.crossOrigin = value;

      return this;
    },

    /**
     * Returns original size of an image
     * @return {Object} Object with "width" and "height" properties
     */
    getOriginalSize: function() {
      var element = this.getElement();
      return {
        width: element.width,
        height: element.height
      };
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _stroke: function(ctx) {
      if (!this.stroke || this.strokeWidth === 0) {
        return;
      }
      var w = this.width / 2, h = this.height / 2;
      ctx.beginPath();
      ctx.moveTo(-w, -h);
      ctx.lineTo(w, -h);
      ctx.lineTo(w, h);
      ctx.lineTo(-w, h);
      ctx.lineTo(-w, -h);
      ctx.closePath();
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderDashedStroke: function(ctx) {
      var x = -this.width / 2,
          y = -this.height / 2,
          w = this.width,
          h = this.height;

      ctx.save();
      this._setStrokeStyles(ctx, this);

      ctx.beginPath();
      fabric.util.drawDashedLine(ctx, x, y, x + w, y, this.strokeDashArray);
      fabric.util.drawDashedLine(ctx, x + w, y, x + w, y + h, this.strokeDashArray);
      fabric.util.drawDashedLine(ctx, x + w, y + h, x, y + h, this.strokeDashArray);
      fabric.util.drawDashedLine(ctx, x, y + h, x, y, this.strokeDashArray);
      ctx.closePath();
      ctx.restore();
    },

    /**
     * Returns object representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} Object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      var filters = [];

      this.filters.forEach(function(filterObj) {
        if (filterObj) {
          filters.push(filterObj.toObject());
        }
      });
      var object = extend(
        this.callSuper(
          'toObject',
          ['crossOrigin', 'cropX', 'cropY'].concat(propertiesToInclude)
        ), {
          src: this.getSrc(),
          filters: filters,
        });
      if (this.resizeFilter) {
        object.resizeFilter = this.resizeFilter.toObject();
      }
      return object;
    },

    /**
     * Returns true if an image has crop applied, inspecting values of cropX,cropY,width,hight.
     * @return {Boolean}
     */
    hasCrop: function() {
      return this.cropX || this.cropY || this.width < this._element.width || this.height < this._element.height;
    },

    /* _TO_SVG_START_ */
    /**
     * Returns SVG representation of an instance
     * @param {Function} [reviver] Method for further parsing of svg representation.
     * @return {String} svg representation of an instance
     */
    toSVG: function(reviver) {
      var markup = this._createBaseSVGMarkup(), x = -this.width / 2, y = -this.height / 2, clipPath = '';
      if (this.hasCrop()) {
        var clipPathId = fabric.Object.__uid++;
        markup.push(
          '<clipPath id="imageCrop_' + clipPathId + '">\n',
          '\t<rect x="' + x + '" y="' + y + '" width="' + this.width + '" height="' + this.height + '" />\n',
          '</clipPath>\n'
        );
        clipPath = ' clip-path="url(#imageCrop_' + clipPathId + ')" ';
      }
      markup.push('<g transform="', this.getSvgTransform(), this.getSvgTransformMatrix(), '">\n');
      var imageMarkup = ['\t<image ', this.getSvgId(), 'xlink:href="', this.getSvgSrc(true),
        '" x="', x - this.cropX, '" y="', y - this.cropY,
        '" style="', this.getSvgStyles(),
        // we're essentially moving origin of transformation from top/left corner to the center of the shape
        // by wrapping it in container <g> element with actual transformation, then offsetting object to the top/left
        // so that object's center aligns with container's left/top
        '" width="', this._element.width || this._element.naturalWidth,
        '" height="', this._element.height || this._element.height,
        '"', clipPath,
        '></image>\n'];
      if (this.paintFirst === 'fill') {
        Array.prototype.push.apply(markup, imageMarkup);
      }
      if (this.stroke || this.strokeDashArray) {
        var origFill = this.fill;
        this.fill = null;
        markup.push(
          '\t<rect ',
          'x="', x, '" y="', y,
          '" width="', this.width, '" height="', this.height,
          '" style="', this.getSvgStyles(),
          '"/>\n'
        );
        this.fill = origFill;
      }
      if (this.paintFirst !== 'fill') {
        Array.prototype.push.apply(markup, imageMarkup);
      }
      markup.push('</g>\n');

      return reviver ? reviver(markup.join('')) : markup.join('');
    },
    /* _TO_SVG_END_ */

    /**
     * Returns source of an image
     * @param {Boolean} filtered indicates if the src is needed for svg
     * @return {String} Source of an image
     */
    getSrc: function(filtered) {
      var element = filtered ? this._element : this._originalElement;
      if (element) {
        if (element.toDataURL) {
          return element.toDataURL();
        }
        return element.src;
      }
      else {
        return this.src || '';
      }
    },

    /**
     * Sets source of an image
     * @param {String} src Source string (URL)
     * @param {Function} [callback] Callback is invoked when image has been loaded (and all filters have been applied)
     * @param {Object} [options] Options object
     * @return {fabric.Image} thisArg
     * @chainable
     */
    setSrc: function(src, callback, options) {
      fabric.util.loadImage(src, function(img) {
        this.setElement(img, options);
        this._setWidthHeight();
        callback(this);
      }, this, options && options.crossOrigin);
      return this;
    },

    /**
     * Returns string representation of an instance
     * @return {String} String representation of an instance
     */
    toString: function() {
      return '#<fabric.Image: { src: "' + this.getSrc() + '" }>';
    },

    applyResizeFilters: function() {
      var filter = this.resizeFilter,
          retinaScaling = this.canvas ? this.canvas.getRetinaScaling() : 1,
          minimumScale = this.minimumScaleTrigger,
          scaleX = this.scaleX * retinaScaling,
          scaleY = this.scaleY * retinaScaling,
          elementToFilter = this._filteredEl || this._originalElement;
      if (this.group) {
        this.set('dirty', true);
      }
      if (!filter || (scaleX > minimumScale && scaleY > minimumScale)) {
        this._element = elementToFilter;
        this._filterScalingX = 1;
        this._filterScalingY = 1;
        return;
      }
      if (!fabric.filterBackend) {
        fabric.filterBackend = fabric.initFilterBackend();
      }
      var canvasEl = fabric.util.createCanvasElement(),
          cacheKey = this._filteredEl ? this.cacheKey : (this.cacheKey + '_filtered'),
          sourceWidth = elementToFilter.width, sourceHeight = elementToFilter.height;
      canvasEl.width = sourceWidth;
      canvasEl.height = sourceHeight;
      this._element = canvasEl;
      filter.scaleX = scaleX;
      filter.scaleY = scaleY;
      fabric.filterBackend.applyFilters(
        [filter], elementToFilter, sourceWidth, sourceHeight, this._element, cacheKey);
      this._filterScalingX = canvasEl.width / this._originalElement.width;
      this._filterScalingY = canvasEl.height / this._originalElement.height;
    },

    /**
     * Applies filters assigned to this image (from "filters" array) or from filter param
     * @method applyFilters
     * @param {Array} filters to be applied
     * @param {Boolean} forResizing specify if the filter operation is a resize operation
     * @return {thisArg} return the fabric.Image object
     * @chainable
     */
    applyFilters: function(filters) {

      filters = filters || this.filters || [];
      filters = filters.filter(function(filter) { return filter; });
      if (this.group) {
        this.set('dirty', true);
      }
      if (filters.length === 0) {
        this._element = this._originalElement;
        this._filteredEl = null;
        this._filterScalingX = 1;
        this._filterScalingY = 1;
        return this;
      }

      var imgElement = this._originalElement,
          sourceWidth = imgElement.naturalWidth || imgElement.width,
          sourceHeight = imgElement.naturalHeight || imgElement.height;

      if (this._element === this._originalElement) {
        // if the element is the same we need to create a new element
        var canvasEl = fabric.util.createCanvasElement();
        canvasEl.width = sourceWidth;
        canvasEl.height = sourceHeight;
        this._element = canvasEl;
        this._filteredEl = canvasEl;
      }
      else {
        // clear the existing element to get new filter data
        this._element.getContext('2d').clearRect(0, 0, sourceWidth, sourceHeight);
      }
      if (!fabric.filterBackend) {
        fabric.filterBackend = fabric.initFilterBackend();
      }
      fabric.filterBackend.applyFilters(
        filters, this._originalElement, sourceWidth, sourceHeight, this._element, this.cacheKey);
      if (this._originalElement.width !== this._element.width ||
        this._originalElement.height !== this._element.height) {
        this._filterScalingX = this._element.width / this._originalElement.width;
        this._filterScalingY = this._element.height / this._originalElement.height;
      }
      return this;
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _render: function(ctx) {
      if (this.isMoving === false && this.resizeFilter && this._needsResize()) {
        this._lastScaleX = this.scaleX;
        this._lastScaleY = this.scaleY;
        this.applyResizeFilters();
      }
      this._stroke(ctx);
      this._renderPaintInOrder(ctx);
    },

    _renderFill: function(ctx) {
      var w = this.width, h = this.height, sW = w * this._filterScalingX, sH = h * this._filterScalingY,
          x = -w / 2, y = -h / 2, elementToDraw = this._element;
      elementToDraw && ctx.drawImage(elementToDraw,
        this.cropX * this._filterScalingX,
        this.cropY * this._filterScalingY,
        sW,
        sH,
        x, y, w, h);
    },

    /**
     * @private, needed to check if image needs resize
     */
    _needsResize: function() {
      return (this.scaleX !== this._lastScaleX || this.scaleY !== this._lastScaleY);
    },

    /**
     * @private
     */
    _resetWidthHeight: function() {
      var element = this.getElement();

      this.set('width', element.width);
      this.set('height', element.height);
    },

    /**
     * The Image class's initialization method. This method is automatically
     * called by the constructor.
     * @private
     * @param {HTMLImageElement|String} element The element representing the image
     * @param {Object} [options] Options object
     */
    _initElement: function(element, options) {
      this.setElement(fabric.util.getById(element), options);
      fabric.util.addClass(this.getElement(), fabric.Image.CSS_CANVAS);
    },

    /**
     * @private
     * @param {Object} [options] Options object
     */
    _initConfig: function(options) {
      options || (options = { });
      this.setOptions(options);
      this._setWidthHeight(options);
      if (this._element && this.crossOrigin) {
        this._element.crossOrigin = this.crossOrigin;
      }
    },

    /**
     * @private
     * @param {Array} filters to be initialized
     * @param {Function} callback Callback to invoke when all fabric.Image.filters instances are created
     */
    _initFilters: function(filters, callback) {
      if (filters && filters.length) {
        fabric.util.enlivenObjects(filters, function(enlivenedObjects) {
          callback && callback(enlivenedObjects);
        }, 'fabric.Image.filters');
      }
      else {
        callback && callback();
      }
    },

    /**
     * @private
     * @param {Object} [options] Object with width/height properties
     */
    _setWidthHeight: function(options) {
      this.width = options && ('width' in options)
        ? options.width
        : (this.getElement()
          ? this.getElement().width || 0
          : 0);

      this.height = options && ('height' in options)
        ? options.height
        : (this.getElement()
          ? this.getElement().height || 0
          : 0);
    },

    /**
     * Calculate offset for center and scale factor for the image in order to respect
     * the preserveAspectRatio attribute
     * @private
     * @return {Object}
     */
    parsePreserveAspectRatioAttribute: function() {
      var pAR = fabric.util.parsePreserveAspectRatioAttribute(this.preserveAspectRatio || ''),
          rWidth = this._element.width, rHeight = this._element.height,
          scaleX = 1, scaleY = 1, offsetLeft = 0, offsetTop = 0, cropX = 0, cropY = 0,
          offset, pWidth = this.width, pHeight = this.height, parsedAttributes = { width: pWidth, height: pHeight };
      if (pAR && (pAR.alignX !== 'none' || pAR.alignY !== 'none')) {
        if (pAR.meetOrSlice === 'meet') {
          scaleX = scaleY = fabric.util.findScaleToFit(this._element, parsedAttributes);
          offset = (pWidth - rWidth * scaleX) / 2;
          if (pAR.alignX === 'Min') {
            offsetLeft = -offset;
          }
          if (pAR.alignX === 'Max') {
            offsetLeft = offset;
          }
          offset = (pHeight - rHeight * scaleY) / 2;
          if (pAR.alignY === 'Min') {
            offsetTop = -offset;
          }
          if (pAR.alignY === 'Max') {
            offsetTop = offset;
          }
        }
        if (pAR.meetOrSlice === 'slice') {
          scaleX = scaleY = fabric.util.findScaleToCover(this._element, parsedAttributes);
          offset = rWidth - pWidth / scaleX;
          if (pAR.alignX === 'Mid') {
            cropX = offset / 2;
          }
          if (pAR.alignX === 'Max') {
            cropX = offset;
          }
          offset = rHeight - pHeight / scaleY;
          if (pAR.alignY === 'Mid') {
            cropY = offset / 2;
          }
          if (pAR.alignY === 'Max') {
            cropY = offset;
          }
          rWidth = pWidth / scaleX;
          rHeight = pHeight / scaleY;
        }
      }
      else {
        scaleX = pWidth / rWidth;
        scaleY = pHeight / rHeight;
      }
      return {
        width: rWidth,
        height: rHeight,
        scaleX: scaleX,
        scaleY: scaleY,
        offsetLeft: offsetLeft,
        offsetTop: offsetTop,
        cropX: cropX,
        cropY: cropY
      };
    }
  });

  /**
   * Default CSS class name for canvas
   * @static
   * @type String
   * @default
   */
  fabric.Image.CSS_CANVAS = 'canvas-img';

  /**
   * Alias for getSrc
   * @static
   */
  fabric.Image.prototype.getSvgSrc = fabric.Image.prototype.getSrc;

  /**
   * Creates an instance of fabric.Image from its object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {Function} callback Callback to invoke when an image instance is created
   */
  fabric.Image.fromObject = function(_object, callback) {
    var object = fabric.util.object.clone(_object);
    fabric.util.loadImage(object.src, function(img, error) {
      if (error) {
        callback && callback(null, error);
        return;
      }
      fabric.Image.prototype._initFilters.call(object, object.filters, function(filters) {
        object.filters = filters || [];
        fabric.Image.prototype._initFilters.call(object, [object.resizeFilter], function(resizeFilters) {
          object.resizeFilter = resizeFilters[0];
          var image = new fabric.Image(img, object);
          callback(image);
        });
      });
    }, null, object.crossOrigin);
  };

  /**
   * Creates an instance of fabric.Image from an URL string
   * @static
   * @param {String} url URL to create an image from
   * @param {Function} [callback] Callback to invoke when image is created (newly created image is passed as a first argument)
   * @param {Object} [imgOptions] Options object
   */
  fabric.Image.fromURL = function(url, callback, imgOptions) {
    fabric.util.loadImage(url, function(img) {
      callback && callback(new fabric.Image(img, imgOptions));
    }, null, imgOptions && imgOptions.crossOrigin);
  };

  /* _FROM_SVG_START_ */
  /**
   * List of attribute names to account for when parsing SVG element (used by {@link fabric.Image.fromElement})
   * @static
   * @see {@link http://www.w3.org/TR/SVG/struct.html#ImageElement}
   */
  fabric.Image.ATTRIBUTE_NAMES =
    fabric.SHARED_ATTRIBUTES.concat('x y width height preserveAspectRatio xlink:href crossOrigin'.split(' '));

  /**
   * Returns {@link fabric.Image} instance from an SVG element
   * @static
   * @param {SVGElement} element Element to parse
   * @param {Object} [options] Options object
   * @param {Function} callback Callback to execute when fabric.Image object is created
   * @return {fabric.Image} Instance of fabric.Image
   */
  fabric.Image.fromElement = function(element, callback, options) {
    var parsedAttributes = fabric.parseAttributes(element, fabric.Image.ATTRIBUTE_NAMES);
    fabric.Image.fromURL(parsedAttributes['xlink:href'], callback,
      extend((options ? fabric.util.object.clone(options) : { }), parsedAttributes));
  };
  /* _FROM_SVG_END_ */

})(typeof exports !== 'undefined' ? exports : this);


fabric.util.object.extend(fabric.Object.prototype, /** @lends fabric.Object.prototype */ {

  /**
   * @private
   * @return {Number} angle value
   */
  _getAngleValueForStraighten: function() {
    var angle = this.angle % 360;
    if (angle > 0) {
      return Math.round((angle - 1) / 90) * 90;
    }
    return Math.round(angle / 90) * 90;
  },

  /**
   * Straightens an object (rotating it from current angle to one of 0, 90, 180, 270, etc. depending on which is closer)
   * @return {fabric.Object} thisArg
   * @chainable
   */
  straighten: function() {
    this.rotate(this._getAngleValueForStraighten());
    return this;
  },

  /**
   * Same as {@link fabric.Object.prototype.straighten} but with animation
   * @param {Object} callbacks Object with callback functions
   * @param {Function} [callbacks.onComplete] Invoked on completion
   * @param {Function} [callbacks.onChange] Invoked on every step of animation
   * @return {fabric.Object} thisArg
   * @chainable
   */
  fxStraighten: function(callbacks) {
    callbacks = callbacks || { };

    var empty = function() { },
        onComplete = callbacks.onComplete || empty,
        onChange = callbacks.onChange || empty,
        _this = this;

    fabric.util.animate({
      startValue: this.get('angle'),
      endValue: this._getAngleValueForStraighten(),
      duration: this.FX_DURATION,
      onChange: function(value) {
        _this.rotate(value);
        onChange();
      },
      onComplete: function() {
        _this.setCoords();
        onComplete();
      },
    });

    return this;
  }
});

fabric.util.object.extend(fabric.StaticCanvas.prototype, /** @lends fabric.StaticCanvas.prototype */ {

  /**
   * Straightens object, then rerenders canvas
   * @param {fabric.Object} object Object to straighten
   * @return {fabric.Canvas} thisArg
   * @chainable
   */
  straightenObject: function (object) {
    object.straighten();
    this.requestRenderAll();
    return this;
  },

  /**
   * Same as {@link fabric.Canvas.prototype.straightenObject}, but animated
   * @param {fabric.Object} object Object to straighten
   * @return {fabric.Canvas} thisArg
   * @chainable
   */
  fxStraightenObject: function (object) {
    object.fxStraighten({
      onChange: this.requestRenderAllBound
    });
    return this;
  }
});


(function() {

  'use strict';

  /**
   * Tests if webgl supports certain precision
   * @param {WebGL} Canvas WebGL context to test on
   * @param {String} Precision to test can be any of following: 'lowp', 'mediump', 'highp'
   * @returns {Boolean} Whether the user's browser WebGL supports given precision.
   */
  function testPrecision(gl, precision){
    var fragmentSource = 'precision ' + precision + ' float;\nvoid main(){}';
    var fragmentShader = gl.createShader(gl.FRAGMENT_SHADER);
    gl.shaderSource(fragmentShader, fragmentSource);
    gl.compileShader(fragmentShader);
    if (!gl.getShaderParameter(fragmentShader, gl.COMPILE_STATUS)) {
      return false;
    }
    return true;
  }

  /**
   * Indicate whether this filtering backend is supported by the user's browser.
   * @param {Number} tileSize check if the tileSize is supported
   * @returns {Boolean} Whether the user's browser supports WebGL.
   */
  fabric.isWebglSupported = function(tileSize) {
    if (fabric.isLikelyNode) {
      return false;
    }
    tileSize = tileSize || fabric.WebglFilterBackend.prototype.tileSize;
    var canvas = document.createElement('canvas');
    var gl = canvas.getContext('webgl') || canvas.getContext('experimental-webgl');
    var isSupported = false;
    // eslint-disable-next-line
    if (gl) {
      fabric.maxTextureSize = gl.getParameter(gl.MAX_TEXTURE_SIZE);
      isSupported = fabric.maxTextureSize >= tileSize;
      var precisions = ['highp', 'mediump', 'lowp'];
      for (var i = 0; i < 3; i++){
        if (testPrecision(gl, precisions[i])){
          fabric.webGlPrecision = precisions[i];
          break;
        };
      }
    }
    this.isSupported = isSupported;
    return isSupported;
  };

  fabric.WebglFilterBackend = WebglFilterBackend;

  /**
   * WebGL filter backend.
   */
  function WebglFilterBackend(options) {
    if (options && options.tileSize) {
      this.tileSize = options.tileSize;
    }
    this.setupGLContext(this.tileSize, this.tileSize);
    this.captureGPUInfo();
  };

  WebglFilterBackend.prototype = /** @lends fabric.WebglFilterBackend.prototype */ {

    tileSize: 2048,

    /**
     * Experimental. This object is a sort of repository of help layers used to avoid
     * of recreating them during frequent filtering. If you are previewing a filter with
     * a slider you problably do not want to create help layers every filter step.
     * in this object there will be appended some canvases, created once, resized sometimes
     * cleared never. Clearing is left to the developer.
     **/
    resources: {

    },

    /**
     * Setup a WebGL context suitable for filtering, and bind any needed event handlers.
     */
    setupGLContext: function(width, height) {
      this.dispose();
      this.createWebGLCanvas(width, height);
      // eslint-disable-next-line
      this.aPosition = new Float32Array([0, 0, 0, 1, 1, 0, 1, 1]);
      this.chooseFastestCopyGLTo2DMethod(width, height);
    },

    /**
     * Pick a method to copy data from GL context to 2d canvas.  In some browsers using
     * putImageData is faster than drawImage for that specific operation.
     */
    chooseFastestCopyGLTo2DMethod: function(width, height) {
      var canMeasurePerf = typeof window.performance !== 'undefined';
      var canUseImageData;
      try {
        new ImageData(1, 1);
        canUseImageData = true;
      }
      catch (e) {
        canUseImageData = false;
      }
      // eslint-disable-next-line no-undef
      var canUseArrayBuffer = typeof ArrayBuffer !== 'undefined';
      // eslint-disable-next-line no-undef
      var canUseUint8Clamped = typeof Uint8ClampedArray !== 'undefined';

      if (!(canMeasurePerf && canUseImageData && canUseArrayBuffer && canUseUint8Clamped)) {
        return;
      }

      var targetCanvas = fabric.util.createCanvasElement();
      // eslint-disable-next-line no-undef
      var imageBuffer = new ArrayBuffer(width * height * 4);
      var testContext = {
        imageBuffer: imageBuffer,
        destinationWidth: width,
        destinationHeight: height,
        targetCanvas: targetCanvas
      };
      var startTime, drawImageTime, putImageDataTime;
      targetCanvas.width = width;
      targetCanvas.height = height;

      startTime = window.performance.now();
      copyGLTo2DDrawImage.call(testContext, this.gl, testContext);
      drawImageTime = window.performance.now() - startTime;

      startTime = window.performance.now();
      copyGLTo2DPutImageData.call(testContext, this.gl, testContext);
      putImageDataTime = window.performance.now() - startTime;

      if (drawImageTime > putImageDataTime) {
        this.imageBuffer = imageBuffer;
        this.copyGLTo2D = copyGLTo2DPutImageData;
      }
      else {
        this.copyGLTo2D = copyGLTo2DDrawImage;
      }
    },

    /**
     * Create a canvas element and associated WebGL context and attaches them as
     * class properties to the GLFilterBackend class.
     */
    createWebGLCanvas: function(width, height) {
      var canvas = fabric.util.createCanvasElement();
      canvas.width = width;
      canvas.height = height;
      var glOptions = {
            alpha: true,
            premultipliedAlpha: false,
            depth: false,
            stencil: false,
            antialias: false
          },
          gl = canvas.getContext('webgl', glOptions);
      if (!gl) {
        gl = canvas.getContext('experimental-webgl', glOptions);
      }
      if (!gl) {
        return;
      }
      gl.clearColor(0, 0, 0, 0);
      // this canvas can fire webglcontextlost and webglcontextrestored
      this.canvas = canvas;
      this.gl = gl;
    },

    /**
     * Attempts to apply the requested filters to the source provided, drawing the filtered output
     * to the provided target canvas.
     *
     * @param {Array} filters The filters to apply.
     * @param {HTMLImageElement|HTMLCanvasElement} source The source to be filtered.
     * @param {Number} width The width of the source input.
     * @param {Number} height The height of the source input.
     * @param {HTMLCanvasElement} targetCanvas The destination for filtered output to be drawn.
     * @param {String|undefined} cacheKey A key used to cache resources related to the source. If
     * omitted, caching will be skipped.
     */
    applyFilters: function(filters, source, width, height, targetCanvas, cacheKey) {
      var gl = this.gl;
      var cachedTexture;
      if (cacheKey) {
        cachedTexture = this.getCachedTexture(cacheKey, source);
      }
      var pipelineState = {
        originalWidth: source.width || source.originalWidth,
        originalHeight: source.height || source.originalHeight,
        sourceWidth: width,
        sourceHeight: height,
        destinationWidth: width,
        destinationHeight: height,
        context: gl,
        sourceTexture: this.createTexture(gl, width, height, !cachedTexture && source),
        targetTexture: this.createTexture(gl, width, height),
        originalTexture: cachedTexture ||
          this.createTexture(gl, width, height, !cachedTexture && source),
        passes: filters.length,
        webgl: true,
        aPosition: this.aPosition,
        programCache: this.programCache,
        pass: 0,
        filterBackend: this,
        targetCanvas: targetCanvas
      };
      var tempFbo = gl.createFramebuffer();
      gl.bindFramebuffer(gl.FRAMEBUFFER, tempFbo);
      filters.forEach(function(filter) { filter && filter.applyTo(pipelineState); });
      resizeCanvasIfNeeded(pipelineState);
      this.copyGLTo2D(gl, pipelineState);
      gl.bindTexture(gl.TEXTURE_2D, null);
      gl.deleteTexture(pipelineState.sourceTexture);
      gl.deleteTexture(pipelineState.targetTexture);
      gl.deleteFramebuffer(tempFbo);
      targetCanvas.getContext('2d').setTransform(1, 0, 0, 1, 0, 0);
      return pipelineState;
    },

    /**
     * The same as the applyFilter method but with additional logging of WebGL
     * errors.
     */
    applyFiltersDebug: function(filters, source, width, height, targetCanvas, cacheKey) {
      // The following code is useful when debugging a specific issue but adds ~10x slowdown.
      var gl = this.gl;
      var ret = this.applyFilters(filters, source, width, height, targetCanvas, cacheKey);
      var glError = gl.getError();
      if (glError !== gl.NO_ERROR) {
        var errorString = this.glErrorToString(gl, glError);
        var error = new Error('WebGL Error ' + errorString);
        error.glErrorCode = glError;
        throw error;
      }
      return ret;
    },

    glErrorToString: function(context, errorCode) {
      if (!context) {
        return 'Context undefined for error code: ' + errorCode;
      }
      else if (typeof errorCode !== 'number') {
        return 'Error code is not a number';
      }
      switch (errorCode) {
        case context.NO_ERROR:
          return 'NO_ERROR';
        case context.INVALID_ENUM:
          return 'INVALID_ENUM';
        case context.INVALID_VALUE:
          return 'INVALID_VALUE';
        case context.INVALID_OPERATION:
          return 'INVALID_OPERATION';
        case context.INVALID_FRAMEBUFFER_OPERATION:
          return 'INVALID_FRAMEBUFFER_OPERATION';
        case context.OUT_OF_MEMORY:
          return 'OUT_OF_MEMORY';
        case context.CONTEXT_LOST_WEBGL:
          return 'CONTEXT_LOST_WEBGL';
        default:
          return 'UNKNOWN_ERROR';
      }
    },

    /**
     * Detach event listeners, remove references, and clean up caches.
     */
    dispose: function() {
      if (this.canvas) {
        this.canvas = null;
        this.gl = null;
      }
      this.clearWebGLCaches();
    },

    /**
     * Wipe out WebGL-related caches.
     */
    clearWebGLCaches: function() {
      this.programCache = {};
      this.textureCache = {};
    },

    /**
     * Create a WebGL texture object.
     *
     * Accepts specific dimensions to initialize the textuer to or a source image.
     *
     * @param {WebGLRenderingContext} gl The GL context to use for creating the texture.
     * @param {Number} width The width to initialize the texture at.
     * @param {Number} height The height to initialize the texture.
     * @param {HTMLImageElement|HTMLCanvasElement} textureImageSource A source for the texture data.
     * @returns {WebGLTexture}
     */
    createTexture: function(gl, width, height, textureImageSource) {
      var texture = gl.createTexture();
      gl.bindTexture(gl.TEXTURE_2D, texture);
      gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
      gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
      gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
      gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
      if (textureImageSource) {
        gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, textureImageSource);
      }
      else {
        gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
      }
      return texture;
    },

    /**
     * Can be optionally used to get a texture from the cache array
     *
     * If an existing texture is not found, a new texture is created and cached.
     *
     * @param {String} uniqueId A cache key to use to find an existing texture.
     * @param {HTMLImageElement|HTMLCanvasElement} textureImageSource A source to use to create the
     * texture cache entry if one does not already exist.
     */
    getCachedTexture: function(uniqueId, textureImageSource) {
      if (this.textureCache[uniqueId]) {
        return this.textureCache[uniqueId];
      }
      else {
        var texture = this.createTexture(
          this.gl, textureImageSource.width, textureImageSource.height, textureImageSource);
        this.textureCache[uniqueId] = texture;
        return texture;
      }
    },

    /**
     * Clear out cached resources related to a source image that has been
     * filtered previously.
     *
     * @param {String} cacheKey The cache key provided when the source image was filtered.
     */
    evictCachesForKey: function(cacheKey) {
      if (this.textureCache[cacheKey]) {
        this.gl.deleteTexture(this.textureCache[cacheKey]);
        delete this.textureCache[cacheKey];
      }
    },

    copyGLTo2D: copyGLTo2DDrawImage,

    /**
     * Attempt to extract GPU information strings from a WebGL context.
     *
     * Useful information when debugging or blacklisting specific GPUs.
     *
     * @returns {Object} A GPU info object with renderer and vendor strings.
     */
    captureGPUInfo: function() {
      if (this.gpuInfo) {
        return this.gpuInfo;
      }
      var gl = this.gl;
      var ext = gl.getExtension('WEBGL_debug_renderer_info');
      var gpuInfo = { renderer: '', vendor: '' };
      if (ext) {
        var renderer = gl.getParameter(ext.UNMASKED_RENDERER_WEBGL);
        var vendor = gl.getParameter(ext.UNMASKED_VENDOR_WEBGL);
        if (renderer) {
          gpuInfo.renderer = renderer.toLowerCase();
        }
        if (vendor) {
          gpuInfo.vendor = vendor.toLowerCase();
        }
      }
      this.gpuInfo = gpuInfo;
      return gpuInfo;
    },
  };
})();

function resizeCanvasIfNeeded(pipelineState) {
  var targetCanvas = pipelineState.targetCanvas,
      width = targetCanvas.width, height = targetCanvas.height,
      dWidth = pipelineState.destinationWidth,
      dHeight = pipelineState.destinationHeight;

  if (width !== dWidth || height !== dHeight) {
    targetCanvas.width = dWidth;
    targetCanvas.height = dHeight;
  }
}

/**
 * Copy an input WebGL canvas on to an output 2D canvas.
 *
 * The WebGL canvas is assumed to be upside down, with the top-left pixel of the
 * desired output image appearing in the bottom-left corner of the WebGL canvas.
 *
 * @param {WebGLRenderingContext} sourceContext The WebGL context to copy from.
 * @param {HTMLCanvasElement} targetCanvas The 2D target canvas to copy on to.
 * @param {Object} pipelineState The 2D target canvas to copy on to.
 */
function copyGLTo2DDrawImage(gl, pipelineState) {
  var glCanvas = gl.canvas, targetCanvas = pipelineState.targetCanvas,
      ctx = targetCanvas.getContext('2d');
  ctx.translate(0, targetCanvas.height); // move it down again
  ctx.scale(1, -1); // vertical flip
  // where is my image on the big glcanvas?
  var sourceY = glCanvas.height - targetCanvas.height;
  ctx.drawImage(glCanvas, 0, sourceY, targetCanvas.width, targetCanvas.height, 0, 0,
    targetCanvas.width, targetCanvas.height);
}

/**
 * Copy an input WebGL canvas on to an output 2D canvas using 2d canvas' putImageData
 * API. Measurably faster than using ctx.drawImage in Firefox (version 54 on OSX Sierra).
 *
 * @param {WebGLRenderingContext} sourceContext The WebGL context to copy from.
 * @param {HTMLCanvasElement} targetCanvas The 2D target canvas to copy on to.
 * @param {Object} pipelineState The 2D target canvas to copy on to.
 */
function copyGLTo2DPutImageData(gl, pipelineState) {
  var targetCanvas = pipelineState.targetCanvas, ctx = targetCanvas.getContext('2d'),
      dWidth = pipelineState.destinationWidth,
      dHeight = pipelineState.destinationHeight,
      numBytes = dWidth * dHeight * 4;

  // eslint-disable-next-line no-undef
  var u8 = new Uint8Array(this.imageBuffer, 0, numBytes);
  // eslint-disable-next-line no-undef
  var u8Clamped = new Uint8ClampedArray(this.imageBuffer, 0, numBytes);

  gl.readPixels(0, 0, dWidth, dHeight, gl.RGBA, gl.UNSIGNED_BYTE, u8);
  var imgData = new ImageData(u8Clamped, dWidth, dHeight);
  ctx.putImageData(imgData, 0, 0);
}


(function() {

  'use strict';

  var noop = function() {};

  fabric.Canvas2dFilterBackend = Canvas2dFilterBackend;

  /**
   * Canvas 2D filter backend.
   */
  function Canvas2dFilterBackend() {};

  Canvas2dFilterBackend.prototype = /** @lends fabric.Canvas2dFilterBackend.prototype */ {
    evictCachesForKey: noop,
    dispose: noop,
    clearWebGLCaches: noop,

    /**
     * Experimental. This object is a sort of repository of help layers used to avoid
     * of recreating them during frequent filtering. If you are previewing a filter with
     * a slider you probably do not want to create help layers every filter step.
     * in this object there will be appended some canvases, created once, resized sometimes
     * cleared never. Clearing is left to the developer.
     **/
    resources: {

    },

    /**
     * Apply a set of filters against a source image and draw the filtered output
     * to the provided destination canvas.
     *
     * @param {EnhancedFilter} filters The filter to apply.
     * @param {HTMLImageElement|HTMLCanvasElement} sourceElement The source to be filtered.
     * @param {Number} sourceWidth The width of the source input.
     * @param {Number} sourceHeight The height of the source input.
     * @param {HTMLCanvasElement} targetCanvas The destination for filtered output to be drawn.
     */
    applyFilters: function(filters, sourceElement, sourceWidth, sourceHeight, targetCanvas) {
      var ctx = targetCanvas.getContext('2d');
      ctx.drawImage(sourceElement, 0, 0, sourceWidth, sourceHeight);
      var imageData = ctx.getImageData(0, 0, sourceWidth, sourceHeight);
      var originalImageData = ctx.getImageData(0, 0, sourceWidth, sourceHeight);
      var pipelineState = {
        sourceWidth: sourceWidth,
        sourceHeight: sourceHeight,
        imageData: imageData,
        originalEl: sourceElement,
        originalImageData: originalImageData,
        canvasEl: targetCanvas,
        ctx: ctx,
        filterBackend: this,
      };
      filters.forEach(function(filter) { filter.applyTo(pipelineState); });
      if (pipelineState.imageData.width !== sourceWidth || pipelineState.imageData.height !== sourceHeight) {
        targetCanvas.width = pipelineState.imageData.width;
        targetCanvas.height = pipelineState.imageData.height;
      }
      ctx.putImageData(pipelineState.imageData, 0, 0);
      return pipelineState;
    },

  };
})();


/**
 * @namespace fabric.Image.filters
 * @memberOf fabric.Image
 * @tutorial {@link http://fabricjs.com/fabric-intro-part-2#image_filters}
 * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
 */
fabric.Image.filters = fabric.Image.filters || { };

/**
 * Root filter class from which all filter classes inherit from
 * @class fabric.Image.filters.BaseFilter
 * @memberOf fabric.Image.filters
 */
fabric.Image.filters.BaseFilter = fabric.util.createClass(/** @lends fabric.Image.filters.BaseFilter.prototype */ {

  /**
   * Filter type
   * @param {String} type
   * @default
   */
  type: 'BaseFilter',

  /**
   * Array of attributes to send with buffers. do not modify
   * @private
   */

  vertexSource: 'attribute vec2 aPosition;\n' +
    'varying vec2 vTexCoord;\n' +
    'void main() {\n' +
      'vTexCoord = aPosition;\n' +
      'gl_Position = vec4(aPosition * 2.0 - 1.0, 0.0, 1.0);\n' +
    '}',

  fragmentSource: 'precision highp float;\n' +
    'varying vec2 vTexCoord;\n' +
    'uniform sampler2D uTexture;\n' +
    'void main() {\n' +
      'gl_FragColor = texture2D(uTexture, vTexCoord);\n' +
    '}',

  /**
   * Constructor
   * @param {Object} [options] Options object
   */
  initialize: function(options) {
    if (options) {
      this.setOptions(options);
    }
  },

  /**
   * Sets filter's properties from options
   * @param {Object} [options] Options object
   */
  setOptions: function(options) {
    for (var prop in options) {
      this[prop] = options[prop];
    }
  },

  /**
   * Compile this filter's shader program.
   *
   * @param {WebGLRenderingContext} gl The GL canvas context to use for shader compilation.
   * @param {String} fragmentSource fragmentShader source for compilation
   * @param {String} vertexSource vertexShader source for compilation
   */
  createProgram: function(gl, fragmentSource, vertexSource) {
    fragmentSource = fragmentSource || this.fragmentSource;
    vertexSource = vertexSource || this.vertexSource;
    if (fabric.webGlPrecision !== 'highp'){
      fragmentSource = fragmentSource.replace(
        /precision highp float/g,
        'precision ' + fabric.webGlPrecision + ' float'
      );
    }
    var vertexShader = gl.createShader(gl.VERTEX_SHADER);
    gl.shaderSource(vertexShader, vertexSource);
    gl.compileShader(vertexShader);
    if (!gl.getShaderParameter(vertexShader, gl.COMPILE_STATUS)) {
      throw new Error(
        // eslint-disable-next-line prefer-template
        'Vertex shader compile error for ' + this.type + ': ' +
        gl.getShaderInfoLog(vertexShader)
      );
    }

    var fragmentShader = gl.createShader(gl.FRAGMENT_SHADER);
    gl.shaderSource(fragmentShader, fragmentSource);
    gl.compileShader(fragmentShader);
    if (!gl.getShaderParameter(fragmentShader, gl.COMPILE_STATUS)) {
      throw new Error(
        // eslint-disable-next-line prefer-template
        'Fragment shader compile error for ' + this.type + ': ' +
        gl.getShaderInfoLog(fragmentShader)
      );
    }

    var program = gl.createProgram();
    gl.attachShader(program, vertexShader);
    gl.attachShader(program, fragmentShader);
    gl.linkProgram(program);
    if (!gl.getProgramParameter(program, gl.LINK_STATUS)) {
      throw new Error(
        // eslint-disable-next-line prefer-template
        'Shader link error for "${this.type}" ' +
        gl.getProgramInfoLog(program)
      );
    }

    var attributeLocations = this.getAttributeLocations(gl, program);
    var uniformLocations = this.getUniformLocations(gl, program) || { };
    uniformLocations.uStepW = gl.getUniformLocation(program, 'uStepW');
    uniformLocations.uStepH = gl.getUniformLocation(program, 'uStepH');
    return {
      program: program,
      attributeLocations: attributeLocations,
      uniformLocations: uniformLocations
    };
  },

  /**
   * Return a map of attribute names to WebGLAttributeLocation objects.
   *
   * @param {WebGLRenderingContext} gl The canvas context used to compile the shader program.
   * @param {WebGLShaderProgram} program The shader program from which to take attribute locations.
   * @returns {Object} A map of attribute names to attribute locations.
   */
  getAttributeLocations: function(gl, program) {
    return {
      aPosition: gl.getAttribLocation(program, 'aPosition'),
    };
  },

  /**
   * Return a map of uniform names to WebGLUniformLocation objects.
   *
   * Intended to be overridden by subclasses.
   *
   * @param {WebGLRenderingContext} gl The canvas context used to compile the shader program.
   * @param {WebGLShaderProgram} program The shader program from which to take uniform locations.
   * @returns {Object} A map of uniform names to uniform locations.
   */
  getUniformLocations: function (/* gl, program */) {
    // in case i do not need any special uniform i need to return an empty object
    return { };
  },

  /**
   * Send attribute data from this filter to its shader program on the GPU.
   *
   * @param {WebGLRenderingContext} gl The canvas context used to compile the shader program.
   * @param {Object} attributeLocations A map of shader attribute names to their locations.
   */
  sendAttributeData: function(gl, attributeLocations, aPositionData) {
    var attributeLocation = attributeLocations.aPosition;
    var buffer = gl.createBuffer();
    gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
    gl.enableVertexAttribArray(attributeLocation);
    gl.vertexAttribPointer(attributeLocation, 2, gl.FLOAT, false, 0, 0);
    gl.bufferData(gl.ARRAY_BUFFER, aPositionData, gl.STATIC_DRAW);
  },

  _setupFrameBuffer: function(options) {
    var gl = options.context, width, height;
    if (options.passes > 1) {
      width = options.destinationWidth;
      height = options.destinationHeight;
      if (options.sourceWidth !== width || options.sourceHeight !== height) {
        gl.deleteTexture(options.targetTexture);
        options.targetTexture = options.filterBackend.createTexture(gl, width, height);
      }
      gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D,
        options.targetTexture, 0);
    }
    else {
      // draw last filter on canvas and not to framebuffer.
      gl.bindFramebuffer(gl.FRAMEBUFFER, null);
      gl.finish();
    }
  },

  _swapTextures: function(options) {
    options.passes--;
    options.pass++;
    var temp = options.targetTexture;
    options.targetTexture = options.sourceTexture;
    options.sourceTexture = temp;
  },

  /**
   * Intentionally left blank, to be overridden in custom filters
   * @param {Object} options
   **/
  isNeutralState: function(/* options */) {
    return false;
  },

  /**
   * Apply this filter to the input image data provided.
   *
   * Determines whether to use WebGL or Canvas2D based on the options.webgl flag.
   *
   * @param {Object} options
   * @param {Number} options.passes The number of filters remaining to be executed
   * @param {Boolean} options.webgl Whether to use webgl to render the filter.
   * @param {WebGLTexture} options.sourceTexture The texture setup as the source to be filtered.
   * @param {WebGLTexture} options.targetTexture The texture where filtered output should be drawn.
   * @param {WebGLRenderingContext} options.context The GL context used for rendering.
   * @param {Object} options.programCache A map of compiled shader programs, keyed by filter type.
   */
  applyTo: function(options) {
    if (options.webgl) {
      if (options.passes > 1 && this.isNeutralState(options)) {
        // avoid doing something that we do not need
        return;
      }
      this._setupFrameBuffer(options);
      this.applyToWebGL(options);
      this._swapTextures(options);
    }
    else if (!this.isNeutralState()) {
      this.applyTo2d(options);
    }
  },

  /**
   * Retrieves the cached shader.
   * @param {Object} options
   * @param {WebGLRenderingContext} options.context The GL context used for rendering.
   * @param {Object} options.programCache A map of compiled shader programs, keyed by filter type.
   */
  retrieveShader: function(options) {
    if (!options.programCache.hasOwnProperty(this.type)) {
      options.programCache[this.type] = this.createProgram(options.context);
    }
    return options.programCache[this.type];
  },

  /**
   * Apply this filter using webgl.
   *
   * @param {Object} options
   * @param {Number} options.passes The number of filters remaining to be executed
   * @param {Boolean} options.webgl Whether to use webgl to render the filter.
   * @param {WebGLTexture} options.originalTexture The texture of the original input image.
   * @param {WebGLTexture} options.sourceTexture The texture setup as the source to be filtered.
   * @param {WebGLTexture} options.targetTexture The texture where filtered output should be drawn.
   * @param {WebGLRenderingContext} options.context The GL context used for rendering.
   * @param {Object} options.programCache A map of compiled shader programs, keyed by filter type.
   */
  applyToWebGL: function(options) {
    var gl = options.context;
    var shader = this.retrieveShader(options);
    if (options.pass === 0 && options.originalTexture) {
      gl.bindTexture(gl.TEXTURE_2D, options.originalTexture);
    }
    else {
      gl.bindTexture(gl.TEXTURE_2D, options.sourceTexture);
    }
    gl.useProgram(shader.program);
    this.sendAttributeData(gl, shader.attributeLocations, options.aPosition);

    gl.uniform1f(shader.uniformLocations.uStepW, 1 / options.sourceWidth);
    gl.uniform1f(shader.uniformLocations.uStepH, 1 / options.sourceHeight);

    this.sendUniformData(gl, shader.uniformLocations);
    gl.viewport(0, 0, options.destinationWidth, options.destinationHeight);
    gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);
  },

  bindAdditionalTexture: function(gl, texture, textureUnit) {
    gl.activeTexture(textureUnit);
    gl.bindTexture(gl.TEXTURE_2D, texture);
    // reset active texture to 0 as usual
    gl.activeTexture(gl.TEXTURE0);
  },

  unbindAdditionalTexture: function(gl, textureUnit) {
    gl.activeTexture(textureUnit);
    gl.bindTexture(gl.TEXTURE_2D, null);
    gl.activeTexture(gl.TEXTURE0);
  },

  getMainParameter: function() {
    return this[this.mainParameter];
  },

  setMainParameter: function(value) {
    this[this.mainParameter] = value;
  },

  /**
   * Send uniform data from this filter to its shader program on the GPU.
   *
   * Intended to be overridden by subclasses.
   *
   * @param {WebGLRenderingContext} gl The canvas context used to compile the shader program.
   * @param {Object} uniformLocations A map of shader uniform names to their locations.
   */
  sendUniformData: function(/* gl, uniformLocations */) {
    // Intentionally left blank.  Override me in subclasses.
  },

  /**
   * If needed by a 2d filter, this functions can create an helper canvas to be used
   * remember that options.targetCanvas is available for use till end of chain.
   */
  createHelpLayer: function(options) {
    if (!options.helpLayer) {
      var helpLayer = document.createElement('canvas');
      helpLayer.width = options.sourceWidth;
      helpLayer.height = options.sourceHeight;
      options.helpLayer = helpLayer;
    }
  },

  /**
   * Returns object representation of an instance
   * @return {Object} Object representation of an instance
   */
  toObject: function() {
    var object = { type: this.type }, mainP = this.mainParameter;
    if (mainP) {
      object[mainP] = this[mainP];
    }
    return object;
  },

  /**
   * Returns a JSON representation of an instance
   * @return {Object} JSON
   */
  toJSON: function() {
    // delegate, not alias
    return this.toObject();
  }
});

fabric.Image.filters.BaseFilter.fromObject = function(object, callback) {
  var filter = new fabric.Image.filters[object.type](object);
  callback && callback(filter);
  return filter;
};


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Color Matrix filter class
   * @class fabric.Image.filters.ColorMatrix
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link fabric.Image.filters.ColorMatrix#initialize} for constructor definition
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @see {@Link http://www.webwasp.co.uk/tutorials/219/Color_Matrix_Filter.php}
   * @see {@Link http://phoboslab.org/log/2013/11/fast-image-filters-with-webgl}
   * @example <caption>Kodachrome filter</caption>
   * var filter = new fabric.Image.filters.ColorMatrix({
   *  matrix: [
       1.1285582396593525, -0.3967382283601348, -0.03992559172921793, 0, 63.72958762196502,
       -0.16404339962244616, 1.0835251566291304, -0.05498805115633132, 0, 24.732407896706203,
       -0.16786010706155763, -0.5603416277695248, 1.6014850761964943, 0, 35.62982807460946,
       0, 0, 0, 1, 0
      ]
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   */
  filters.ColorMatrix = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.ColorMatrix.prototype */ {

    /**
     * Filter type
     * @param {String} type
     * @default
     */
    type: 'ColorMatrix',

    fragmentSource: 'precision highp float;\n' +
      'uniform sampler2D uTexture;\n' +
      'varying vec2 vTexCoord;\n' +
      'uniform mat4 uColorMatrix;\n' +
      'uniform vec4 uConstants;\n' +
      'void main() {\n' +
        'vec4 color = texture2D(uTexture, vTexCoord);\n' +
        'color *= uColorMatrix;\n' +
        'color += uConstants;\n' +
        'gl_FragColor = color;\n' +
      '}',

    /**
     * Colormatrix for pixels.
     * array of 20 floats. Numbers in positions 4, 9, 14, 19 loose meaning
     * outside the -1, 1 range.
     * 0.0039215686 is the part of 1 that get translated to 1 in 2d
     * @param {Array} matrix array of 20 numbers.
     * @default
     */
    matrix: [
      1, 0, 0, 0, 0,
      0, 1, 0, 0, 0,
      0, 0, 1, 0, 0,
      0, 0, 0, 1, 0
    ],

    mainParameter: 'matrix',

    /**
     * Lock the colormatrix on the color part, skipping alpha, manly for non webgl scenario
     * to save some calculation
     */
    colorsOnly: true,

    /**
     * Constructor
     * @param {Object} [options] Options object
     */
    initialize: function(options) {
      this.callSuper('initialize', options);
      // create a new array instead mutating the prototype with push
      this.matrix = this.matrix.slice(0);
    },

    /**
     * Intentionally left blank, to be overridden in custom filters
     * @param {Object} options
     **/
    isNeutralState: function(/* options */) {
      var _class = filters.ColorMatrix;
      for (var i = 20; i--;) {
        if (this.matrix[i] !== _class.prototype.matrix[i]) {
          return false;
        }
      }
      return true;
    },

    /**
     * Apply the ColorMatrix operation to a Uint8Array representing the pixels of an image.
     *
     * @param {Object} options
     * @param {ImageData} options.imageData The Uint8Array to be filtered.
     */
    applyTo2d: function(options) {
      var imageData = options.imageData,
          data = imageData.data,
          iLen = data.length,
          m = this.matrix,
          r, g, b, a, i, colorsOnly = this.colorsOnly;

      for (i = 0; i < iLen; i += 4) {
        r = data[i];
        g = data[i + 1];
        b = data[i + 2];
        if (colorsOnly) {
          data[i] = r * m[0] + g * m[1] + b * m[2] + m[4] * 255;
          data[i + 1] = r * m[5] + g * m[6] + b * m[7] + m[9] * 255;
          data[i + 2] = r * m[10] + g * m[11] + b * m[12] + m[14] * 255;
        }
        else {
          a = data[i + 3];
          data[i] = r * m[0] + g * m[1] + b * m[2] + a * m[3] + m[4] * 255;
          data[i + 1] = r * m[5] + g * m[6] + b * m[7] + a * m[8] + m[9] * 255;
          data[i + 2] = r * m[10] + g * m[11] + b * m[12] + a * m[13] + m[14] * 255;
          data[i + 3] = r * m[15] + g * m[16] + b * m[17] + a * m[18] + m[19] * 255;
        }
      }
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uColorMatrix: gl.getUniformLocation(program, 'uColorMatrix'),
        uConstants: gl.getUniformLocation(program, 'uConstants'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      var m = this.matrix,
          matrix = [
            m[0], m[1], m[2], m[3],
            m[5], m[6], m[7], m[8],
            m[10], m[11], m[12], m[13],
            m[15], m[16], m[17], m[18]
          ],
          constants = [m[4], m[9], m[14], m[19]];
      gl.uniformMatrix4fv(uniformLocations.uColorMatrix, false, matrix);
      gl.uniform4fv(uniformLocations.uConstants, constants);
    },
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] function to invoke after filter creation
   * @return {fabric.Image.filters.ColorMatrix} Instance of fabric.Image.filters.ColorMatrix
   */
  fabric.Image.filters.ColorMatrix.fromObject = fabric.Image.filters.BaseFilter.fromObject;
})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Brightness filter class
   * @class fabric.Image.filters.Brightness
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link fabric.Image.filters.Brightness#initialize} for constructor definition
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @example
   * var filter = new fabric.Image.filters.Brightness({
   *   brightness: 0.05
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   */
  filters.Brightness = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.Brightness.prototype */ {

    /**
     * Filter type
     * @param {String} type
     * @default
     */
    type: 'Brightness',

    /**
     * Fragment source for the brightness program
     */
    fragmentSource: 'precision highp float;\n' +
      'uniform sampler2D uTexture;\n' +
      'uniform float uBrightness;\n' +
      'varying vec2 vTexCoord;\n' +
      'void main() {\n' +
        'vec4 color = texture2D(uTexture, vTexCoord);\n' +
        'color.rgb += uBrightness;\n' +
        'gl_FragColor = color;\n' +
      '}',

    /**
     * Brightness value, from -1 to 1.
     * translated to -255 to 255 for 2d
     * 0.0039215686 is the part of 1 that get translated to 1 in 2d
     * @param {Number} brightness
     * @default
     */
    brightness: 0,

    /**
     * Describe the property that is the filter parameter
     * @param {String} m
     * @default
     */
    mainParameter: 'brightness',

    /**
    * Apply the Brightness operation to a Uint8ClampedArray representing the pixels of an image.
    *
    * @param {Object} options
    * @param {ImageData} options.imageData The Uint8ClampedArray to be filtered.
    */
    applyTo2d: function(options) {
      if (this.brightness === 0) {
        return;
      }
      var imageData = options.imageData,
          data = imageData.data, i, len = data.length,
          brightness = Math.round(this.brightness * 255);
      for (i = 0; i < len; i += 4) {
        data[i] = data[i] + brightness;
        data[i + 1] = data[i + 1] + brightness;
        data[i + 2] = data[i + 2] + brightness;
      }
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uBrightness: gl.getUniformLocation(program, 'uBrightness'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      gl.uniform1f(uniformLocations.uBrightness, this.brightness);
    },
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] to be invoked after filter creation
   * @return {fabric.Image.filters.Brightness} Instance of fabric.Image.filters.Brightness
   */
  fabric.Image.filters.Brightness.fromObject = fabric.Image.filters.BaseFilter.fromObject;

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      extend = fabric.util.object.extend,
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Adapted from <a href="http://www.html5rocks.com/en/tutorials/canvas/imagefilters/">html5rocks article</a>
   * @class fabric.Image.filters.Convolute
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link fabric.Image.filters.Convolute#initialize} for constructor definition
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @example <caption>Sharpen filter</caption>
   * var filter = new fabric.Image.filters.Convolute({
   *   matrix: [ 0, -1,  0,
   *            -1,  5, -1,
   *             0, -1,  0 ]
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   * canvas.renderAll();
   * @example <caption>Blur filter</caption>
   * var filter = new fabric.Image.filters.Convolute({
   *   matrix: [ 1/9, 1/9, 1/9,
   *             1/9, 1/9, 1/9,
   *             1/9, 1/9, 1/9 ]
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   * canvas.renderAll();
   * @example <caption>Emboss filter</caption>
   * var filter = new fabric.Image.filters.Convolute({
   *   matrix: [ 1,   1,  1,
   *             1, 0.7, -1,
   *            -1,  -1, -1 ]
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   * canvas.renderAll();
   * @example <caption>Emboss filter with opaqueness</caption>
   * var filter = new fabric.Image.filters.Convolute({
   *   opaque: true,
   *   matrix: [ 1,   1,  1,
   *             1, 0.7, -1,
   *            -1,  -1, -1 ]
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   * canvas.renderAll();
   */
  filters.Convolute = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.Convolute.prototype */ {

    /**
     * Filter type
     * @param {String} type
     * @default
     */
    type: 'Convolute',

    /*
     * Opaque value (true/false)
     */
    opaque: false,

    /*
     * matrix for the filter, max 9x9
     */
    matrix: [0, 0, 0, 0, 1, 0, 0, 0, 0],

    /**
     * Fragment source for the brightness program
     */
    fragmentSource: {
      Convolute_3_1: 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'uniform float uMatrix[9];\n' +
        'uniform float uStepW;\n' +
        'uniform float uStepH;\n' +
        'varying vec2 vTexCoord;\n' +
        'void main() {\n' +
          'vec4 color = vec4(0, 0, 0, 0);\n' +
          'for (float h = 0.0; h < 3.0; h+=1.0) {\n' +
            'for (float w = 0.0; w < 3.0; w+=1.0) {\n' +
              'vec2 matrixPos = vec2(uStepW * (w - 1), uStepH * (h - 1));\n' +
              'color += texture2D(uTexture, vTexCoord + matrixPos) * uMatrix[int(h * 3.0 + w)];\n' +
            '}\n' +
          '}\n' +
          'gl_FragColor = color;\n' +
        '}',
      Convolute_3_0: 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'uniform float uMatrix[9];\n' +
        'uniform float uStepW;\n' +
        'uniform float uStepH;\n' +
        'varying vec2 vTexCoord;\n' +
        'void main() {\n' +
          'vec4 color = vec4(0, 0, 0, 1);\n' +
          'for (float h = 0.0; h < 3.0; h+=1.0) {\n' +
            'for (float w = 0.0; w < 3.0; w+=1.0) {\n' +
              'vec2 matrixPos = vec2(uStepW * (w - 1.0), uStepH * (h - 1.0));\n' +
              'color.rgb += texture2D(uTexture, vTexCoord + matrixPos).rgb * uMatrix[int(h * 3.0 + w)];\n' +
            '}\n' +
          '}\n' +
          'float alpha = texture2D(uTexture, vTexCoord).a;\n' +
          'gl_FragColor = color;\n' +
          'gl_FragColor.a = alpha;\n' +
        '}',
      Convolute_5_1: 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'uniform float uMatrix[25];\n' +
        'uniform float uStepW;\n' +
        'uniform float uStepH;\n' +
        'varying vec2 vTexCoord;\n' +
        'void main() {\n' +
          'vec4 color = vec4(0, 0, 0, 0);\n' +
          'for (float h = 0.0; h < 5.0; h+=1.0) {\n' +
            'for (float w = 0.0; w < 5.0; w+=1.0) {\n' +
              'vec2 matrixPos = vec2(uStepW * (w - 2.0), uStepH * (h - 2.0));\n' +
              'color += texture2D(uTexture, vTexCoord + matrixPos) * uMatrix[int(h * 5.0 + w)];\n' +
            '}\n' +
          '}\n' +
          'gl_FragColor = color;\n' +
        '}',
      Convolute_5_0: 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'uniform float uMatrix[25];\n' +
        'uniform float uStepW;\n' +
        'uniform float uStepH;\n' +
        'varying vec2 vTexCoord;\n' +
        'void main() {\n' +
          'vec4 color = vec4(0, 0, 0, 1);\n' +
          'for (float h = 0.0; h < 5.0; h+=1.0) {\n' +
            'for (float w = 0.0; w < 5.0; w+=1.0) {\n' +
              'vec2 matrixPos = vec2(uStepW * (w - 2.0), uStepH * (h - 2.0));\n' +
              'color.rgb += texture2D(uTexture, vTexCoord + matrixPos).rgb * uMatrix[int(h * 5.0 + w)];\n' +
            '}\n' +
          '}\n' +
          'float alpha = texture2D(uTexture, vTexCoord).a;\n' +
          'gl_FragColor = color;\n' +
          'gl_FragColor.a = alpha;\n' +
        '}',
      Convolute_7_1: 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'uniform float uMatrix[49];\n' +
        'uniform float uStepW;\n' +
        'uniform float uStepH;\n' +
        'varying vec2 vTexCoord;\n' +
        'void main() {\n' +
          'vec4 color = vec4(0, 0, 0, 0);\n' +
          'for (float h = 0.0; h < 7.0; h+=1.0) {\n' +
            'for (float w = 0.0; w < 7.0; w+=1.0) {\n' +
              'vec2 matrixPos = vec2(uStepW * (w - 3.0), uStepH * (h - 3.0));\n' +
              'color += texture2D(uTexture, vTexCoord + matrixPos) * uMatrix[int(h * 7.0 + w)];\n' +
            '}\n' +
          '}\n' +
          'gl_FragColor = color;\n' +
        '}',
      Convolute_7_0: 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'uniform float uMatrix[49];\n' +
        'uniform float uStepW;\n' +
        'uniform float uStepH;\n' +
        'varying vec2 vTexCoord;\n' +
        'void main() {\n' +
          'vec4 color = vec4(0, 0, 0, 1);\n' +
          'for (float h = 0.0; h < 7.0; h+=1.0) {\n' +
            'for (float w = 0.0; w < 7.0; w+=1.0) {\n' +
              'vec2 matrixPos = vec2(uStepW * (w - 3.0), uStepH * (h - 3.0));\n' +
              'color.rgb += texture2D(uTexture, vTexCoord + matrixPos).rgb * uMatrix[int(h * 7.0 + w)];\n' +
            '}\n' +
          '}\n' +
          'float alpha = texture2D(uTexture, vTexCoord).a;\n' +
          'gl_FragColor = color;\n' +
          'gl_FragColor.a = alpha;\n' +
        '}',
      Convolute_9_1: 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'uniform float uMatrix[81];\n' +
        'uniform float uStepW;\n' +
        'uniform float uStepH;\n' +
        'varying vec2 vTexCoord;\n' +
        'void main() {\n' +
          'vec4 color = vec4(0, 0, 0, 0);\n' +
          'for (float h = 0.0; h < 9.0; h+=1.0) {\n' +
            'for (float w = 0.0; w < 9.0; w+=1.0) {\n' +
              'vec2 matrixPos = vec2(uStepW * (w - 4.0), uStepH * (h - 4.0));\n' +
              'color += texture2D(uTexture, vTexCoord + matrixPos) * uMatrix[int(h * 9.0 + w)];\n' +
            '}\n' +
          '}\n' +
          'gl_FragColor = color;\n' +
        '}',
      Convolute_9_0: 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'uniform float uMatrix[81];\n' +
        'uniform float uStepW;\n' +
        'uniform float uStepH;\n' +
        'varying vec2 vTexCoord;\n' +
        'void main() {\n' +
          'vec4 color = vec4(0, 0, 0, 1);\n' +
          'for (float h = 0.0; h < 9.0; h+=1.0) {\n' +
            'for (float w = 0.0; w < 9.0; w+=1.0) {\n' +
              'vec2 matrixPos = vec2(uStepW * (w - 4.0), uStepH * (h - 4.0));\n' +
              'color.rgb += texture2D(uTexture, vTexCoord + matrixPos).rgb * uMatrix[int(h * 9.0 + w)];\n' +
            '}\n' +
          '}\n' +
          'float alpha = texture2D(uTexture, vTexCoord).a;\n' +
          'gl_FragColor = color;\n' +
          'gl_FragColor.a = alpha;\n' +
        '}',
    },

    /**
     * Constructor
     * @memberOf fabric.Image.filters.Convolute.prototype
     * @param {Object} [options] Options object
     * @param {Boolean} [options.opaque=false] Opaque value (true/false)
     * @param {Array} [options.matrix] Filter matrix
     */


    /**
    * Retrieves the cached shader.
    * @param {Object} options
    * @param {WebGLRenderingContext} options.context The GL context used for rendering.
    * @param {Object} options.programCache A map of compiled shader programs, keyed by filter type.
    */
    retrieveShader: function(options) {
      var size = Math.sqrt(this.matrix.length);
      var cacheKey = this.type + '_' + size + '_' + (this.opaque ? 1 : 0);
      var shaderSource = this.fragmentSource[cacheKey];
      if (!options.programCache.hasOwnProperty(cacheKey)) {
        options.programCache[cacheKey] = this.createProgram(options.context, shaderSource);
      }
      return options.programCache[cacheKey];
    },

    /**
     * Apply the Brightness operation to a Uint8ClampedArray representing the pixels of an image.
     *
     * @param {Object} options
     * @param {ImageData} options.imageData The Uint8ClampedArray to be filtered.
     */
    applyTo2d: function(options) {
      var imageData = options.imageData,
          data = imageData.data,
          weights = this.matrix,
          side = Math.round(Math.sqrt(weights.length)),
          halfSide = Math.floor(side / 2),
          sw = imageData.width,
          sh = imageData.height,
          output = options.ctx.createImageData(sw, sh),
          dst = output.data,
          // go through the destination image pixels
          alphaFac = this.opaque ? 1 : 0,
          r, g, b, a, dstOff,
          scx, scy, srcOff, wt,
          x, y, cx, cy;

      for (y = 0; y < sh; y++) {
        for (x = 0; x < sw; x++) {
          dstOff = (y * sw + x) * 4;
          // calculate the weighed sum of the source image pixels that
          // fall under the convolution matrix
          r = 0; g = 0; b = 0; a = 0;

          for (cy = 0; cy < side; cy++) {
            for (cx = 0; cx < side; cx++) {
              scy = y + cy - halfSide;
              scx = x + cx - halfSide;

              // eslint-disable-next-line max-depth
              if (scy < 0 || scy > sh || scx < 0 || scx > sw) {
                continue;
              }

              srcOff = (scy * sw + scx) * 4;
              wt = weights[cy * side + cx];

              r += data[srcOff] * wt;
              g += data[srcOff + 1] * wt;
              b += data[srcOff + 2] * wt;
              // eslint-disable-next-line max-depth
              if (!alphaFac) {
                a += data[srcOff + 3] * wt;
              }
            }
          }
          dst[dstOff] = r;
          dst[dstOff + 1] = g;
          dst[dstOff + 2] = b;
          if (!alphaFac) {
            dst[dstOff + 3] = a;
          }
          else {
            dst[dstOff + 3] = data[dstOff + 3];
          }
        }
      }
      options.imageData = output;
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uMatrix: gl.getUniformLocation(program, 'uMatrix'),
        uOpaque: gl.getUniformLocation(program, 'uOpaque'),
        uHalfSize: gl.getUniformLocation(program, 'uHalfSize'),
        uSize: gl.getUniformLocation(program, 'uSize'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      gl.uniform1fv(uniformLocations.uMatrix, this.matrix);
    },

    /**
     * Returns object representation of an instance
     * @return {Object} Object representation of an instance
     */
    toObject: function() {
      return extend(this.callSuper('toObject'), {
        opaque: this.opaque,
        matrix: this.matrix
      });
    }
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] to be invoked after filter creation
   * @return {fabric.Image.filters.Convolute} Instance of fabric.Image.filters.Convolute
   */
  fabric.Image.filters.Convolute.fromObject = fabric.Image.filters.BaseFilter.fromObject;

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Grayscale image filter class
   * @class fabric.Image.filters.Grayscale
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @example
   * var filter = new fabric.Image.filters.Grayscale();
   * object.filters.push(filter);
   * object.applyFilters();
   */
  filters.Grayscale = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.Grayscale.prototype */ {

    /**
     * Filter type
     * @param {String} type
     * @default
     */
    type: 'Grayscale',

    fragmentSource: {
      average: 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'varying vec2 vTexCoord;\n' +
        'void main() {\n' +
          'vec4 color = texture2D(uTexture, vTexCoord);\n' +
          'float average = (color.r + color.b + color.g) / 3.0;\n' +
          'gl_FragColor = vec4(average, average, average, color.a);\n' +
        '}',
      lightness: 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'uniform int uMode;\n' +
        'varying vec2 vTexCoord;\n' +
        'void main() {\n' +
          'vec4 col = texture2D(uTexture, vTexCoord);\n' +
          'float average = (max(max(col.r, col.g),col.b) + min(min(col.r, col.g),col.b)) / 2.0;\n' +
          'gl_FragColor = vec4(average, average, average, col.a);\n' +
        '}',
      luminosity: 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'uniform int uMode;\n' +
        'varying vec2 vTexCoord;\n' +
        'void main() {\n' +
          'vec4 col = texture2D(uTexture, vTexCoord);\n' +
          'float average = 0.21 * col.r + 0.72 * col.g + 0.07 * col.b;\n' +
          'gl_FragColor = vec4(average, average, average, col.a);\n' +
        '}',
    },


    /**
     * Grayscale mode, between 'average', 'lightness', 'luminosity'
     * @param {String} type
     * @default
     */
    mode: 'average',

    mainParameter: 'mode',

    /**
     * Apply the Grayscale operation to a Uint8Array representing the pixels of an image.
     *
     * @param {Object} options
     * @param {ImageData} options.imageData The Uint8Array to be filtered.
     */
    applyTo2d: function(options) {
      var imageData = options.imageData,
          data = imageData.data, i,
          len = data.length, value,
          mode = this.mode;
      for (i = 0; i < len; i += 4) {
        if (mode === 'average') {
          value = (data[i] + data[i + 1] + data[i + 2]) / 3;
        }
        else if (mode === 'lightness') {
          value = (Math.min(data[i], data[i + 1], data[i + 2]) +
            Math.max(data[i], data[i + 1], data[i + 2])) / 2;
        }
        else if (mode === 'luminosity') {
          value = 0.21 * data[i] + 0.72 * data[i + 1] + 0.07 * data[i + 2];
        }
        data[i] = value;
        data[i + 1] = value;
        data[i + 2] = value;
      }
    },

    /**
     * Retrieves the cached shader.
     * @param {Object} options
     * @param {WebGLRenderingContext} options.context The GL context used for rendering.
     * @param {Object} options.programCache A map of compiled shader programs, keyed by filter type.
     */
    retrieveShader: function(options) {
      var cacheKey = this.type + '_' + this.mode;
      if (!options.programCache.hasOwnProperty(cacheKey)) {
        var shaderSource = this.fragmentSource[this.mode];
        options.programCache[cacheKey] = this.createProgram(options.context, shaderSource);
      }
      return options.programCache[cacheKey];
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uMode: gl.getUniformLocation(program, 'uMode'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      // default average mode.
      var mode = 1;
      gl.uniform1i(uniformLocations.uMode, mode);
    },
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] to be invoked after filter creation
   * @return {fabric.Image.filters.Grayscale} Instance of fabric.Image.filters.Grayscale
   */
  fabric.Image.filters.Grayscale.fromObject = fabric.Image.filters.BaseFilter.fromObject;

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Invert filter class
   * @class fabric.Image.filters.Invert
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @example
   * var filter = new fabric.Image.filters.Invert();
   * object.filters.push(filter);
   * object.applyFilters(canvas.renderAll.bind(canvas));
   */
  filters.Invert = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.Invert.prototype */ {

    /**
     * Filter type
     * @param {String} type
     * @default
     */
    type: 'Invert',

    fragmentSource: 'precision highp float;\n' +
      'uniform sampler2D uTexture;\n' +
      'uniform int uInvert;\n' +
      'varying vec2 vTexCoord;\n' +
      'void main() {\n' +
        'vec4 color = texture2D(uTexture, vTexCoord);\n' +
        'if (uInvert == 1) {\n' +
          'gl_FragColor = vec4(1.0 - color.r,1.0 -color.g,1.0 -color.b,color.a);\n' +
        '} else {\n' +
          'gl_FragColor = color;\n' +
        '}\n' +
      '}',

    /**
     * Filter invert. if false, does nothing
     * @param {Boolean} invert
     * @default
     */
    invert: true,

    mainParameter: 'invert',

    /**
     * Apply the Invert operation to a Uint8Array representing the pixels of an image.
     *
     * @param {Object} options
     * @param {ImageData} options.imageData The Uint8Array to be filtered.
     */
    applyTo2d: function(options) {
      if (!this.invert) {
        return;
      }
      var imageData = options.imageData,
          data = imageData.data, i,
          len = data.length;
      for (i = 0; i < len; i += 4) {
        data[i] = 255 - data[i];
        data[i + 1] = 255 - data[i + 1];
        data[i + 2] = 255 - data[i + 2];
      }
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uInvert: gl.getUniformLocation(program, 'uInvert'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      gl.uniform1i(uniformLocations.uInvert, this.invert);
    },
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] to be invoked after filter creation
   * @return {fabric.Image.filters.Invert} Instance of fabric.Image.filters.Invert
   */
  fabric.Image.filters.Invert.fromObject = fabric.Image.filters.BaseFilter.fromObject;


})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      extend = fabric.util.object.extend,
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Noise filter class
   * @class fabric.Image.filters.Noise
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link fabric.Image.filters.Noise#initialize} for constructor definition
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @example
   * var filter = new fabric.Image.filters.Noise({
   *   noise: 700
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   * canvas.renderAll();
   */
  filters.Noise = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.Noise.prototype */ {

    /**
     * Filter type
     * @param {String} type
     * @default
     */
    type: 'Noise',

    /**
     * Fragment source for the noise program
     */
    fragmentSource: 'precision highp float;\n' +
      'uniform sampler2D uTexture;\n' +
      'uniform float uStepH;\n' +
      'uniform float uNoise;\n' +
      'uniform float uSeed;\n' +
      'varying vec2 vTexCoord;\n' +
      'float rand(vec2 co, float seed, float vScale) {\n' +
        'return fract(sin(dot(co.xy * vScale ,vec2(12.9898 , 78.233))) * 43758.5453 * (seed + 0.01) / 2.0);\n' +
      '}\n' +
      'void main() {\n' +
        'vec4 color = texture2D(uTexture, vTexCoord);\n' +
        'color.rgb += (0.5 - rand(vTexCoord, uSeed, 0.1 / uStepH)) * uNoise;\n' +
        'gl_FragColor = color;\n' +
      '}',

    /**
     * Describe the property that is the filter parameter
     * @param {String} m
     * @default
     */
    mainParameter: 'noise',

    /**
     * Noise value, from
     * @param {Number} noise
     * @default
     */
    noise: 0,

    /**
     * Apply the Brightness operation to a Uint8ClampedArray representing the pixels of an image.
     *
     * @param {Object} options
     * @param {ImageData} options.imageData The Uint8ClampedArray to be filtered.
     */
    applyTo2d: function(options) {
      if (this.noise === 0) {
        return;
      }
      var imageData = options.imageData,
          data = imageData.data, i, len = data.length,
          noise = this.noise, rand;

      for (i = 0, len = data.length; i < len; i += 4) {

        rand = (0.5 - Math.random()) * noise;

        data[i] += rand;
        data[i + 1] += rand;
        data[i + 2] += rand;
      }
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uNoise: gl.getUniformLocation(program, 'uNoise'),
        uSeed: gl.getUniformLocation(program, 'uSeed'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      gl.uniform1f(uniformLocations.uNoise, this.noise / 255);
      gl.uniform1f(uniformLocations.uSeed, Math.random());
    },

    /**
     * Returns object representation of an instance
     * @return {Object} Object representation of an instance
     */
    toObject: function() {
      return extend(this.callSuper('toObject'), {
        noise: this.noise
      });
    }
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {Function} [callback] to be invoked after filter creation
   * @return {fabric.Image.filters.Noise} Instance of fabric.Image.filters.Noise
   */
  fabric.Image.filters.Noise.fromObject = fabric.Image.filters.BaseFilter.fromObject;

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Pixelate filter class
   * @class fabric.Image.filters.Pixelate
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link fabric.Image.filters.Pixelate#initialize} for constructor definition
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @example
   * var filter = new fabric.Image.filters.Pixelate({
   *   blocksize: 8
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   */
  filters.Pixelate = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.Pixelate.prototype */ {

    /**
     * Filter type
     * @param {String} type
     * @default
     */
    type: 'Pixelate',

    blocksize: 4,

    mainParameter: 'blocksize',

    /**
     * Fragment source for the Pixelate program
     */
    fragmentSource: 'precision highp float;\n' +
      'uniform sampler2D uTexture;\n' +
      'uniform float uBlocksize;\n' +
      'uniform float uStepW;\n' +
      'uniform float uStepH;\n' +
      'varying vec2 vTexCoord;\n' +
      'void main() {\n' +
        'float blockW = uBlocksize * uStepW;\n' +
        'float blockH = uBlocksize * uStepW;\n' +
        'int posX = int(vTexCoord.x / blockW);\n' +
        'int posY = int(vTexCoord.y / blockH);\n' +
        'float fposX = float(posX);\n' +
        'float fposY = float(posY);\n' +
        'vec2 squareCoords = vec2(fposX * blockW, fposY * blockH);\n' +
        'vec4 color = texture2D(uTexture, squareCoords);\n' +
        'gl_FragColor = color;\n' +
      '}',

    /**
     * Apply the Pixelate operation to a Uint8ClampedArray representing the pixels of an image.
     *
     * @param {Object} options
     * @param {ImageData} options.imageData The Uint8ClampedArray to be filtered.
     */
    applyTo2d: function(options) {
      if (this.blocksize === 1) {
        return;
      }
      var imageData = options.imageData,
          data = imageData.data,
          iLen = imageData.height,
          jLen = imageData.width,
          index, i, j, r, g, b, a,
          _i, _j, _iLen, _jLen;

      for (i = 0; i < iLen; i += this.blocksize) {
        for (j = 0; j < jLen; j += this.blocksize) {

          index = (i * 4) * jLen + (j * 4);

          r = data[index];
          g = data[index + 1];
          b = data[index + 2];
          a = data[index + 3];

          _iLen = Math.min(i + this.blocksize, iLen);
          _jLen = Math.min(j + this.blocksize, jLen);
          for (_i = i; _i < _iLen; _i++) {
            for (_j = j; _j < _jLen; _j++) {
              index = (_i * 4) * jLen + (_j * 4);
              data[index] = r;
              data[index + 1] = g;
              data[index + 2] = b;
              data[index + 3] = a;
            }
          }
        }
      }
    },

    /**
     * Indicate when the filter is not gonna apply changes to the image
     **/
    isNeutralState: function() {
      return this.blocksize === 1;
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uBlocksize: gl.getUniformLocation(program, 'uBlocksize'),
        uStepW: gl.getUniformLocation(program, 'uStepW'),
        uStepH: gl.getUniformLocation(program, 'uStepH'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      gl.uniform1f(uniformLocations.uBlocksize, this.blocksize);
    },
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {Function} [callback] to be invoked after filter creation
   * @return {fabric.Image.filters.Pixelate} Instance of fabric.Image.filters.Pixelate
   */
  fabric.Image.filters.Pixelate.fromObject = fabric.Image.filters.BaseFilter.fromObject;

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      extend = fabric.util.object.extend,
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Remove white filter class
   * @class fabric.Image.filters.RemoveColor
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link fabric.Image.filters.RemoveColor#initialize} for constructor definition
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @example
   * var filter = new fabric.Image.filters.RemoveColor({
   *   threshold: 0.2,
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   * canvas.renderAll();
   */
  filters.RemoveColor = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.RemoveColor.prototype */ {

    /**
     * Filter type
     * @param {String} type
     * @default
     */
    type: 'RemoveColor',

    /**
     * Color to remove, in any format understood by fabric.Color.
     * @param {String} type
     * @default
     */
    color: '#FFFFFF',

    /**
     * Fragment source for the brightness program
     */
    fragmentSource: 'precision highp float;\n' +
      'uniform sampler2D uTexture;\n' +
      'uniform vec4 uLow;\n' +
      'uniform vec4 uHigh;\n' +
      'varying vec2 vTexCoord;\n' +
      'void main() {\n' +
        'gl_FragColor = texture2D(uTexture, vTexCoord);\n' +
        'if(all(greaterThan(gl_FragColor.rgb,uLow.rgb)) && all(greaterThan(uHigh.rgb,gl_FragColor.rgb))) {\n' +
          'gl_FragColor.a = 0.0;\n' +
        '}\n' +
      '}',

    /**
     * distance to actual color, as value up or down from each r,g,b
     * between 0 and 1
     **/
    distance: 0.02,

    /**
     * For color to remove inside distance, use alpha channel for a smoother deletion
     * NOT IMPLEMENTED YET
     **/
    useAlpha: false,

    /**
     * Constructor
     * @memberOf fabric.Image.filters.RemoveWhite.prototype
     * @param {Object} [options] Options object
     * @param {Number} [options.color=#RRGGBB] Threshold value
     * @param {Number} [options.distance=10] Distance value
     */

    /**
     * Applies filter to canvas element
     * @param {Object} canvasEl Canvas element to apply filter to
     */
    applyTo2d: function(options) {
      var imageData = options.imageData,
          data = imageData.data, i,
          distance = this.distance * 255,
          r, g, b,
          source = new fabric.Color(this.color).getSource(),
          lowC = [
            source[0] - distance,
            source[1] - distance,
            source[2] - distance,
          ],
          highC = [
            source[0] + distance,
            source[1] + distance,
            source[2] + distance,
          ];


      for (i = 0; i < data.length; i += 4) {
        r = data[i];
        g = data[i + 1];
        b = data[i + 2];

        if (r > lowC[0] &&
            g > lowC[1] &&
            b > lowC[2] &&
            r < highC[0] &&
            g < highC[1] &&
            b < highC[2]) {
          data[i + 3] = 0;
        }
      }
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uLow: gl.getUniformLocation(program, 'uLow'),
        uHigh: gl.getUniformLocation(program, 'uHigh'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      var source = new fabric.Color(this.color).getSource(),
          distance = parseFloat(this.distance),
          lowC = [
            0 + source[0] / 255 - distance,
            0 + source[1] / 255 - distance,
            0 + source[2] / 255 - distance,
            1
          ],
          highC = [
            source[0] / 255 + distance,
            source[1] / 255 + distance,
            source[2] / 255 + distance,
            1
          ];
      gl.uniform4fv(uniformLocations.uLow, lowC);
      gl.uniform4fv(uniformLocations.uHigh, highC);
    },

    /**
     * Returns object representation of an instance
     * @return {Object} Object representation of an instance
     */
    toObject: function() {
      return extend(this.callSuper('toObject'), {
        color: this.color,
        distance: this.distance
      });
    }
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {Function} [callback] to be invoked after filter creation
   * @return {fabric.Image.filters.RemoveColor} Instance of fabric.Image.filters.RemoveWhite
   */
  fabric.Image.filters.RemoveColor.fromObject = fabric.Image.filters.BaseFilter.fromObject;

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  var matrices = {
    Brownie: [
      0.59970,0.34553,-0.27082,0,0.186,
      -0.03770,0.86095,0.15059,0,-0.1449,
      0.24113,-0.07441,0.44972,0,-0.02965,
      0,0,0,1,0
    ],
    Vintage: [
      0.62793,0.32021,-0.03965,0,0.03784,
      0.02578,0.64411,0.03259,0,0.02926,
      0.04660,-0.08512,0.52416,0,0.02023,
      0,0,0,1,0
    ],
    Kodachrome: [
      1.12855,-0.39673,-0.03992,0,0.24991,
      -0.16404,1.08352,-0.05498,0,0.09698,
      -0.16786,-0.56034,1.60148,0,0.13972,
      0,0,0,1,0
    ],
    Technicolor: [
      1.91252,-0.85453,-0.09155,0,0.04624,
      -0.30878,1.76589,-0.10601,0,-0.27589,
      -0.23110,-0.75018,1.84759,0,0.12137,
      0,0,0,1,0
    ],
    Polaroid: [
      1.438,-0.062,-0.062,0,0,
      -0.122,1.378,-0.122,0,0,
      -0.016,-0.016,1.483,0,0,
      0,0,0,1,0
    ],
    Sepia: [
      0.393, 0.769, 0.189, 0, 0,
      0.349, 0.686, 0.168, 0, 0,
      0.272, 0.534, 0.131, 0, 0,
      0, 0, 0, 1, 0
    ],
    BlackWhite: [
      1.5, 1.5, 1.5, 0, -1,
      1.5, 1.5, 1.5, 0, -1,
      1.5, 1.5, 1.5, 0, -1,
      0, 0, 0, 1, 0,
    ]
  };

  for (var key in matrices) {
    filters[key] = createClass(filters.ColorMatrix, /** @lends fabric.Image.filters.Sepia.prototype */ {

      /**
       * Filter type
       * @param {String} type
       * @default
       */
      type: key,

      /**
       * Colormatrix for the effect
       * array of 20 floats. Numbers in positions 4, 9, 14, 19 loose meaning
       * outside the -1, 1 range.
       * @param {Array} matrix array of 20 numbers.
       * @default
       */
      matrix: matrices[key],

      /**
       * Lock the matrix export for this kind of static, parameter less filters.
       */
      mainParameter: false,
      /**
       * Lock the colormatrix on the color part, skipping alpha
       */
      colorsOnly: true,

    });
    fabric.Image.filters[key].fromObject = fabric.Image.filters.BaseFilter.fromObject;
  }
})(typeof exports !== 'undefined' ? exports : this);


(function(global) {
  'use strict';

  var fabric = global.fabric,
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Color Blend filter class
   * @class fabric.Image.filter.BlendColor
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @example
   * var filter = new fabric.Image.filters.BlendColor({
   *  color: '#000',
   *  mode: 'multiply'
   * });
   *
   * var filter = new fabric.Image.filters.BlendImage({
   *  image: fabricImageObject,
   *  mode: 'multiply',
   *  alpha: 0.5
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   * canvas.renderAll();
   */

  filters.BlendColor = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.Blend.prototype */ {
    type: 'BlendColor',

    /**
     * Color to make the blend operation with. default to a reddish color since black or white
     * gives always strong result.
     **/
    color: '#F95C63',

    /**
     * Blend mode for the filter: one of multiply, add, diff, screen, subtract,
     * darken, lighten, overlay, exclusion, tint.
     **/
    mode: 'multiply',

    /**
     * alpha value. represent the strength of the blend color operation.
     **/
    alpha: 1,

    /**
     * Fragment source for the Multiply program
     */
    fragmentSource: {
      multiply: 'gl_FragColor.rgb *= uColor.rgb;\n',
      screen: 'gl_FragColor.rgb = 1.0 - (1.0 - gl_FragColor.rgb) * (1.0 - uColor.rgb);\n',
      add: 'gl_FragColor.rgb += uColor.rgb;\n',
      diff: 'gl_FragColor.rgb = abs(gl_FragColor.rgb - uColor.rgb);\n',
      subtract: 'gl_FragColor.rgb -= uColor.rgb;\n',
      lighten: 'gl_FragColor.rgb = max(gl_FragColor.rgb, uColor.rgb);\n',
      darken: 'gl_FragColor.rgb = min(gl_FragColor.rgb, uColor.rgb);\n',
      exclusion: 'gl_FragColor.rgb += uColor.rgb - 2.0 * (uColor.rgb * gl_FragColor.rgb);\n',
      overlay: 'if (uColor.r < 0.5) {\n' +
          'gl_FragColor.r *= 2.0 * uColor.r;\n' +
        '} else {\n' +
          'gl_FragColor.r = 1.0 - 2.0 * (1.0 - gl_FragColor.r) * (1.0 - uColor.r);\n' +
        '}\n' +
        'if (uColor.g < 0.5) {\n' +
          'gl_FragColor.g *= 2.0 * uColor.g;\n' +
        '} else {\n' +
          'gl_FragColor.g = 1.0 - 2.0 * (1.0 - gl_FragColor.g) * (1.0 - uColor.g);\n' +
        '}\n' +
        'if (uColor.b < 0.5) {\n' +
          'gl_FragColor.b *= 2.0 * uColor.b;\n' +
        '} else {\n' +
          'gl_FragColor.b = 1.0 - 2.0 * (1.0 - gl_FragColor.b) * (1.0 - uColor.b);\n' +
        '}\n',
      tint: 'gl_FragColor.rgb *= (1.0 - uColor.a);\n' +
        'gl_FragColor.rgb += uColor.rgb;\n',
    },

    /**
     * build the fragment source for the filters, joining the common part with
     * the specific one.
     * @param {String} mode the mode of the filter, a key of this.fragmentSource
     * @return {String} the source to be compiled
     * @private
     */
    buildSource: function(mode) {
      return 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'uniform vec4 uColor;\n' +
        'varying vec2 vTexCoord;\n' +
        'void main() {\n' +
          'vec4 color = texture2D(uTexture, vTexCoord);\n' +
          'gl_FragColor = color;\n' +
          'if (color.a > 0.0) {\n' +
            this.fragmentSource[mode] +
          '}\n' +
        '}';
    },

    /**
     * Retrieves the cached shader.
     * @param {Object} options
     * @param {WebGLRenderingContext} options.context The GL context used for rendering.
     * @param {Object} options.programCache A map of compiled shader programs, keyed by filter type.
     */
    retrieveShader: function(options) {
      var cacheKey = this.type + '_' + this.mode, shaderSource;
      if (!options.programCache.hasOwnProperty(cacheKey)) {
        shaderSource = this.buildSource(this.mode);
        options.programCache[cacheKey] = this.createProgram(options.context, shaderSource);
      }
      return options.programCache[cacheKey];
    },

    /**
     * Apply the Blend operation to a Uint8ClampedArray representing the pixels of an image.
     *
     * @param {Object} options
     * @param {ImageData} options.imageData The Uint8ClampedArray to be filtered.
     */
    applyTo2d: function(options) {
      var imageData = options.imageData,
          data = imageData.data, iLen = data.length,
          tr, tg, tb,
          r, g, b,
          source, alpha1 = 1 - this.alpha;

      source = new fabric.Color(this.color).getSource();
      tr = source[0] * this.alpha;
      tg = source[1] * this.alpha;
      tb = source[2] * this.alpha;

      for (var i = 0; i < iLen; i += 4) {

        r = data[i];
        g = data[i + 1];
        b = data[i + 2];

        switch (this.mode) {
          case 'multiply':
            data[i] = r * tr / 255;
            data[i + 1] = g * tg / 255;
            data[i + 2] = b * tb / 255;
            break;
          case 'screen':
            data[i] = 255 - (255 - r) * (255 - tr) / 255;
            data[i + 1] = 255 - (255 - g) * (255 - tg) / 255;
            data[i + 2] = 255 - (255 - b) * (255 - tb) / 255;
            break;
          case 'add':
            data[i] = r + tr;
            data[i + 1] = g + tg;
            data[i + 2] = b + tb;
            break;
          case 'diff':
          case 'difference':
            data[i] = Math.abs(r - tr);
            data[i + 1] = Math.abs(g - tg);
            data[i + 2] = Math.abs(b - tb);
            break;
          case 'subtract':
            data[i] = r - tr;
            data[i + 1] = g - tg;
            data[i + 2] = b - tb;
            break;
          case 'darken':
            data[i] = Math.min(r, tr);
            data[i + 1] = Math.min(g, tg);
            data[i + 2] = Math.min(b, tb);
            break;
          case 'lighten':
            data[i] = Math.max(r, tr);
            data[i + 1] = Math.max(g, tg);
            data[i + 2] = Math.max(b, tb);
            break;
          case 'overlay':
            data[i] = tr < 128 ? (2 * r * tr / 255) : (255 - 2 * (255 - r) * (255 - tr) / 255);
            data[i + 1] = tg < 128 ? (2 * g * tg / 255) : (255 - 2 * (255 - g) * (255 - tg) / 255);
            data[i + 2] = tb < 128 ? (2 * b * tb / 255) : (255 - 2 * (255 - b) * (255 - tb) / 255);
            break;
          case 'exclusion':
            data[i] = tr + r - ((2 * tr * r) / 255);
            data[i + 1] = tg + g - ((2 * tg * g) / 255);
            data[i + 2] = tb + b - ((2 * tb * b) / 255);
            break;
          case 'tint':
            data[i] = tr + r * alpha1;
            data[i + 1] = tg + g * alpha1;
            data[i + 2] = tb + b * alpha1;
        }
      }
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uColor: gl.getUniformLocation(program, 'uColor'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      var source = new fabric.Color(this.color).getSource();
      source[0] = this.alpha * source[0] / 255;
      source[1] = this.alpha * source[1] / 255;
      source[2] = this.alpha * source[2] / 255;
      source[3] = this.alpha;
      gl.uniform4fv(uniformLocations.uColor, source);
    },

    /**
     * Returns object representation of an instance
     * @return {Object} Object representation of an instance
     */
    toObject: function() {
      return {
        type: this.type,
        color: this.color,
        mode: this.mode,
        alpha: this.alpha
      };
    }
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] to be invoked after filter creation
   * @return {fabric.Image.filters.BlendColor} Instance of fabric.Image.filters.BlendColor
   */
  fabric.Image.filters.BlendColor.fromObject = fabric.Image.filters.BaseFilter.fromObject;

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {
  'use strict';

  var fabric = global.fabric,
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Image Blend filter class
   * @class fabric.Image.filter.BlendImage
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @example
   * var filter = new fabric.Image.filters.BlendColor({
   *  color: '#000',
   *  mode: 'multiply'
   * });
   *
   * var filter = new fabric.Image.filters.BlendImage({
   *  image: fabricImageObject,
   *  mode: 'multiply',
   *  alpha: 0.5
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   * canvas.renderAll();
   */

  filters.BlendImage = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.BlendImage.prototype */ {
    type: 'BlendImage',

    /**
     * Color to make the blend operation with. default to a reddish color since black or white
     * gives always strong result.
     **/
    image: null,

    /**
     * Blend mode for the filter: one of multiply, add, diff, screen, subtract,
     * darken, lighten, overlay, exclusion, tint.
     **/
    mode: 'multiply',

    /**
     * alpha value. represent the strength of the blend color operation.
     **/
    alpha: 1,

    vertexSource: 'attribute vec2 aPosition;\n' +
      'varying vec2 vTexCoord;\n' +
      'varying vec2 vTexCoord2;\n' +
      'uniform mat3 uTransformMatrix;\n' +
      'void main() {\n' +
        'vTexCoord = aPosition;\n' +
        'vTexCoord2 = (uTransformMatrix * vec3(aPosition, 1.0)).xy;\n' +
        'gl_Position = vec4(aPosition * 2.0 - 1.0, 0.0, 1.0);\n' +
      '}',

    /**
     * Fragment source for the Multiply program
     */
    fragmentSource: {
      multiply: 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'uniform sampler2D uImage;\n' +
        'uniform vec4 uColor;\n' +
        'varying vec2 vTexCoord;\n' +
        'varying vec2 vTexCoord2;\n' +
        'void main() {\n' +
          'vec4 color = texture2D(uTexture, vTexCoord);\n' +
          'vec4 color2 = texture2D(uImage, vTexCoord2);\n' +
          'color.rgba *= color2.rgba;\n' +
          'gl_FragColor = color;\n' +
        '}',
      mask: 'precision highp float;\n' +
        'uniform sampler2D uTexture;\n' +
        'uniform sampler2D uImage;\n' +
        'uniform vec4 uColor;\n' +
        'varying vec2 vTexCoord;\n' +
        'varying vec2 vTexCoord2;\n' +
        'void main() {\n' +
          'vec4 color = texture2D(uTexture, vTexCoord);\n' +
          'vec4 color2 = texture2D(uImage, vTexCoord2);\n' +
          'color.a = color2.a;\n' +
          'gl_FragColor = color;\n' +
        '}',
    },

    /**
     * Retrieves the cached shader.
     * @param {Object} options
     * @param {WebGLRenderingContext} options.context The GL context used for rendering.
     * @param {Object} options.programCache A map of compiled shader programs, keyed by filter type.
     */
    retrieveShader: function(options) {
      var cacheKey = this.type + '_' + this.mode;
      var shaderSource = this.fragmentSource[this.mode];
      if (!options.programCache.hasOwnProperty(cacheKey)) {
        options.programCache[cacheKey] = this.createProgram(options.context, shaderSource);
      }
      return options.programCache[cacheKey];
    },

    applyToWebGL: function(options) {
      // load texture to blend.
      var gl = options.context,
          texture = this.createTexture(options.filterBackend, this.image);
      this.bindAdditionalTexture(gl, texture, gl.TEXTURE1);
      this.callSuper('applyToWebGL', options);
      this.unbindAdditionalTexture(gl, gl.TEXTURE1);
    },

    createTexture: function(backend, image) {
      return backend.getCachedTexture(image.cacheKey, image._element);
    },

    /**
     * Calculate a transformMatrix to adapt the image to blend over
     * @param {Object} options
     * @param {WebGLRenderingContext} options.context The GL context used for rendering.
     * @param {Object} options.programCache A map of compiled shader programs, keyed by filter type.
     */
    calculateMatrix: function() {
      var image = this.image,
          width = image._element.width,
          height = image._element.height;
      return [
        1 / image.scaleX, 0, 0,
        0, 1 / image.scaleY, 0,
        -image.left / width, -image.top / height, 1
      ];
    },

    /**
     * Apply the Blend operation to a Uint8ClampedArray representing the pixels of an image.
     *
     * @param {Object} options
     * @param {ImageData} options.imageData The Uint8ClampedArray to be filtered.
     */
    applyTo2d: function(options) {
      var imageData = options.imageData,
          resources = options.filterBackend.resources,
          data = imageData.data, iLen = data.length,
          width = options.imageData.width,
          height = options.imageData.height,
          tr, tg, tb, ta,
          r, g, b, a,
          canvas1, context, image = this.image, blendData;

      if (!resources.blendImage) {
        resources.blendImage = document.createElement('canvas');
      }
      canvas1 = resources.blendImage;
      if (canvas1.width !== width || canvas1.height !== height) {
        canvas1.width = width;
        canvas1.height = height;
      }
      context = canvas1.getContext('2d');
      context.setTransform(image.scaleX, 0, 0, image.scaleY, image.left, image.top);
      context.drawImage(image._element, 0, 0, width, height);
      blendData = context.getImageData(0, 0, width, height).data;
      for (var i = 0; i < iLen; i += 4) {

        r = data[i];
        g = data[i + 1];
        b = data[i + 2];
        a = data[i + 3];

        tr = blendData[i];
        tg = blendData[i + 1];
        tb = blendData[i + 2];
        ta = blendData[i + 3];

        switch (this.mode) {
          case 'multiply':
            data[i] = r * tr / 255;
            data[i + 1] = g * tg / 255;
            data[i + 2] = b * tb / 255;
            data[i + 3] = a * ta / 255;
            break;
          case 'mask':
            data[i + 3] = ta;
            break;
        }
      }
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uTransformMatrix: gl.getUniformLocation(program, 'uTransformMatrix'),
        uImage: gl.getUniformLocation(program, 'uImage'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      var matrix = this.calculateMatrix();
      gl.uniform1i(uniformLocations.uImage, 1); // texture unit 1.
      gl.uniformMatrix3fv(uniformLocations.uTransformMatrix, false, matrix);
    },

    /**
     * Returns object representation of an instance
     * @return {Object} Object representation of an instance
     */
    toObject: function() {
      return {
        type: this.type,
        image: this.image && this.image.toObject(),
        mode: this.mode,
        alpha: this.alpha
      };
    }
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {function} callback to be invoked after filter creation
   * @return {fabric.Image.filters.BlendImage} Instance of fabric.Image.filters.BlendImage
   */
  fabric.Image.filters.BlendImage.fromObject = function(object, callback) {
    fabric.Image.fromObject(object.image, function(image) {
      var options = fabric.util.object.clone(object);
      options.image = image;
      callback(new fabric.Image.filters.BlendImage(options));
    });
  };

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }), pow = Math.pow, floor = Math.floor,
      sqrt = Math.sqrt, abs = Math.abs, round = Math.round, sin = Math.sin,
      ceil = Math.ceil,
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Resize image filter class
   * @class fabric.Image.filters.Resize
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @example
   * var filter = new fabric.Image.filters.Resize();
   * object.filters.push(filter);
   * object.applyFilters(canvas.renderAll.bind(canvas));
   */
  filters.Resize = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.Resize.prototype */ {

    /**
     * Filter type
     * @param {String} type
     * @default
     */
    type: 'Resize',

    /**
     * Resize type
     * @param {String} resizeType
     * @default
     */
    resizeType: 'hermite',

    /**
     * Scale factor for resizing, x axis
     * @param {Number} scaleX
     * @default
     */
    scaleX: 0,

    /**
     * Scale factor for resizing, y axis
     * @param {Number} scaleY
     * @default
     */
    scaleY: 0,

    /**
     * LanczosLobes parameter for lanczos filter
     * @param {Number} lanczosLobes
     * @default
     */
    lanczosLobes: 3,


    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uDelta: gl.getUniformLocation(program, 'uDelta'),
        uTaps: gl.getUniformLocation(program, 'uTaps'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      gl.uniform2fv(uniformLocations.uDelta, this.horizontal ? [1 / this.width, 0] : [0, 1 / this.height]);
      gl.uniform1fv(uniformLocations.uTaps, this.taps);
    },

    /**
     * Retrieves the cached shader.
     * @param {Object} options
     * @param {WebGLRenderingContext} options.context The GL context used for rendering.
     * @param {Object} options.programCache A map of compiled shader programs, keyed by filter type.
     */
    retrieveShader: function(options) {
      var filterWindow = this.getFilterWindow(), cacheKey = this.type + '_' + filterWindow;
      if (!options.programCache.hasOwnProperty(cacheKey)) {
        var fragmentShader = this.generateShader(filterWindow);
        options.programCache[cacheKey] = this.createProgram(options.context, fragmentShader);
      }
      return options.programCache[cacheKey];
    },

    getFilterWindow: function() {
      var scale = this.tempScale;
      return Math.ceil(this.lanczosLobes / scale);
    },

    getTaps: function() {
      var lobeFunction = this.lanczosCreate(this.lanczosLobes), scale = this.tempScale,
          filterWindow = this.getFilterWindow(), taps = new Array(filterWindow);
      for (var i = 1; i <= filterWindow; i++) {
        taps[i - 1] = lobeFunction(i * scale);
      }
      return taps;
    },

    /**
     * Generate vertex and shader sources from the necessary steps numbers
     * @param {Number} filterWindow
     */
    generateShader: function(filterWindow) {
      var offsets = new Array(filterWindow),
          fragmentShader = this.fragmentSourceTOP, filterWindow;

      for (var i = 1; i <= filterWindow; i++) {
        offsets[i - 1] = i + '.0 * uDelta';
      }

      fragmentShader += 'uniform float uTaps[' + filterWindow + '];\n';
      fragmentShader += 'void main() {\n';
      fragmentShader += '  vec4 color = texture2D(uTexture, vTexCoord);\n';
      fragmentShader += '  float sum = 1.0;\n';

      offsets.forEach(function(offset, i) {
        fragmentShader += '  color += texture2D(uTexture, vTexCoord + ' + offset + ') * uTaps[' + i + '];\n';
        fragmentShader += '  color += texture2D(uTexture, vTexCoord - ' + offset + ') * uTaps[' + i + '];\n';
        fragmentShader += '  sum += 2.0 * uTaps[' + i + '];\n';
      });
      fragmentShader += '  gl_FragColor = color / sum;\n';
      fragmentShader += '}';
      return fragmentShader;
    },

    fragmentSourceTOP: 'precision highp float;\n' +
      'uniform sampler2D uTexture;\n' +
      'uniform vec2 uDelta;\n' +
      'varying vec2 vTexCoord;\n',

    /**
     * Apply the resize filter to the image
     * Determines whether to use WebGL or Canvas2D based on the options.webgl flag.
     *
     * @param {Object} options
     * @param {Number} options.passes The number of filters remaining to be executed
     * @param {Boolean} options.webgl Whether to use webgl to render the filter.
     * @param {WebGLTexture} options.sourceTexture The texture setup as the source to be filtered.
     * @param {WebGLTexture} options.targetTexture The texture where filtered output should be drawn.
     * @param {WebGLRenderingContext} options.context The GL context used for rendering.
     * @param {Object} options.programCache A map of compiled shader programs, keyed by filter type.
     */
    applyTo: function(options) {
      if (options.webgl) {
        if (options.passes > 1 && this.isNeutralState(options)) {
          // avoid doing something that we do not need
          return;
        }
        options.passes++;
        this.width = options.sourceWidth;
        this.horizontal = true;
        this.dW = Math.round(this.width * this.scaleX);
        this.dH = options.sourceHeight;
        this.tempScale = this.dW / this.width;
        this.taps = this.getTaps();
        options.destinationWidth = this.dW;
        this._setupFrameBuffer(options);
        this.applyToWebGL(options);
        this._swapTextures(options);
        options.sourceWidth = options.destinationWidth;

        this.height = options.sourceHeight;
        this.horizontal = false;
        this.dH = Math.round(this.height * this.scaleY);
        this.tempScale = this.dH / this.height;
        this.taps = this.getTaps();
        options.destinationHeight = this.dH;
        this._setupFrameBuffer(options);
        this.applyToWebGL(options);
        this._swapTextures(options);
        options.sourceHeight = options.destinationHeight;
      }
      else if (!this.isNeutralState(options)) {
        this.applyTo2d(options);
      }
    },

    isNeutralState: function(options) {
      var scaleX = options.scaleX || this.scaleX,
          scaleY = options.scaleY || this.scaleY;
      return scaleX === 1 && scaleY === 1;
    },

    lanczosCreate: function(lobes) {
      return function(x) {
        if (x >= lobes || x <= -lobes) {
          return 0.0;
        }
        if (x < 1.19209290E-07 && x > -1.19209290E-07) {
          return 1.0;
        }
        x *= Math.PI;
        var xx = x / lobes;
        return (sin(x) / x) * sin(xx) / xx;
      };
    },

    /**
     * Applies filter to canvas element
     * @memberOf fabric.Image.filters.Resize.prototype
     * @param {Object} canvasEl Canvas element to apply filter to
     * @param {Number} scaleX
     * @param {Number} scaleY
     */
    applyTo2d: function(options) {
      var imageData = options.imageData,
          scaleX = this.scaleX,
          scaleY = this.scaleY;

      this.rcpScaleX = 1 / scaleX;
      this.rcpScaleY = 1 / scaleY;

      var oW = imageData.width, oH = imageData.height,
          dW = round(oW * scaleX), dH = round(oH * scaleY),
          newData;

      if (this.resizeType === 'sliceHack') {
        newData = this.sliceByTwo(options, oW, oH, dW, dH);
      }
      else if (this.resizeType === 'hermite') {
        newData = this.hermiteFastResize(options, oW, oH, dW, dH);
      }
      else if (this.resizeType === 'bilinear') {
        newData = this.bilinearFiltering(options, oW, oH, dW, dH);
      }
      else if (this.resizeType === 'lanczos') {
        newData = this.lanczosResize(options, oW, oH, dW, dH);
      }
      options.imageData = newData;
    },

    /**
     * Filter sliceByTwo
     * @param {Object} canvasEl Canvas element to apply filter to
     * @param {Number} oW Original Width
     * @param {Number} oH Original Height
     * @param {Number} dW Destination Width
     * @param {Number} dH Destination Height
     * @returns {ImageData}
     */
    sliceByTwo: function(options, oW, oH, dW, dH) {
      var imageData = options.imageData,
          mult = 0.5, doneW = false, doneH = false, stepW = oW * mult,
          stepH = oH * mult, resources = fabric.filterBackend.resources,
          tmpCanvas, ctx, sX = 0, sY = 0, dX = oW, dY = 0;
      if (!resources.sliceByTwo) {
        resources.sliceByTwo = document.createElement('canvas');
      }
      tmpCanvas = resources.sliceByTwo;
      if (tmpCanvas.width < oW * 1.5 || tmpCanvas.height < oH) {
        tmpCanvas.width = oW * 1.5;
        tmpCanvas.height = oH;
      }
      ctx = tmpCanvas.getContext('2d');
      ctx.clearRect(0, 0, oW * 1.5, oH);
      ctx.putImageData(imageData, 0, 0);

      dW = floor(dW);
      dH = floor(dH);

      while (!doneW || !doneH) {
        oW = stepW;
        oH = stepH;
        if (dW < floor(stepW * mult)) {
          stepW = floor(stepW * mult);
        }
        else {
          stepW = dW;
          doneW = true;
        }
        if (dH < floor(stepH * mult)) {
          stepH = floor(stepH * mult);
        }
        else {
          stepH = dH;
          doneH = true;
        }
        ctx.drawImage(tmpCanvas, sX, sY, oW, oH, dX, dY, stepW, stepH);
        sX = dX;
        sY = dY;
        dY += stepH;
      }
      return ctx.getImageData(sX, sY, dW, dH);
    },

    /**
     * Filter lanczosResize
     * @param {Object} canvasEl Canvas element to apply filter to
     * @param {Number} oW Original Width
     * @param {Number} oH Original Height
     * @param {Number} dW Destination Width
     * @param {Number} dH Destination Height
     * @returns {ImageData}
     */
    lanczosResize: function(options, oW, oH, dW, dH) {

      function process(u) {
        var v, i, weight, idx, a, red, green,
            blue, alpha, fX, fY;
        center.x = (u + 0.5) * ratioX;
        icenter.x = floor(center.x);
        for (v = 0; v < dH; v++) {
          center.y = (v + 0.5) * ratioY;
          icenter.y = floor(center.y);
          a = 0; red = 0; green = 0; blue = 0; alpha = 0;
          for (i = icenter.x - range2X; i <= icenter.x + range2X; i++) {
            if (i < 0 || i >= oW) {
              continue;
            }
            fX = floor(1000 * abs(i - center.x));
            if (!cacheLanc[fX]) {
              cacheLanc[fX] = { };
            }
            for (var j = icenter.y - range2Y; j <= icenter.y + range2Y; j++) {
              if (j < 0 || j >= oH) {
                continue;
              }
              fY = floor(1000 * abs(j - center.y));
              if (!cacheLanc[fX][fY]) {
                cacheLanc[fX][fY] = lanczos(sqrt(pow(fX * rcpRatioX, 2) + pow(fY * rcpRatioY, 2)) / 1000);
              }
              weight = cacheLanc[fX][fY];
              if (weight > 0) {
                idx = (j * oW + i) * 4;
                a += weight;
                red += weight * srcData[idx];
                green += weight * srcData[idx + 1];
                blue += weight * srcData[idx + 2];
                alpha += weight * srcData[idx + 3];
              }
            }
          }
          idx = (v * dW + u) * 4;
          destData[idx] = red / a;
          destData[idx + 1] = green / a;
          destData[idx + 2] = blue / a;
          destData[idx + 3] = alpha / a;
        }

        if (++u < dW) {
          return process(u);
        }
        else {
          return destImg;
        }
      }

      var srcData = options.imageData.data,
          destImg = options.ctx.createImageData(dW, dH),
          destData = destImg.data,
          lanczos = this.lanczosCreate(this.lanczosLobes),
          ratioX = this.rcpScaleX, ratioY = this.rcpScaleY,
          rcpRatioX = 2 / this.rcpScaleX, rcpRatioY = 2 / this.rcpScaleY,
          range2X = ceil(ratioX * this.lanczosLobes / 2),
          range2Y = ceil(ratioY * this.lanczosLobes / 2),
          cacheLanc = { }, center = { }, icenter = { };

      return process(0);
    },

    /**
     * bilinearFiltering
     * @param {Object} canvasEl Canvas element to apply filter to
     * @param {Number} oW Original Width
     * @param {Number} oH Original Height
     * @param {Number} dW Destination Width
     * @param {Number} dH Destination Height
     * @returns {ImageData}
     */
    bilinearFiltering: function(options, oW, oH, dW, dH) {
      var a, b, c, d, x, y, i, j, xDiff, yDiff, chnl,
          color, offset = 0, origPix, ratioX = this.rcpScaleX,
          ratioY = this.rcpScaleY,
          w4 = 4 * (oW - 1), img = options.imageData,
          pixels = img.data, destImage = options.ctx.createImageData(dW, dH),
          destPixels = destImage.data;
      for (i = 0; i < dH; i++) {
        for (j = 0; j < dW; j++) {
          x = floor(ratioX * j);
          y = floor(ratioY * i);
          xDiff = ratioX * j - x;
          yDiff = ratioY * i - y;
          origPix = 4 * (y * oW + x);

          for (chnl = 0; chnl < 4; chnl++) {
            a = pixels[origPix + chnl];
            b = pixels[origPix + 4 + chnl];
            c = pixels[origPix + w4 + chnl];
            d = pixels[origPix + w4 + 4 + chnl];
            color = a * (1 - xDiff) * (1 - yDiff) + b * xDiff * (1 - yDiff) +
                    c * yDiff * (1 - xDiff) + d * xDiff * yDiff;
            destPixels[offset++] = color;
          }
        }
      }
      return destImage;
    },

    /**
     * hermiteFastResize
     * @param {Object} canvasEl Canvas element to apply filter to
     * @param {Number} oW Original Width
     * @param {Number} oH Original Height
     * @param {Number} dW Destination Width
     * @param {Number} dH Destination Height
     * @returns {ImageData}
     */
    hermiteFastResize: function(options, oW, oH, dW, dH) {
      var ratioW = this.rcpScaleX, ratioH = this.rcpScaleY,
          ratioWHalf = ceil(ratioW / 2),
          ratioHHalf = ceil(ratioH / 2),
          img = options.imageData, data = img.data,
          img2 = options.ctx.createImageData(dW, dH), data2 = img2.data;
      for (var j = 0; j < dH; j++) {
        for (var i = 0; i < dW; i++) {
          var x2 = (i + j * dW) * 4, weight = 0, weights = 0, weightsAlpha = 0,
              gxR = 0, gxG = 0, gxB = 0, gxA = 0, centerY = (j + 0.5) * ratioH;
          for (var yy = floor(j * ratioH); yy < (j + 1) * ratioH; yy++) {
            var dy = abs(centerY - (yy + 0.5)) / ratioHHalf,
                centerX = (i + 0.5) * ratioW, w0 = dy * dy;
            for (var xx = floor(i * ratioW); xx < (i + 1) * ratioW; xx++) {
              var dx = abs(centerX - (xx + 0.5)) / ratioWHalf,
                  w = sqrt(w0 + dx * dx);
              /* eslint-disable max-depth */
              if (w > 1 && w < -1) {
                continue;
              }
              //hermite filter
              weight = 2 * w * w * w - 3 * w * w + 1;
              if (weight > 0) {
                dx = 4 * (xx + yy * oW);
                //alpha
                gxA += weight * data[dx + 3];
                weightsAlpha += weight;
                //colors
                if (data[dx + 3] < 255) {
                  weight = weight * data[dx + 3] / 250;
                }
                gxR += weight * data[dx];
                gxG += weight * data[dx + 1];
                gxB += weight * data[dx + 2];
                weights += weight;
              }
              /* eslint-enable max-depth */
            }
          }
          data2[x2] = gxR / weights;
          data2[x2 + 1] = gxG / weights;
          data2[x2 + 2] = gxB / weights;
          data2[x2 + 3] = gxA / weightsAlpha;
        }
      }
      return img2;
    },

    /**
     * Returns object representation of an instance
     * @return {Object} Object representation of an instance
     */
    toObject: function() {
      return {
        type: this.type,
        scaleX: this.scaleX,
        scaleY: this.scaleY,
        resizeType: this.resizeType,
        lanczosLobes: this.lanczosLobes
      };
    }
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {Function} [callback] to be invoked after filter creation
   * @return {fabric.Image.filters.Resize} Instance of fabric.Image.filters.Resize
   */
  fabric.Image.filters.Resize.fromObject = fabric.Image.filters.BaseFilter.fromObject;

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Contrast filter class
   * @class fabric.Image.filters.Contrast
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link fabric.Image.filters.Contrast#initialize} for constructor definition
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @example
   * var filter = new fabric.Image.filters.Contrast({
   *   contrast: 40
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   */
  filters.Contrast = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.Contrast.prototype */ {

    /**
     * Filter type
     * @param {String} type
     * @default
     */
    type: 'Contrast',

    fragmentSource: 'precision highp float;\n' +
      'uniform sampler2D uTexture;\n' +
      'uniform float uContrast;\n' +
      'varying vec2 vTexCoord;\n' +
      'void main() {\n' +
        'vec4 color = texture2D(uTexture, vTexCoord);\n' +
        'float contrastF = 1.015 * (uContrast + 1.0) / (1.0 * (1.015 - uContrast));\n' +
        'color.rgb = contrastF * (color.rgb - 0.5) + 0.5;\n' +
        'gl_FragColor = color;\n' +
      '}',

    contrast: 0,

    mainParameter: 'contrast',

    /**
     * Constructor
     * @memberOf fabric.Image.filters.Contrast.prototype
     * @param {Object} [options] Options object
     * @param {Number} [options.contrast=0] Value to contrast the image up (-1...1)
     */

    /**
      * Apply the Contrast operation to a Uint8Array representing the pixels of an image.
      *
      * @param {Object} options
      * @param {ImageData} options.imageData The Uint8Array to be filtered.
      */
    applyTo2d: function(options) {
      if (this.contrast === 0) {
        return;
      }
      var imageData = options.imageData, i, len,
          data = imageData.data, len = data.length,
          contrast = Math.floor(this.contrast * 255),
          contrastF = 259 * (contrast + 255) / (255 * (259 - contrast));

      for (i = 0; i < len; i += 4) {
        data[i] = contrastF * (data[i] - 128) + 128;
        data[i + 1] = contrastF * (data[i + 1] - 128) + 128;
        data[i + 2] = contrastF * (data[i + 2] - 128) + 128;
      }
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uContrast: gl.getUniformLocation(program, 'uContrast'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      gl.uniform1f(uniformLocations.uContrast, this.contrast);
    },
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] to be invoked after filter creation
   * @return {fabric.Image.filters.Contrast} Instance of fabric.Image.filters.Contrast
   */
  fabric.Image.filters.Contrast.fromObject = fabric.Image.filters.BaseFilter.fromObject;

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Saturate filter class
   * @class fabric.Image.filters.Saturation
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link fabric.Image.filters.Saturation#initialize} for constructor definition
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @example
   * var filter = new fabric.Image.filters.Saturation({
   *   saturation: 100
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   */
  filters.Saturation = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.Saturation.prototype */ {

    /**
     * Filter type
     * @param {String} type
     * @default
     */
    type: 'Saturation',

    fragmentSource: 'precision highp float;\n' +
      'uniform sampler2D uTexture;\n' +
      'uniform float uSaturation;\n' +
      'varying vec2 vTexCoord;\n' +
      'void main() {\n' +
        'vec4 color = texture2D(uTexture, vTexCoord);\n' +
        'float rgMax = max(color.r, color.g);\n' +
        'float rgbMax = max(rgMax, color.b);\n' +
        'color.r += rgbMax != color.r ? (rgbMax - color.r) * uSaturation : 0.00;\n' +
        'color.g += rgbMax != color.g ? (rgbMax - color.g) * uSaturation : 0.00;\n' +
        'color.b += rgbMax != color.b ? (rgbMax - color.b) * uSaturation : 0.00;\n' +
        'gl_FragColor = color;\n' +
      '}',

    saturation: 0,

    mainParameter: 'saturation',

    /**
     * Constructor
     * @memberOf fabric.Image.filters.Saturate.prototype
     * @param {Object} [options] Options object
     * @param {Number} [options.saturate=0] Value to saturate the image (-1...1)
     */

    /**
     * Apply the Saturation operation to a Uint8ClampedArray representing the pixels of an image.
     *
     * @param {Object} options
     * @param {ImageData} options.imageData The Uint8ClampedArray to be filtered.
     */
    applyTo2d: function(options) {
      if (this.saturation === 0) {
        return;
      }
      var imageData = options.imageData,
          data = imageData.data, len = data.length,
          adjust = -this.saturation, i, max;

      for (i = 0; i < len; i += 4) {
        max = Math.max(data[i], data[i + 1], data[i + 2]);
        data[i] += max !== data[i] ? (max - data[i]) * adjust : 0;
        data[i + 1] += max !== data[i + 1] ? (max - data[i + 1]) * adjust : 0;
        data[i + 2] += max !== data[i + 2] ? (max - data[i + 2]) * adjust : 0;
      }
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uSaturation: gl.getUniformLocation(program, 'uSaturation'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      gl.uniform1f(uniformLocations.uSaturation, -this.saturation);
    },
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {Function} [callback] to be invoked after filter creation
   * @return {fabric.Image.filters.Saturation} Instance of fabric.Image.filters.Saturate
   */
  fabric.Image.filters.Saturation.fromObject = fabric.Image.filters.BaseFilter.fromObject;

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Blur filter class
   * @class fabric.Image.filters.Blur
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link fabric.Image.filters.Blur#initialize} for constructor definition
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @example
   * var filter = new fabric.Image.filters.Blur({
   *   blur: 0.5
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   * canvas.renderAll();
   */
  filters.Blur = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.Blur.prototype */ {

    type: 'Blur',

    /*
'gl_FragColor = vec4(0.0);',
'gl_FragColor += texture2D(texture, vTexCoord + -7 * uDelta)*0.0044299121055113265;',
'gl_FragColor += texture2D(texture, vTexCoord + -6 * uDelta)*0.00895781211794;',
'gl_FragColor += texture2D(texture, vTexCoord + -5 * uDelta)*0.0215963866053;',
'gl_FragColor += texture2D(texture, vTexCoord + -4 * uDelta)*0.0443683338718;',
'gl_FragColor += texture2D(texture, vTexCoord + -3 * uDelta)*0.0776744219933;',
'gl_FragColor += texture2D(texture, vTexCoord + -2 * uDelta)*0.115876621105;',
'gl_FragColor += texture2D(texture, vTexCoord + -1 * uDelta)*0.147308056121;',
'gl_FragColor += texture2D(texture, vTexCoord              )*0.159576912161;',
'gl_FragColor += texture2D(texture, vTexCoord + 1 * uDelta)*0.147308056121;',
'gl_FragColor += texture2D(texture, vTexCoord + 2 * uDelta)*0.115876621105;',
'gl_FragColor += texture2D(texture, vTexCoord + 3 * uDelta)*0.0776744219933;',
'gl_FragColor += texture2D(texture, vTexCoord + 4 * uDelta)*0.0443683338718;',
'gl_FragColor += texture2D(texture, vTexCoord + 5 * uDelta)*0.0215963866053;',
'gl_FragColor += texture2D(texture, vTexCoord + 6 * uDelta)*0.00895781211794;',
'gl_FragColor += texture2D(texture, vTexCoord + 7 * uDelta)*0.0044299121055113265;',
*/

    /* eslint-disable max-len */
    fragmentSource: 'precision highp float;\n' +
      'uniform sampler2D uTexture;\n' +
      'uniform vec2 uDelta;\n' +
      'varying vec2 vTexCoord;\n' +
      'const float nSamples = 15.0;\n' +
      'vec3 v3offset = vec3(12.9898, 78.233, 151.7182);\n' +
      'float random(vec3 scale) {\n' +
        /* use the fragment position for a different seed per-pixel */
        'return fract(sin(dot(gl_FragCoord.xyz, scale)) * 43758.5453);\n' +
      '}\n' +
      'void main() {\n' +
        'vec4 color = vec4(0.0);\n' +
        'float total = 0.0;\n' +
        'float offset = random(v3offset);\n' +
        'for (float t = -nSamples; t <= nSamples; t++) {\n' +
          'float percent = (t + offset - 0.5) / nSamples;\n' +
          'float weight = 1.0 - abs(percent);\n' +
          'color += texture2D(uTexture, vTexCoord + uDelta * percent) * weight;\n' +
          'total += weight;\n' +
        '}\n' +
        'gl_FragColor = color / total;\n' +
      '}',
    /* eslint-enable max-len */

    /**
     * blur value, in percentage of image dimensions.
     * specific to keep the image blur constant at different resolutions
     * range bewteen 0 and 1.
     */
    blur: 0,

    mainParameter: 'blur',

    applyTo: function(options) {
      if (options.webgl) {
        // this aspectRatio is used to give the same blur to vertical and horizontal
        this.aspectRatio = options.sourceWidth / options.sourceHeight;
        options.passes++;
        this._setupFrameBuffer(options);
        this.horizontal = true;
        this.applyToWebGL(options);
        this._swapTextures(options);
        this._setupFrameBuffer(options);
        this.horizontal = false;
        this.applyToWebGL(options);
        this._swapTextures(options);
      }
      else {
        this.applyTo2d(options);
      }
    },

    applyTo2d: function(options) {
      // paint canvasEl with current image data.
      //options.ctx.putImageData(options.imageData, 0, 0);
      options.imageData = this.simpleBlur(options);
    },

    simpleBlur: function(options) {
      var resources = options.filterBackend.resources, canvas1, canvas2,
          width = options.imageData.width,
          height = options.imageData.height;

      if (!resources.blurLayer1) {
        resources.blurLayer1 = fabric.util.createCanvasElement();
        resources.blurLayer2 = fabric.util.createCanvasElement();
      }
      canvas1 = resources.blurLayer1;
      canvas2 = resources.blurLayer2;
      if (canvas1.width !== width || canvas1.height !== height) {
        canvas2.width = canvas1.width = width;
        canvas2.height = canvas1.height = height;
      }
      var ctx1 = canvas1.getContext('2d'),
          ctx2 = canvas2.getContext('2d'),
          nSamples = 15,
          random, percent, j, i,
          blur = this.blur * 0.06 * 0.5;

      // load first canvas
      ctx1.putImageData(options.imageData, 0, 0);
      ctx2.clearRect(0, 0, width, height);

      for (i = -nSamples; i <= nSamples; i++) {
        random = (Math.random() - 0.5) / 4;
        percent = i / nSamples;
        j = blur * percent * width + random;
        ctx2.globalAlpha = 1 - Math.abs(percent);
        ctx2.drawImage(canvas1, j, random);
        ctx1.drawImage(canvas2, 0, 0);
        ctx2.globalAlpha = 1;
        ctx2.clearRect(0, 0, canvas2.width, canvas2.height);
      }
      for (i = -nSamples; i <= nSamples; i++) {
        random = (Math.random() - 0.5) / 4;
        percent = i / nSamples;
        j = blur * percent * height + random;
        ctx2.globalAlpha = 1 - Math.abs(percent);
        ctx2.drawImage(canvas1, random, j);
        ctx1.drawImage(canvas2, 0, 0);
        ctx2.globalAlpha = 1;
        ctx2.clearRect(0, 0, canvas2.width, canvas2.height);
      }
      options.ctx.drawImage(canvas1, 0, 0);
      var newImageData = options.ctx.getImageData(0, 0, canvas1.width, canvas1.height);
      ctx1.globalAlpha = 1;
      ctx1.clearRect(0, 0, canvas1.width, canvas1.height);
      return newImageData;
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        delta: gl.getUniformLocation(program, 'uDelta'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      var delta = this.chooseRightDelta();
      gl.uniform2fv(uniformLocations.delta, delta);
    },

    /**
     * choose right value of image percentage to blur with
     * @returns {Array} a numeric array with delta values
     */
    chooseRightDelta: function() {
      var blurScale = 1, delta = [0, 0], blur;
      if (this.horizontal) {
        if (this.aspectRatio > 1) {
          // image is wide, i want to shrink radius horizontal
          blurScale = 1 / this.aspectRatio;
        }
      }
      else {
        if (this.aspectRatio < 1) {
          // image is tall, i want to shrink radius vertical
          blurScale = this.aspectRatio;
        }
      }
      blur = blurScale * this.blur * 0.12;
      if (this.horizontal) {
        delta[0] = blur;
      }
      else {
        delta[1] = blur;
      }
      return delta;
    },
  });

  /**
   * Deserialize a JSON definition of a BlurFilter into a concrete instance.
   */
  filters.Blur.fromObject = fabric.Image.filters.BaseFilter.fromObject;

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * Gamma filter class
   * @class fabric.Image.filters.Gamma
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link fabric.Image.filters.Gamma#initialize} for constructor definition
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @example
   * var filter = new fabric.Image.filters.Gamma({
   *   brightness: 200
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   */
  filters.Gamma = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.Gamma.prototype */ {

    /**
     * Filter type
     * @param {String} type
     * @default
     */
    type: 'Gamma',

    fragmentSource: 'precision highp float;\n' +
      'uniform sampler2D uTexture;\n' +
      'uniform vec3 uGamma;\n' +
      'varying vec2 vTexCoord;\n' +
      'void main() {\n' +
        'vec4 color = texture2D(uTexture, vTexCoord);\n' +
        'vec3 correction = (1.0 / uGamma);\n' +
        'color.r = pow(color.r, correction.r);\n' +
        'color.g = pow(color.g, correction.g);\n' +
        'color.b = pow(color.b, correction.b);\n' +
        'gl_FragColor = color;\n' +
        'gl_FragColor.rgb *= color.a;\n' +
      '}',

    /**
     * Gamma array value, from 0.01 to 2.2.
     * @param {Array} gamma
     * @default
     */
    gamma: [1, 1, 1],

    /**
     * Describe the property that is the filter parameter
     * @param {String} m
     * @default
     */
    mainParameter: 'gamma',

    /**
     * Apply the Gamma operation to a Uint8Array representing the pixels of an image.
     *
     * @param {Object} options
     * @param {ImageData} options.imageData The Uint8Array to be filtered.
     */
    applyTo2d: function(options) {
      var imageData = options.imageData, data = imageData.data,
          gamma = this.gamma, len = data.length,
          rInv = 1 / gamma[0], gInv = 1 / gamma[1],
          bInv = 1 / gamma[2], i;

      if (!this.rVals) {
        // eslint-disable-next-line
        this.rVals = new Uint8Array(256);
        // eslint-disable-next-line
        this.gVals = new Uint8Array(256);
        // eslint-disable-next-line
        this.bVals = new Uint8Array(256);
      }

      // This is an optimization - pre-compute a look-up table for each color channel
      // instead of performing these pow calls for each pixel in the image.
      for (i = 0, len = 256; i < len; i++) {
        this.rVals[i] = Math.pow(i / 255, rInv) * 255;
        this.gVals[i] = Math.pow(i / 255, gInv) * 255;
        this.bVals[i] = Math.pow(i / 255, bInv) * 255;
      }
      for (i = 0, len = data.length; i < len; i += 4) {
        data[i] = this.rVals[data[i]];
        data[i + 1] = this.gVals[data[i + 1]];
        data[i + 2] = this.bVals[data[i + 2]];
      }
    },

    /**
     * Return WebGL uniform locations for this filter's shader.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {WebGLShaderProgram} program This filter's compiled shader program.
     */
    getUniformLocations: function(gl, program) {
      return {
        uGamma: gl.getUniformLocation(program, 'uGamma'),
      };
    },

    /**
     * Send data from this filter to its shader program's uniforms.
     *
     * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
     * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
     */
    sendUniformData: function(gl, uniformLocations) {
      gl.uniform3fv(uniformLocations.uGamma, this.gamma);
    },
  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] to be invoked after filter creation
   * @return {fabric.Image.filters.Gamma} Instance of fabric.Image.filters.Gamma
   */
  fabric.Image.filters.Gamma.fromObject = fabric.Image.filters.BaseFilter.fromObject;

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * A container class that knows how to apply a sequence of filters to an input image.
   */
  filters.Composed = createClass(filters.BaseFilter, /** @lends fabric.Image.filters.Composed.prototype */ {

    type: 'Composed',

    /**
     * A non sparse array of filters to apply
     */
    subFilters: [],

    /**
     * Constructor
     * @param {Object} [options] Options object
     */
    initialize: function(options) {
      this.callSuper('initialize', options);
      // create a new array instead mutating the prototype with push
      this.subFilters = this.subFilters.slice(0);
    },

    /**
     * Apply this container's filters to the input image provided.
     *
     * @param {Object} options
     * @param {Number} options.passes The number of filters remaining to be applied.
     */
    applyTo: function(options) {
      options.passes += this.subFilters.length - 1;
      this.subFilters.forEach(function(filter) {
        filter.applyTo(options);
      });
    },

    /**
     * Serialize this filter into JSON.
     *
     * @returns {Object} A JSON representation of this filter.
     */
    toObject: function() {
      return fabric.util.object.extend(this.callSuper('toObject'), {
        subFilters: this.subFilters.map(function(filter) { return filter.toObject(); }),
      });
    },
  });

  /**
   * Deserialize a JSON definition of a ComposedFilter into a concrete instance.
   */
  fabric.Image.filters.Composed.fromObject = function(object, callback) {
    var filters = object.subFilters || [],
        subFilters = filters.map(function(filter) {
          return new fabric.Image.filters[filter.type](filter);
        }),
        instance = new fabric.Image.filters.Composed({ subFilters: subFilters });
    callback && callback(instance);
    return instance;
  };
})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric  = global.fabric || (global.fabric = { }),
      filters = fabric.Image.filters,
      createClass = fabric.util.createClass;

  /**
   * HueRotation filter class
   * @class fabric.Image.filters.HueRotation
   * @memberOf fabric.Image.filters
   * @extends fabric.Image.filters.BaseFilter
   * @see {@link fabric.Image.filters.HueRotation#initialize} for constructor definition
   * @see {@link http://fabricjs.com/image-filters|ImageFilters demo}
   * @example
   * var filter = new fabric.Image.filters.HueRotation({
   *   rotation: -0.5
   * });
   * object.filters.push(filter);
   * object.applyFilters();
   */
  filters.HueRotation = createClass(filters.ColorMatrix, /** @lends fabric.Image.filters.HueRotation.prototype */ {

    /**
     * Filter type
     * @param {String} type
     * @default
     */
    type: 'HueRotation',

    /**
     * HueRotation value, from -1 to 1.
     * the unit is radians
     * @param {Number} myParameter
     * @default
     */
    rotation: 0,

    /**
     * Describe the property that is the filter parameter
     * @param {String} m
     * @default
     */
    mainParameter: 'rotation',

    calculateMatrix: function() {
      var rad = this.rotation * Math.PI, cos = fabric.util.cos(rad), sin = fabric.util.sin(rad),
          aThird = 1 / 3, aThirdSqtSin = Math.sqrt(aThird) * sin, OneMinusCos = 1 - cos;
      this.matrix = [
        1, 0, 0, 0, 0,
        0, 1, 0, 0, 0,
        0, 0, 1, 0, 0,
        0, 0, 0, 1, 0
      ];
      this.matrix[0] = cos + OneMinusCos / 3;
      this.matrix[1] = aThird * OneMinusCos - aThirdSqtSin;
      this.matrix[2] = aThird * OneMinusCos + aThirdSqtSin;
      this.matrix[5] = aThird * OneMinusCos + aThirdSqtSin;
      this.matrix[6] = cos + aThird * OneMinusCos;
      this.matrix[7] = aThird * OneMinusCos - aThirdSqtSin;
      this.matrix[10] = aThird * OneMinusCos - aThirdSqtSin;
      this.matrix[11] = aThird * OneMinusCos + aThirdSqtSin;
      this.matrix[12] = cos + aThird * OneMinusCos;
    },

    /**
     * Apply this filter to the input image data provided.
     *
     * Determines whether to use WebGL or Canvas2D based on the options.webgl flag.
     *
     * @param {Object} options
     * @param {Number} options.passes The number of filters remaining to be executed
     * @param {Boolean} options.webgl Whether to use webgl to render the filter.
     * @param {WebGLTexture} options.sourceTexture The texture setup as the source to be filtered.
     * @param {WebGLTexture} options.targetTexture The texture where filtered output should be drawn.
     * @param {WebGLRenderingContext} options.context The GL context used for rendering.
     * @param {Object} options.programCache A map of compiled shader programs, keyed by filter type.
     */
    applyTo: function(options) {
      this.calculateMatrix();
      fabric.Image.filters.BaseFilter.prototype.applyTo.call(this, options);
    },

  });

  /**
   * Returns filter instance from an object representation
   * @static
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] to be invoked after filter creation
   * @return {fabric.Image.filters.HueRotation} Instance of fabric.Image.filters.HueRotation
   */
  fabric.Image.filters.HueRotation.fromObject = fabric.Image.filters.BaseFilter.fromObject;

})(typeof exports !== 'undefined' ? exports : this);


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { }),
      clone = fabric.util.object.clone;

  if (fabric.Text) {
    fabric.warn('fabric.Text is already defined');
    return;
  }

  /**
   * Text class
   * @class fabric.Text
   * @extends fabric.Object
   * @return {fabric.Text} thisArg
   * @tutorial {@link http://fabricjs.com/fabric-intro-part-2#text}
   * @see {@link fabric.Text#initialize} for constructor definition
   */
  fabric.Text = fabric.util.createClass(fabric.Object, /** @lends fabric.Text.prototype */ {

    /**
     * Properties which when set cause object to change dimensions
     * @type Array
     * @private
     */
    _dimensionAffectingProps: [
      'fontSize',
      'fontWeight',
      'fontFamily',
      'fontStyle',
      'lineHeight',
      'text',
      'charSpacing',
      'textAlign',
      'styles',
    ],

    /**
     * @private
     */
    _reNewline: /\r?\n/,

    /**
     * Use this regular expression to filter for whitespaces that is not a new line.
     * Mostly used when text is 'justify' aligned.
     * @private
     */
    _reSpacesAndTabs: /[ \t\r]/g,

    /**
     * Use this regular expression to filter for whitespace that is not a new line.
     * Mostly used when text is 'justify' aligned.
     * @private
     */
    _reSpaceAndTab: /[ \t\r]/,

    /**
     * Use this regular expression to filter consecutive groups of non spaces.
     * Mostly used when text is 'justify' aligned.
     * @private
     */
    _reWords: /\S+/g,

    /**
     * Type of an object
     * @type String
     * @default
     */
    type:                 'text',

    /**
     * Font size (in pixels)
     * @type Number
     * @default
     */
    fontSize:             40,

    /**
     * Font weight (e.g. bold, normal, 400, 600, 800)
     * @type {(Number|String)}
     * @default
     */
    fontWeight:           'normal',

    /**
     * Font family
     * @type String
     * @default
     */
    fontFamily:           'Times New Roman',

    /**
     * Text decoration underline.
     * @type String
     * @default
     */
    underline:       false,

    /**
     * Text decoration overline.
     * @type String
     * @default
     */
    overline:       false,

    /**
     * Text decoration linethrough.
     * @type String
     * @default
     */
    linethrough:       false,

    /**
     * Text alignment. Possible values: "left", "center", "right", "justify",
     * "justify-left", "justify-center" or "justify-right".
     * @type String
     * @default
     */
    textAlign:            'left',

    /**
     * Font style . Possible values: "", "normal", "italic" or "oblique".
     * @type String
     * @default
     */
    fontStyle:            'normal',

    /**
     * Line height
     * @type Number
     * @default
     */
    lineHeight:           1.16,

    /**
     * Superscript schema object (minimum overlap)
     * @type {Object}
     * @default
     */
    superscript: {
      size:      0.60, // fontSize factor
      baseline: -0.35  // baseline-shift factor (upwards)
    },

    /**
     * Subscript schema object (minimum overlap)
     * @type {Object}
     * @default
     */
    subscript: {
      size:      0.60, // fontSize factor
      baseline:  0.11  // baseline-shift factor (downwards)
    },

    /**
     * Background color of text lines
     * @type String
     * @default
     */
    textBackgroundColor:  '',

    /**
     * List of properties to consider when checking if
     * state of an object is changed ({@link fabric.Object#hasStateChanged})
     * as well as for history (undo/redo) purposes
     * @type Array
     */
    stateProperties: fabric.Object.prototype.stateProperties.concat('fontFamily',
      'fontWeight',
      'fontSize',
      'text',
      'underline',
      'overline',
      'linethrough',
      'textAlign',
      'fontStyle',
      'lineHeight',
      'textBackgroundColor',
      'charSpacing',
      'styles'),

    /**
     * List of properties to consider when checking if cache needs refresh
     * @type Array
     */
    cacheProperties: fabric.Object.prototype.cacheProperties.concat('fontFamily',
      'fontWeight',
      'fontSize',
      'text',
      'underline',
      'overline',
      'linethrough',
      'textAlign',
      'fontStyle',
      'lineHeight',
      'textBackgroundColor',
      'charSpacing',
      'styles'),

    /**
     * When defined, an object is rendered via stroke and this property specifies its color.
     * <b>Backwards incompatibility note:</b> This property was named "strokeStyle" until v1.1.6
     * @type String
     * @default
     */
    stroke:               null,

    /**
     * Shadow object representing shadow of this shape.
     * <b>Backwards incompatibility note:</b> This property was named "textShadow" (String) until v1.2.11
     * @type fabric.Shadow
     * @default
     */
    shadow:               null,

    /**
     * @private
     */
    _fontSizeFraction: 0.222,

    /**
     * @private
     */
    offsets: {
      underline: 0.10,
      linethrough: -0.315,
      overline: -0.88
    },

    /**
     * Text Line proportion to font Size (in pixels)
     * @type Number
     * @default
     */
    _fontSizeMult:             1.13,

    /**
     * additional space between characters
     * expressed in thousands of em unit
     * @type Number
     * @default
     */
    charSpacing:             0,

    /**
     * Object containing character styles - top-level properties -> line numbers,
     * 2nd-level properties - charater numbers
     * @type Object
     * @default
     */
    styles: null,

    /**
     * Reference to a context to measure text char or couple of chars
     * the cacheContext of the canvas will be used or a freshly created one if the object is not on canvas
     * once created it will be referenced on fabric._measuringContext to avoide creating a canvas for every
     * text object created.
     * @type {CanvasRenderingContext2D}
     * @default
     */
    _measuringContext: null,

    /**
     * Baseline shift, stlyes only, keep at 0 for the main text object
     * @type {Number}
     * @default
     */
    deltaY: 0,

    /**
     * Array of properties that define a style unit (of 'styles').
     * @type {Array}
     * @default
     */
    _styleProperties: [
      'stroke',
      'strokeWidth',
      'fill',
      'fontFamily',
      'fontSize',
      'fontWeight',
      'fontStyle',
      'underline',
      'overline',
      'linethrough',
      'deltaY',
      'textBackgroundColor',
    ],

    /**
     * contains characters bounding boxes
     */
    __charBounds: [],

    /**
     * use this size when measuring text. To avoid IE11 rounding errors
     * @type {Number}
     * @default
     * @readonly
     * @private
     */
    CACHE_FONT_SIZE: 400,

    /**
     * contains the min text width to avoid getting 0
     * @type {Number}
     * @default
     */
    MIN_TEXT_WIDTH: 2,

    /**
     * Constructor
     * @param {String} text Text string
     * @param {Object} [options] Options object
     * @return {fabric.Text} thisArg
     */
    initialize: function(text, options) {
      this.styles = options ? (options.styles || { }) : { };
      this.text = text;
      this.__skipDimension = true;
      this.callSuper('initialize', options);
      this.__skipDimension = false;
      this.initDimensions();
      this.setCoords();
      this.setupState({ propertySet: '_dimensionAffectingProps' });
    },

    /**
     * Return a contex for measurement of text string.
     * if created it gets stored for reuse
     * @param {String} text Text string
     * @param {Object} [options] Options object
     * @return {fabric.Text} thisArg
     */
    getMeasuringContext: function() {
      // if we did not return we have to measure something.
      if (!fabric._measuringContext) {
        fabric._measuringContext = this.canvas && this.canvas.contextCache ||
          fabric.util.createCanvasElement().getContext('2d');
      }
      return fabric._measuringContext;
    },

    /**
     * @private
     * Divides text into lines of text and lines of graphemes.
     */
    _splitText: function() {
      var newLines = this._splitTextIntoLines(this.text);
      this.textLines = newLines.lines;
      this._textLines = newLines.graphemeLines;
      this._unwrappedTextLines = newLines._unwrappedLines;
      this._text = newLines.graphemeText;
      return newLines;
    },

    /**
     * Initialize or update text dimensions.
     * Updates this.width and this.height with the proper values.
     * Does not return dimensions.
     */
    initDimensions: function() {
      if (this.__skipDimension) {
        return;
      }
      this._splitText();
      this._clearCache();
      this.width = this.calcTextWidth() || this.cursorWidth || this.MIN_TEXT_WIDTH;
      if (this.textAlign.indexOf('justify') !== -1) {
        // once text is measured we need to make space fatter to make justified text.
        this.enlargeSpaces();
      }
      this.height = this.calcTextHeight();
      this.saveState({ propertySet: '_dimensionAffectingProps' });
    },

    /**
     * Enlarge space boxes and shift the others
     */
    enlargeSpaces: function() {
      var diffSpace, currentLineWidth, numberOfSpaces, accumulatedSpace, line, charBound, spaces;
      for (var i = 0, len = this._textLines.length; i < len; i++) {
        if (this.textAlign !== 'justify' && (i === len - 1 || this.isEndOfWrapping(i))) {
          continue;
        }
        accumulatedSpace = 0;
        line = this._textLines[i];
        currentLineWidth = this.getLineWidth(i);
        if (currentLineWidth < this.width && (spaces = this.textLines[i].match(this._reSpacesAndTabs))) {
          numberOfSpaces = spaces.length;
          diffSpace = (this.width - currentLineWidth) / numberOfSpaces;
          for (var j = 0, jlen = line.length; j <= jlen; j++) {
            charBound = this.__charBounds[i][j];
            if (this._reSpaceAndTab.test(line[j])) {
              charBound.width += diffSpace;
              charBound.kernedWidth += diffSpace;
              charBound.left += accumulatedSpace;
              accumulatedSpace += diffSpace;
            }
            else {
              charBound.left += accumulatedSpace;
            }
          }
        }
      }
    },

    /**
     * Detect if the text line is ended with an hard break
     * text and itext do not have wrapping, return false
     * @return {Boolean}
     */
    isEndOfWrapping: function(lineIndex) {
      return lineIndex === this._textLines.length - 1;
    },

    /**
     * Returns string representation of an instance
     * @return {String} String representation of text object
     */
    toString: function() {
      return '#<fabric.Text (' + this.complexity() +
        '): { "text": "' + this.text + '", "fontFamily": "' + this.fontFamily + '" }>';
    },

    /**
     * Return the dimension and the zoom level needed to create a cache canvas
     * big enough to host the object to be cached.
     * @private
     * @param {Object} dim.x width of object to be cached
     * @param {Object} dim.y height of object to be cached
     * @return {Object}.width width of canvas
     * @return {Object}.height height of canvas
     * @return {Object}.zoomX zoomX zoom value to unscale the canvas before drawing cache
     * @return {Object}.zoomY zoomY zoom value to unscale the canvas before drawing cache
     */
    _getCacheCanvasDimensions: function() {
      var dims = this.callSuper('_getCacheCanvasDimensions');
      var fontSize = this.fontSize;
      dims.width += fontSize * dims.zoomX;
      dims.height += fontSize * dims.zoomY;
      return dims;
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _render: function(ctx) {
      this._setTextStyles(ctx);
      this._renderTextLinesBackground(ctx);
      this._renderTextDecoration(ctx, 'underline');
      this._renderText(ctx);
      this._renderTextDecoration(ctx, 'overline');
      this._renderTextDecoration(ctx, 'linethrough');
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderText: function(ctx) {
      if (this.paintFirst === 'stroke') {
        this._renderTextStroke(ctx);
        this._renderTextFill(ctx);
      }
      else {
        this._renderTextFill(ctx);
        this._renderTextStroke(ctx);
      }
    },

    /**
     * Set the font parameter of the context with the object properties or with charStyle
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     * @param {Object} [charStyle] object with font style properties
     * @param {String} [charStyle.fontFamily] Font Family
     * @param {Number} [charStyle.fontSize] Font size in pixels. ( without px suffix )
     * @param {String} [charStyle.fontWeight] Font weight
     * @param {String} [charStyle.fontStyle] Font style (italic|normal)
     */
    _setTextStyles: function(ctx, charStyle, forMeasuring) {
      ctx.textBaseline = 'alphabetic';
      ctx.font = this._getFontDeclaration(charStyle, forMeasuring);
    },

    /**
     * calculate and return the text Width measuring each line.
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     * @return {Number} Maximum width of fabric.Text object
     */
    calcTextWidth: function() {
      var maxWidth = this.getLineWidth(0);

      for (var i = 1, len = this._textLines.length; i < len; i++) {
        var currentLineWidth = this.getLineWidth(i);
        if (currentLineWidth > maxWidth) {
          maxWidth = currentLineWidth;
        }
      }
      return maxWidth;
    },

    /**
     * @private
     * @param {String} method Method name ("fillText" or "strokeText")
     * @param {CanvasRenderingContext2D} ctx Context to render on
     * @param {String} line Text to render
     * @param {Number} left Left position of text
     * @param {Number} top Top position of text
     * @param {Number} lineIndex Index of a line in a text
     */
    _renderTextLine: function(method, ctx, line, left, top, lineIndex) {
      this._renderChars(method, ctx, line, left, top, lineIndex);
    },

    /**
     * Renders the text background for lines, taking care of style
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderTextLinesBackground: function(ctx) {
      if (!this.textBackgroundColor && !this.styleHas('textBackgroundColor')) {
        return;
      }
      var lineTopOffset = 0, heightOfLine,
          lineLeftOffset, originalFill = ctx.fillStyle,
          line, lastColor,
          leftOffset = this._getLeftOffset(),
          topOffset = this._getTopOffset(),
          boxStart = 0, boxWidth = 0, charBox, currentColor;

      for (var i = 0, len = this._textLines.length; i < len; i++) {
        heightOfLine = this.getHeightOfLine(i);
        if (!this.textBackgroundColor && !this.styleHas('textBackgroundColor', i)) {
          lineTopOffset += heightOfLine;
          continue;
        }
        line = this._textLines[i];
        lineLeftOffset = this._getLineLeftOffset(i);
        boxWidth = 0;
        boxStart = 0;
        lastColor = this.getValueOfPropertyAt(i, 0, 'textBackgroundColor');
        for (var j = 0, jlen = line.length; j < jlen; j++) {
          charBox = this.__charBounds[i][j];
          currentColor = this.getValueOfPropertyAt(i, j, 'textBackgroundColor');
          if (currentColor !== lastColor) {
            ctx.fillStyle = lastColor;
            lastColor && ctx.fillRect(
              leftOffset + lineLeftOffset + boxStart,
              topOffset + lineTopOffset,
              boxWidth,
              heightOfLine / this.lineHeight
            );
            boxStart = charBox.left;
            boxWidth = charBox.width;
            lastColor = currentColor;
          }
          else {
            boxWidth += charBox.kernedWidth;
          }
        }
        if (currentColor) {
          ctx.fillStyle = currentColor;
          ctx.fillRect(
            leftOffset + lineLeftOffset + boxStart,
            topOffset + lineTopOffset,
            boxWidth,
            heightOfLine / this.lineHeight
          );
        }
        lineTopOffset += heightOfLine;
      }
      ctx.fillStyle = originalFill;
      // if there is text background color no
      // other shadows should be casted
      this._removeShadow(ctx);
    },

    /**
     * @private
     * @param {Object} decl style declaration for cache
     * @param {String} decl.fontFamily fontFamily
     * @param {String} decl.fontStyle fontStyle
     * @param {String} decl.fontWeight fontWeight
     * @return {Object} reference to cache
     */
    getFontCache: function(decl) {
      var fontFamily = decl.fontFamily.toLowerCase();
      if (!fabric.charWidthsCache[fontFamily]) {
        fabric.charWidthsCache[fontFamily] = { };
      }
      var cache = fabric.charWidthsCache[fontFamily],
          cacheProp = decl.fontStyle.toLowerCase() + '_' + (decl.fontWeight + '').toLowerCase();
      if (!cache[cacheProp]) {
        cache[cacheProp] = { };
      }
      return cache[cacheProp];
    },

    /**
     * apply all the character style to canvas for rendering
     * @private
     * @param {String} _char
     * @param {Number} lineIndex
     * @param {Number} charIndex
     * @param {Object} [decl]
     */
    _applyCharStyles: function(method, ctx, lineIndex, charIndex, styleDeclaration) {

      this._setFillStyles(ctx, styleDeclaration);
      this._setStrokeStyles(ctx, styleDeclaration);

      ctx.font = this._getFontDeclaration(styleDeclaration);
    },

    /**
     * measure and return the width of a single character.
     * possibly overridden to accommodate different measure logic or
     * to hook some external lib for character measurement
     * @private
     * @param {String} char to be measured
     * @param {Object} charStyle style of char to be measured
     * @param {String} [previousChar] previous char
     * @param {Object} [prevCharStyle] style of previous char
     */
    _measureChar: function(_char, charStyle, previousChar, prevCharStyle) {
      // first i try to return from cache
      var fontCache = this.getFontCache(charStyle), fontDeclaration = this._getFontDeclaration(charStyle),
          previousFontDeclaration = this._getFontDeclaration(prevCharStyle), couple = previousChar + _char,
          stylesAreEqual = fontDeclaration === previousFontDeclaration, width, coupleWidth, previousWidth,
          fontMultiplier = charStyle.fontSize / this.CACHE_FONT_SIZE, kernedWidth;

      if (previousChar && fontCache[previousChar]) {
        previousWidth = fontCache[previousChar];
      }
      if (fontCache[_char]) {
        kernedWidth = width = fontCache[_char];
      }
      if (stylesAreEqual && fontCache[couple]) {
        coupleWidth = fontCache[couple];
        kernedWidth = coupleWidth - previousWidth;
      }
      if (!width || !previousWidth || !coupleWidth) {
        var ctx = this.getMeasuringContext();
        // send a TRUE to specify measuring font size CACHE_FONT_SIZE
        this._setTextStyles(ctx, charStyle, true);
      }
      if (!width) {
        kernedWidth = width = ctx.measureText(_char).width;
        fontCache[_char] = width;
      }
      if (!previousWidth && stylesAreEqual && previousChar) {
        previousWidth = ctx.measureText(previousChar).width;
        fontCache[previousChar] = previousWidth;
      }
      if (stylesAreEqual && !coupleWidth) {
        // we can measure the kerning couple and subtract the width of the previous character
        coupleWidth = ctx.measureText(couple).width;
        fontCache[couple] = coupleWidth;
        kernedWidth = coupleWidth - previousWidth;
      }
      return { width: width * fontMultiplier, kernedWidth: kernedWidth * fontMultiplier };
    },

    /**
     * Computes height of character at given position
     * @param {Number} line the line number
     * @param {Number} char the character number
     * @return {Number} fontSize of the character
     */
    getHeightOfChar: function(line, char) {
      return this.getValueOfPropertyAt(line, char, 'fontSize');
    },

    /**
     * measure a text line measuring all characters.
     * @param {Number} lineIndex line number
     * @return {Number} Line width
     */
    measureLine: function(lineIndex) {
      var lineInfo = this._measureLine(lineIndex);
      if (this.charSpacing !== 0) {
        lineInfo.width -= this._getWidthOfCharSpacing();
      }
      if (lineInfo.width < 0) {
        lineInfo.width = 0;
      }
      return lineInfo;
    },

    /**
     * measure every grapheme of a line, populating __charBounds
     * @param {Number} lineIndex
     * @return {Object} object.width total width of characters
     * @return {Object} object.widthOfSpaces length of chars that match this._reSpacesAndTabs
     */
    _measureLine: function(lineIndex) {
      var width = 0, i, grapheme, line = this._textLines[lineIndex], prevGrapheme,
          graphemeInfo, numOfSpaces = 0, lineBounds = new Array(line.length);

      this.__charBounds[lineIndex] = lineBounds;
      for (i = 0; i < line.length; i++) {
        grapheme = line[i];
        graphemeInfo = this._getGraphemeBox(grapheme, lineIndex, i, prevGrapheme);
        lineBounds[i] = graphemeInfo;
        width += graphemeInfo.kernedWidth;
        prevGrapheme = grapheme;
      }
      // this latest bound box represent the last character of the line
      // to simplify cursor handling in interactive mode.
      lineBounds[i] = {
        left: graphemeInfo ? graphemeInfo.left + graphemeInfo.width : 0,
        width: 0,
        kernedWidth: 0,
        height: this.fontSize
      };
      return { width: width, numOfSpaces: numOfSpaces };
    },

    /**
     * Measure and return the info of a single grapheme.
     * needs the the info of previous graphemes already filled
     * @private
     * @param {String} grapheme to be measured
     * @param {Number} lineIndex index of the line where the char is
     * @param {Number} charIndex position in the line
     * @param {String} [prevGrapheme] character preceding the one to be measured
     */
    _getGraphemeBox: function(grapheme, lineIndex, charIndex, prevGrapheme, skipLeft) {
      var style = this.getCompleteStyleDeclaration(lineIndex, charIndex),
          prevStyle = prevGrapheme ? this.getCompleteStyleDeclaration(lineIndex, charIndex - 1) : { },
          info = this._measureChar(grapheme, style, prevGrapheme, prevStyle),
          kernedWidth = info.kernedWidth,
          width = info.width, charSpacing;

      if (this.charSpacing !== 0) {
        charSpacing = this._getWidthOfCharSpacing();
        width += charSpacing;
        kernedWidth += charSpacing;
      }

      var box = {
        width: width,
        left: 0,
        height: style.fontSize,
        kernedWidth: kernedWidth,
        deltaY: style.deltaY,
      };
      if (charIndex > 0 && !skipLeft) {
        var previousBox = this.__charBounds[lineIndex][charIndex - 1];
        box.left = previousBox.left + previousBox.width + info.kernedWidth - info.width;
      }
      return box;
    },

    /**
     * Calculate height of line at 'lineIndex'
     * @param {Number} lineIndex index of line to calculate
     * @return {Number}
     */
    getHeightOfLine: function(lineIndex) {
      if (this.__lineHeights[lineIndex]) {
        return this.__lineHeights[lineIndex];
      }

      var line = this._textLines[lineIndex],
          // char 0 is measured before the line cycle because it nneds to char
          // emptylines
          maxHeight = this.getHeightOfChar(lineIndex, 0);
      for (var i = 1, len = line.length; i < len; i++) {
        maxHeight = Math.max(this.getHeightOfChar(lineIndex, i), maxHeight);
      }

      return this.__lineHeights[lineIndex] = maxHeight * this.lineHeight * this._fontSizeMult;
    },

    /**
     * Calculate text box height
     */
    calcTextHeight: function() {
      var lineHeight, height = 0;
      for (var i = 0, len = this._textLines.length; i < len; i++) {
        lineHeight = this.getHeightOfLine(i);
        height += (i === len - 1 ? lineHeight / this.lineHeight : lineHeight);
      }
      return height;
    },

    /**
     * @private
     * @return {Number} Left offset
     */
    _getLeftOffset: function() {
      return -this.width / 2;
    },

    /**
     * @private
     * @return {Number} Top offset
     */
    _getTopOffset: function() {
      return -this.height / 2;
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     * @param {String} method Method name ("fillText" or "strokeText")
     */
    _renderTextCommon: function(ctx, method) {
      ctx.save();
      var lineHeights = 0, left = this._getLeftOffset(), top = this._getTopOffset(),
          offsets = this._applyPatternGradientTransform(ctx, method === 'fillText' ? this.fill : this.stroke);
      for (var i = 0, len = this._textLines.length; i < len; i++) {
        var heightOfLine = this.getHeightOfLine(i),
            maxHeight = heightOfLine / this.lineHeight,
            leftOffset = this._getLineLeftOffset(i);
        this._renderTextLine(
          method,
          ctx,
          this._textLines[i],
          left + leftOffset - offsets.offsetX,
          top + lineHeights + maxHeight - offsets.offsetY,
          i
        );
        lineHeights += heightOfLine;
      }
      ctx.restore();
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderTextFill: function(ctx) {
      if (!this.fill && !this.styleHas('fill')) {
        return;
      }

      this._renderTextCommon(ctx, 'fillText');
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderTextStroke: function(ctx) {
      if ((!this.stroke || this.strokeWidth === 0) && this.isEmptyStyles()) {
        return;
      }

      if (this.shadow && !this.shadow.affectStroke) {
        this._removeShadow(ctx);
      }

      ctx.save();
      this._setLineDash(ctx, this.strokeDashArray);
      ctx.beginPath();
      this._renderTextCommon(ctx, 'strokeText');
      ctx.closePath();
      ctx.restore();
    },

    /**
     * @private
     * @param {String} method
     * @param {CanvasRenderingContext2D} ctx Context to render on
     * @param {String} line Content of the line
     * @param {Number} left
     * @param {Number} top
     * @param {Number} lineIndex
     * @param {Number} charOffset
     */
    _renderChars: function(method, ctx, line, left, top, lineIndex) {
      // set proper line offset
      var lineHeight = this.getHeightOfLine(lineIndex),
          isJustify = this.textAlign.indexOf('justify') !== -1,
          actualStyle,
          nextStyle,
          charsToRender = '',
          charBox,
          boxWidth = 0,
          timeToRender,
          shortCut = !isJustify && this.charSpacing === 0 && this.isEmptyStyles(lineIndex);

      ctx.save();
      top -= lineHeight * this._fontSizeFraction / this.lineHeight;
      if (shortCut) {
        // render all the line in one pass without checking
        this._renderChar(method, ctx, lineIndex, 0, this.textLines[lineIndex], left, top, lineHeight);
        ctx.restore();
        return;
      }
      for (var i = 0, len = line.length - 1; i <= len; i++) {
        timeToRender = i === len || this.charSpacing;
        charsToRender += line[i];
        charBox = this.__charBounds[lineIndex][i];
        if (boxWidth === 0) {
          left += charBox.kernedWidth - charBox.width;
          boxWidth += charBox.width;
        }
        else {
          boxWidth += charBox.kernedWidth;
        }
        if (isJustify && !timeToRender) {
          if (this._reSpaceAndTab.test(line[i])) {
            timeToRender = true;
          }
        }
        if (!timeToRender) {
          // if we have charSpacing, we render char by char
          actualStyle = actualStyle || this.getCompleteStyleDeclaration(lineIndex, i);
          nextStyle = this.getCompleteStyleDeclaration(lineIndex, i + 1);
          timeToRender = this._hasStyleChanged(actualStyle, nextStyle);
        }
        if (timeToRender) {
          this._renderChar(method, ctx, lineIndex, i, charsToRender, left, top, lineHeight);
          charsToRender = '';
          actualStyle = nextStyle;
          left += boxWidth;
          boxWidth = 0;
        }
      }
      ctx.restore();
    },

    /**
     * @private
     * @param {String} method
     * @param {CanvasRenderingContext2D} ctx Context to render on
     * @param {Number} lineIndex
     * @param {Number} charIndex
     * @param {String} _char
     * @param {Number} left Left coordinate
     * @param {Number} top Top coordinate
     * @param {Number} lineHeight Height of the line
     */
    _renderChar: function(method, ctx, lineIndex, charIndex, _char, left, top) {
      var decl = this._getStyleDeclaration(lineIndex, charIndex),
          fullDecl = this.getCompleteStyleDeclaration(lineIndex, charIndex),
          shouldFill = method === 'fillText' && fullDecl.fill,
          shouldStroke = method === 'strokeText' && fullDecl.stroke && fullDecl.strokeWidth;

      if (!shouldStroke && !shouldFill) {
        return;
      }
      decl && ctx.save();

      this._applyCharStyles(method, ctx, lineIndex, charIndex, fullDecl);

      if (decl && decl.textBackgroundColor) {
        this._removeShadow(ctx);
      }
      if (decl && decl.deltaY) {
        top += decl.deltaY;
      }

      shouldFill && ctx.fillText(_char, left, top);
      shouldStroke && ctx.strokeText(_char, left, top);
      decl && ctx.restore();
    },

    /**
     * Turns the character into a 'superior figure' (i.e. 'superscript')
     * @param {Number} start selection start
     * @param {Number} end selection end
     * @returns {fabric.Text} thisArg
     * @chainable
     */
    setSuperscript: function(start, end) {
      return this._setScript(start, end, this.superscript);
    },

    /**
     * Turns the character into an 'inferior figure' (i.e. 'subscript')
     * @param {Number} start selection start
     * @param {Number} end selection end
     * @returns {fabric.Text} thisArg
     * @chainable
     */
    setSubscript: function(start, end) {
      return this._setScript(start, end, this.subscript);
    },

    /**
     * Applies 'schema' at given position
     * @private
     * @param {Number} start selection start
     * @param {Number} end selection end
     * @param {Number} schema
     * @returns {fabric.Text} thisArg
     * @chainable
     */
    _setScript: function(start, end, schema) {
      var loc = this.get2DCursorLocation(start, true),
          fontSize = this.getValueOfPropertyAt(loc.lineIndex, loc.charIndex, 'fontSize'),
          dy = this.getValueOfPropertyAt(loc.lineIndex, loc.charIndex, 'deltaY'),
          style = { fontSize: fontSize * schema.size, deltaY: dy + fontSize * schema.baseline };
      this.setSelectionStyles(style, start, end);
      return this;
    },

    /**
     * @private
     * @param {Object} prevStyle
     * @param {Object} thisStyle
     */
    _hasStyleChanged: function(prevStyle, thisStyle) {
      return prevStyle.fill !== thisStyle.fill ||
              prevStyle.stroke !== thisStyle.stroke ||
              prevStyle.strokeWidth !== thisStyle.strokeWidth ||
              prevStyle.fontSize !== thisStyle.fontSize ||
              prevStyle.fontFamily !== thisStyle.fontFamily ||
              prevStyle.fontWeight !== thisStyle.fontWeight ||
              prevStyle.fontStyle !== thisStyle.fontStyle ||
              prevStyle.deltaY !== thisStyle.deltaY;
    },

    /**
     * @private
     * @param {Object} prevStyle
     * @param {Object} thisStyle
     */
    _hasStyleChangedForSvg: function(prevStyle, thisStyle) {
      return this._hasStyleChanged(prevStyle, thisStyle) ||
        prevStyle.overline !== thisStyle.overline ||
        prevStyle.underline !== thisStyle.underline ||
        prevStyle.linethrough !== thisStyle.linethrough;
    },

    /**
     * @private
     * @param {Number} lineIndex index text line
     * @return {Number} Line left offset
     */
    _getLineLeftOffset: function(lineIndex) {
      var lineWidth = this.getLineWidth(lineIndex);
      if (this.textAlign === 'center') {
        return (this.width - lineWidth) / 2;
      }
      if (this.textAlign === 'right') {
        return this.width - lineWidth;
      }
      if (this.textAlign === 'justify-center' && this.isEndOfWrapping(lineIndex)) {
        return (this.width - lineWidth) / 2;
      }
      if (this.textAlign === 'justify-right' && this.isEndOfWrapping(lineIndex)) {
        return this.width - lineWidth;
      }
      return 0;
    },

    /**
     * @private
     */
    _clearCache: function() {
      this.__lineWidths = [];
      this.__lineHeights = [];
      this.__charBounds = [];
    },

    /**
     * @private
     */
    _shouldClearDimensionCache: function() {
      var shouldClear = this._forceClearCache;
      shouldClear || (shouldClear = this.hasStateChanged('_dimensionAffectingProps'));
      if (shouldClear) {
        this.dirty = true;
        this._forceClearCache = false;
      }
      return shouldClear;
    },

    /**
     * Measure a single line given its index. Used to calculate the initial
     * text bounding box. The values are calculated and stored in __lineWidths cache.
     * @private
     * @param {Number} lineIndex line number
     * @return {Number} Line width
     */
    getLineWidth: function(lineIndex) {
      if (this.__lineWidths[lineIndex]) {
        return this.__lineWidths[lineIndex];
      }

      var width, line = this._textLines[lineIndex], lineInfo;

      if (line === '') {
        width = 0;
      }
      else {
        lineInfo = this.measureLine(lineIndex);
        width = lineInfo.width;
      }
      this.__lineWidths[lineIndex] = width;
      return width;
    },

    _getWidthOfCharSpacing: function() {
      if (this.charSpacing !== 0) {
        return this.fontSize * this.charSpacing / 1000;
      }
      return 0;
    },

    /**
     * Retrieves the value of property at given character position
     * @param {Number} lineIndex the line number
     * @param {Number} charIndex the charater number
     * @param {String} property the property name
     * @returns the value of 'property'
     */
    getValueOfPropertyAt: function(lineIndex, charIndex, property) {
      var charStyle = this._getStyleDeclaration(lineIndex, charIndex);
      if (charStyle && typeof charStyle[property] !== 'undefined') {
        return charStyle[property];
      }
      return this[property];
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _renderTextDecoration: function(ctx, type) {
      if (!this[type] && !this.styleHas(type)) {
        return;
      }
      var heightOfLine, size, _size,
          lineLeftOffset, dy, _dy,
          line, lastDecoration,
          leftOffset = this._getLeftOffset(),
          topOffset = this._getTopOffset(), top,
          boxStart, boxWidth, charBox, currentDecoration,
          maxHeight, currentFill, lastFill,
          charSpacing = this._getWidthOfCharSpacing();

      for (var i = 0, len = this._textLines.length; i < len; i++) {
        heightOfLine = this.getHeightOfLine(i);
        if (!this[type] && !this.styleHas(type, i)) {
          topOffset += heightOfLine;
          continue;
        }
        line = this._textLines[i];
        maxHeight = heightOfLine / this.lineHeight;
        lineLeftOffset = this._getLineLeftOffset(i);
        boxStart = 0;
        boxWidth = 0;
        lastDecoration = this.getValueOfPropertyAt(i, 0, type);
        lastFill = this.getValueOfPropertyAt(i, 0, 'fill');
        top = topOffset + maxHeight * (1 - this._fontSizeFraction);
        size = this.getHeightOfChar(i, 0);
        dy = this.getValueOfPropertyAt(i, 0, 'deltaY');
        for (var j = 0, jlen = line.length; j < jlen; j++) {
          charBox = this.__charBounds[i][j];
          currentDecoration = this.getValueOfPropertyAt(i, j, type);
          currentFill = this.getValueOfPropertyAt(i, j, 'fill');
          _size = this.getHeightOfChar(i, j);
          _dy = this.getValueOfPropertyAt(i, j, 'deltaY');
          if ((currentDecoration !== lastDecoration || currentFill !== lastFill || _size !== size || _dy !== dy) &&
              boxWidth > 0) {
            ctx.fillStyle = lastFill;
            lastDecoration && lastFill && ctx.fillRect(
              leftOffset + lineLeftOffset + boxStart,
              top + this.offsets[type] * size + dy,
              boxWidth,
              this.fontSize / 15
            );
            boxStart = charBox.left;
            boxWidth = charBox.width;
            lastDecoration = currentDecoration;
            lastFill = currentFill;
            size = _size;
            dy = _dy;
          }
          else {
            boxWidth += charBox.kernedWidth;
          }
        }
        ctx.fillStyle = currentFill;
        currentDecoration && currentFill && ctx.fillRect(
          leftOffset + lineLeftOffset + boxStart,
          top + this.offsets[type] * size + dy,
          boxWidth - charSpacing,
          this.fontSize / 15
        );
        topOffset += heightOfLine;
      }
      // if there is text background color no
      // other shadows should be casted
      this._removeShadow(ctx);
    },

    /**
     * return font declaration string for canvas context
     * @param {Object} [styleObject] object
     * @returns {String} font declaration formatted for canvas context.
     */
    _getFontDeclaration: function(styleObject, forMeasuring) {
      var style = styleObject || this;
      var fontFamily = style.fontFamily === undefined ||
      style.fontFamily.indexOf('\'') > -1 ||
      style.fontFamily.indexOf('"') > -1
        ? style.fontFamily : '"' + style.fontFamily + '"';
      return [
        // node-canvas needs "weight style", while browsers need "style weight"
        (fabric.isLikelyNode ? style.fontWeight : style.fontStyle),
        (fabric.isLikelyNode ? style.fontStyle : style.fontWeight),
        forMeasuring ? this.CACHE_FONT_SIZE + 'px' : style.fontSize + 'px',
        fontFamily
      ].join(' ');
    },

    /**
     * Renders text instance on a specified context
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    render: function(ctx) {
      // do not render if object is not visible
      if (!this.visible) {
        return;
      }
      if (this.canvas && this.canvas.skipOffscreen && !this.group && !this.isOnScreen()) {
        return;
      }
      if (this._shouldClearDimensionCache()) {
        this.initDimensions();
      }
      this.callSuper('render', ctx);
    },

    /**
     * Returns the text as an array of lines.
     * @param {String} text text to split
     * @returns {Array} Lines in the text
     */
    _splitTextIntoLines: function(text) {
      var lines = text.split(this._reNewline),
          newLines = new Array(lines.length),
          newLine = ['\n'],
          newText = [];
      for (var i = 0; i < lines.length; i++) {
        newLines[i] = fabric.util.string.graphemeSplit(lines[i]);
        newText = newText.concat(newLines[i], newLine);
      }
      newText.pop();
      return { _unwrappedLines: newLines, lines: lines, graphemeText: newText, graphemeLines: newLines };
    },

    /**
     * Returns object representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} Object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      var additionalProperties = [
        'text',
        'fontSize',
        'fontWeight',
        'fontFamily',
        'fontStyle',
        'lineHeight',
        'underline',
        'overline',
        'linethrough',
        'textAlign',
        'textBackgroundColor',
        'charSpacing',
      ].concat(propertiesToInclude);
      var obj = this.callSuper('toObject', additionalProperties);
      obj.styles = clone(this.styles, true);
      return obj;
    },

    /**
     * Sets property to a given value. When changing position/dimension -related properties (left, top, scale, angle, etc.) `set` does not update position of object's borders/controls. If you need to update those, call `setCoords()`.
     * @param {String|Object} key Property name or object (if object, iterate over the object properties)
     * @param {Object|Function} value Property value (if function, the value is passed into it and its return value is used as a new one)
     * @return {fabric.Object} thisArg
     * @chainable
     */
    set: function(key, value) {
      this.callSuper('set', key, value);
      var needsDims = false;
      if (typeof key === 'object') {
        for (var _key in key) {
          needsDims = needsDims || this._dimensionAffectingProps.indexOf(_key) !== -1;
        }
      }
      else {
        needsDims = this._dimensionAffectingProps.indexOf(key) !== -1;
      }
      if (needsDims) {
        this.initDimensions();
        this.setCoords();
      }
      return this;
    },

    /**
     * Returns complexity of an instance
     * @return {Number} complexity
     */
    complexity: function() {
      return 1;
    }
  });

  /* _FROM_SVG_START_ */
  /**
   * List of attribute names to account for when parsing SVG element (used by {@link fabric.Text.fromElement})
   * @static
   * @memberOf fabric.Text
   * @see: http://www.w3.org/TR/SVG/text.html#TextElement
   */
  fabric.Text.ATTRIBUTE_NAMES = fabric.SHARED_ATTRIBUTES.concat(
    'x y dx dy font-family font-style font-weight font-size letter-spacing text-decoration text-anchor'.split(' '));

  /**
   * Default SVG font size
   * @static
   * @memberOf fabric.Text
   */
  fabric.Text.DEFAULT_SVG_FONT_SIZE = 16;

  /**
   * Returns fabric.Text instance from an SVG element (<b>not yet implemented</b>)
   * @static
   * @memberOf fabric.Text
   * @param {SVGElement} element Element to parse
   * @param {Function} callback callback function invoked after parsing
   * @param {Object} [options] Options object
   */
  fabric.Text.fromElement = function(element, callback, options) {
    if (!element) {
      return callback(null);
    }

    var parsedAttributes = fabric.parseAttributes(element, fabric.Text.ATTRIBUTE_NAMES),
        parsedAnchor = parsedAttributes.textAnchor || 'left';
    options = fabric.util.object.extend((options ? clone(options) : { }), parsedAttributes);

    options.top = options.top || 0;
    options.left = options.left || 0;
    if (parsedAttributes.textDecoration) {
      var textDecoration = parsedAttributes.textDecoration;
      if (textDecoration.indexOf('underline') !== -1) {
        options.underline = true;
      }
      if (textDecoration.indexOf('overline') !== -1) {
        options.overline = true;
      }
      if (textDecoration.indexOf('line-through') !== -1) {
        options.linethrough = true;
      }
      delete options.textDecoration;
    }
    if ('dx' in parsedAttributes) {
      options.left += parsedAttributes.dx;
    }
    if ('dy' in parsedAttributes) {
      options.top += parsedAttributes.dy;
    }
    if (!('fontSize' in options)) {
      options.fontSize = fabric.Text.DEFAULT_SVG_FONT_SIZE;
    }

    var textContent = '';

    // The XML is not properly parsed in IE9 so a workaround to get
    // textContent is through firstChild.data. Another workaround would be
    // to convert XML loaded from a file to be converted using DOMParser (same way loadSVGFromString() does)
    if (!('textContent' in element)) {
      if ('firstChild' in element && element.firstChild !== null) {
        if ('data' in element.firstChild && element.firstChild.data !== null) {
          textContent = element.firstChild.data;
        }
      }
    }
    else {
      textContent = element.textContent;
    }

    textContent = textContent.replace(/^\s+|\s+$|\n+/g, '').replace(/\s+/g, ' ');
    var originalStrokeWidth = options.strokeWidth;
    options.strokeWidth = 0;

    var text = new fabric.Text(textContent, options),
        textHeightScaleFactor = text.getScaledHeight() / text.height,
        lineHeightDiff = (text.height + text.strokeWidth) * text.lineHeight - text.height,
        scaledDiff = lineHeightDiff * textHeightScaleFactor,
        textHeight = text.getScaledHeight() + scaledDiff,
        offX = 0;
    /*
      Adjust positioning:
        x/y attributes in SVG correspond to the bottom-left corner of text bounding box
        fabric output by default at top, left.
    */
    if (parsedAnchor === 'center') {
      offX = text.getScaledWidth() / 2;
    }
    if (parsedAnchor === 'right') {
      offX = text.getScaledWidth();
    }
    text.set({
      left: text.left - offX,
      top: text.top - (textHeight - text.fontSize * (0.07 + text._fontSizeFraction)) / text.lineHeight,
      strokeWidth: typeof originalStrokeWidth !== 'undefined' ? originalStrokeWidth : 1,
    });
    callback(text);
  };
  /* _FROM_SVG_END_ */

  /**
   * Returns fabric.Text instance from an object representation
   * @static
   * @memberOf fabric.Text
   * @param {Object} object Object to create an instance from
   * @param {Function} [callback] Callback to invoke when an fabric.Text instance is created
   */
  fabric.Text.fromObject = function(object, callback) {
    return fabric.Object._fromObject('Text', object, callback, 'text');
  };

  fabric.util.createAccessors && fabric.util.createAccessors(fabric.Text);

})(typeof exports !== 'undefined' ? exports : this);


(function() {
  fabric.util.object.extend(fabric.Text.prototype, /** @lends fabric.Text.prototype */ {
    /**
     * Returns true if object has no styling or no styling in a line
     * @param {Number} lineIndex , lineIndex is on wrapped lines.
     * @return {Boolean}
     */
    isEmptyStyles: function(lineIndex) {
      if (!this.styles) {
        return true;
      }
      if (typeof lineIndex !== 'undefined' && !this.styles[lineIndex]) {
        return true;
      }
      var obj = typeof lineIndex === 'undefined' ? this.styles : { line: this.styles[lineIndex] };
      for (var p1 in obj) {
        for (var p2 in obj[p1]) {
          // eslint-disable-next-line no-unused-vars
          for (var p3 in obj[p1][p2]) {
            return false;
          }
        }
      }
      return true;
    },

    /**
     * Returns true if object has a style property or has it ina specified line
     * @param {Number} lineIndex
     * @return {Boolean}
     */
    styleHas: function(property, lineIndex) {
      if (!this.styles || !property || property === '') {
        return false;
      }
      if (typeof lineIndex !== 'undefined' && !this.styles[lineIndex]) {
        return false;
      }
      var obj = typeof lineIndex === 'undefined' ? this.styles : { line: this.styles[lineIndex] };
      // eslint-disable-next-line
      for (var p1 in obj) {
        // eslint-disable-next-line
        for (var p2 in obj[p1]) {
          if (typeof obj[p1][p2][property] !== 'undefined') {
            return true;
          }
        }
      }
      return false;
    },

    /**
     * Check if characters in a text have a value for a property
     * whose value matches the textbox's value for that property.  If so,
     * the character-level property is deleted.  If the character
     * has no other properties, then it is also deleted.  Finally,
     * if the line containing that character has no other characters
     * then it also is deleted.
     *
     * @param {string} property The property to compare between characters and text.
     */
    cleanStyle: function(property) {
      if (!this.styles || !property || property === '') {
        return false;
      }
      var obj = this.styles, stylesCount = 0, letterCount, stylePropertyValue,
          allStyleObjectPropertiesMatch = true, graphemeCount = 0, styleObject;
      // eslint-disable-next-line
      for (var p1 in obj) {
        letterCount = 0;
        // eslint-disable-next-line
        for (var p2 in obj[p1]) {
          var styleObject = obj[p1][p2],
              stylePropertyHasBeenSet = styleObject.hasOwnProperty(property);

          stylesCount++;

          if (stylePropertyHasBeenSet) {
            if (!stylePropertyValue) {
              stylePropertyValue = styleObject[property];
            }
            else if (styleObject[property] !== stylePropertyValue) {
              allStyleObjectPropertiesMatch = false;
            }

            if (styleObject[property] === this[property]) {
              delete styleObject[property];
            }
          }
          else {
            allStyleObjectPropertiesMatch = false;
          }

          if (Object.keys(styleObject).length !== 0) {
            letterCount++;
          }
          else {
            delete obj[p1][p2];
          }
        }

        if (letterCount === 0) {
          delete obj[p1];
        }
      }
      // if every grapheme has the same style set then
      // delete those styles and set it on the parent
      for (var i = 0; i < this._textLines.length; i++) {
        graphemeCount += this._textLines[i].length;
      }
      if (allStyleObjectPropertiesMatch && stylesCount === graphemeCount) {
        this[property] = stylePropertyValue;
        this.removeStyle(property);
      }
    },

    /**
     * Remove a style property or properties from all individual character styles
     * in a text object.  Deletes the character style object if it contains no other style
     * props.  Deletes a line style object if it contains no other character styles.
     *
     * @param {String} props The property to remove from character styles.
     */
    removeStyle: function(property) {
      if (!this.styles || !property || property === '') {
        return;
      }
      var obj = this.styles, line, lineNum, charNum;
      for (lineNum in obj) {
        line = obj[lineNum];
        for (charNum in line) {
          delete line[charNum][property];
          if (Object.keys(line[charNum]).length === 0) {
            delete line[charNum];
          }
        }
        if (Object.keys(line).length === 0) {
          delete obj[lineNum];
        }
      }
    },

    /**
     * @private
     */
    _extendStyles: function(index, styles) {
      var loc = this.get2DCursorLocation(index);

      if (!this._getLineStyle(loc.lineIndex)) {
        this._setLineStyle(loc.lineIndex, {});
      }

      if (!this._getStyleDeclaration(loc.lineIndex, loc.charIndex)) {
        this._setStyleDeclaration(loc.lineIndex, loc.charIndex, {});
      }

      fabric.util.object.extend(this._getStyleDeclaration(loc.lineIndex, loc.charIndex), styles);
    },

    /**
     * Returns 2d representation (lineIndex and charIndex) of cursor (or selection start)
     * @param {Number} [selectionStart] Optional index. When not given, current selectionStart is used.
     * @param {Boolean} [skipWrapping] consider the location for unwrapped lines. usefull to manage styles.
     */
    get2DCursorLocation: function(selectionStart, skipWrapping) {
      if (typeof selectionStart === 'undefined') {
        selectionStart = this.selectionStart;
      }
      var lines = skipWrapping ? this._unwrappedTextLines : this._textLines;
      var len = lines.length;
      for (var i = 0; i < len; i++) {
        if (selectionStart <= lines[i].length) {
          return {
            lineIndex: i,
            charIndex: selectionStart
          };
        }
        selectionStart -= lines[i].length + 1;
      }
      return {
        lineIndex: i - 1,
        charIndex: lines[i - 1].length < selectionStart ? lines[i - 1].length : selectionStart
      };
    },

    /**
     * Gets style of a current selection/cursor (at the start position)
     * if startIndex or endIndex are not provided, slectionStart or selectionEnd will be used.
     * @param {Number} [startIndex] Start index to get styles at
     * @param {Number} [endIndex] End index to get styles at, if not specified selectionEnd or startIndex + 1
     * @param {Boolean} [complete] get full style or not
     * @return {Array} styles an array with one, zero or more Style objects
     */
    getSelectionStyles: function(startIndex, endIndex, complete) {
      if (typeof startIndex === 'undefined') {
        startIndex = this.selectionStart || 0;
      }
      if (typeof endIndex === 'undefined') {
        endIndex = this.selectionEnd || startIndex;
      }
      var styles = [];
      for (var i = startIndex; i < endIndex; i++) {
        styles.push(this.getStyleAtPosition(i, complete));
      }
      return styles;
    },

    /**
     * Gets style of a current selection/cursor position
     * @param {Number} position  to get styles at
     * @param {Boolean} [complete] full style if true
     * @return {Object} style Style object at a specified index
     * @private
     */
    getStyleAtPosition: function(position, complete) {
      var loc = this.get2DCursorLocation(position),
          style = complete ? this.getCompleteStyleDeclaration(loc.lineIndex, loc.charIndex) :
            this._getStyleDeclaration(loc.lineIndex, loc.charIndex);
      return style || {};
    },

    /**
     * Sets style of a current selection, if no selection exist, do not set anything.
     * @param {Object} [styles] Styles object
     * @param {Number} [startIndex] Start index to get styles at
     * @param {Number} [endIndex] End index to get styles at, if not specified selectionEnd or startIndex + 1
     * @return {fabric.IText} thisArg
     * @chainable
     */
    setSelectionStyles: function(styles, startIndex, endIndex) {
      if (typeof startIndex === 'undefined') {
        startIndex = this.selectionStart || 0;
      }
      if (typeof endIndex === 'undefined') {
        endIndex = this.selectionEnd || startIndex;
      }
      for (var i = startIndex; i < endIndex; i++) {
        this._extendStyles(i, styles);
      }
      /* not included in _extendStyles to avoid clearing cache more than once */
      this._forceClearCache = true;
      return this;
    },

    /**
     * get the reference, not a clone, of the style object for a given character
     * @param {Number} lineIndex
     * @param {Number} charIndex
     * @return {Object} style object
     */
    _getStyleDeclaration: function(lineIndex, charIndex) {
      var lineStyle = this.styles && this.styles[lineIndex];
      if (!lineStyle) {
        return null;
      }
      return lineStyle[charIndex];
    },

    /**
     * return a new object that contains all the style property for a character
     * the object returned is newly created
     * @param {Number} lineIndex of the line where the character is
     * @param {Number} charIndex position of the character on the line
     * @return {Object} style object
     */
    getCompleteStyleDeclaration: function(lineIndex, charIndex) {
      var style = this._getStyleDeclaration(lineIndex, charIndex) || { },
          styleObject = { }, prop;
      for (var i = 0; i < this._styleProperties.length; i++) {
        prop = this._styleProperties[i];
        styleObject[prop] = typeof style[prop] === 'undefined' ? this[prop] : style[prop];
      }
      return styleObject;
    },

    /**
     * @param {Number} lineIndex
     * @param {Number} charIndex
     * @param {Object} style
     * @private
     */
    _setStyleDeclaration: function(lineIndex, charIndex, style) {
      this.styles[lineIndex][charIndex] = style;
    },

    /**
     *
     * @param {Number} lineIndex
     * @param {Number} charIndex
     * @private
     */
    _deleteStyleDeclaration: function(lineIndex, charIndex) {
      delete this.styles[lineIndex][charIndex];
    },

    /**
     * @param {Number} lineIndex
     * @private
     */
    _getLineStyle: function(lineIndex) {
      return this.styles[lineIndex];
    },

    /**
     * @param {Number} lineIndex
     * @param {Object} style
     * @private
     */
    _setLineStyle: function(lineIndex, style) {
      this.styles[lineIndex] = style;
    },

    /**
     * @param {Number} lineIndex
     * @private
     */
    _deleteLineStyle: function(lineIndex) {
      delete this.styles[lineIndex];
    }
  });
})();


(function() {

  function parseDecoration(object) {
    if (object.textDecoration) {
      object.textDecoration.indexOf('underline') > -1 && (object.underline = true);
      object.textDecoration.indexOf('line-through') > -1 && (object.linethrough = true);
      object.textDecoration.indexOf('overline') > -1 && (object.overline = true);
      delete object.textDecoration;
    }
  }

  /**
   * IText class (introduced in <b>v1.4</b>) Events are also fired with "text:"
   * prefix when observing canvas.
   * @class fabric.IText
   * @extends fabric.Text
   * @mixes fabric.Observable
   *
   * @fires changed
   * @fires selection:changed
   * @fires editing:entered
   * @fires editing:exited
   *
   * @return {fabric.IText} thisArg
   * @see {@link fabric.IText#initialize} for constructor definition
   *
   * <p>Supported key combinations:</p>
   * <pre>
   *   Move cursor:                    left, right, up, down
   *   Select character:               shift + left, shift + right
   *   Select text vertically:         shift + up, shift + down
   *   Move cursor by word:            alt + left, alt + right
   *   Select words:                   shift + alt + left, shift + alt + right
   *   Move cursor to line start/end:  cmd + left, cmd + right or home, end
   *   Select till start/end of line:  cmd + shift + left, cmd + shift + right or shift + home, shift + end
   *   Jump to start/end of text:      cmd + up, cmd + down
   *   Select till start/end of text:  cmd + shift + up, cmd + shift + down or shift + pgUp, shift + pgDown
   *   Delete character:               backspace
   *   Delete word:                    alt + backspace
   *   Delete line:                    cmd + backspace
   *   Forward delete:                 delete
   *   Copy text:                      ctrl/cmd + c
   *   Paste text:                     ctrl/cmd + v
   *   Cut text:                       ctrl/cmd + x
   *   Select entire text:             ctrl/cmd + a
   *   Quit editing                    tab or esc
   * </pre>
   *
   * <p>Supported mouse/touch combination</p>
   * <pre>
   *   Position cursor:                click/touch
   *   Create selection:               click/touch & drag
   *   Create selection:               click & shift + click
   *   Select word:                    double click
   *   Select line:                    triple click
   * </pre>
   */
  fabric.IText = fabric.util.createClass(fabric.Text, fabric.Observable, /** @lends fabric.IText.prototype */ {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'i-text',

    /**
     * Index where text selection starts (or where cursor is when there is no selection)
     * @type Number
     * @default
     */
    selectionStart: 0,

    /**
     * Index where text selection ends
     * @type Number
     * @default
     */
    selectionEnd: 0,

    /**
     * Color of text selection
     * @type String
     * @default
     */
    selectionColor: 'rgba(17,119,255,0.3)',

    /**
     * Indicates whether text is in editing mode
     * @type Boolean
     * @default
     */
    isEditing: false,

    /**
     * Indicates whether a text can be edited
     * @type Boolean
     * @default
     */
    editable: true,

    /**
     * Border color of text object while it's in editing mode
     * @type String
     * @default
     */
    editingBorderColor: 'rgba(102,153,255,0.25)',

    /**
     * Width of cursor (in px)
     * @type Number
     * @default
     */
    cursorWidth: 2,

    /**
     * Color of default cursor (when not overwritten by character style)
     * @type String
     * @default
     */
    cursorColor: '#333',

    /**
     * Delay between cursor blink (in ms)
     * @type Number
     * @default
     */
    cursorDelay: 1000,

    /**
     * Duration of cursor fadein (in ms)
     * @type Number
     * @default
     */
    cursorDuration: 600,

    /**
     * Indicates whether internal text char widths can be cached
     * @type Boolean
     * @default
     */
    caching: true,

    /**
     * @private
     */
    _reSpace: /\s|\n/,

    /**
     * @private
     */
    _currentCursorOpacity: 0,

    /**
     * @private
     */
    _selectionDirection: null,

    /**
     * @private
     */
    _abortCursorAnimation: false,

    /**
     * @private
     */
    __widthOfSpace: [],

    /**
     * Helps determining when the text is in composition, so that the cursor
     * rendering is altered.
     */
    inCompositionMode: false,

    /**
     * Constructor
     * @param {String} text Text string
     * @param {Object} [options] Options object
     * @return {fabric.IText} thisArg
     */
    initialize: function(text, options) {
      this.callSuper('initialize', text, options);
      this.initBehavior();
    },

    /**
     * Sets selection start (left boundary of a selection)
     * @param {Number} index Index to set selection start to
     */
    setSelectionStart: function(index) {
      index = Math.max(index, 0);
      this._updateAndFire('selectionStart', index);
    },

    /**
     * Sets selection end (right boundary of a selection)
     * @param {Number} index Index to set selection end to
     */
    setSelectionEnd: function(index) {
      index = Math.min(index, this.text.length);
      this._updateAndFire('selectionEnd', index);
    },

    /**
     * @private
     * @param {String} property 'selectionStart' or 'selectionEnd'
     * @param {Number} index new position of property
     */
    _updateAndFire: function(property, index) {
      if (this[property] !== index) {
        this._fireSelectionChanged();
        this[property] = index;
      }
      this._updateTextarea();
    },

    /**
     * Fires the even of selection changed
     * @private
     */
    _fireSelectionChanged: function() {
      this.fire('selection:changed');
      this.canvas && this.canvas.fire('text:selection:changed', { target: this });
    },

    /**
     * Initialize text dimensions. Render all text on given context
     * or on a offscreen canvas to get the text width with measureText.
     * Updates this.width and this.height with the proper values.
     * Does not return dimensions.
     * @private
     */
    initDimensions: function() {
      this.isEditing && this.initDelayedCursor();
      this.clearContextTop();
      this.callSuper('initDimensions');
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    render: function(ctx) {
      this.clearContextTop();
      this.callSuper('render', ctx);
      // clear the cursorOffsetCache, so we ensure to calculate once per renderCursor
      // the correct position but not at every cursor animation.
      this.cursorOffsetCache = { };
      this.renderCursorOrSelection();
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _render: function(ctx) {
      this.callSuper('_render', ctx);
    },

    /**
     * Prepare and clean the contextTop
     */
    clearContextTop: function(skipRestore) {
      if (!this.isEditing) {
        return;
      }
      if (this.canvas && this.canvas.contextTop) {
        var ctx = this.canvas.contextTop, v = this.canvas.viewportTransform;
        ctx.save();
        ctx.transform(v[0], v[1], v[2], v[3], v[4], v[5]);
        this.transform(ctx);
        this.transformMatrix && ctx.transform.apply(ctx, this.transformMatrix);
        this._clearTextArea(ctx);
        skipRestore || ctx.restore();
      }
    },

    /**
     * Renders cursor or selection (depending on what exists)
     */
    renderCursorOrSelection: function() {
      if (!this.isEditing || !this.canvas) {
        return;
      }
      var boundaries = this._getCursorBoundaries(), ctx;
      if (this.canvas && this.canvas.contextTop) {
        ctx = this.canvas.contextTop;
        this.clearContextTop(true);
      }
      else {
        ctx = this.canvas.contextContainer;
        ctx.save();
      }
      if (this.selectionStart === this.selectionEnd) {
        this.renderCursor(boundaries, ctx);
      }
      else {
        this.renderSelection(boundaries, ctx);
      }
      ctx.restore();
    },

    _clearTextArea: function(ctx) {
      // we add 4 pixel, to be sure to do not leave any pixel out
      var width = this.width + 4, height = this.height + 4;
      ctx.clearRect(-width / 2, -height / 2, width, height);
    },

    /**
     * Returns cursor boundaries (left, top, leftOffset, topOffset)
     * @private
     * @param {Array} chars Array of characters
     * @param {String} typeOfBoundaries
     */
    _getCursorBoundaries: function(position) {

      // left/top are left/top of entire text box
      // leftOffset/topOffset are offset from that left/top point of a text box

      if (typeof position === 'undefined') {
        position = this.selectionStart;
      }

      var left = this._getLeftOffset(),
          top = this._getTopOffset(),
          offsets = this._getCursorBoundariesOffsets(position);

      return {
        left: left,
        top: top,
        leftOffset: offsets.left,
        topOffset: offsets.top
      };
    },

    /**
     * @private
     */
    _getCursorBoundariesOffsets: function(position) {
      if (this.cursorOffsetCache && 'top' in this.cursorOffsetCache) {
        return this.cursorOffsetCache;
      }
      var lineLeftOffset,
          lineIndex,
          charIndex,
          topOffset = 0,
          leftOffset = 0,
          boundaries,
          cursorPosition = this.get2DCursorLocation(position);
      charIndex = cursorPosition.charIndex;
      lineIndex = cursorPosition.lineIndex;
      for (var i = 0; i < lineIndex; i++) {
        topOffset += this.getHeightOfLine(i);
      }
      lineLeftOffset = this._getLineLeftOffset(lineIndex);
      var bound = this.__charBounds[lineIndex][charIndex];
      bound && (leftOffset = bound.left);
      if (this.charSpacing !== 0 && charIndex === this._textLines[lineIndex].length) {
        leftOffset -= this._getWidthOfCharSpacing();
      }
      boundaries = {
        top: topOffset,
        left: lineLeftOffset + (leftOffset > 0 ? leftOffset : 0),
      };
      this.cursorOffsetCache = boundaries;
      return this.cursorOffsetCache;
    },

    /**
     * Renders cursor
     * @param {Object} boundaries
     * @param {CanvasRenderingContext2D} ctx transformed context to draw on
     */
    renderCursor: function(boundaries, ctx) {
      var cursorLocation = this.get2DCursorLocation(),
          lineIndex = cursorLocation.lineIndex,
          charIndex = cursorLocation.charIndex > 0 ? cursorLocation.charIndex - 1 : 0,
          charHeight = this.getValueOfPropertyAt(lineIndex, charIndex, 'fontSize'),
          multiplier = this.scaleX * this.canvas.getZoom(),
          cursorWidth = this.cursorWidth / multiplier,
          topOffset = boundaries.topOffset,
          dy = this.getValueOfPropertyAt(lineIndex, charIndex, 'deltaY');

      topOffset += (1 - this._fontSizeFraction) * this.getHeightOfLine(lineIndex) / this.lineHeight
        - charHeight * (1 - this._fontSizeFraction);

      if (this.inCompositionMode) {
        this.renderSelection(boundaries, ctx);
      }

      ctx.fillStyle = this.getValueOfPropertyAt(lineIndex, charIndex, 'fill');
      ctx.globalAlpha = this.__isMousedown ? 1 : this._currentCursorOpacity;
      ctx.fillRect(
        boundaries.left + boundaries.leftOffset - cursorWidth / 2,
        topOffset + boundaries.top + dy,
        cursorWidth,
        charHeight);
    },

    /**
     * Renders text selection
     * @param {Object} boundaries Object with left/top/leftOffset/topOffset
     * @param {CanvasRenderingContext2D} ctx transformed context to draw on
     */
    renderSelection: function(boundaries, ctx) {

      var selectionStart = this.inCompositionMode ? this.hiddenTextarea.selectionStart : this.selectionStart,
          selectionEnd = this.inCompositionMode ? this.hiddenTextarea.selectionEnd : this.selectionEnd,
          isJustify = this.textAlign.indexOf('justify') !== -1,
          start = this.get2DCursorLocation(selectionStart),
          end = this.get2DCursorLocation(selectionEnd),
          startLine = start.lineIndex,
          endLine = end.lineIndex,
          startChar = start.charIndex < 0 ? 0 : start.charIndex,
          endChar = end.charIndex < 0 ? 0 : end.charIndex;

      for (var i = startLine; i <= endLine; i++) {
        var lineOffset = this._getLineLeftOffset(i) || 0,
            lineHeight = this.getHeightOfLine(i),
            realLineHeight = 0, boxStart = 0, boxEnd = 0;

        if (i === startLine) {
          boxStart = this.__charBounds[startLine][startChar].left;
        }
        if (i >= startLine && i < endLine) {
          boxEnd = isJustify && !this.isEndOfWrapping(i) ? this.width : this.getLineWidth(i) || 5; // WTF is this 5?
        }
        else if (i === endLine) {
          if (endChar === 0) {
            boxEnd = this.__charBounds[endLine][endChar].left;
          }
          else {
            var charSpacing = this._getWidthOfCharSpacing();
            boxEnd = this.__charBounds[endLine][endChar - 1].left
              + this.__charBounds[endLine][endChar - 1].width - charSpacing;
          }
        }
        realLineHeight = lineHeight;
        if (this.lineHeight < 1 || (i === endLine && this.lineHeight > 1)) {
          lineHeight /= this.lineHeight;
        }
        if (this.inCompositionMode) {
          ctx.fillStyle = this.compositionColor || 'black';
          ctx.fillRect(
            boundaries.left + lineOffset + boxStart,
            boundaries.top + boundaries.topOffset + lineHeight,
            boxEnd - boxStart,
            1);
        }
        else {
          ctx.fillStyle = this.selectionColor;
          ctx.fillRect(
            boundaries.left + lineOffset + boxStart,
            boundaries.top + boundaries.topOffset,
            boxEnd - boxStart,
            lineHeight);
        }


        boundaries.topOffset += realLineHeight;
      }
    },

    /**
     * High level function to know the height of the cursor.
     * the currentChar is the one that precedes the cursor
     * Returns fontSize of char at the current cursor
     * @return {Number} Character font size
     */
    getCurrentCharFontSize: function() {
      var cp = this._getCurrentCharIndex();
      return this.getValueOfPropertyAt(cp.l, cp.c, 'fontSize');
    },

    /**
     * High level function to know the color of the cursor.
     * the currentChar is the one that precedes the cursor
     * Returns color (fill) of char at the current cursor
     * @return {String} Character color (fill)
     */
    getCurrentCharColor: function() {
      var cp = this._getCurrentCharIndex();
      return this.getValueOfPropertyAt(cp.l, cp.c, 'fill');
    },

    /**
     * Returns the cursor position for the getCurrent.. functions
     * @private
     */
    _getCurrentCharIndex: function() {
      var cursorPosition = this.get2DCursorLocation(this.selectionStart, true),
          charIndex = cursorPosition.charIndex > 0 ? cursorPosition.charIndex - 1 : 0;
      return { l: cursorPosition.lineIndex, c: charIndex };
    }
  });

  /**
   * Returns fabric.IText instance from an object representation
   * @static
   * @memberOf fabric.IText
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] invoked with new instance as argument
   */
  fabric.IText.fromObject = function(object, callback) {
    parseDecoration(object);
    if (object.styles) {
      for (var i in object.styles) {
        for (var j in object.styles[i]) {
          parseDecoration(object.styles[i][j]);
        }
      }
    }
    fabric.Object._fromObject('IText', object, callback, 'text');
  };
})();


(function() {

  var clone = fabric.util.object.clone;

  fabric.util.object.extend(fabric.IText.prototype, /** @lends fabric.IText.prototype */ {

    /**
     * Initializes all the interactive behavior of IText
     */
    initBehavior: function() {
      this.initAddedHandler();
      this.initRemovedHandler();
      this.initCursorSelectionHandlers();
      this.initDoubleClickSimulation();
      this.mouseMoveHandler = this.mouseMoveHandler.bind(this);
    },

    onDeselect: function() {
      this.isEditing && this.exitEditing();
      this.selected = false;
    },

    /**
     * Initializes "added" event handler
     */
    initAddedHandler: function() {
      var _this = this;
      this.on('added', function() {
        var canvas = _this.canvas;
        if (canvas) {
          if (!canvas._hasITextHandlers) {
            canvas._hasITextHandlers = true;
            _this._initCanvasHandlers(canvas);
          }
          canvas._iTextInstances = canvas._iTextInstances || [];
          canvas._iTextInstances.push(_this);
        }
      });
    },

    initRemovedHandler: function() {
      var _this = this;
      this.on('removed', function() {
        var canvas = _this.canvas;
        if (canvas) {
          canvas._iTextInstances = canvas._iTextInstances || [];
          fabric.util.removeFromArray(canvas._iTextInstances, _this);
          if (canvas._iTextInstances.length === 0) {
            canvas._hasITextHandlers = false;
            _this._removeCanvasHandlers(canvas);
          }
        }
      });
    },

    /**
     * register canvas event to manage exiting on other instances
     * @private
     */
    _initCanvasHandlers: function(canvas) {
      canvas._mouseUpITextHandler = function() {
        if (canvas._iTextInstances) {
          canvas._iTextInstances.forEach(function(obj) {
            obj.__isMousedown = false;
          });
        }
      };
      canvas.on('mouse:up', canvas._mouseUpITextHandler);
    },

    /**
     * remove canvas event to manage exiting on other instances
     * @private
     */
    _removeCanvasHandlers: function(canvas) {
      canvas.off('mouse:up', canvas._mouseUpITextHandler);
    },

    /**
     * @private
     */
    _tick: function() {
      this._currentTickState = this._animateCursor(this, 1, this.cursorDuration, '_onTickComplete');
    },

    /**
     * @private
     */
    _animateCursor: function(obj, targetOpacity, duration, completeMethod) {

      var tickState;

      tickState = {
        isAborted: false,
        abort: function() {
          this.isAborted = true;
        },
      };

      obj.animate('_currentCursorOpacity', targetOpacity, {
        duration: duration,
        onComplete: function() {
          if (!tickState.isAborted) {
            obj[completeMethod]();
          }
        },
        onChange: function() {
          // we do not want to animate a selection, only cursor
          if (obj.canvas && obj.selectionStart === obj.selectionEnd) {
            obj.renderCursorOrSelection();
          }
        },
        abort: function() {
          return tickState.isAborted;
        }
      });
      return tickState;
    },

    /**
     * @private
     */
    _onTickComplete: function() {

      var _this = this;

      if (this._cursorTimeout1) {
        clearTimeout(this._cursorTimeout1);
      }
      this._cursorTimeout1 = setTimeout(function() {
        _this._currentTickCompleteState = _this._animateCursor(_this, 0, this.cursorDuration / 2, '_tick');
      }, 100);
    },

    /**
     * Initializes delayed cursor
     */
    initDelayedCursor: function(restart) {
      var _this = this,
          delay = restart ? 0 : this.cursorDelay;

      this.abortCursorAnimation();
      this._currentCursorOpacity = 1;
      this._cursorTimeout2 = setTimeout(function() {
        _this._tick();
      }, delay);
    },

    /**
     * Aborts cursor animation and clears all timeouts
     */
    abortCursorAnimation: function() {
      var shouldClear = this._currentTickState || this._currentTickCompleteState,
          canvas = this.canvas;
      this._currentTickState && this._currentTickState.abort();
      this._currentTickCompleteState && this._currentTickCompleteState.abort();

      clearTimeout(this._cursorTimeout1);
      clearTimeout(this._cursorTimeout2);

      this._currentCursorOpacity = 0;
      // to clear just itext area we need to transform the context
      // it may not be worth it
      if (shouldClear && canvas) {
        canvas.clearContext(canvas.contextTop || canvas.contextContainer);
      }

    },

    /**
     * Selects entire text
     * @return {fabric.IText} thisArg
     * @chainable
     */
    selectAll: function() {
      this.selectionStart = 0;
      this.selectionEnd = this._text.length;
      this._fireSelectionChanged();
      this._updateTextarea();
      return this;
    },

    /**
     * Returns selected text
     * @return {String}
     */
    getSelectedText: function() {
      return this._text.slice(this.selectionStart, this.selectionEnd).join('');
    },

    /**
     * Find new selection index representing start of current word according to current selection index
     * @param {Number} startFrom Surrent selection index
     * @return {Number} New selection index
     */
    findWordBoundaryLeft: function(startFrom) {
      var offset = 0, index = startFrom - 1;

      // remove space before cursor first
      if (this._reSpace.test(this._text[index])) {
        while (this._reSpace.test(this._text[index])) {
          offset++;
          index--;
        }
      }
      while (/\S/.test(this._text[index]) && index > -1) {
        offset++;
        index--;
      }

      return startFrom - offset;
    },

    /**
     * Find new selection index representing end of current word according to current selection index
     * @param {Number} startFrom Current selection index
     * @return {Number} New selection index
     */
    findWordBoundaryRight: function(startFrom) {
      var offset = 0, index = startFrom;

      // remove space after cursor first
      if (this._reSpace.test(this._text[index])) {
        while (this._reSpace.test(this._text[index])) {
          offset++;
          index++;
        }
      }
      while (/\S/.test(this._text[index]) && index < this.text.length) {
        offset++;
        index++;
      }

      return startFrom + offset;
    },

    /**
     * Find new selection index representing start of current line according to current selection index
     * @param {Number} startFrom Current selection index
     * @return {Number} New selection index
     */
    findLineBoundaryLeft: function(startFrom) {
      var offset = 0, index = startFrom - 1;

      while (!/\n/.test(this._text[index]) && index > -1) {
        offset++;
        index--;
      }

      return startFrom - offset;
    },

    /**
     * Find new selection index representing end of current line according to current selection index
     * @param {Number} startFrom Current selection index
     * @return {Number} New selection index
     */
    findLineBoundaryRight: function(startFrom) {
      var offset = 0, index = startFrom;

      while (!/\n/.test(this._text[index]) && index < this.text.length) {
        offset++;
        index++;
      }

      return startFrom + offset;
    },

    /**
     * Finds index corresponding to beginning or end of a word
     * @param {Number} selectionStart Index of a character
     * @param {Number} direction 1 or -1
     * @return {Number} Index of the beginning or end of a word
     */
    searchWordBoundary: function(selectionStart, direction) {
      var index     = this._reSpace.test(this.text.charAt(selectionStart)) ? selectionStart - 1 : selectionStart,
          _char     = this.text.charAt(index),
          reNonWord = /[ \n\.,;!\?\-]/;

      while (!reNonWord.test(_char) && index > 0 && index < this.text.length) {
        index += direction;
        _char = this.text.charAt(index);
      }
      if (reNonWord.test(_char) && _char !== '\n') {
        index += direction === 1 ? 0 : 1;
      }
      return index;
    },

    /**
     * Selects a word based on the index
     * @param {Number} selectionStart Index of a character
     */
    selectWord: function(selectionStart) {
      selectionStart = selectionStart || this.selectionStart;
      var newSelectionStart = this.searchWordBoundary(selectionStart, -1), /* search backwards */
          newSelectionEnd = this.searchWordBoundary(selectionStart, 1); /* search forward */

      this.selectionStart = newSelectionStart;
      this.selectionEnd = newSelectionEnd;
      this._fireSelectionChanged();
      this._updateTextarea();
      this.renderCursorOrSelection();
    },

    /**
     * Selects a line based on the index
     * @param {Number} selectionStart Index of a character
     * @return {fabric.IText} thisArg
     * @chainable
     */
    selectLine: function(selectionStart) {
      selectionStart = selectionStart || this.selectionStart;
      var newSelectionStart = this.findLineBoundaryLeft(selectionStart),
          newSelectionEnd = this.findLineBoundaryRight(selectionStart);

      this.selectionStart = newSelectionStart;
      this.selectionEnd = newSelectionEnd;
      this._fireSelectionChanged();
      this._updateTextarea();
      return this;
    },

    /**
     * Enters editing state
     * @return {fabric.IText} thisArg
     * @chainable
     */
    enterEditing: function(e) {
      if (this.isEditing || !this.editable) {
        return;
      }

      if (this.canvas) {
        this.canvas.calcOffset();
        this.exitEditingOnOthers(this.canvas);
      }

      this.isEditing = true;

      this.initHiddenTextarea(e);
      this.hiddenTextarea.focus();
      this.hiddenTextarea.value = this.text;
      this._updateTextarea();
      this._saveEditingProps();
      this._setEditingProps();
      this._textBeforeEdit = this.text;

      this._tick();
      this.fire('editing:entered');
      this._fireSelectionChanged();
      if (!this.canvas) {
        return this;
      }
      this.canvas.fire('text:editing:entered', { target: this });
      this.initMouseMoveHandler();
      this.canvas.requestRenderAll();
      return this;
    },

    exitEditingOnOthers: function(canvas) {
      if (canvas._iTextInstances) {
        canvas._iTextInstances.forEach(function(obj) {
          obj.selected = false;
          if (obj.isEditing) {
            obj.exitEditing();
          }
        });
      }
    },

    /**
     * Initializes "mousemove" event handler
     */
    initMouseMoveHandler: function() {
      this.canvas.on('mouse:move', this.mouseMoveHandler);
    },

    /**
     * @private
     */
    mouseMoveHandler: function(options) {
      if (!this.__isMousedown || !this.isEditing) {
        return;
      }

      var newSelectionStart = this.getSelectionStartFromPointer(options.e),
          currentStart = this.selectionStart,
          currentEnd = this.selectionEnd;
      if (
        (newSelectionStart !== this.__selectionStartOnMouseDown || currentStart === currentEnd)
        &&
        (currentStart === newSelectionStart || currentEnd === newSelectionStart)
      ) {
        return;
      }
      if (newSelectionStart > this.__selectionStartOnMouseDown) {
        this.selectionStart = this.__selectionStartOnMouseDown;
        this.selectionEnd = newSelectionStart;
      }
      else {
        this.selectionStart = newSelectionStart;
        this.selectionEnd = this.__selectionStartOnMouseDown;
      }
      if (this.selectionStart !== currentStart || this.selectionEnd !== currentEnd) {
        this.restartCursorIfNeeded();
        this._fireSelectionChanged();
        this._updateTextarea();
        this.renderCursorOrSelection();
      }
    },

    /**
     * @private
     */
    _setEditingProps: function() {
      this.hoverCursor = 'text';

      if (this.canvas) {
        this.canvas.defaultCursor = this.canvas.moveCursor = 'text';
      }

      this.borderColor = this.editingBorderColor;

      this.hasControls = this.selectable = false;
      this.lockMovementX = this.lockMovementY = true;
    },

    /**
     * convert from textarea to grapheme indexes
     */
    fromStringToGraphemeSelection: function(start, end, text) {
      var smallerTextStart = text.slice(0, start),
          graphemeStart = fabric.util.string.graphemeSplit(smallerTextStart).length;
      if (start === end) {
        return { selectionStart: graphemeStart, selectionEnd: graphemeStart };
      }
      var smallerTextEnd = text.slice(start, end),
          graphemeEnd = fabric.util.string.graphemeSplit(smallerTextEnd).length;
      return { selectionStart: graphemeStart, selectionEnd: graphemeStart + graphemeEnd };
    },

    /**
     * convert from fabric to textarea values
     */
    fromGraphemeToStringSelection: function(start, end, _text) {
      var smallerTextStart = _text.slice(0, start),
          graphemeStart = smallerTextStart.join('').length;
      if (start === end) {
        return { selectionStart: graphemeStart, selectionEnd: graphemeStart };
      }
      var smallerTextEnd = _text.slice(start, end),
          graphemeEnd = smallerTextEnd.join('').length;
      return { selectionStart: graphemeStart, selectionEnd: graphemeStart + graphemeEnd };
    },

    /**
     * @private
     */
    _updateTextarea: function() {
      this.cursorOffsetCache = { };
      if (!this.hiddenTextarea) {
        return;
      }
      if (!this.inCompositionMode) {
        var newSelection = this.fromGraphemeToStringSelection(this.selectionStart, this.selectionEnd, this._text);
        this.hiddenTextarea.selectionStart = newSelection.selectionStart;
        this.hiddenTextarea.selectionEnd = newSelection.selectionEnd;
      }
      this.updateTextareaPosition();
    },

    /**
     * @private
     */
    updateFromTextArea: function() {
      if (!this.hiddenTextarea) {
        return;
      }
      this.cursorOffsetCache = { };
      this.text = this.hiddenTextarea.value;
      if (this._shouldClearDimensionCache()) {
        this.initDimensions();
        this.setCoords();
      }
      var newSelection = this.fromStringToGraphemeSelection(
        this.hiddenTextarea.selectionStart, this.hiddenTextarea.selectionEnd, this.hiddenTextarea.value);
      this.selectionEnd = this.selectionStart = newSelection.selectionEnd;
      if (!this.inCompositionMode) {
        this.selectionStart = newSelection.selectionStart;
      }
      this.updateTextareaPosition();
    },

    /**
     * @private
     */
    updateTextareaPosition: function() {
      if (this.selectionStart === this.selectionEnd) {
        var style = this._calcTextareaPosition();
        this.hiddenTextarea.style.left = style.left;
        this.hiddenTextarea.style.top = style.top;
      }
    },

    /**
     * @private
     * @return {Object} style contains style for hiddenTextarea
     */
    _calcTextareaPosition: function() {
      if (!this.canvas) {
        return { x: 1, y: 1 };
      }
      var desiredPostion = this.inCompositionMode ? this.compositionStart : this.selectionStart,
          boundaries = this._getCursorBoundaries(desiredPostion),
          cursorLocation = this.get2DCursorLocation(desiredPostion),
          lineIndex = cursorLocation.lineIndex,
          charIndex = cursorLocation.charIndex,
          charHeight = this.getValueOfPropertyAt(lineIndex, charIndex, 'fontSize') * this.lineHeight,
          leftOffset = boundaries.leftOffset,
          m = this.calcTransformMatrix(),
          p = {
            x: boundaries.left + leftOffset,
            y: boundaries.top + boundaries.topOffset + charHeight
          },
          upperCanvas = this.canvas.upperCanvasEl,
          upperCanvasWidth = upperCanvas.width,
          upperCanvasHeight = upperCanvas.height,
          maxWidth = upperCanvasWidth - charHeight,
          maxHeight = upperCanvasHeight - charHeight,
          scaleX = upperCanvas.clientWidth / upperCanvasWidth,
          scaleY = upperCanvas.clientHeight / upperCanvasHeight;

      p = fabric.util.transformPoint(p, m);
      p = fabric.util.transformPoint(p, this.canvas.viewportTransform);
      p.x *= scaleX;
      p.y *= scaleY;
      if (p.x < 0) {
        p.x = 0;
      }
      if (p.x > maxWidth) {
        p.x = maxWidth;
      }
      if (p.y < 0) {
        p.y = 0;
      }
      if (p.y > maxHeight) {
        p.y = maxHeight;
      }

      // add canvas offset on document
      p.x += this.canvas._offset.left;
      p.y += this.canvas._offset.top;

      return { left: p.x + 'px', top: p.y + 'px', fontSize: charHeight + 'px', charHeight: charHeight };
    },

    /**
     * @private
     */
    _saveEditingProps: function() {
      this._savedProps = {
        hasControls: this.hasControls,
        borderColor: this.borderColor,
        lockMovementX: this.lockMovementX,
        lockMovementY: this.lockMovementY,
        hoverCursor: this.hoverCursor,
        defaultCursor: this.canvas && this.canvas.defaultCursor,
        moveCursor: this.canvas && this.canvas.moveCursor
      };
    },

    /**
     * @private
     */
    _restoreEditingProps: function() {
      if (!this._savedProps) {
        return;
      }

      this.hoverCursor = this._savedProps.hoverCursor;
      this.hasControls = this._savedProps.hasControls;
      this.borderColor = this._savedProps.borderColor;
      this.lockMovementX = this._savedProps.lockMovementX;
      this.lockMovementY = this._savedProps.lockMovementY;

      if (this.canvas) {
        this.canvas.defaultCursor = this._savedProps.defaultCursor;
        this.canvas.moveCursor = this._savedProps.moveCursor;
      }
    },

    /**
     * Exits from editing state
     * @return {fabric.IText} thisArg
     * @chainable
     */
    exitEditing: function() {
      var isTextChanged = (this._textBeforeEdit !== this.text);
      this.selected = false;
      this.isEditing = false;
      this.selectable = true;

      this.selectionEnd = this.selectionStart;

      if (this.hiddenTextarea) {
        this.hiddenTextarea.blur && this.hiddenTextarea.blur();
        this.canvas && this.hiddenTextarea.parentNode.removeChild(this.hiddenTextarea);
        this.hiddenTextarea = null;
      }

      this.abortCursorAnimation();
      this._restoreEditingProps();
      this._currentCursorOpacity = 0;
      if (this._shouldClearDimensionCache()) {
        this.initDimensions();
        this.setCoords();
      }
      this.fire('editing:exited');
      isTextChanged && this.fire('modified');
      if (this.canvas) {
        this.canvas.off('mouse:move', this.mouseMoveHandler);
        this.canvas.fire('text:editing:exited', { target: this });
        isTextChanged && this.canvas.fire('object:modified', { target: this });
      }
      return this;
    },

    /**
     * @private
     */
    _removeExtraneousStyles: function() {
      for (var prop in this.styles) {
        if (!this._textLines[prop]) {
          delete this.styles[prop];
        }
      }
    },

    /**
     * remove and reflow a style block from start to end.
     * @param {Number} start linear start position for removal (included in removal)
     * @param {Number} end linear end position for removal ( excluded from removal )
     */
    removeStyleFromTo: function(start, end) {
      var cursorStart = this.get2DCursorLocation(start, true),
          cursorEnd = this.get2DCursorLocation(end, true),
          lineStart = cursorStart.lineIndex,
          charStart = cursorStart.charIndex,
          lineEnd = cursorEnd.lineIndex,
          charEnd = cursorEnd.charIndex,
          i, styleObj;
      if (lineStart !== lineEnd) {
        // step1 remove the trailing of lineStart
        if (this.styles[lineStart]) {
          for (i = charStart; i < this._unwrappedTextLines[lineStart].length; i++) {
            delete this.styles[lineStart][i];
          }
        }
        // step2 move the trailing of lineEnd to lineStart if needed
        if (this.styles[lineEnd]) {
          for (i = charEnd; i < this._unwrappedTextLines[lineEnd].length; i++) {
            styleObj = this.styles[lineEnd][i];
            if (styleObj) {
              this.styles[lineStart] || (this.styles[lineStart] = { });
              this.styles[lineStart][charStart + i - charEnd] = styleObj;
            }
          }
        }
        // step3 detects lines will be completely removed.
        for (i = lineStart + 1; i <= lineEnd; i++) {
          delete this.styles[i];
        }
        // step4 shift remaining lines.
        this.shiftLineStyles(lineEnd, lineStart - lineEnd);
      }
      else {
        // remove and shift left on the same line
        if (this.styles[lineStart]) {
          styleObj = this.styles[lineStart];
          var diff = charEnd - charStart, numericChar, _char;
          for (i = charStart; i < charEnd; i++) {
            delete styleObj[i];
          }
          for (_char in this.styles[lineStart]) {
            numericChar = parseInt(_char, 10);
            if (numericChar >= charEnd) {
              styleObj[numericChar - diff] = styleObj[_char];
              delete styleObj[_char];
            }
          }
        }
      }
    },

    /**
     * Shifts line styles up or down
     * @param {Number} lineIndex Index of a line
     * @param {Number} offset Can any number?
     */
    shiftLineStyles: function(lineIndex, offset) {
      // shift all line styles by offset upward or downward
      // do not clone deep. we need new array, not new style objects
      var clonedStyles = clone(this.styles);
      for (var line in this.styles) {
        var numericLine = parseInt(line, 10);
        if (numericLine > lineIndex) {
          this.styles[numericLine + offset] = clonedStyles[numericLine];
          if (!clonedStyles[numericLine - offset]) {
            delete this.styles[numericLine];
          }
        }
      }
    },

    restartCursorIfNeeded: function() {
      if (!this._currentTickState || this._currentTickState.isAborted
        || !this._currentTickCompleteState || this._currentTickCompleteState.isAborted
      ) {
        this.initDelayedCursor();
      }
    },

    /**
     * Inserts new style object
     * @param {Number} lineIndex Index of a line
     * @param {Number} charIndex Index of a char
     * @param {Number} qty number of lines to add
     * @param {Array} copiedStyle Array of objects styles
     */
    insertNewlineStyleObject: function(lineIndex, charIndex, qty, copiedStyle) {
      var currentCharStyle,
          newLineStyles = {},
          somethingAdded = false;

      qty || (qty = 1);
      this.shiftLineStyles(lineIndex, qty);
      if (this.styles[lineIndex]) {
        currentCharStyle = this.styles[lineIndex][charIndex === 0 ? charIndex : charIndex - 1];
      }

      // we clone styles of all chars
      // after cursor onto the current line
      for (var index in this.styles[lineIndex]) {
        var numIndex = parseInt(index, 10);
        if (numIndex >= charIndex) {
          somethingAdded = true;
          newLineStyles[numIndex - charIndex] = this.styles[lineIndex][index];
          // remove lines from the previous line since they're on a new line now
          delete this.styles[lineIndex][index];
        }
      }
      if (somethingAdded) {
        this.styles[lineIndex + qty] = newLineStyles;
      }
      else {
        delete this.styles[lineIndex + qty];
      }
      // for the other lines
      // we clone current char style onto the next (otherwise empty) line
      while (qty > 1) {
        qty--;
        if (copiedStyle && copiedStyle[qty]) {
          this.styles[lineIndex + qty] = { 0: clone(copiedStyle[qty]) };
        }
        else if (currentCharStyle) {
          this.styles[lineIndex + qty] = { 0: clone(currentCharStyle) };
        }
        else {
          delete this.styles[lineIndex + qty];
        }
      }
      this._forceClearCache = true;
    },

    /**
     * Inserts style object for a given line/char index
     * @param {Number} lineIndex Index of a line
     * @param {Number} charIndex Index of a char
     * @param {Number} quantity number Style object to insert, if given
     * @param {Array} copiedStyle array of style objecs
     */
    insertCharStyleObject: function(lineIndex, charIndex, quantity, copiedStyle) {
      if (!this.styles) {
        this.styles = {};
      }
      var currentLineStyles       = this.styles[lineIndex],
          currentLineStylesCloned = currentLineStyles ? clone(currentLineStyles) : {};

      quantity || (quantity = 1);
      // shift all char styles by quantity forward
      // 0,1,2,3 -> (charIndex=2) -> 0,1,3,4 -> (insert 2) -> 0,1,2,3,4
      for (var index in currentLineStylesCloned) {
        var numericIndex = parseInt(index, 10);
        if (numericIndex >= charIndex) {
          currentLineStyles[numericIndex + quantity] = currentLineStylesCloned[numericIndex];
          // only delete the style if there was nothing moved there
          if (!currentLineStylesCloned[numericIndex - quantity]) {
            delete currentLineStyles[numericIndex];
          }
        }
      }
      this._forceClearCache = true;
      if (copiedStyle) {
        while (quantity--) {
          if (!Object.keys(copiedStyle[quantity]).length) {
            continue;
          }
          if (!this.styles[lineIndex]) {
            this.styles[lineIndex] = {};
          }
          this.styles[lineIndex][charIndex + quantity] = clone(copiedStyle[quantity]);
        }
        return;
      }
      if (!currentLineStyles) {
        return;
      }
      var newStyle = currentLineStyles[charIndex ? charIndex - 1 : 1];
      while (newStyle && quantity--) {
        this.styles[lineIndex][charIndex + quantity] = clone(newStyle);
      }
    },

    /**
     * Inserts style object(s)
     * @param {Array} insertedText Characters at the location where style is inserted
     * @param {Number} start cursor index for inserting style
     * @param {Array} [copiedStyle] array of style objects to insert.
     */
    insertNewStyleBlock: function(insertedText, start, copiedStyle) {
      var cursorLoc = this.get2DCursorLocation(start, true),
          addedLines = [0], linesLenght = 0;
      for (var i = 0; i < insertedText.length; i++) {
        if (insertedText[i] === '\n') {
          linesLenght++;
          addedLines[linesLenght] = 0;
        }
        else {
          addedLines[linesLenght]++;
        }
      }
      if (addedLines[0] > 0) {
        this.insertCharStyleObject(cursorLoc.lineIndex, cursorLoc.charIndex, addedLines[0], copiedStyle);
        copiedStyle = copiedStyle && copiedStyle.slice(addedLines[0] + 1);
      }
      linesLenght && this.insertNewlineStyleObject(
        cursorLoc.lineIndex, cursorLoc.charIndex + addedLines[0], linesLenght);
      for (var i = 1; i < linesLenght; i++) {
        if (addedLines[i] > 0) {
          this.insertCharStyleObject(cursorLoc.lineIndex + i, 0, addedLines[i], copiedStyle);
        }
        else if (copiedStyle) {
          this.styles[cursorLoc.lineIndex + i][0] = copiedStyle[0];
        }
        copiedStyle = copiedStyle && copiedStyle.slice(addedLines[i] + 1);
      }
      // we use i outside the loop to get it like linesLength
      if (addedLines[i] > 0) {
        this.insertCharStyleObject(cursorLoc.lineIndex + i, 0, addedLines[i], copiedStyle);
      }
    },

    /**
     * Set the selectionStart and selectionEnd according to the ne postion of cursor
     * mimic the key - mouse navigation when shift is pressed.
     */
    setSelectionStartEndWithShift: function(start, end, newSelection) {
      if (newSelection <= start) {
        if (end === start) {
          this._selectionDirection = 'left';
        }
        else if (this._selectionDirection === 'right') {
          this._selectionDirection = 'left';
          this.selectionEnd = start;
        }
        this.selectionStart = newSelection;
      }
      else if (newSelection > start && newSelection < end) {
        if (this._selectionDirection === 'right') {
          this.selectionEnd = newSelection;
        }
        else {
          this.selectionStart = newSelection;
        }
      }
      else {
        // newSelection is > selection start and end
        if (end === start) {
          this._selectionDirection = 'right';
        }
        else if (this._selectionDirection === 'left') {
          this._selectionDirection = 'right';
          this.selectionStart = end;
        }
        this.selectionEnd = newSelection;
      }
    },

    setSelectionInBoundaries: function() {
      var length = this.text.length;
      if (this.selectionStart > length) {
        this.selectionStart = length;
      }
      else if (this.selectionStart < 0) {
        this.selectionStart = 0;
      }
      if (this.selectionEnd > length) {
        this.selectionEnd = length;
      }
      else if (this.selectionEnd < 0) {
        this.selectionEnd = 0;
      }
    }
  });
})();


fabric.util.object.extend(fabric.IText.prototype, /** @lends fabric.IText.prototype */ {
  /**
   * Initializes "dbclick" event handler
   */
  initDoubleClickSimulation: function() {

    // for double click
    this.__lastClickTime = +new Date();

    // for triple click
    this.__lastLastClickTime = +new Date();

    this.__lastPointer = { };

    this.on('mousedown', this.onMouseDown);
  },

  /**
   * Default event handler to simulate triple click
   * @private
   */
  onMouseDown: function(options) {
    if (!this.canvas) {
      return;
    }
    this.__newClickTime = +new Date();
    var newPointer = options.pointer;
    if (this.isTripleClick(newPointer)) {
      this.fire('tripleclick', options);
      this._stopEvent(options.e);
    }
    this.__lastLastClickTime = this.__lastClickTime;
    this.__lastClickTime = this.__newClickTime;
    this.__lastPointer = newPointer;
    this.__lastIsEditing = this.isEditing;
    this.__lastSelected = this.selected;
  },

  isTripleClick: function(newPointer) {
    return this.__newClickTime - this.__lastClickTime < 500 &&
        this.__lastClickTime - this.__lastLastClickTime < 500 &&
        this.__lastPointer.x === newPointer.x &&
        this.__lastPointer.y === newPointer.y;
  },

  /**
   * @private
   */
  _stopEvent: function(e) {
    e.preventDefault && e.preventDefault();
    e.stopPropagation && e.stopPropagation();
  },

  /**
   * Initializes event handlers related to cursor or selection
   */
  initCursorSelectionHandlers: function() {
    this.initMousedownHandler();
    this.initMouseupHandler();
    this.initClicks();
  },

  /**
   * Initializes double and triple click event handlers
   */
  initClicks: function() {
    this.on('mousedblclick', function(options) {
      this.selectWord(this.getSelectionStartFromPointer(options.e));
    });
    this.on('tripleclick', function(options) {
      this.selectLine(this.getSelectionStartFromPointer(options.e));
    });
  },

  /**
   * Default event handler for the basic functionalities needed on _mouseDown
   * can be overridden to do something different.
   * Scope of this implementation is: find the click position, set selectionStart
   * find selectionEnd, initialize the drawing of either cursor or selection area
   */
  _mouseDownHandler: function(options) {
    if (!this.canvas || !this.editable || (options.e.button && options.e.button !== 1)) {
      return;
    }

    this.__isMousedown = true;

    if (this.selected) {
      this.setCursorByClick(options.e);
    }

    if (this.isEditing) {
      this.__selectionStartOnMouseDown = this.selectionStart;
      if (this.selectionStart === this.selectionEnd) {
        this.abortCursorAnimation();
      }
      this.renderCursorOrSelection();
    }
  },

  /**
   * Default event handler for the basic functionalities needed on mousedown:before
   * can be overridden to do something different.
   * Scope of this implementation is: verify the object is already selected when mousing down
   */
  _mouseDownHandlerBefore: function(options) {
    if (!this.canvas || !this.editable || (options.e.button && options.e.button !== 1)) {
      return;
    }
    if (this === this.canvas._activeObject) {
      this.selected = true;
    }
  },

  /**
   * Initializes "mousedown" event handler
   */
  initMousedownHandler: function() {
    this.on('mousedown', this._mouseDownHandler);
    this.on('mousedown:before', this._mouseDownHandlerBefore);
  },

  /**
   * Initializes "mouseup" event handler
   */
  initMouseupHandler: function() {
    this.on('mouseup', this.mouseUpHandler);
  },

  /**
   * standard hander for mouse up, overridable
   * @private
   */
  mouseUpHandler: function(options) {
    this.__isMousedown = false;
    if (!this.editable ||
      (options.transform && options.transform.actionPerformed) ||
      (options.e.button && options.e.button !== 1)) {
      return;
    }

    if (this.__lastSelected && !this.__corner) {
      this.enterEditing(options.e);
      if (this.selectionStart === this.selectionEnd) {
        this.initDelayedCursor(true);
      }
      else {
        this.renderCursorOrSelection();
      }
    }
    this.selected = true;
  },

  /**
   * Changes cursor location in a text depending on passed pointer (x/y) object
   * @param {Event} e Event object
   */
  setCursorByClick: function(e) {
    var newSelection = this.getSelectionStartFromPointer(e),
        start = this.selectionStart, end = this.selectionEnd;
    if (e.shiftKey) {
      this.setSelectionStartEndWithShift(start, end, newSelection);
    }
    else {
      this.selectionStart = newSelection;
      this.selectionEnd = newSelection;
    }
    if (this.isEditing) {
      this._fireSelectionChanged();
      this._updateTextarea();
    }
  },

  /**
   * Returns index of a character corresponding to where an object was clicked
   * @param {Event} e Event object
   * @return {Number} Index of a character
   */
  getSelectionStartFromPointer: function(e) {
    var mouseOffset = this.getLocalPointer(e),
        prevWidth = 0,
        width = 0,
        height = 0,
        charIndex = 0,
        lineIndex = 0,
        lineLeftOffset,
        line;

    for (var i = 0, len = this._textLines.length; i < len; i++) {
      if (height <= mouseOffset.y) {
        height += this.getHeightOfLine(i) * this.scaleY;
        lineIndex = i;
        if (i > 0) {
          charIndex += this._textLines[i - 1].length + 1;
        }
      }
      else {
        break;
      }
    }
    lineLeftOffset = this._getLineLeftOffset(lineIndex);
    width = lineLeftOffset * this.scaleX;
    line = this._textLines[lineIndex];
    for (var j = 0, jlen = line.length; j < jlen; j++) {
      prevWidth = width;
      // i removed something about flipX here, check.
      width += this.__charBounds[lineIndex][j].kernedWidth * this.scaleX;
      if (width <= mouseOffset.x) {
        charIndex++;
      }
      else {
        break;
      }
    }
    return this._getNewSelectionStartFromOffset(mouseOffset, prevWidth, width, charIndex, jlen);
  },

  /**
   * @private
   */
  _getNewSelectionStartFromOffset: function(mouseOffset, prevWidth, width, index, jlen) {
    // we need Math.abs because when width is after the last char, the offset is given as 1, while is 0
    var distanceBtwLastCharAndCursor = mouseOffset.x - prevWidth,
        distanceBtwNextCharAndCursor = width - mouseOffset.x,
        offset = distanceBtwNextCharAndCursor > distanceBtwLastCharAndCursor ||
          distanceBtwNextCharAndCursor < 0 ? 0 : 1,
        newSelectionStart = index + offset;
    // if object is horizontally flipped, mirror cursor location from the end
    if (this.flipX) {
      newSelectionStart = jlen - newSelectionStart;
    }

    if (newSelectionStart > this._text.length) {
      newSelectionStart = this._text.length;
    }

    return newSelectionStart;
  }
});


fabric.util.object.extend(fabric.IText.prototype, /** @lends fabric.IText.prototype */ {

  /**
   * Initializes hidden textarea (needed to bring up keyboard in iOS)
   */
  initHiddenTextarea: function() {
    this.hiddenTextarea = fabric.document.createElement('textarea');
    this.hiddenTextarea.setAttribute('autocapitalize', 'off');
    this.hiddenTextarea.setAttribute('autocorrect', 'off');
    this.hiddenTextarea.setAttribute('autocomplete', 'off');
    this.hiddenTextarea.setAttribute('spellcheck', 'false');
    this.hiddenTextarea.setAttribute('data-fabric-hiddentextarea', '');
    this.hiddenTextarea.setAttribute('wrap', 'off');
    var style = this._calcTextareaPosition();
    this.hiddenTextarea.style.cssText = 'position: absolute; top: ' + style.top +
    '; left: ' + style.left + '; z-index: -999; opacity: 0; width: 1px; height: 1px; font-size: 1px;' +
    ' line-height: 1px; paddingｰtop: ' + style.fontSize + ';';
    fabric.document.body.appendChild(this.hiddenTextarea);

    fabric.util.addListener(this.hiddenTextarea, 'keydown', this.onKeyDown.bind(this));
    fabric.util.addListener(this.hiddenTextarea, 'keyup', this.onKeyUp.bind(this));
    fabric.util.addListener(this.hiddenTextarea, 'input', this.onInput.bind(this));
    fabric.util.addListener(this.hiddenTextarea, 'copy', this.copy.bind(this));
    fabric.util.addListener(this.hiddenTextarea, 'cut', this.copy.bind(this));
    fabric.util.addListener(this.hiddenTextarea, 'paste', this.paste.bind(this));
    fabric.util.addListener(this.hiddenTextarea, 'compositionstart', this.onCompositionStart.bind(this));
    fabric.util.addListener(this.hiddenTextarea, 'compositionupdate', this.onCompositionUpdate.bind(this));
    fabric.util.addListener(this.hiddenTextarea, 'compositionend', this.onCompositionEnd.bind(this));

    if (!this._clickHandlerInitialized && this.canvas) {
      fabric.util.addListener(this.canvas.upperCanvasEl, 'click', this.onClick.bind(this));
      this._clickHandlerInitialized = true;
    }
  },

  /**
   * For functionalities on keyDown
   * Map a special key to a function of the instance/prototype
   * If you need different behaviour for ESC or TAB or arrows, you have to change
   * this map setting the name of a function that you build on the fabric.Itext or
   * your prototype.
   * the map change will affect all Instances unless you need for only some text Instances
   * in that case you have to clone this object and assign your Instance.
   * this.keysMap = fabric.util.object.clone(this.keysMap);
   * The function must be in fabric.Itext.prototype.myFunction And will receive event as args[0]
   */
  keysMap: {
    9:  'exitEditing',
    27: 'exitEditing',
    33: 'moveCursorUp',
    34: 'moveCursorDown',
    35: 'moveCursorRight',
    36: 'moveCursorLeft',
    37: 'moveCursorLeft',
    38: 'moveCursorUp',
    39: 'moveCursorRight',
    40: 'moveCursorDown',
  },

  /**
   * For functionalities on keyUp + ctrl || cmd
   */
  ctrlKeysMapUp: {
    67: 'copy',
    88: 'cut'
  },

  /**
   * For functionalities on keyDown + ctrl || cmd
   */
  ctrlKeysMapDown: {
    65: 'selectAll'
  },

  onClick: function() {
    // No need to trigger click event here, focus is enough to have the keyboard appear on Android
    this.hiddenTextarea && this.hiddenTextarea.focus();
  },

  /**
   * Handles keyup event
   * @param {Event} e Event object
   */
  onKeyDown: function(e) {
    if (!this.isEditing || this.inCompositionMode) {
      return;
    }
    if (e.keyCode in this.keysMap) {
      this[this.keysMap[e.keyCode]](e);
    }
    else if ((e.keyCode in this.ctrlKeysMapDown) && (e.ctrlKey || e.metaKey)) {
      this[this.ctrlKeysMapDown[e.keyCode]](e);
    }
    else {
      return;
    }
    e.stopImmediatePropagation();
    e.preventDefault();
    if (e.keyCode >= 33 && e.keyCode <= 40) {
      // if i press an arrow key just update selection
      this.clearContextTop();
      this.renderCursorOrSelection();
    }
    else {
      this.canvas && this.canvas.requestRenderAll();
    }
  },

  /**
   * Handles keyup event
   * We handle KeyUp because ie11 and edge have difficulties copy/pasting
   * if a copy/cut event fired, keyup is dismissed
   * @param {Event} e Event object
   */
  onKeyUp: function(e) {
    if (!this.isEditing || this._copyDone || this.inCompositionMode) {
      this._copyDone = false;
      return;
    }
    if ((e.keyCode in this.ctrlKeysMapUp) && (e.ctrlKey || e.metaKey)) {
      this[this.ctrlKeysMapUp[e.keyCode]](e);
    }
    else {
      return;
    }
    e.stopImmediatePropagation();
    e.preventDefault();
    this.canvas && this.canvas.requestRenderAll();
  },

  /**
   * Handles onInput event
   * @param {Event} e Event object
   */
  onInput: function(e) {
    var fromPaste = this.fromPaste;
    this.fromPaste = false;
    e && e.stopPropagation();
    if (!this.isEditing) {
      return;
    }
    // decisions about style changes.
    var nextText = this._splitTextIntoLines(this.hiddenTextarea.value).graphemeText,
        charCount = this._text.length,
        nextCharCount = nextText.length,
        removedText, insertedText,
        charDiff = nextCharCount - charCount;
    if (this.hiddenTextarea.value === '') {
      this.styles = { };
      this.updateFromTextArea();
      this.fire('changed');
      if (this.canvas) {
        this.canvas.fire('text:changed', { target: this });
        this.canvas.requestRenderAll();
      }
      return;
    }

    var textareaSelection = this.fromStringToGraphemeSelection(
      this.hiddenTextarea.selectionStart,
      this.hiddenTextarea.selectionEnd,
      this.hiddenTextarea.value
    );
    var backDelete = this.selectionStart > textareaSelection.selectionStart;

    if (this.selectionStart !== this.selectionEnd) {
      removedText = this._text.slice(this.selectionStart, this.selectionEnd);
      charDiff += this.selectionEnd - this.selectionStart;
    }
    else if (nextCharCount < charCount) {
      if (backDelete) {
        removedText = this._text.slice(this.selectionEnd + charDiff, this.selectionEnd);
      }
      else {
        removedText = this._text.slice(this.selectionStart, this.selectionStart - charDiff);
      }
    }
    insertedText = nextText.slice(textareaSelection.selectionEnd - charDiff, textareaSelection.selectionEnd);
    if (removedText && removedText.length) {
      if (this.selectionStart !== this.selectionEnd) {
        this.removeStyleFromTo(this.selectionStart, this.selectionEnd);
      }
      else if (backDelete) {
        // detect differencies between forwardDelete and backDelete
        this.removeStyleFromTo(this.selectionEnd - removedText.length, this.selectionEnd);
      }
      else {
        this.removeStyleFromTo(this.selectionEnd, this.selectionEnd + removedText.length);
      }
    }
    if (insertedText.length) {
      if (fromPaste && insertedText.join('') === fabric.copiedText) {
        this.insertNewStyleBlock(insertedText, this.selectionStart, fabric.copiedTextStyle);
      }
      else {
        this.insertNewStyleBlock(insertedText, this.selectionStart);
      }
    }
    this.updateFromTextArea();
    this.fire('changed');
    if (this.canvas) {
      this.canvas.fire('text:changed', { target: this });
      this.canvas.requestRenderAll();
    }
  },
  /**
   * Composition start
   */
  onCompositionStart: function() {
    this.inCompositionMode = true;
  },

  /**
   * Composition end
   */
  onCompositionEnd: function() {
    this.inCompositionMode = false;
  },

  // /**
  //  * Composition update
  //  */
  onCompositionUpdate: function(e) {
    this.compositionStart = e.target.selectionStart;
    this.compositionEnd = e.target.selectionEnd;
    this.updateTextareaPosition();
  },

  /**
   * Copies selected text
   * @param {Event} e Event object
   */
  copy: function() {
    if (this.selectionStart === this.selectionEnd) {
      //do not cut-copy if no selection
      return;
    }

    fabric.copiedText = this.getSelectedText();
    fabric.copiedTextStyle = this.getSelectionStyles(this.selectionStart, this.selectionEnd, true);
    this._copyDone = true;
  },

  /**
   * Pastes text
   * @param {Event} e Event object
   */
  paste: function() {
    this.fromPaste = true;
  },

  /**
   * @private
   * @param {Event} e Event object
   * @return {Object} Clipboard data object
   */
  _getClipboardData: function(e) {
    return (e && e.clipboardData) || fabric.window.clipboardData;
  },

  /**
   * Finds the width in pixels before the cursor on the same line
   * @private
   * @param {Number} lineIndex
   * @param {Number} charIndex
   * @return {Number} widthBeforeCursor width before cursor
   */
  _getWidthBeforeCursor: function(lineIndex, charIndex) {
    var widthBeforeCursor = this._getLineLeftOffset(lineIndex), bound;

    if (charIndex > 0) {
      bound = this.__charBounds[lineIndex][charIndex - 1];
      widthBeforeCursor += bound.left + bound.width;
    }
    return widthBeforeCursor;
  },

  /**
   * Gets start offset of a selection
   * @param {Event} e Event object
   * @param {Boolean} isRight
   * @return {Number}
   */
  getDownCursorOffset: function(e, isRight) {
    var selectionProp = this._getSelectionForOffset(e, isRight),
        cursorLocation = this.get2DCursorLocation(selectionProp),
        lineIndex = cursorLocation.lineIndex;
    // if on last line, down cursor goes to end of line
    if (lineIndex === this._textLines.length - 1 || e.metaKey || e.keyCode === 34) {
      // move to the end of a text
      return this._text.length - selectionProp;
    }
    var charIndex = cursorLocation.charIndex,
        widthBeforeCursor = this._getWidthBeforeCursor(lineIndex, charIndex),
        indexOnOtherLine = this._getIndexOnLine(lineIndex + 1, widthBeforeCursor),
        textAfterCursor = this._textLines[lineIndex].slice(charIndex);
    return textAfterCursor.length + indexOnOtherLine + 2;
  },

  /**
   * private
   * Helps finding if the offset should be counted from Start or End
   * @param {Event} e Event object
   * @param {Boolean} isRight
   * @return {Number}
   */
  _getSelectionForOffset: function(e, isRight) {
    if (e.shiftKey && this.selectionStart !== this.selectionEnd && isRight) {
      return this.selectionEnd;
    }
    else {
      return this.selectionStart;
    }
  },

  /**
   * @param {Event} e Event object
   * @param {Boolean} isRight
   * @return {Number}
   */
  getUpCursorOffset: function(e, isRight) {
    var selectionProp = this._getSelectionForOffset(e, isRight),
        cursorLocation = this.get2DCursorLocation(selectionProp),
        lineIndex = cursorLocation.lineIndex;
    if (lineIndex === 0 || e.metaKey || e.keyCode === 33) {
      // if on first line, up cursor goes to start of line
      return -selectionProp;
    }
    var charIndex = cursorLocation.charIndex,
        widthBeforeCursor = this._getWidthBeforeCursor(lineIndex, charIndex),
        indexOnOtherLine = this._getIndexOnLine(lineIndex - 1, widthBeforeCursor),
        textBeforeCursor = this._textLines[lineIndex].slice(0, charIndex);
    // return a negative offset
    return -this._textLines[lineIndex - 1].length + indexOnOtherLine - textBeforeCursor.length;
  },

  /**
   * for a given width it founds the matching character.
   * @private
   */
  _getIndexOnLine: function(lineIndex, width) {

    var line = this._textLines[lineIndex],
        lineLeftOffset = this._getLineLeftOffset(lineIndex),
        widthOfCharsOnLine = lineLeftOffset,
        indexOnLine = 0, charWidth, foundMatch;

    for (var j = 0, jlen = line.length; j < jlen; j++) {
      charWidth = this.__charBounds[lineIndex][j].width;
      widthOfCharsOnLine += charWidth;
      if (widthOfCharsOnLine > width) {
        foundMatch = true;
        var leftEdge = widthOfCharsOnLine - charWidth,
            rightEdge = widthOfCharsOnLine,
            offsetFromLeftEdge = Math.abs(leftEdge - width),
            offsetFromRightEdge = Math.abs(rightEdge - width);

        indexOnLine = offsetFromRightEdge < offsetFromLeftEdge ? j : (j - 1);
        break;
      }
    }

    // reached end
    if (!foundMatch) {
      indexOnLine = line.length - 1;
    }

    return indexOnLine;
  },


  /**
   * Moves cursor down
   * @param {Event} e Event object
   */
  moveCursorDown: function(e) {
    if (this.selectionStart >= this._text.length && this.selectionEnd >= this._text.length) {
      return;
    }
    this._moveCursorUpOrDown('Down', e);
  },

  /**
   * Moves cursor up
   * @param {Event} e Event object
   */
  moveCursorUp: function(e) {
    if (this.selectionStart === 0 && this.selectionEnd === 0) {
      return;
    }
    this._moveCursorUpOrDown('Up', e);
  },

  /**
   * Moves cursor up or down, fires the events
   * @param {String} direction 'Up' or 'Down'
   * @param {Event} e Event object
   */
  _moveCursorUpOrDown: function(direction, e) {
    // getUpCursorOffset
    // getDownCursorOffset
    var action = 'get' + direction + 'CursorOffset',
        offset = this[action](e, this._selectionDirection === 'right');
    if (e.shiftKey) {
      this.moveCursorWithShift(offset);
    }
    else {
      this.moveCursorWithoutShift(offset);
    }
    if (offset !== 0) {
      this.setSelectionInBoundaries();
      this.abortCursorAnimation();
      this._currentCursorOpacity = 1;
      this.initDelayedCursor();
      this._fireSelectionChanged();
      this._updateTextarea();
    }
  },

  /**
   * Moves cursor with shift
   * @param {Number} offset
   */
  moveCursorWithShift: function(offset) {
    var newSelection = this._selectionDirection === 'left'
      ? this.selectionStart + offset
      : this.selectionEnd + offset;
    this.setSelectionStartEndWithShift(this.selectionStart, this.selectionEnd, newSelection);
    return offset !== 0;
  },

  /**
   * Moves cursor up without shift
   * @param {Number} offset
   */
  moveCursorWithoutShift: function(offset) {
    if (offset < 0) {
      this.selectionStart += offset;
      this.selectionEnd = this.selectionStart;
    }
    else {
      this.selectionEnd += offset;
      this.selectionStart = this.selectionEnd;
    }
    return offset !== 0;
  },

  /**
   * Moves cursor left
   * @param {Event} e Event object
   */
  moveCursorLeft: function(e) {
    if (this.selectionStart === 0 && this.selectionEnd === 0) {
      return;
    }
    this._moveCursorLeftOrRight('Left', e);
  },

  /**
   * @private
   * @return {Boolean} true if a change happened
   */
  _move: function(e, prop, direction) {
    var newValue;
    if (e.altKey) {
      newValue = this['findWordBoundary' + direction](this[prop]);
    }
    else if (e.metaKey || e.keyCode === 35 ||  e.keyCode === 36 ) {
      newValue = this['findLineBoundary' + direction](this[prop]);
    }
    else {
      this[prop] += direction === 'Left' ? -1 : 1;
      return true;
    }
    if (typeof newValue !== undefined && this[prop] !== newValue) {
      this[prop] = newValue;
      return true;
    }
  },

  /**
   * @private
   */
  _moveLeft: function(e, prop) {
    return this._move(e, prop, 'Left');
  },

  /**
   * @private
   */
  _moveRight: function(e, prop) {
    return this._move(e, prop, 'Right');
  },

  /**
   * Moves cursor left without keeping selection
   * @param {Event} e
   */
  moveCursorLeftWithoutShift: function(e) {
    var change = true;
    this._selectionDirection = 'left';

    // only move cursor when there is no selection,
    // otherwise we discard it, and leave cursor on same place
    if (this.selectionEnd === this.selectionStart && this.selectionStart !== 0) {
      change = this._moveLeft(e, 'selectionStart');

    }
    this.selectionEnd = this.selectionStart;
    return change;
  },

  /**
   * Moves cursor left while keeping selection
   * @param {Event} e
   */
  moveCursorLeftWithShift: function(e) {
    if (this._selectionDirection === 'right' && this.selectionStart !== this.selectionEnd) {
      return this._moveLeft(e, 'selectionEnd');
    }
    else if (this.selectionStart !== 0){
      this._selectionDirection = 'left';
      return this._moveLeft(e, 'selectionStart');
    }
  },

  /**
   * Moves cursor right
   * @param {Event} e Event object
   */
  moveCursorRight: function(e) {
    if (this.selectionStart >= this._text.length && this.selectionEnd >= this._text.length) {
      return;
    }
    this._moveCursorLeftOrRight('Right', e);
  },

  /**
   * Moves cursor right or Left, fires event
   * @param {String} direction 'Left', 'Right'
   * @param {Event} e Event object
   */
  _moveCursorLeftOrRight: function(direction, e) {
    var actionName = 'moveCursor' + direction + 'With';
    this._currentCursorOpacity = 1;

    if (e.shiftKey) {
      actionName += 'Shift';
    }
    else {
      actionName += 'outShift';
    }
    if (this[actionName](e)) {
      this.abortCursorAnimation();
      this.initDelayedCursor();
      this._fireSelectionChanged();
      this._updateTextarea();
    }
  },

  /**
   * Moves cursor right while keeping selection
   * @param {Event} e
   */
  moveCursorRightWithShift: function(e) {
    if (this._selectionDirection === 'left' && this.selectionStart !== this.selectionEnd) {
      return this._moveRight(e, 'selectionStart');
    }
    else if (this.selectionEnd !== this._text.length) {
      this._selectionDirection = 'right';
      return this._moveRight(e, 'selectionEnd');
    }
  },

  /**
   * Moves cursor right without keeping selection
   * @param {Event} e Event object
   */
  moveCursorRightWithoutShift: function(e) {
    var changed = true;
    this._selectionDirection = 'right';

    if (this.selectionStart === this.selectionEnd) {
      changed = this._moveRight(e, 'selectionStart');
      this.selectionEnd = this.selectionStart;
    }
    else {
      this.selectionStart = this.selectionEnd;
    }
    return changed;
  },

  /**
   * Removes characters from start/end
   * start/end ar per grapheme position in _text array.
   *
   * @param {Number} start
   * @param {Number} end default to start + 1
   */
  removeChars: function(start, end) {
    if (typeof end === 'undefined') {
      end = start + 1;
    }
    this.removeStyleFromTo(start, end);
    this._text.splice(start, end - start);
    this.text = this._text.join('');
    this.set('dirty', true);
    if (this._shouldClearDimensionCache()) {
      this.initDimensions();
      this.setCoords();
    }
    this._removeExtraneousStyles();
  },

  /**
   * insert characters at start position, before start position.
   * start  equal 1 it means the text get inserted between actual grapheme 0 and 1
   * if style array is provided, it must be as the same length of text in graphemes
   * if end is provided and is bigger than start, old text is replaced.
   * start/end ar per grapheme position in _text array.
   *
   * @param {String} text text to insert
   * @param {Array} style array of style objects
   * @param {Number} start
   * @param {Number} end default to start + 1
   */
  insertChars: function(text, style, start, end) {
    if (typeof end === 'undefined') {
      end = start;
    }
    if (end > start) {
      this.removeStyleFromTo(start, end);
    }
    var graphemes = fabric.util.string.graphemeSplit(text);
    this.insertNewStyleBlock(graphemes, start, style);
    this._text = [].concat(this._text.slice(0, start), graphemes, this._text.slice(end));
    this.text = this._text.join('');
    this.set('dirty', true);
    if (this._shouldClearDimensionCache()) {
      this.initDimensions();
      this.setCoords();
    }
    this._removeExtraneousStyles();
  },

});


/* _TO_SVG_START_ */
(function() {
  var toFixed = fabric.util.toFixed,
      multipleSpacesRegex = /  +/g;

  fabric.util.object.extend(fabric.Text.prototype, /** @lends fabric.Text.prototype */ {

    /**
     * Returns SVG representation of an instance
     * @param {Function} [reviver] Method for further parsing of svg representation.
     * @return {String} svg representation of an instance
     */
    toSVG: function(reviver) {
      var markup = this._createBaseSVGMarkup(),
          offsets = this._getSVGLeftTopOffsets(),
          textAndBg = this._getSVGTextAndBg(offsets.textTop, offsets.textLeft);
      this._wrapSVGTextAndBg(markup, textAndBg);

      return reviver ? reviver(markup.join('')) : markup.join('');
    },

    /**
     * @private
     */
    _getSVGLeftTopOffsets: function() {
      return {
        textLeft: -this.width / 2,
        textTop: -this.height / 2,
        lineTop: this.getHeightOfLine(0)
      };
    },

    /**
     * @private
     */
    _wrapSVGTextAndBg: function(markup, textAndBg) {
      var noShadow = true, filter = this.getSvgFilter(),
          style = filter === '' ? '' : ' style="' + filter + '"',
          textDecoration = this.getSvgTextDecoration(this);
      markup.push(
        '\t<g ', this.getSvgId(), 'transform="', this.getSvgTransform(), this.getSvgTransformMatrix(), '"',
        style, '>\n',
        textAndBg.textBgRects.join(''),
        '\t\t<text xml:space="preserve" ',
        (this.fontFamily ? 'font-family="' + this.fontFamily.replace(/"/g, '\'') + '" ' : ''),
        (this.fontSize ? 'font-size="' + this.fontSize + '" ' : ''),
        (this.fontStyle ? 'font-style="' + this.fontStyle + '" ' : ''),
        (this.fontWeight ? 'font-weight="' + this.fontWeight + '" ' : ''),
        (textDecoration ? 'text-decoration="' + textDecoration + '" ' : ''),
        'style="', this.getSvgStyles(noShadow), '"', this.addPaintOrder(), ' >',
        textAndBg.textSpans.join(''),
        '</text>\n',
        '\t</g>\n'
      );
    },

    /**
     * @private
     * @param {Number} textTopOffset Text top offset
     * @param {Number} textLeftOffset Text left offset
     * @return {Object}
     */
    _getSVGTextAndBg: function(textTopOffset, textLeftOffset) {
      var textSpans = [],
          textBgRects = [],
          height = textTopOffset, lineOffset;
      // bounding-box background
      this._setSVGBg(textBgRects);

      // text and text-background
      for (var i = 0, len = this._textLines.length; i < len; i++) {
        lineOffset = this._getLineLeftOffset(i);
        if (this.textBackgroundColor || this.styleHas('textBackgroundColor', i)) {
          this._setSVGTextLineBg(textBgRects, i, textLeftOffset + lineOffset, height);
        }
        this._setSVGTextLineText(textSpans, i, textLeftOffset + lineOffset, height);
        height += this.getHeightOfLine(i);
      }

      return {
        textSpans: textSpans,
        textBgRects: textBgRects
      };
    },

    /**
     * @private
     */
    _createTextCharSpan: function(_char, styleDecl, left, top) {
      var shouldUseWhitespace = _char !== _char.trim() || _char.match(multipleSpacesRegex),
          styleProps = this.getSvgSpanStyles(styleDecl, shouldUseWhitespace),
          fillStyles = styleProps ? 'style="' + styleProps + '"' : '',
          dy = styleDecl.deltaY, dySpan = '',
          NUM_FRACTION_DIGITS = fabric.Object.NUM_FRACTION_DIGITS;
      if (dy) {
        dySpan = ' dy="' + toFixed(dy, NUM_FRACTION_DIGITS) + '" ';
      }
      return [
        '<tspan x="', toFixed(left, NUM_FRACTION_DIGITS), '" y="',
        toFixed(top, NUM_FRACTION_DIGITS), '" ', dySpan,
        fillStyles, '>',
        fabric.util.string.escapeXml(_char),
        '</tspan>'
      ].join('');
    },

    _setSVGTextLineText: function(textSpans, lineIndex, textLeftOffset, textTopOffset) {
      // set proper line offset
      var lineHeight = this.getHeightOfLine(lineIndex),
          isJustify = this.textAlign.indexOf('justify') !== -1,
          actualStyle,
          nextStyle,
          charsToRender = '',
          charBox, style,
          boxWidth = 0,
          line = this._textLines[lineIndex],
          timeToRender;

      textTopOffset += lineHeight * (1 - this._fontSizeFraction) / this.lineHeight;
      for (var i = 0, len = line.length - 1; i <= len; i++) {
        timeToRender = i === len || this.charSpacing;
        charsToRender += line[i];
        charBox = this.__charBounds[lineIndex][i];
        if (boxWidth === 0) {
          textLeftOffset += charBox.kernedWidth - charBox.width;
          boxWidth += charBox.width;
        }
        else {
          boxWidth += charBox.kernedWidth;
        }
        if (isJustify && !timeToRender) {
          if (this._reSpaceAndTab.test(line[i])) {
            timeToRender = true;
          }
        }
        if (!timeToRender) {
          // if we have charSpacing, we render char by char
          actualStyle = actualStyle || this.getCompleteStyleDeclaration(lineIndex, i);
          nextStyle = this.getCompleteStyleDeclaration(lineIndex, i + 1);
          timeToRender = this._hasStyleChangedForSvg(actualStyle, nextStyle);
        }
        if (timeToRender) {
          style = this._getStyleDeclaration(lineIndex, i) || { };
          textSpans.push(this._createTextCharSpan(charsToRender, style, textLeftOffset, textTopOffset));
          charsToRender = '';
          actualStyle = nextStyle;
          textLeftOffset += boxWidth;
          boxWidth = 0;
        }
      }
    },

    _pushTextBgRect: function(textBgRects, color, left, top, width, height) {
      var NUM_FRACTION_DIGITS = fabric.Object.NUM_FRACTION_DIGITS;
      textBgRects.push(
        '\t\t<rect ',
        this._getFillAttributes(color),
        ' x="',
        toFixed(left, NUM_FRACTION_DIGITS),
        '" y="',
        toFixed(top, NUM_FRACTION_DIGITS),
        '" width="',
        toFixed(width, NUM_FRACTION_DIGITS),
        '" height="',
        toFixed(height, NUM_FRACTION_DIGITS),
        '"></rect>\n');
    },

    _setSVGTextLineBg: function(textBgRects, i, leftOffset, textTopOffset) {
      var line = this._textLines[i],
          heightOfLine = this.getHeightOfLine(i) / this.lineHeight,
          boxWidth = 0,
          boxStart = 0,
          charBox, currentColor,
          lastColor = this.getValueOfPropertyAt(i, 0, 'textBackgroundColor');
      for (var j = 0, jlen = line.length; j < jlen; j++) {
        charBox = this.__charBounds[i][j];
        currentColor = this.getValueOfPropertyAt(i, j, 'textBackgroundColor');
        if (currentColor !== lastColor) {
          lastColor && this._pushTextBgRect(textBgRects, lastColor, leftOffset + boxStart,
            textTopOffset, boxWidth, heightOfLine);
          boxStart = charBox.left;
          boxWidth = charBox.width;
          lastColor = currentColor;
        }
        else {
          boxWidth += charBox.kernedWidth;
        }
      }
      currentColor && this._pushTextBgRect(textBgRects, currentColor, leftOffset + boxStart,
        textTopOffset, boxWidth, heightOfLine);
    },

    /**
     * Adobe Illustrator (at least CS5) is unable to render rgba()-based fill values
     * we work around it by "moving" alpha channel into opacity attribute and setting fill's alpha to 1
     *
     * @private
     * @param {*} value
     * @return {String}
     */
    _getFillAttributes: function(value) {
      var fillColor = (value && typeof value === 'string') ? new fabric.Color(value) : '';
      if (!fillColor || !fillColor.getSource() || fillColor.getAlpha() === 1) {
        return 'fill="' + value + '"';
      }
      return 'opacity="' + fillColor.getAlpha() + '" fill="' + fillColor.setAlpha(1).toRgb() + '"';
    },

    /**
     * @private
     */
    _getSVGLineTopOffset: function(lineIndex) {
      var lineTopOffset = 0, lastHeight = 0;
      for (var j = 0; j < lineIndex; j++) {
        lineTopOffset += this.getHeightOfLine(j);
      }
      lastHeight = this.getHeightOfLine(j);
      return {
        lineTop: lineTopOffset,
        offset: (this._fontSizeMult - this._fontSizeFraction) * lastHeight / (this.lineHeight * this._fontSizeMult)
      };
    },

    /**
     * Returns styles-string for svg-export
     * @param {Boolean} skipShadow a boolean to skip shadow filter output
     * @return {String}
     */
    getSvgStyles: function(skipShadow) {
      var svgStyle = fabric.Object.prototype.getSvgStyles.call(this, skipShadow);
      return svgStyle + ' white-space: pre;';
    },
  });
})();
/* _TO_SVG_END_ */


(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = {});

  /**
   * Textbox class, based on IText, allows the user to resize the text rectangle
   * and wraps lines automatically. Textboxes have their Y scaling locked, the
   * user can only change width. Height is adjusted automatically based on the
   * wrapping of lines.
   * @class fabric.Textbox
   * @extends fabric.IText
   * @mixes fabric.Observable
   * @return {fabric.Textbox} thisArg
   * @see {@link fabric.Textbox#initialize} for constructor definition
   */
  fabric.Textbox = fabric.util.createClass(fabric.IText, fabric.Observable, {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'textbox',

    /**
     * Minimum width of textbox, in pixels.
     * @type Number
     * @default
     */
    minWidth: 20,

    /**
     * Minimum calculated width of a textbox, in pixels.
     * fixed to 2 so that an empty textbox cannot go to 0
     * and is still selectable without text.
     * @type Number
     * @default
     */
    dynamicMinWidth: 2,

    /**
     * Cached array of text wrapping.
     * @type Array
     */
    __cachedLines: null,

    /**
     * Override standard Object class values
     */
    lockScalingFlip: true,

    /**
     * Override standard Object class values
     * Textbox needs this on false
     */
    noScaleCache: false,

    /**
     * Properties which when set cause object to change dimensions
     * @type Object
     * @private
     */
    _dimensionAffectingProps: fabric.Text.prototype._dimensionAffectingProps.concat('width'),

    /**
     * Unlike superclass's version of this function, Textbox does not update
     * its width.
     * @private
     * @override
     */
    initDimensions: function() {
      if (this.__skipDimension) {
        return;
      }
      this.isEditing && this.initDelayedCursor();
      this.clearContextTop();
      this._clearCache();
      // clear dynamicMinWidth as it will be different after we re-wrap line
      this.dynamicMinWidth = 0;
      // wrap lines
      this._styleMap = this._generateStyleMap(this._splitText());
      // if after wrapping, the width is smaller than dynamicMinWidth, change the width and re-wrap
      if (this.dynamicMinWidth > this.width) {
        this._set('width', this.dynamicMinWidth);
      }
      if (this.textAlign.indexOf('justify') !== -1) {
        // once text is measured we need to make space fatter to make justified text.
        this.enlargeSpaces();
      }
      // clear cache and re-calculate height
      this.height = this.calcTextHeight();
      this.saveState({ propertySet: '_dimensionAffectingProps' });
    },

    /**
     * Generate an object that translates the style object so that it is
     * broken up by visual lines (new lines and automatic wrapping).
     * The original text styles object is broken up by actual lines (new lines only),
     * which is only sufficient for Text / IText
     * @private
     */
    _generateStyleMap: function(textInfo) {
      var realLineCount     = 0,
          realLineCharCount = 0,
          charCount         = 0,
          map               = {};

      for (var i = 0; i < textInfo.graphemeLines.length; i++) {
        if (textInfo.graphemeText[charCount] === '\n' && i > 0) {
          realLineCharCount = 0;
          charCount++;
          realLineCount++;
        }
        else if (this._reSpaceAndTab.test(textInfo.graphemeText[charCount]) && i > 0) {
          // this case deals with space's that are removed from end of lines when wrapping
          realLineCharCount++;
          charCount++;
        }

        map[i] = { line: realLineCount, offset: realLineCharCount };

        charCount += textInfo.graphemeLines[i].length;
        realLineCharCount += textInfo.graphemeLines[i].length;
      }

      return map;
    },

    /**
     * Returns true if object has a style property or has it ina specified line
     * @param {Number} lineIndex
     * @return {Boolean}
     */
    styleHas: function(property, lineIndex) {
      if (this._styleMap && !this.isWrapping) {
        var map = this._styleMap[lineIndex];
        if (map) {
          lineIndex = map.line;
        }
      }
      return fabric.Text.prototype.styleHas.call(this, property, lineIndex);
    },

    /**
     * Returns true if object has no styling or no styling in a line
     * @param {Number} lineIndex , lineIndex is on wrapped lines.
     * @return {Boolean}
     */
    isEmptyStyles: function(lineIndex) {
      var offset = 0, nextLineIndex = lineIndex + 1, nextOffset, obj, shouldLimit = false;
      var map = this._styleMap[lineIndex];
      var mapNextLine = this._styleMap[lineIndex + 1];
      if (map) {
        lineIndex = map.line;
        offset = map.offset;
      }
      if (mapNextLine) {
        nextLineIndex = mapNextLine.line;
        shouldLimit = nextLineIndex === lineIndex;
        nextOffset = mapNextLine.offset;
      }
      obj = typeof lineIndex === 'undefined' ? this.styles : { line: this.styles[lineIndex] };
      for (var p1 in obj) {
        for (var p2 in obj[p1]) {
          if (p2 >= offset && (!shouldLimit || p2 < nextOffset)) {
            // eslint-disable-next-line no-unused-vars
            for (var p3 in obj[p1][p2]) {
              return false;
            }
          }
        }
      }
      return true;
    },

    /**
     * @param {Number} lineIndex
     * @param {Number} charIndex
     * @private
     */
    _getStyleDeclaration: function(lineIndex, charIndex) {
      if (this._styleMap && !this.isWrapping) {
        var map = this._styleMap[lineIndex];
        if (!map) {
          return null;
        }
        lineIndex = map.line;
        charIndex = map.offset + charIndex;
      }
      return this.callSuper('_getStyleDeclaration', lineIndex, charIndex);
    },

    /**
     * @param {Number} lineIndex
     * @param {Number} charIndex
     * @param {Object} style
     * @private
     */
    _setStyleDeclaration: function(lineIndex, charIndex, style) {
      var map = this._styleMap[lineIndex];
      lineIndex = map.line;
      charIndex = map.offset + charIndex;

      this.styles[lineIndex][charIndex] = style;
    },

    /**
     * @param {Number} lineIndex
     * @param {Number} charIndex
     * @private
     */
    _deleteStyleDeclaration: function(lineIndex, charIndex) {
      var map = this._styleMap[lineIndex];
      lineIndex = map.line;
      charIndex = map.offset + charIndex;

      delete this.styles[lineIndex][charIndex];
    },

    /**
    * probably broken need a fix
     * @param {Number} lineIndex
     * @private
     */
    _getLineStyle: function(lineIndex) {
      var map = this._styleMap[lineIndex];
      return this.styles[map.line];
    },

    /**
     * probably broken need a fix
     * @param {Number} lineIndex
     * @param {Object} style
     * @private
     */
    _setLineStyle: function(lineIndex, style) {
      var map = this._styleMap[lineIndex];
      this.styles[map.line] = style;
    },

    /**
     * probably broken need a fix
     * @param {Number} lineIndex
     * @private
     */
    _deleteLineStyle: function(lineIndex) {
      var map = this._styleMap[lineIndex];
      delete this.styles[map.line];
    },

    /**
     * Wraps text using the 'width' property of Textbox. First this function
     * splits text on newlines, so we preserve newlines entered by the user.
     * Then it wraps each line using the width of the Textbox by calling
     * _wrapLine().
     * @param {Array} lines The string array of text that is split into lines
     * @param {Number} desiredWidth width you want to wrap to
     * @returns {Array} Array of lines
     */
    _wrapText: function(lines, desiredWidth) {
      var wrapped = [], i;
      this.isWrapping = true;
      for (i = 0; i < lines.length; i++) {
        wrapped = wrapped.concat(this._wrapLine(lines[i], i, desiredWidth));
      }
      this.isWrapping = false;
      return wrapped;
    },

    /**
     * Helper function to measure a string of text, given its lineIndex and charIndex offset
     * it gets called when charBounds are not available yet.
     * @param {CanvasRenderingContext2D} ctx
     * @param {String} text
     * @param {number} lineIndex
     * @param {number} charOffset
     * @returns {number}
     * @private
     */
    _measureWord: function(word, lineIndex, charOffset) {
      var width = 0, prevGrapheme, skipLeft = true;
      charOffset = charOffset || 0;
      for (var i = 0, len = word.length; i < len; i++) {
        var box = this._getGraphemeBox(word[i], lineIndex, i + charOffset, prevGrapheme, skipLeft);
        width += box.kernedWidth;
        prevGrapheme = word[i];
      }
      return width;
    },

    /**
     * Wraps a line of text using the width of the Textbox and a context.
     * @param {Array} line The grapheme array that represent the line
     * @param {Number} lineIndex
     * @param {Number} desiredWidth width you want to wrap the line to
     * @param {Number} reservedSpace space to remove from wrapping for custom functionalities
     * @returns {Array} Array of line(s) into which the given text is wrapped
     * to.
     */
    _wrapLine: function(_line, lineIndex, desiredWidth, reservedSpace) {
      var lineWidth        = 0,
          graphemeLines    = [],
          line             = [],
          // spaces in different languges?
          words            = _line.split(this._reSpaceAndTab),
          word             = '',
          offset           = 0,
          infix            = ' ',
          wordWidth        = 0,
          infixWidth       = 0,
          largestWordWidth = 0,
          lineJustStarted = true,
          additionalSpace = this._getWidthOfCharSpacing(),
          reservedSpace = reservedSpace || 0;

      desiredWidth -= reservedSpace;
      for (var i = 0; i < words.length; i++) {
        // i would avoid resplitting the graphemes
        word = fabric.util.string.graphemeSplit(words[i]);
        wordWidth = this._measureWord(word, lineIndex, offset);
        offset += word.length;

        lineWidth += infixWidth + wordWidth - additionalSpace;

        if (lineWidth >= desiredWidth && !lineJustStarted) {
          graphemeLines.push(line);
          line = [];
          lineWidth = wordWidth;
          lineJustStarted = true;
        }
        else {
          lineWidth += additionalSpace;
        }

        if (!lineJustStarted) {
          line.push(infix);
        }
        line = line.concat(word);

        infixWidth = this._measureWord([infix], lineIndex, offset);
        offset++;
        lineJustStarted = false;
        // keep track of largest word
        if (wordWidth > largestWordWidth) {
          largestWordWidth = wordWidth;
        }
      }

      i && graphemeLines.push(line);

      if (largestWordWidth + reservedSpace > this.dynamicMinWidth) {
        this.dynamicMinWidth = largestWordWidth - additionalSpace + reservedSpace;
      }

      return graphemeLines;
    },

    /**
     * Detect if the text line is ended with an hard break
     * text and itext do not have wrapping, return false
     * @param {Number} lineIndex text to split
     * @return {Boolean}
     */
    isEndOfWrapping: function(lineIndex) {
      if (!this._styleMap[lineIndex + 1]) {
        // is last line, return true;
        return true;
      }
      if (this._styleMap[lineIndex + 1].line !== this._styleMap[lineIndex].line) {
        // this is last line before a line break, return true;
        return true;
      }
      return false;
    },

    /**
    * Gets lines of text to render in the Textbox. This function calculates
    * text wrapping on the fly every time it is called.
    * @param {String} text text to split
    * @returns {Array} Array of lines in the Textbox.
    * @override
    */
    _splitTextIntoLines: function(text) {
      var newText = fabric.Text.prototype._splitTextIntoLines.call(this, text),
          graphemeLines = this._wrapText(newText.lines, this.width),
          lines = new Array(graphemeLines.length);

      for (var i = 0; i < graphemeLines.length; i++) {
        lines[i] = graphemeLines[i].join('');
      }
      newText.lines = lines;
      newText.graphemeLines = graphemeLines;
      return newText;
    },

    getMinWidth: function() {
      return Math.max(this.minWidth, this.dynamicMinWidth);
    },

    /**
     * Returns object representation of an instance
     * @method toObject
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      return this.callSuper('toObject', ['minWidth'].concat(propertiesToInclude));
    }
  });

  /**
   * Returns fabric.Textbox instance from an object representation
   * @static
   * @memberOf fabric.Textbox
   * @param {Object} object Object to create an instance from
   * @param {Function} [callback] Callback to invoke when an fabric.Textbox instance is created
   */
  fabric.Textbox.fromObject = function(object, callback) {
    return fabric.Object._fromObject('Textbox', object, callback, 'text');
  };
})(typeof exports !== 'undefined' ? exports : this);


(function() {

  /**
   * Override _setObjectScale and add Textbox specific resizing behavior. Resizing
   * a Textbox doesn't scale text, it only changes width and makes text wrap automatically.
   */
  var setObjectScaleOverridden = fabric.Canvas.prototype._setObjectScale;

  fabric.Canvas.prototype._setObjectScale = function(localMouse, transform,
    lockScalingX, lockScalingY, by, lockScalingFlip, _dim) {

    var t = transform.target;
    if (by === 'x' && t instanceof fabric.Textbox) {
      var tw = t._getTransformedDimensions().x;
      var w = t.width * (localMouse.x / tw);
      if (w >= t.getMinWidth()) {
        t.set('width', w);
        return true;
      }
    }
    else {
      return setObjectScaleOverridden.call(fabric.Canvas.prototype, localMouse, transform,
        lockScalingX, lockScalingY, by, lockScalingFlip, _dim);
    }
  };

  fabric.util.object.extend(fabric.Textbox.prototype, /** @lends fabric.IText.prototype */ {
    /**
     * @private
     */
    _removeExtraneousStyles: function() {
      for (var prop in this._styleMap) {
        if (!this._textLines[prop]) {
          delete this.styles[this._styleMap[prop].line];
        }
      }
    },

  });
})();

