/*
* ColorFilter
* Visit http://createjs.com/ for documentation, updates and examples.
*
* Copyright (c) 2010 gskinner.com, inc.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/

/**
 * @module EaselJS
 */

// namespace:
this.createjs = this.createjs||{};

(function() {
	"use strict";

/**
 * Applies a color transform to DisplayObjects.
 *
 * <h4>Example</h4>
 * This example draws a red circle, and then transforms it to Blue. This is accomplished by multiplying all the channels
 * to 0 (except alpha, which is set to 1), and then adding 255 to the blue channel.
 *
 *      var shape = new createjs.Shape().set({x:100,y:100});
 *      shape.graphics.beginFill("#ff0000").drawCircle(0,0,50);
 *
 *      shape.filters = [
 *          new createjs.ColorFilter(0,0,0,1, 0,0,255,0)
 *      ];
 *      shape.cache(-50, -50, 100, 100);
 *
 * See {{#crossLink "Filter"}}{{/crossLink}} for an more information on applying filters.
 * @class ColorFilter
 * @param {Number} [redMultiplier=1] The amount to multiply against the red channel. This is a range between 0 and 1.
 * @param {Number} [greenMultiplier=1] The amount to multiply against the green channel. This is a range between 0 and 1.
 * @param {Number} [blueMultiplier=1] The amount to multiply against the blue channel. This is a range between 0 and 1.
 * @param {Number} [alphaMultiplier=1] The amount to multiply against the alpha channel. This is a range between 0 and 1.
 * @param {Number} [redOffset=0] The amount to add to the red channel after it has been multiplied. This is a range
 * between -255 and 255.
 * @param {Number} [greenOffset=0] The amount to add to the green channel after it has been multiplied. This is a range
  * between -255 and 255.
 * @param {Number} [blueOffset=0] The amount to add to the blue channel after it has been multiplied. This is a range
  * between -255 and 255.
 * @param {Number} [alphaOffset=0] The amount to add to the alpha channel after it has been multiplied. This is a range
  * between -255 and 255.
 * @constructor
 * @extends Filter
 **/
var ColorFilter = function(redMultiplier, greenMultiplier, blueMultiplier, alphaMultiplier, redOffset, greenOffset, blueOffset, alphaOffset) {
  this.initialize(redMultiplier, greenMultiplier, blueMultiplier, alphaMultiplier, redOffset, greenOffset, blueOffset, alphaOffset);
}
var p = ColorFilter.prototype = new createjs.Filter();

// public properties:
	/**
	 * Red channel multiplier.
	 * @property redMultiplier
	 * @type Number
	 **/
	p.redMultiplier = 1;

	/**
	 * Green channel multiplier.
	 * @property greenMultiplier
	 * @type Number
	 **/
	p.greenMultiplier = 1;

	/**
	 * Blue channel multiplier.
	 * @property blueMultiplier
	 * @type Number
	 **/
	p.blueMultiplier = 1;

	/**
	 * Alpha channel multiplier.
	 * @property alphaMultiplier
	 * @type Number
	 **/
	p.alphaMultiplier = 1;

	/**
	 * Red channel offset (added to value).
	 * @property redOffset
	 * @type Number
	 **/
	p.redOffset = 0;

	/**
	 * Green channel offset (added to value).
	 * @property greenOffset
	 * @type Number
	 **/
	p.greenOffset = 0;

	/**
	 * Blue channel offset (added to value).
	 * @property blueOffset
	 * @type Number
	 **/
	p.blueOffset = 0;

	/**
	 * Alpha channel offset (added to value).
	 * @property alphaOffset
	 * @type Number
	 **/
	p.alphaOffset = 0;

// constructor:
	/**
	 * Initialization method.
	 * @method initialize
	 * @param {Number} [redMultiplier=1] The amount to multiply against the red channel. This is a range between 0 and 1.
	 * @param {Number} [greenMultiplier=1] The amount to multiply against the green channel. This is a range between 0 and 1.
	 * @param {Number} [blueMultiplier=1] The amount to multiply against the blue channel. This is a range between 0 and 1.
	 * @param {Number} [alphaMultiplier=1] The amount to multiply against the alpha channel. This is a range between 0 and 1.
	 * @param {Number} [redOffset=0] The amount to add to the red channel after it has been multiplied. This is a range
	 * between -255 and 255.
	 * @param {Number} [greenOffset=0] The amount to add to the green channel after it has been multiplied. This is a range
	 * between -255 and 255.
	 * @param {Number} [blueOffset=0] The amount to add to the blue channel after it has been multiplied. This is a range
	 * between -255 and 255.
	 * @param {Number} [alphaOffset=0] The amount to add to the alpha channel after it has been multiplied. This is a range
	 * between -255 and 255.
	 * @protected
	 **/
	p.initialize = function(redMultiplier, greenMultiplier, blueMultiplier, alphaMultiplier, redOffset, greenOffset, blueOffset, alphaOffset) {
		this.redMultiplier = redMultiplier != null ? redMultiplier : 1;
		this.greenMultiplier = greenMultiplier != null ? greenMultiplier : 1;
		this.blueMultiplier = blueMultiplier != null ? blueMultiplier : 1;
		this.alphaMultiplier = alphaMultiplier != null ? alphaMultiplier : 1;
		this.redOffset = redOffset || 0;
		this.greenOffset = greenOffset || 0;
		this.blueOffset = blueOffset || 0;
		this.alphaOffset = alphaOffset || 0;
	}

// public methods:
	p.applyFilter = function(ctx, x, y, width, height, targetCtx, targetX, targetY) {
		targetCtx = targetCtx || ctx;
		if (targetX == null) { targetX = x; }
		if (targetY == null) { targetY = y; }
		try {
			var imageData = ctx.getImageData(x, y, width, height);
		} catch(e) {
			//if (!this.suppressCrossDomainErrors) throw new Error("unable to access local image data: " + e);
			return false;
		}
		var data = imageData.data;
		var l = data.length;
		for (var i=0; i<l; i+=4) {
			data[i] = data[i]*this.redMultiplier+this.redOffset;
			data[i+1] = data[i+1]*this.greenMultiplier+this.greenOffset;
			data[i+2] = data[i+2]*this.blueMultiplier+this.blueOffset;
			data[i+3] = data[i+3]*this.alphaMultiplier+this.alphaOffset;
		}
		targetCtx.putImageData(imageData, targetX, targetY);
		return true;
	}

	p.toString = function() {
		return "[ColorFilter]";
	}

	/**
	 * Returns a clone of this ColorFilter instance.
	 * @method clone
	 * @return {ColorFilter} A clone of the current ColorFilter instance.
	 **/
	p.clone = function() {
		return new ColorFilter(this.redMultiplier, this.greenMultiplier, this.blueMultiplier, this.alphaMultiplier, this.redOffset, this.greenOffset, this.blueOffset, this.alphaOffset);
	}

	createjs.ColorFilter = ColorFilter;

}());
