/*
* 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";


// constructor:
	/**
	 * 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
	 **/
	function ColorFilter(redMultiplier, greenMultiplier, blueMultiplier, alphaMultiplier, redOffset, greenOffset, blueOffset, alphaOffset) {
		this.Filter_constructor();

	// public properties:
		/**
		 * Red channel multiplier.
		 * @property redMultiplier
		 * @type Number
		 **/
		this.redMultiplier = redMultiplier != null ? redMultiplier : 1;
	
		/**
		 * Green channel multiplier.
		 * @property greenMultiplier
		 * @type Number
		 **/
		this.greenMultiplier = greenMultiplier != null ? greenMultiplier : 1;
	
		/**
		 * Blue channel multiplier.
		 * @property blueMultiplier
		 * @type Number
		 **/
		this.blueMultiplier = blueMultiplier != null ? blueMultiplier : 1;
	
		/**
		 * Alpha channel multiplier.
		 * @property alphaMultiplier
		 * @type Number
		 **/
		this.alphaMultiplier = alphaMultiplier != null ? alphaMultiplier : 1;
	
		/**
		 * Red channel offset (added to value).
		 * @property redOffset
		 * @type Number
		 **/
		this.redOffset = redOffset || 0;
	
		/**
		 * Green channel offset (added to value).
		 * @property greenOffset
		 * @type Number
		 **/
		this.greenOffset = greenOffset || 0;
	
		/**
		 * Blue channel offset (added to value).
		 * @property blueOffset
		 * @type Number
		 **/
		this.blueOffset = blueOffset || 0;
	
		/**
		 * Alpha channel offset (added to value).
		 * @property alphaOffset
		 * @type Number
		 **/
		this.alphaOffset = alphaOffset || 0;

		this.FRAG_SHADER_BODY = (
			"uniform vec4 uColorMultiplier;" +
			"uniform vec4 uColorOffset;" +

			"void main(void) {" +
				"vec4 color = texture2D(uSampler, vTextureCoord);" +
				"color = clamp(vec4(0.0), vec4(1.0), vec4(vec3(color.rgb / color.a), color.a));" +
				"color = clamp(vec4(0.0), vec4(1.0), color * uColorMultiplier + uColorOffset);" +

				"gl_FragColor = vec4(color.rgb * color.a, color.a);" +
			"}"
		);

	}
	var p = createjs.extend(ColorFilter, createjs.Filter);

	// TODO: deprecated
	// p.initialize = function() {}; // searchable for devs wondering where it is. REMOVED. See docs for details.


// public methods:
	// Docced in superclass
	p.shaderParamSetup = function(gl, stage, shaderProgram) {
		gl.uniform4f(
			gl.getUniformLocation(shaderProgram, "uColorMultiplier"),
			this.redMultiplier, this.greenMultiplier, this.blueMultiplier, this.alphaMultiplier
		);

		gl.uniform4f(
			gl.getUniformLocation(shaderProgram, "uColorOffset"),
			this.redOffset/255, this.greenOffset/255, this.blueOffset/255, this.alphaOffset/255
		);
	};

	// Docced in superclass
	p.toString = function() {
		return "[ColorFilter]";
	};

	// Docced in superclass
	p.clone = function() {
		return new ColorFilter(
			this.redMultiplier, this.greenMultiplier, this.blueMultiplier, this.alphaMultiplier,
			this.redOffset, this.greenOffset, this.blueOffset, this.alphaOffset
		);
	};

// private methods:
	// Docced in superclass
	p._applyFilter = function(imageData) {
		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;
		}
		return true;
	};


	createjs.ColorFilter = createjs.promote(ColorFilter, "Filter");
}());