/*
* ColorMatrix
* 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:
	/**
	 * Provides helper functions for assembling a matrix for use with the {{#crossLink "ColorMatrixFilter"}}{{/crossLink}}.
	 * Most methods return the instance to facilitate chained calls.
	 *
	 * <h4>Example</h4>
	 *
	 *      myColorMatrix.adjustHue(20).adjustBrightness(50);
	 *
	 * See {{#crossLink "Filter"}}{{/crossLink}} for an example of how to apply filters, or {{#crossLink "ColorMatrixFilter"}}{{/crossLink}}
	 * for an example of how to use ColorMatrix to change a DisplayObject's color.
	 * @class ColorMatrix
	 * @param {Number} brightness
	 * @param {Number} contrast
	 * @param {Number} saturation
	 * @param {Number} hue
	 * @constructor
	 **/
	function ColorMatrix(brightness, contrast, saturation, hue) {
		this.setColor(brightness, contrast, saturation, hue);
	}
	var p = ColorMatrix.prototype;

// constants:
	/**
	 * Array of delta values for contrast calculations.
	 * @property DELTA_INDEX
	 * @type Array
	 * @protected
	 * @static
	 **/
	ColorMatrix.DELTA_INDEX = [
		0,    0.01, 0.02, 0.04, 0.05, 0.06, 0.07, 0.08, 0.1,  0.11,
		0.12, 0.14, 0.15, 0.16, 0.17, 0.18, 0.20, 0.21, 0.22, 0.24,
		0.25, 0.27, 0.28, 0.30, 0.32, 0.34, 0.36, 0.38, 0.40, 0.42,
		0.44, 0.46, 0.48, 0.5,  0.53, 0.56, 0.59, 0.62, 0.65, 0.68,
		0.71, 0.74, 0.77, 0.80, 0.83, 0.86, 0.89, 0.92, 0.95, 0.98,
		1.0,  1.06, 1.12, 1.18, 1.24, 1.30, 1.36, 1.42, 1.48, 1.54,
		1.60, 1.66, 1.72, 1.78, 1.84, 1.90, 1.96, 2.0,  2.12, 2.25,
		2.37, 2.50, 2.62, 2.75, 2.87, 3.0,  3.2,  3.4,  3.6,  3.8,
		4.0,  4.3,  4.7,  4.9,  5.0,  5.5,  6.0,  6.5,  6.8,  7.0,
		7.3,  7.5,  7.8,  8.0,  8.4,  8.7,  9.0,  9.4,  9.6,  9.8,
		10.0
	];

	/**
	 * Identity matrix values.
	 * @property IDENTITY_MATRIX
	 * @type Array
	 * @protected
	 * @static
	 **/
	ColorMatrix.IDENTITY_MATRIX = [
		1,0,0,0,0,
		0,1,0,0,0,
		0,0,1,0,0,
		0,0,0,1,0,
		0,0,0,0,1
	];

	/**
	 * The constant length of a color matrix.
	 * @property LENGTH
	 * @type Number
	 * @protected
	 * @static
	 **/
	ColorMatrix.LENGTH = ColorMatrix.IDENTITY_MATRIX.length;


// public methods:
	/**
	 * Resets the instance with the specified values.
	 * @method setColor
	 * @param {Number} brightness
	 * @param {Number} contrast
	 * @param {Number} saturation
	 * @param {Number} hue
	 * @return {ColorMatrix} The ColorMatrix instance the method is called on (useful for chaining calls.)
	 * @chainable
	 */
	p.setColor = function(brightness,contrast,saturation,hue) {
		return this.reset().adjustColor(brightness,contrast,saturation,hue);
	};

	/**
	 * Resets the matrix to identity values.
	 * @method reset
	 * @return {ColorMatrix} The ColorMatrix instance the method is called on (useful for chaining calls.)
	 * @chainable
	 */
	p.reset = function() {
		return this.copy(ColorMatrix.IDENTITY_MATRIX);
	};

	/**
	 * Shortcut method to adjust brightness, contrast, saturation and hue.
	 * Equivalent to calling adjustHue(hue), adjustContrast(contrast),
	 * adjustBrightness(brightness), adjustSaturation(saturation), in that order.
	 * @method adjustColor
	 * @param {Number} brightness
	 * @param {Number} contrast
	 * @param {Number} saturation
	 * @param {Number} hue
	 * @return {ColorMatrix} The ColorMatrix instance the method is called on (useful for chaining calls.)
	 * @chainable
	 **/
	p.adjustColor = function(brightness,contrast,saturation,hue) {
		this.adjustHue(hue);
		this.adjustContrast(contrast);
		this.adjustBrightness(brightness);
		return this.adjustSaturation(saturation);
	};

	/**
	 * Adjusts the brightness of pixel color by adding the specified value to the red, green and blue channels.
	 * Positive values will make the image brighter, negative values will make it darker.
	 * @method adjustBrightness
	 * @param {Number} value A value between -255 & 255 that will be added to the RGB channels.
	 * @return {ColorMatrix} The ColorMatrix instance the method is called on (useful for chaining calls.)
	 * @chainable
	 **/
	p.adjustBrightness = function(value) {
		if (value == 0 || isNaN(value)) { return this; }
		value = this._cleanValue(value,255);
		this._multiplyMatrix([
			1,0,0,0,value,
			0,1,0,0,value,
			0,0,1,0,value,
			0,0,0,1,0,
			0,0,0,0,1
		]);
		return this;
	};

	/**
	 * Adjusts the contrast of pixel color.
	 * Positive values will increase contrast, negative values will decrease contrast.
	 * @method adjustContrast
	 * @param {Number} value A value between -100 & 100.
	 * @return {ColorMatrix} The ColorMatrix instance the method is called on (useful for chaining calls.)
	 * @chainable
	 **/
	p.adjustContrast = function(value) {
		if (value == 0 || isNaN(value)) { return this; }
		value = this._cleanValue(value,100);
		var x;
		if (value<0) {
			x = 127+value/100*127;
		} else {
			x = value%1;
			if (x == 0) {
				x = ColorMatrix.DELTA_INDEX[value];
			} else {
				x = ColorMatrix.DELTA_INDEX[(value<<0)]*(1-x)+ColorMatrix.DELTA_INDEX[(value<<0)+1]*x; // use linear interpolation for more granularity.
			}
			x = x*127+127;
		}
		this._multiplyMatrix([
			x/127,0,0,0,0.5*(127-x),
			0,x/127,0,0,0.5*(127-x),
			0,0,x/127,0,0.5*(127-x),
			0,0,0,1,0,
			0,0,0,0,1
		]);
		return this;
	};

	/**
	 * Adjusts the color saturation of the pixel.
	 * Positive values will increase saturation, negative values will decrease saturation (trend towards greyscale).
	 * @method adjustSaturation
	 * @param {Number} value A value between -100 & 100.
	 * @return {ColorMatrix} The ColorMatrix instance the method is called on (useful for chaining calls.)
	 * @chainable
	 **/
	p.adjustSaturation = function(value) {
		if (value == 0 || isNaN(value)) { return this; }
		value = this._cleanValue(value,100);
		var x = 1+((value > 0) ? 3*value/100 : value/100);
		var lumR = 0.3086;
		var lumG = 0.6094;
		var lumB = 0.0820;
		this._multiplyMatrix([
			lumR*(1-x)+x,lumG*(1-x),lumB*(1-x),0,0,
			lumR*(1-x),lumG*(1-x)+x,lumB*(1-x),0,0,
			lumR*(1-x),lumG*(1-x),lumB*(1-x)+x,0,0,
			0,0,0,1,0,
			0,0,0,0,1
		]);
		return this;
	};


	/**
	 * Adjusts the hue of the pixel color.
	 * @method adjustHue
	 * @param {Number} value A value between -180 & 180.
	 * @return {ColorMatrix} The ColorMatrix instance the method is called on (useful for chaining calls.)
	 * @chainable
	 **/
	p.adjustHue = function(value) {
		if (value == 0 || isNaN(value)) { return this; }
		value = this._cleanValue(value,180)/180*Math.PI;
		var cosVal = Math.cos(value);
		var sinVal = Math.sin(value);
		var lumR = 0.213;
		var lumG = 0.715;
		var lumB = 0.072;
		this._multiplyMatrix([
			lumR+cosVal*(1-lumR)+sinVal*(-lumR),lumG+cosVal*(-lumG)+sinVal*(-lumG),lumB+cosVal*(-lumB)+sinVal*(1-lumB),0,0,
			lumR+cosVal*(-lumR)+sinVal*(0.143),lumG+cosVal*(1-lumG)+sinVal*(0.140),lumB+cosVal*(-lumB)+sinVal*(-0.283),0,0,
			lumR+cosVal*(-lumR)+sinVal*(-(1-lumR)),lumG+cosVal*(-lumG)+sinVal*(lumG),lumB+cosVal*(1-lumB)+sinVal*(lumB),0,0,
			0,0,0,1,0,
			0,0,0,0,1
		]);
		return this;
	};

	/**
	 * Concatenates (multiplies) the specified matrix with this one.
	 * @method concat
	 * @param {Array} matrix An array or ColorMatrix instance.
	 * @return {ColorMatrix} The ColorMatrix instance the method is called on (useful for chaining calls.)
	 * @chainable
	 **/
	p.concat = function(matrix) {
		matrix = this._fixMatrix(matrix);
		if (matrix.length != ColorMatrix.LENGTH) { return this; }
		this._multiplyMatrix(matrix);
		return this;
	};

	/**
	 * Returns a clone of this ColorMatrix.
	 * @method clone
	 * @return {ColorMatrix} A clone of this ColorMatrix.
	 **/
	p.clone = function() {
		return (new ColorMatrix()).copy(this);
	};

	/**
	 * Return a length 25 (5x5) array instance containing this matrix's values.
	 * @method toArray
	 * @return {Array} An array holding this matrix's values.
	 **/
	p.toArray = function() {
		var arr = [];
		for (var i= 0, l=ColorMatrix.LENGTH; i<l; i++) {
			arr[i] = this[i];
		}
		return arr;
	};

	/**
	 * Copy the specified matrix's values to this matrix.
	 * @method copy
	 * @param {Array} matrix An array or ColorMatrix instance.
	 * @return {ColorMatrix} The ColorMatrix instance the method is called on (useful for chaining calls.)
	 * @chainable
	 **/
	p.copy = function(matrix) {
		var l = ColorMatrix.LENGTH;
		for (var i=0;i<l;i++) {
			this[i] = matrix[i];
		}
		return this;
	};
	
	/**
	 * Returns a string representation of this object.
	 * @method toString
	 * @return {String} a string representation of the instance.
	 **/
	p.toString = function() {
		return "[ColorMatrix]";
	};


// private methods:
	/**
	 * @method _multiplyMatrix
	 * @param {Array} matrix
	 * @protected
	 **/
	p._multiplyMatrix = function(matrix) {
		var i, j, k, col = [];

		for (i=0;i<5;i++) {
			for (j=0;j<5;j++) {
				col[j] = this[j+i*5];
			}
			for (j=0;j<5;j++) {
				var val=0;
				for (k=0;k<5;k++) {
					val += matrix[j+k*5]*col[k];
				}
				this[j+i*5] = val;
			}
		}
	};

	/**
	 * Make sure values are within the specified range, hue has a limit of 180, brightness is 255, others are 100.
	 * @method _cleanValue
	 * @param {Number} value The raw number
	 * @param {Number} limit The maximum that the number can be. The minimum is the limit * -1.
	 * @protected
	 **/
	p._cleanValue = function(value, limit) {
		return Math.min(limit,Math.max(-limit,value));
	};

	/**
	 * Makes sure matrixes are 5x5 (25 long).
	 * @method _fixMatrix
	 * @param {Array} matrix
	 * @protected
	 **/
	p._fixMatrix = function(matrix) {
		if (matrix instanceof ColorMatrix) { matrix = matrix.toArray(); }
		if (matrix.length < ColorMatrix.LENGTH) {
			matrix = matrix.slice(0,matrix.length).concat(ColorMatrix.IDENTITY_MATRIX.slice(matrix.length,ColorMatrix.LENGTH));
		} else if (matrix.length > ColorMatrix.LENGTH) {
			matrix = matrix.slice(0,ColorMatrix.LENGTH);
		}
		return matrix;
	};


	createjs.ColorMatrix = ColorMatrix;
}());