/**
 * @author Mat Groves http://matgroves.com/ @Doormat23
 */


/**
 * 
 * This turns your displayObjects to black and white.
 * @class GrayFilter
 * @contructor
 */
PIXI.GrayFilter = function()
{
	PIXI.AbstractFilter.call( this );
	
	this.passes = [this];
	
	// set the uniforms
	this.uniforms = {
		gray: {type: 'f', value: 1},
	};
	
	this.fragmentSrc = [
	  "precision mediump float;",
	  "varying vec2 vTextureCoord;",
	  "varying float vColor;",
	  "uniform sampler2D uSampler;",
	  "uniform float gray;",
	  "void main(void) {",
	    "gl_FragColor = texture2D(uSampler, vTextureCoord);",
		"gl_FragColor.rgb = mix(gl_FragColor.rgb, vec3(0.2126*gl_FragColor.r + 0.7152*gl_FragColor.g + 0.0722*gl_FragColor.b), gray);",
	    "gl_FragColor = gl_FragColor * vColor;",
	  "}"
	];
}

PIXI.GrayFilter.prototype = Object.create( PIXI.AbstractFilter.prototype );
PIXI.GrayFilter.prototype.constructor = PIXI.GrayFilter;

/**
The strength of the gray. 1 will make the object black and white, 0 will make the object its normal color
@property gray
*/
Object.defineProperty(PIXI.GrayFilter.prototype, 'gray', {
    get: function() {
        return this.uniforms.gray.value;
    },
    set: function(value) {
    	this.uniforms.gray.value = value;
    }
});