/**
 * Focus shader
 * based on PaintEffect postprocess from ro.me
 * http://code.google.com/p/3-dreams-of-black/source/browse/deploy/js/effects/PaintEffect.js
 */

var FocusShader = {

	uniforms: {

		'tDiffuse': { value: null },
		'screenWidth': { value: 1024 },
		'screenHeight': { value: 1024 },
		'sampleDistance': { value: 0.94 },
		'waveFactor': { value: 0.00125 }

	},

	vertexShader: [

		'varying vec2 vUv;',

		'void main() {',

		'	vUv = uv;',
		'	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );',

		'}'

	].join( '\n' ),

	fragmentShader: [

		'uniform float screenWidth;',
		'uniform float screenHeight;',
		'uniform float sampleDistance;',
		'uniform float waveFactor;',

		'uniform sampler2D tDiffuse;',

		'varying vec2 vUv;',

		'void main() {',

		'	vec4 color, org, tmp, add;',
		'	float sample_dist, f;',
		'	vec2 vin;',
		'	vec2 uv = vUv;',

		'	add = color = org = texture2D( tDiffuse, uv );',

		'	vin = ( uv - vec2( 0.5 ) ) * vec2( 1.4 );',
		'	sample_dist = dot( vin, vin ) * 2.0;',

		'	f = ( waveFactor * 100.0 + sample_dist ) * sampleDistance * 4.0;',

		'	vec2 sampleSize = vec2(  1.0 / screenWidth, 1.0 / screenHeight ) * vec2( f );',

		'	add += tmp = texture2D( tDiffuse, uv + vec2( 0.111964, 0.993712 ) * sampleSize );',
		'	if( tmp.b < color.b ) color = tmp;',

		'	add += tmp = texture2D( tDiffuse, uv + vec2( 0.846724, 0.532032 ) * sampleSize );',
		'	if( tmp.b < color.b ) color = tmp;',

		'	add += tmp = texture2D( tDiffuse, uv + vec2( 0.943883, -0.330279 ) * sampleSize );',
		'	if( tmp.b < color.b ) color = tmp;',

		'	add += tmp = texture2D( tDiffuse, uv + vec2( 0.330279, -0.943883 ) * sampleSize );',
		'	if( tmp.b < color.b ) color = tmp;',

		'	add += tmp = texture2D( tDiffuse, uv + vec2( -0.532032, -0.846724 ) * sampleSize );',
		'	if( tmp.b < color.b ) color = tmp;',

		'	add += tmp = texture2D( tDiffuse, uv + vec2( -0.993712, -0.111964 ) * sampleSize );',
		'	if( tmp.b < color.b ) color = tmp;',

		'	add += tmp = texture2D( tDiffuse, uv + vec2( -0.707107, 0.707107 ) * sampleSize );',
		'	if( tmp.b < color.b ) color = tmp;',

		'	color = color * vec4( 2.0 ) - ( add / vec4( 8.0 ) );',
		'	color = color + ( add / vec4( 8.0 ) - color ) * ( vec4( 1.0 ) - vec4( sample_dist * 0.5 ) );',

		'	gl_FragColor = vec4( color.rgb * color.rgb * vec3( 0.95 ) + color.rgb, 1.0 );',

		'}'


	].join( '\n' )
};

export { FocusShader };