/**
 * @author alteredq / http://alteredqualia.com/
 *
 * Depth-of-field shader with bokeh
 * ported from GLSL shader by Martins Upitis
 * http://artmartinsh.blogspot.com/2010/02/glsl-lens-blur-filter-with-bokeh.html
 */

THREE.BokehShader = {

	defines: {
		"DEPTH_PACKING": 1,
		"PERSPECTIVE_CAMERA": 1,
	},

	uniforms: {

		"tColor": { value: null },
		"tDepth": { value: null },
		"focus": { value: 1.0 },
		"aspect": { value: 1.0 },
		"aperture": { value: 0.025 },
		"maxblur": { value: 1.0 },
		"nearClip": { value: 1.0 },
		"farClip": { value: 1000.0 },

	},

	vertexShader: [

		"varying vec2 vUv;",

		"void main() {",

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

		"}"

	].join( "\n" ),

	fragmentShader: [
		"#include <common>",

		"varying vec2 vUv;",

		"uniform sampler2D tColor;",
		"uniform sampler2D tDepth;",

		"uniform float maxblur;", // max blur amount
		"uniform float aperture;", // aperture - bigger values for shallower depth of field

		"uniform float nearClip;",
		"uniform float farClip;",

		"uniform float focus;",
		"uniform float aspect;",

		"#include <packing>",

		"float getDepth( const in vec2 screenPosition ) {",
		"	#if DEPTH_PACKING == 1",
		"	return unpackRGBAToDepth( texture2D( tDepth, screenPosition ) );",
		"	#else",
		"	return texture2D( tDepth, screenPosition ).x;",
		"	#endif",
		"}",

		"float getViewZ( const in float depth ) {",
		"	#if PERSPECTIVE_CAMERA == 1",
		"	return perspectiveDepthToViewZ( depth, nearClip, farClip );",
		"	#else",
		"	return orthographicDepthToViewZ( depth, nearClip, farClip );",
		"	#endif",
		"}",


		"void main() {",

			"vec2 aspectcorrect = vec2( 1.0, aspect );",

			"float viewZ = getViewZ( getDepth( vUv ) );",

			"float factor = ( focus + viewZ );", // viewZ is <= 0, so this is a difference equation

			"vec2 dofblur = vec2 ( clamp( factor * aperture, -maxblur, maxblur ) );",

			"vec2 dofblur9 = dofblur * 0.9;",
			"vec2 dofblur7 = dofblur * 0.7;",
			"vec2 dofblur4 = dofblur * 0.4;",

			"vec4 col = vec4( 0.0 );",

			"col += texture2D( tColor, vUv.xy );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.0,   0.4  ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.15,  0.37 ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.29,  0.29 ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.37,  0.15 ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.40,  0.0  ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.37, -0.15 ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.29, -0.29 ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.15, -0.37 ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.0,  -0.4  ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.15,  0.37 ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.29,  0.29 ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.37,  0.15 ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.4,   0.0  ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.37, -0.15 ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.29, -0.29 ) * aspectcorrect ) * dofblur );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.15, -0.37 ) * aspectcorrect ) * dofblur );",

			"col += texture2D( tColor, vUv.xy + ( vec2(  0.15,  0.37 ) * aspectcorrect ) * dofblur9 );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.37,  0.15 ) * aspectcorrect ) * dofblur9 );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.37, -0.15 ) * aspectcorrect ) * dofblur9 );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.15, -0.37 ) * aspectcorrect ) * dofblur9 );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.15,  0.37 ) * aspectcorrect ) * dofblur9 );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.37,  0.15 ) * aspectcorrect ) * dofblur9 );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.37, -0.15 ) * aspectcorrect ) * dofblur9 );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.15, -0.37 ) * aspectcorrect ) * dofblur9 );",

			"col += texture2D( tColor, vUv.xy + ( vec2(  0.29,  0.29 ) * aspectcorrect ) * dofblur7 );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.40,  0.0  ) * aspectcorrect ) * dofblur7 );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.29, -0.29 ) * aspectcorrect ) * dofblur7 );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.0,  -0.4  ) * aspectcorrect ) * dofblur7 );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.29,  0.29 ) * aspectcorrect ) * dofblur7 );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.4,   0.0  ) * aspectcorrect ) * dofblur7 );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.29, -0.29 ) * aspectcorrect ) * dofblur7 );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.0,   0.4  ) * aspectcorrect ) * dofblur7 );",

			"col += texture2D( tColor, vUv.xy + ( vec2(  0.29,  0.29 ) * aspectcorrect ) * dofblur4 );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.4,   0.0  ) * aspectcorrect ) * dofblur4 );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.29, -0.29 ) * aspectcorrect ) * dofblur4 );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.0,  -0.4  ) * aspectcorrect ) * dofblur4 );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.29,  0.29 ) * aspectcorrect ) * dofblur4 );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.4,   0.0  ) * aspectcorrect ) * dofblur4 );",
			"col += texture2D( tColor, vUv.xy + ( vec2( -0.29, -0.29 ) * aspectcorrect ) * dofblur4 );",
			"col += texture2D( tColor, vUv.xy + ( vec2(  0.0,   0.4  ) * aspectcorrect ) * dofblur4 );",

			"gl_FragColor = col / 41.0;",
			"gl_FragColor.a = 1.0;",

		"}"

	].join( "\n" )

};
