/**
 * 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
 */

var 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: 0.01 },
		'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' )

};

export { BokehShader };