/**
 * @author zz85 / https://github.com/zz85 | twitter.com/blurspline
 *
 * Depth-of-field shader with bokeh
 * ported from GLSL shader by Martins Upitis
 * http://blenderartists.org/forum/showthread.php?237488-GLSL-depth-of-field-with-bokeh-v2-4-(update)
 *
 * Requires #define RINGS and SAMPLES integers
 */



THREE.BokehShader = {

	uniforms: {

		"textureWidth":  { type: "f", value: 1.0 },
		"textureHeight":  { type: "f", value: 1.0 },

		"focalDepth":   { type: "f", value: 1.0 },
		"focalLength":   { type: "f", value: 24.0 },
		"fstop": { type: "f", value: 0.9 },

		"tColor":   { type: "t", value: null },
		"tDepth":   { type: "t", value: null },

		"maxblur":  { type: "f", value: 1.0 },

		"showFocus":   { type: "i", value: 0 },
		"manualdof":   { type: "i", value: 0 },
		"vignetting":   { type: "i", value: 0 },
		"depthblur":   { type: "i", value: 0 },

		"threshold":  { type: "f", value: 0.5 },
		"gain":  { type: "f", value: 2.0 },
		"bias":  { type: "f", value: 0.5 },
		"fringe":  { type: "f", value: 0.7 },

		"znear":  { type: "f", value: 0.1 },
		"zfar":  { type: "f", value: 100 },

		"noise":  { type: "i", value: 1 },
		"dithering":  { type: "f", value: 0.0001 },
		"pentagon": { type: "i", value: 0 },

		"shaderFocus":  { type: "i", value: 1 },
		"focusCoords":  { type: "v2", value: new THREE.Vector2() },


	},

	vertexShader: [

		"varying vec2 vUv;",

		"void main() {",

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

		"}"

	].join( "\n" ),

	fragmentShader: [

		"varying vec2 vUv;",

		"uniform sampler2D tColor;",
		"uniform sampler2D tDepth;",
		"uniform float textureWidth;",
		"uniform float textureHeight;",

		"const float PI = 3.14159265;",

		"uniform float focalDepth;  //focal distance value in meters, but you may use autofocus option below",
		"uniform float focalLength; //focal length in mm",
		"uniform float fstop; //f-stop value",
		"uniform bool showFocus; //show debug focus point and focal range (red = focal point, green = focal range)",

		"/*",
		"make sure that these two values are the same for your camera, otherwise distances will be wrong.",
		"*/",

		"uniform float znear; // camera clipping start",
		"uniform float zfar; // camera clipping end",

		"//------------------------------------------",
		"//user variables",

		"const int samples = SAMPLES; //samples on the first ring",
		"const int rings = RINGS; //ring count",

		"const int maxringsamples = rings * samples;",

		"uniform bool manualdof; // manual dof calculation",
		"float ndofstart = 1.0; // near dof blur start",
		"float ndofdist = 2.0; // near dof blur falloff distance",
		"float fdofstart = 1.0; // far dof blur start",
		"float fdofdist = 3.0; // far dof blur falloff distance",

		"float CoC = 0.03; //circle of confusion size in mm (35mm film = 0.03mm)",

		"uniform bool vignetting; // use optical lens vignetting",

		"float vignout = 1.3; // vignetting outer border",
		"float vignin = 0.0; // vignetting inner border",
		"float vignfade = 22.0; // f-stops till vignete fades",

		"uniform bool shaderFocus;",
		"// disable if you use external focalDepth value",

		"uniform vec2 focusCoords;",
		"// autofocus point on screen (0.0,0.0 - left lower corner, 1.0,1.0 - upper right)",
		"// if center of screen use vec2(0.5, 0.5);",

		"uniform float maxblur;",
		"//clamp value of max blur (0.0 = no blur, 1.0 default)",

		"uniform float threshold; // highlight threshold;",
		"uniform float gain; // highlight gain;",

		"uniform float bias; // bokeh edge bias",
		"uniform float fringe; // bokeh chromatic aberration / fringing",

		"uniform bool noise; //use noise instead of pattern for sample dithering",

		"uniform float dithering;",

		"uniform bool depthblur; // blur the depth buffer",
		"float dbsize = 1.25; // depth blur size",

		"/*",
		"next part is experimental",
		"not looking good with small sample and ring count",
		"looks okay starting from samples = 4, rings = 4",
		"*/",

		"uniform bool pentagon; //use pentagon as bokeh shape?",
		"float feather = 0.4; //pentagon shape feather",

		"//------------------------------------------",

		"float penta(vec2 coords) {",
			"//pentagonal shape",
			"float scale = float(rings) - 1.3;",
			"vec4  HS0 = vec4( 1.0,         0.0,         0.0,  1.0);",
			"vec4  HS1 = vec4( 0.309016994, 0.951056516, 0.0,  1.0);",
			"vec4  HS2 = vec4(-0.809016994, 0.587785252, 0.0,  1.0);",
			"vec4  HS3 = vec4(-0.809016994,-0.587785252, 0.0,  1.0);",
			"vec4  HS4 = vec4( 0.309016994,-0.951056516, 0.0,  1.0);",
			"vec4  HS5 = vec4( 0.0        ,0.0         , 1.0,  1.0);",

			"vec4  one = vec4( 1.0 );",

			"vec4 P = vec4((coords),vec2(scale, scale));",

			"vec4 dist = vec4(0.0);",
			"float inorout = -4.0;",

			"dist.x = dot( P, HS0 );",
			"dist.y = dot( P, HS1 );",
			"dist.z = dot( P, HS2 );",
			"dist.w = dot( P, HS3 );",

			"dist = smoothstep( -feather, feather, dist );",

			"inorout += dot( dist, one );",

			"dist.x = dot( P, HS4 );",
			"dist.y = HS5.w - abs( P.z );",

			"dist = smoothstep( -feather, feather, dist );",
			"inorout += dist.x;",

			"return clamp( inorout, 0.0, 1.0 );",
		"}",

		"float bdepth(vec2 coords) {",
			"// Depth buffer blur",
			"float d = 0.0;",
			"float kernel[9];",
			"vec2 offset[9];",

			"vec2 wh = vec2(1.0/textureWidth,1.0/textureHeight) * dbsize;",

			"offset[0] = vec2(-wh.x,-wh.y);",
			"offset[1] = vec2( 0.0, -wh.y);",
			"offset[2] = vec2( wh.x -wh.y);",

			"offset[3] = vec2(-wh.x,  0.0);",
			"offset[4] = vec2( 0.0,   0.0);",
			"offset[5] = vec2( wh.x,  0.0);",

			"offset[6] = vec2(-wh.x, wh.y);",
			"offset[7] = vec2( 0.0,  wh.y);",
			"offset[8] = vec2( wh.x, wh.y);",

			"kernel[0] = 1.0/16.0;   kernel[1] = 2.0/16.0;   kernel[2] = 1.0/16.0;",
			"kernel[3] = 2.0/16.0;   kernel[4] = 4.0/16.0;   kernel[5] = 2.0/16.0;",
			"kernel[6] = 1.0/16.0;   kernel[7] = 2.0/16.0;   kernel[8] = 1.0/16.0;",


			"for( int i=0; i<9; i++ ) {",
				"float tmp = texture2D(tDepth, coords + offset[i]).r;",
				"d += tmp * kernel[i];",
			"}",

			"return d;",
		"}",


		"vec3 color(vec2 coords,float blur) {",
			"//processing the sample",

			"vec3 col = vec3(0.0);",
			"vec2 texel = vec2(1.0/textureWidth,1.0/textureHeight);",

			"col.r = texture2D(tColor,coords + vec2(0.0,1.0)*texel*fringe*blur).r;",
			"col.g = texture2D(tColor,coords + vec2(-0.866,-0.5)*texel*fringe*blur).g;",
			"col.b = texture2D(tColor,coords + vec2(0.866,-0.5)*texel*fringe*blur).b;",

			"vec3 lumcoeff = vec3(0.299,0.587,0.114);",
			"float lum = dot(col.rgb, lumcoeff);",
			"float thresh = max((lum-threshold)*gain, 0.0);",
			"return col+mix(vec3(0.0),col,thresh*blur);",
		"}",

		"vec2 rand(vec2 coord) {",
			"// generating noise / pattern texture for dithering",

			"float noiseX = ((fract(1.0-coord.s*(textureWidth/2.0))*0.25)+(fract(coord.t*(textureHeight/2.0))*0.75))*2.0-1.0;",
			"float noiseY = ((fract(1.0-coord.s*(textureWidth/2.0))*0.75)+(fract(coord.t*(textureHeight/2.0))*0.25))*2.0-1.0;",

			"if (noise) {",
				"noiseX = clamp(fract(sin(dot(coord ,vec2(12.9898,78.233))) * 43758.5453),0.0,1.0)*2.0-1.0;",
				"noiseY = clamp(fract(sin(dot(coord ,vec2(12.9898,78.233)*2.0)) * 43758.5453),0.0,1.0)*2.0-1.0;",
			"}",

			"return vec2(noiseX,noiseY);",
		"}",

		"vec3 debugFocus(vec3 col, float blur, float depth) {",
			"float edge = 0.002*depth; //distance based edge smoothing",
			"float m = clamp(smoothstep(0.0,edge,blur),0.0,1.0);",
			"float e = clamp(smoothstep(1.0-edge,1.0,blur),0.0,1.0);",

			"col = mix(col,vec3(1.0,0.5,0.0),(1.0-m)*0.6);",
			"col = mix(col,vec3(0.0,0.5,1.0),((1.0-e)-(1.0-m))*0.2);",

			"return col;",
		"}",

		"float linearize(float depth) {",
			"return -zfar * znear / (depth * (zfar - znear) - zfar);",
		"}",


		"float vignette() {",
			"float dist = distance(vUv.xy, vec2(0.5,0.5));",
			"dist = smoothstep(vignout+(fstop/vignfade), vignin+(fstop/vignfade), dist);",
			"return clamp(dist,0.0,1.0);",
		"}",

		"float gather(float i, float j, int ringsamples, inout vec3 col, float w, float h, float blur) {",
			"float rings2 = float(rings);",
			"float step = PI*2.0 / float(ringsamples);",
			"float pw = cos(j*step)*i;",
			"float ph = sin(j*step)*i;",
			"float p = 1.0;",
			"if (pentagon) {",
				"p = penta(vec2(pw,ph));",
			"}",
			"col += color(vUv.xy + vec2(pw*w,ph*h), blur) * mix(1.0, i/rings2, bias) * p;",
			"return 1.0 * mix(1.0, i /rings2, bias) * p;",
		"}",

		"void main() {",
			"//scene depth calculation",

			"float depth = linearize(texture2D(tDepth,vUv.xy).x);",

			"// Blur depth?",
			"if (depthblur) {",
				"depth = linearize(bdepth(vUv.xy));",
			"}",

			"//focal plane calculation",

			"float fDepth = focalDepth;",

			"if (shaderFocus) {",

				"fDepth = linearize(texture2D(tDepth,focusCoords).x);",

			"}",

			"// dof blur factor calculation",

			"float blur = 0.0;",

			"if (manualdof) {",
				"float a = depth-fDepth; // Focal plane",
				"float b = (a-fdofstart)/fdofdist; // Far DoF",
				"float c = (-a-ndofstart)/ndofdist; // Near Dof",
				"blur = (a>0.0) ? b : c;",
			"} else {",
				"float f = focalLength; // focal length in mm",
				"float d = fDepth*1000.0; // focal plane in mm",
				"float o = depth*1000.0; // depth in mm",

				"float a = (o*f)/(o-f);",
				"float b = (d*f)/(d-f);",
				"float c = (d-f)/(d*fstop*CoC);",

				"blur = abs(a-b)*c;",
			"}",

			"blur = clamp(blur,0.0,1.0);",

			"// calculation of pattern for dithering",

			"vec2 noise = rand(vUv.xy)*dithering*blur;",

			"// getting blur x and y step factor",

			"float w = (1.0/textureWidth)*blur*maxblur+noise.x;",
			"float h = (1.0/textureHeight)*blur*maxblur+noise.y;",

			"// calculation of final color",

			"vec3 col = vec3(0.0);",

			"if(blur < 0.05) {",
				"//some optimization thingy",
				"col = texture2D(tColor, vUv.xy).rgb;",
			"} else {",
				"col = texture2D(tColor, vUv.xy).rgb;",
				"float s = 1.0;",
				"int ringsamples;",

				"for (int i = 1; i <= rings; i++) {",
					"/*unboxstart*/",
					"ringsamples = i * samples;",

					"for (int j = 0 ; j < maxringsamples ; j++) {",
						"if (j >= ringsamples) break;",
						"s += gather(float(i), float(j), ringsamples, col, w, h, blur);",
					"}",
					"/*unboxend*/",
				"}",

				"col /= s; //divide by sample count",
			"}",

			"if (showFocus) {",
				"col = debugFocus(col, blur, depth);",
			"}",

			"if (vignetting) {",
				"col *= vignette();",
			"}",

			"gl_FragColor.rgb = col;",
			"gl_FragColor.a = 1.0;",
		"} "

	].join( "\n" )

};
