Chromatic dispersion refraction hack

gistfile1.js

	function generateFragmentShader( maxDirLights, maxPointLights ) {

		var chunks = [

			"#ifdef GL_ES",
			"precision highp float;",
			"#endif",

			maxDirLights   ? "#define MAX_DIR_LIGHTS " + maxDirLights     : "",
			maxPointLights ? "#define MAX_POINT_LIGHTS " + maxPointLights : "",

			"uniform int material;", // 0 - Basic, 1 - Lambert, 2 - Phong, 3 - Depth, 4 - Normal, 5 - Cube

			"uniform bool enableMap;",
			"uniform bool enableCubeMap;",
			"uniform bool mixEnvMap;",

			"uniform samplerCube tCube;",
			"uniform float mReflectivity;",

			"uniform sampler2D tMap;",
			"uniform vec4 mColor;",
			"uniform float mOpacity;",

			"uniform vec4 mAmbient;",
			"uniform vec4 mSpecular;",
			"uniform float mShininess;",

			"uniform float m2Near;",
			"uniform float mFarPlusNear;",
			"uniform float mFarMinusNear;",

			"uniform int pointLightNumber;",
			"uniform int directionalLightNumber;",

			maxDirLights ? "uniform mat4 viewMatrix;" : "",
			maxDirLights ? "uniform vec3 directionalLightDirection[ MAX_DIR_LIGHTS ];" : "",

			"varying vec3 vNormal;",
			"varying vec2 vUv;",

			"varying vec3 vLightWeighting;",

			maxPointLights ? "varying vec3 vPointLightVector[ MAX_POINT_LIGHTS ];"     : "",

			"varying vec3 vViewPosition;",

			"varying vec3 vReflect[3];",

			"uniform vec3 cameraPosition;",

			"void main() {",

				"vec4 mapColor = vec4( 1.0, 1.0, 1.0, 1.0 );",
				"vec4 cubeColor = vec4( 1.0, 1.0, 1.0, 1.0 );",

				// diffuse map

				"if ( enableMap ) {",

					"mapColor = texture2D( tMap, vUv );",

				"}",

				// cube map

				"if ( enableCubeMap ) {",

					// "cubeColor = textureCube( tCube, vec3( -vReflect.x, vReflect.yz ) );",
					"cubeColor.r = textureCube( tCube, vec3( -vReflect[0].x, vReflect[0].yz ) ).r;",
					"cubeColor.g = textureCube( tCube, vec3( -vReflect[1].x, vReflect[1].yz ) ).g;",
					"cubeColor.b = textureCube( tCube, vec3( -vReflect[2].x, vReflect[2].yz ) ).b;",

				"}",

				// Cube

				"if ( material == 5 ) { ",

					"vec3 wPos = cameraPosition - vViewPosition;",
					"gl_FragColor = textureCube( tCube, vec3( -wPos.x, wPos.yz ) );",

				// Normals

				"} else if ( material == 4 ) { ",

					"gl_FragColor = vec4( 0.5*normalize( vNormal ) + vec3(0.5, 0.5, 0.5), mOpacity );",

				// Depth

				"} else if ( material == 3 ) { ",

					// this breaks shader validation in Chrome 9.0.576.0 dev
					// and also latest continuous build Chromium 9.0.583.0 (66089)
					// (curiously it works in Chrome 9.0.576.0 canary build and Firefox 4b7)
					//"float w = 1.0 - ( m2Near / ( mFarPlusNear - gl_FragCoord.z * mFarMinusNear ) );",
					"float w = 0.5;",

					"gl_FragColor = vec4( w, w, w, mOpacity );",

				// Blinn-Phong
				// based on o3d example

				"} else if ( material == 2 ) { ",

					"vec3 normal = normalize( vNormal );",
					"vec3 viewPosition = normalize( vViewPosition );",

					// point lights

					maxPointLights ? "vec4 pointDiffuse  = vec4( 0.0, 0.0, 0.0, 0.0 );" : "",
					maxPointLights ? "vec4 pointSpecular = vec4( 0.0, 0.0, 0.0, 0.0 );" : "",

					maxPointLights ? "for( int i = 0; i < MAX_POINT_LIGHTS; i++ ) {" : "",

					maxPointLights ? 	"vec3 pointVector = normalize( vPointLightVector[ i ] );" : "",
					maxPointLights ? 	"vec3 pointHalfVector = normalize( vPointLightVector[ i ] + vViewPosition );" : "",

					maxPointLights ? 	"float pointDotNormalHalf = dot( normal, pointHalfVector );" : "",
					maxPointLights ? 	"float pointDiffuseWeight = max( dot( normal, pointVector ), 0.0 );" : "",

					// Ternary conditional is from the original o3d shader. Here it produces abrupt dark cutoff artefacts.
					// Using just pow works ok in Chrome, but makes different artefact in Firefox 4.
					// Zeroing on negative pointDotNormalHalf seems to work in both.

					//"float specularCompPoint = dot( normal, pointVector ) < 0.0 || pointDotNormalHalf < 0.0 ? 0.0 : pow( pointDotNormalHalf, mShininess );",
					//"float specularCompPoint = pow( pointDotNormalHalf, mShininess );",
					//"float pointSpecularWeight = pointDotNormalHalf < 0.0 ? 0.0 : pow( pointDotNormalHalf, mShininess );",

					// Ternary conditional inside for loop breaks Chrome shader linking.
					// Must do it with if.

					maxPointLights ? 	"float pointSpecularWeight = 0.0;" : "",
					maxPointLights ? 	"if ( pointDotNormalHalf >= 0.0 )" : "",
					maxPointLights ? 		"pointSpecularWeight = pow( pointDotNormalHalf, mShininess );" : "",

					maxPointLights ? 	"pointDiffuse  += mColor * pointDiffuseWeight;" : "",
					maxPointLights ? 	"pointSpecular += mSpecular * pointSpecularWeight;" : "",

					maxPointLights ? "}" : "",

					// directional lights

					maxDirLights ? "vec4 dirDiffuse  = vec4( 0.0, 0.0, 0.0, 0.0 );" : "",
					maxDirLights ? "vec4 dirSpecular = vec4( 0.0, 0.0, 0.0, 0.0 );" : "",

					maxDirLights ? "for( int i = 0; i < MAX_DIR_LIGHTS; i++ ) {" : "",

					maxDirLights ?		"vec4 lDirection = viewMatrix * vec4( directionalLightDirection[ i ], 0.0 );" : "",

					maxDirLights ? 		"vec3 dirVector = normalize( lDirection.xyz );" : "",
					maxDirLights ? 		"vec3 dirHalfVector = normalize( lDirection.xyz + vViewPosition );" : "",

					maxDirLights ? 		"float dirDotNormalHalf = dot( normal, dirHalfVector );" : "",

					maxDirLights ? 		"float dirDiffuseWeight = max( dot( normal, dirVector ), 0.0 );" : "",

					maxDirLights ? 		"float dirSpecularWeight = 0.0;" : "",
					maxDirLights ? 		"if ( dirDotNormalHalf >= 0.0 )" : "",
					maxDirLights ? 			"dirSpecularWeight = pow( dirDotNormalHalf, mShininess );" : "",

					maxDirLights ? 		"dirDiffuse  += mColor * dirDiffuseWeight;" : "",
					maxDirLights ? 		"dirSpecular += mSpecular * dirSpecularWeight;" : "",

					maxDirLights ? "}" : "",

					// all lights contribution summation

					"vec4 totalLight = mAmbient;",
					maxDirLights   ? "totalLight += dirDiffuse + dirSpecular;" : "",
					maxPointLights ? "totalLight += pointDiffuse + pointSpecular;" : "",

					// looks nicer with weighting

					"if ( mixEnvMap ) {",

						"gl_FragColor = vec4( mix( mapColor.rgb * totalLight.xyz * vLightWeighting, cubeColor.rgb, mReflectivity ), mapColor.a );",

					"} else {",

						"gl_FragColor = vec4( mapColor.rgb * cubeColor.rgb * totalLight.xyz * vLightWeighting, mapColor.a );",

					"}",

				// Lambert: diffuse lighting

				"} else if ( material == 1 ) {",

				"if ( mixEnvMap ) {",

						"gl_FragColor = vec4( mix( mColor.rgb * mapColor.rgb * vLightWeighting, cubeColor.rgb, mReflectivity ), mColor.a * mapColor.a );",

					"} else {",

						"gl_FragColor = vec4( mColor.rgb * mapColor.rgb * cubeColor.rgb * vLightWeighting, mColor.a * mapColor.a );",

					"}",

				// Basic: unlit color / texture

				"} else {",

					"if ( mixEnvMap ) {",

						"gl_FragColor = mix( mColor * mapColor, cubeColor, mReflectivity );",

					"} else {",

						"gl_FragColor = mColor * mapColor * cubeColor;",

					"}",

				"}",

			"}" ];

		return chunks.join("\n");

	};

	function generateVertexShader( maxDirLights, maxPointLights ) {

		var chunks = [

			maxDirLights   ? "#define MAX_DIR_LIGHTS " + maxDirLights     : "",
			maxPointLights ? "#define MAX_POINT_LIGHTS " + maxPointLights : "",

			"attribute vec3 position;",
			"attribute vec3 normal;",
			"attribute vec2 uv;",

			"uniform vec3 cameraPosition;",

			"uniform bool enableLighting;",
			"uniform bool useRefract;",

			"uniform int pointLightNumber;",
			"uniform int directionalLightNumber;",

			"uniform vec3 ambientLightColor;",

			maxDirLights ? "uniform vec3 directionalLightColor[ MAX_DIR_LIGHTS ];"     : "",
			maxDirLights ? "uniform vec3 directionalLightDirection[ MAX_DIR_LIGHTS ];" : "",

			maxPointLights ? "uniform vec3 pointLightColor[ MAX_POINT_LIGHTS ];"    : "",
			maxPointLights ? "uniform vec3 pointLightPosition[ MAX_POINT_LIGHTS ];" : "",

			"uniform mat4 objMatrix;",
			"uniform mat4 viewMatrix;",
			"uniform mat4 modelViewMatrix;",
			"uniform mat4 projectionMatrix;",
			"uniform mat3 normalMatrix;",

			"varying vec3 vNormal;",
			"varying vec2 vUv;",

			"varying vec3 vLightWeighting;",

			maxPointLights ? "varying vec3 vPointLightVector[ MAX_POINT_LIGHTS ];"     : "",

			"varying vec3 vViewPosition;",

			"varying vec3 vReflect[3];",
			"uniform float mRefractionRatio;",

			"void main(void) {",

				// world space

				"vec4 mPosition = objMatrix * vec4( position, 1.0 );",
				"vViewPosition = cameraPosition - mPosition.xyz;",

				// this doesn't work on Mac
				//"vec3 nWorld = mat3(objMatrix) * normal;",
				"vec3 nWorld = mat3( objMatrix[0].xyz, objMatrix[1].xyz, objMatrix[2].xyz ) * normal;",

				// eye space

				"vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );",
				"vec3 transformedNormal = normalize( normalMatrix * normal );",

				"if ( !enableLighting ) {",

					"vLightWeighting = vec3( 1.0, 1.0, 1.0 );",

				"} else {",

					"vLightWeighting = ambientLightColor;",

					// directional lights

					maxDirLights ? "for( int i = 0; i < MAX_DIR_LIGHTS; i++ ) {" : "",
					maxDirLights ?		"vec4 lDirection = viewMatrix * vec4( directionalLightDirection[ i ], 0.0 );" : "",
					maxDirLights ?		"float directionalLightWeighting = max( dot( transformedNormal, normalize(lDirection.xyz ) ), 0.0 );" : "",
					maxDirLights ?		"vLightWeighting += directionalLightColor[ i ] * directionalLightWeighting;" : "",
					maxDirLights ? "}" : "",

					// point lights

					maxPointLights ? "for( int i = 0; i < MAX_POINT_LIGHTS; i++ ) {" : "",
					maxPointLights ? 	"vec4 lPosition = viewMatrix * vec4( pointLightPosition[ i ], 1.0 );" : "",
					maxPointLights ? 	"vPointLightVector[ i ] = normalize( lPosition.xyz - mvPosition.xyz );" : "",
					maxPointLights ? 	"float pointLightWeighting = max( dot( transformedNormal, vPointLightVector[ i ] ), 0.0 );" : "",
					maxPointLights ? 	"vLightWeighting += pointLightColor[ i ] * pointLightWeighting;" : "",
					maxPointLights ? "}" : "",

				"}",

				"vNormal = transformedNormal;",
				"vUv = uv;",

				"if ( useRefract ) {",

					"vReflect[0] = refract( normalize(mPosition.xyz - cameraPosition), normalize(nWorld.xyz), mRefractionRatio );",
					"vReflect[1] = refract( normalize(mPosition.xyz - cameraPosition), normalize(nWorld.xyz), mRefractionRatio*0.9 );",
					"vReflect[2] = refract( normalize(mPosition.xyz - cameraPosition), normalize(nWorld.xyz), mRefractionRatio*0.8 );",

				"} else {",

					"vReflect[0] = reflect( normalize(mPosition.xyz - cameraPosition), normalize(nWorld.xyz) );",
					"vReflect[1] = reflect( normalize(mPosition.xyz - cameraPosition), normalize(nWorld.xyz) );",
					"vReflect[2] = reflect( normalize(mPosition.xyz - cameraPosition), normalize(nWorld.xyz) );",

				"}",

				"gl_Position = projectionMatrix * mvPosition;",

			"}" ];

		return chunks.join("\n");

	};