THREE.WebGLProgram = ( function () {

	var programIdCount = 0;

	// TODO: Combine the regex
	var structRe = /^([\w\d_]+)\.([\w\d_]+)$/;
	var arrayStructRe = /^([\w\d_]+)\[(\d+)\]\.([\w\d_]+)$/;
	var arrayRe = /^([\w\d_]+)\[0\]$/;

	function getEncodingComponents( encoding ) {

		switch ( encoding ) {

			case THREE.LinearEncoding:
				return [ 'Linear','( value )' ];
			case THREE.sRGBEncoding:
				return [ 'sRGB','( value )' ];
			case THREE.RGBEEncoding:
				return [ 'RGBE','( value )' ];
			case THREE.RGBM7Encoding:
				return [ 'RGBM','( value, 7.0 )' ];
			case THREE.RGBM16Encoding:
				return [ 'RGBM','( value, 16.0 )' ];
			case THREE.RGBDEncoding:
				return [ 'RGBD','( value, 256.0 )' ];
			case THREE.GammaEncoding:
				return [ 'Gamma','( value, float( GAMMA_FACTOR ) )' ];
			default:
				throw new Error( 'unsupported encoding: ' + encoding );

		}

	}

	function getTexelDecodingFunction( functionName, encoding ) {

		var components = getEncodingComponents( encoding );
		return "vec4 " + functionName + "( vec4 value ) { return " + components[ 0 ] + "ToLinear" + components[ 1 ] + "; }";

	}

	function getTexelEncodingFunction( functionName, encoding ) {

		var components = getEncodingComponents( encoding );
		return "vec4 " + functionName + "( vec4 value ) { return LinearTo" + components[ 0 ] + components[ 1 ] + "; }";

	}

	function getToneMappingFunction( functionName, toneMapping ) {

		var toneMappingName;

		switch ( toneMapping ) {

			case THREE.LinearToneMapping:
				toneMappingName = "Linear";
				break;

			case THREE.ReinhardToneMapping:
				toneMappingName = "Reinhard";
				break;

			case THREE.Uncharted2ToneMapping:
				toneMappingName = "Uncharted2";
				break;

			case THREE.CineonToneMapping:
				toneMappingName = "OptimizedCineon";
				break;

			default:
				throw new Error( 'unsupported toneMapping: ' + toneMapping );

		}

		return "vec3 " + functionName + "( vec3 color ) { return " + toneMappingName + "ToneMapping( color ); }";

	}

	function generateExtensions( extensions, parameters, rendererExtensions ) {

		extensions = extensions || {};

		var chunks = [
			( extensions.derivatives || parameters.envMapCubeUV || parameters.bumpMap || parameters.normalMap || parameters.flatShading ) ? '#extension GL_OES_standard_derivatives : enable' : '',
			( extensions.fragDepth || parameters.logarithmicDepthBuffer ) && rendererExtensions.get( 'EXT_frag_depth' ) ? '#extension GL_EXT_frag_depth : enable' : '',
			( extensions.drawBuffers ) && rendererExtensions.get( 'WEBGL_draw_buffers' ) ? '#extension GL_EXT_draw_buffers : require' : '',
			( extensions.shaderTextureLOD || parameters.envMap ) && rendererExtensions.get( 'EXT_shader_texture_lod' ) ? '#extension GL_EXT_shader_texture_lod : enable' : '',
		];

		return chunks.filter( filterEmptyLine ).join( '\n' );

	}

	function generateDefines( defines ) {

		var chunks = [];

		for ( var name in defines ) {

			var value = defines[ name ];

			if ( value === false ) continue;

			chunks.push( '#define ' + name + ' ' + value );

		}

		return chunks.join( '\n' );

	}

	function fetchUniformLocations( gl, program, identifiers ) {

		var uniforms = {};

		var n = gl.getProgramParameter( program, gl.ACTIVE_UNIFORMS );

		for ( var i = 0; i < n; i ++ ) {

			var info = gl.getActiveUniform( program, i );
			var name = info.name;
			var location = gl.getUniformLocation( program, name );

			//console.log("THREE.WebGLProgram: ACTIVE UNIFORM:", name);

			var matches = structRe.exec( name );
			if ( matches ) {

				var structName = matches[ 1 ];
				var structProperty = matches[ 2 ];

				var uniformsStruct = uniforms[ structName ];

				if ( ! uniformsStruct ) {

					uniformsStruct = uniforms[ structName ] = {};

				}

				uniformsStruct[ structProperty ] = location;

				continue;

			}

			matches = arrayStructRe.exec( name );

			if ( matches ) {

				var arrayName = matches[ 1 ];
				var arrayIndex = matches[ 2 ];
				var arrayProperty = matches[ 3 ];

				var uniformsArray = uniforms[ arrayName ];

				if ( ! uniformsArray ) {

					uniformsArray = uniforms[ arrayName ] = [];

				}

				var uniformsArrayIndex = uniformsArray[ arrayIndex ];

				if ( ! uniformsArrayIndex ) {

					uniformsArrayIndex = uniformsArray[ arrayIndex ] = {};

				}

				uniformsArrayIndex[ arrayProperty ] = location;

				continue;

			}

			matches = arrayRe.exec( name );

			if ( matches ) {

				var arrayName = matches[ 1 ];

				uniforms[ arrayName ] = location;

				continue;

			}

			uniforms[ name ] = location;

		}

		return uniforms;

	}

	function fetchAttributeLocations( gl, program, identifiers ) {

		var attributes = {};

		var n = gl.getProgramParameter( program, gl.ACTIVE_ATTRIBUTES );

		for ( var i = 0; i < n; i ++ ) {

			var info = gl.getActiveAttrib( program, i );
			var name = info.name;

			// console.log("THREE.WebGLProgram: ACTIVE VERTEX ATTRIBUTE:", name, i );

			attributes[ name ] = gl.getAttribLocation( program, name );

		}

		return attributes;

	}

	function filterEmptyLine( string ) {

		return string !== '';

	}

	function replaceLightNums( string, parameters ) {

		return string
			.replace( /NUM_DIR_LIGHTS/g, parameters.numDirLights )
			.replace( /NUM_SPOT_LIGHTS/g, parameters.numSpotLights )
			.replace( /NUM_POINT_LIGHTS/g, parameters.numPointLights )
			.replace( /NUM_HEMI_LIGHTS/g, parameters.numHemiLights );

	}

	function parseIncludes( string ) {

		var pattern = /#include +<([\w\d.]+)>/g;

		function replace( match, include ) {

			var replace = THREE.ShaderChunk[ include ];

			if ( replace === undefined ) {

				throw new Error( 'Can not resolve #include <' + include + '>' );

			}

			return parseIncludes( replace );

		}

		return string.replace( pattern, replace );

	}

	function unrollLoops( string ) {

		var pattern = /for \( int i \= (\d+)\; i < (\d+)\; i \+\+ \) \{([\s\S]+?)(?=\})\}/g;

		function replace( match, start, end, snippet ) {

			var unroll = '';

			for ( var i = parseInt( start ); i < parseInt( end ); i ++ ) {

				unroll += snippet.replace( /\[ i \]/g, '[ ' + i + ' ]' );

			}

			return unroll;

		}

		return string.replace( pattern, replace );

	}

	return function WebGLProgram( renderer, code, material, parameters ) {

		var gl = renderer.context;

		var extensions = material.extensions;
		var defines = material.defines;

		var vertexShader = material.__webglShader.vertexShader;
		var fragmentShader = material.__webglShader.fragmentShader;

		var shadowMapTypeDefine = 'SHADOWMAP_TYPE_BASIC';

		if ( parameters.shadowMapType === THREE.PCFShadowMap ) {

			shadowMapTypeDefine = 'SHADOWMAP_TYPE_PCF';

		} else if ( parameters.shadowMapType === THREE.PCFSoftShadowMap ) {

			shadowMapTypeDefine = 'SHADOWMAP_TYPE_PCF_SOFT';

		}

		var envMapTypeDefine = 'ENVMAP_TYPE_CUBE';
		var envMapModeDefine = 'ENVMAP_MODE_REFLECTION';
		var envMapBlendingDefine = 'ENVMAP_BLENDING_MULTIPLY';

		if ( parameters.envMap ) {

			switch ( material.envMap.mapping ) {

				case THREE.CubeReflectionMapping:
				case THREE.CubeRefractionMapping:
					envMapTypeDefine = 'ENVMAP_TYPE_CUBE';
					break;

				case THREE.CubeUVReflectionMapping:
				case THREE.CubeUVRefractionMapping:
					envMapTypeDefine = 'ENVMAP_TYPE_CUBE_UV';
					break;

				case THREE.EquirectangularReflectionMapping:
				case THREE.EquirectangularRefractionMapping:
					envMapTypeDefine = 'ENVMAP_TYPE_EQUIREC';
					break;

				case THREE.SphericalReflectionMapping:
					envMapTypeDefine = 'ENVMAP_TYPE_SPHERE';
					break;

			}

			switch ( material.envMap.mapping ) {

				case THREE.CubeRefractionMapping:
				case THREE.EquirectangularRefractionMapping:
					envMapModeDefine = 'ENVMAP_MODE_REFRACTION';
					break;

			}

			switch ( material.combine ) {

				case THREE.MultiplyOperation:
					envMapBlendingDefine = 'ENVMAP_BLENDING_MULTIPLY';
					break;

				case THREE.MixOperation:
					envMapBlendingDefine = 'ENVMAP_BLENDING_MIX';
					break;

				case THREE.AddOperation:
					envMapBlendingDefine = 'ENVMAP_BLENDING_ADD';
					break;

			}

		}

		var gammaFactorDefine = ( renderer.gammaFactor > 0 ) ? renderer.gammaFactor : 1.0;

		// console.log( 'building new program ' );

		//

		var customExtensions = generateExtensions( extensions, parameters, renderer.extensions );

		var customDefines = generateDefines( defines );

		//

		var program = gl.createProgram();

		var prefixVertex, prefixFragment;

		if ( material instanceof THREE.RawShaderMaterial ) {

			prefixVertex = '';
			prefixFragment = '';

		} else {

			prefixVertex = [

				'precision ' + parameters.precision + ' float;',
				'precision ' + parameters.precision + ' int;',

				'#define SHADER_NAME ' + material.__webglShader.name,

				customDefines,

				parameters.supportsVertexTextures ? '#define VERTEX_TEXTURES' : '',

				'#define GAMMA_FACTOR ' + gammaFactorDefine,

				'#define MAX_BONES ' + parameters.maxBones,

				parameters.map ? '#define USE_MAP' : '',
				parameters.envMap ? '#define USE_ENVMAP' : '',
				parameters.envMap ? '#define ' + envMapModeDefine : '',
				parameters.lightMap ? '#define USE_LIGHTMAP' : '',
				parameters.aoMap ? '#define USE_AOMAP' : '',
				parameters.emissiveMap ? '#define USE_EMISSIVEMAP' : '',
				parameters.bumpMap ? '#define USE_BUMPMAP' : '',
				parameters.normalMap ? '#define USE_NORMALMAP' : '',
				parameters.displacementMap && parameters.supportsVertexTextures ? '#define USE_DISPLACEMENTMAP' : '',
				parameters.specularMap ? '#define USE_SPECULARMAP' : '',
				parameters.roughnessMap ? '#define USE_ROUGHNESSMAP' : '',
				parameters.metalnessMap ? '#define USE_METALNESSMAP' : '',
				parameters.alphaMap ? '#define USE_ALPHAMAP' : '',
				parameters.vertexColors ? '#define USE_COLOR' : '',

				parameters.flatShading ? '#define FLAT_SHADED' : '',

				parameters.skinning ? '#define USE_SKINNING' : '',
				parameters.useVertexTexture ? '#define BONE_TEXTURE' : '',

				parameters.morphTargets ? '#define USE_MORPHTARGETS' : '',
				parameters.morphNormals && parameters.flatShading === false ? '#define USE_MORPHNORMALS' : '',
				parameters.doubleSided ? '#define DOUBLE_SIDED' : '',
				parameters.flipSided ? '#define FLIP_SIDED' : '',

				parameters.shadowMapEnabled ? '#define USE_SHADOWMAP' : '',
				parameters.shadowMapEnabled ? '#define ' + shadowMapTypeDefine : '',

				parameters.sizeAttenuation ? '#define USE_SIZEATTENUATION' : '',

				parameters.logarithmicDepthBuffer ? '#define USE_LOGDEPTHBUF' : '',
				parameters.logarithmicDepthBuffer && renderer.extensions.get( 'EXT_frag_depth' ) ? '#define USE_LOGDEPTHBUF_EXT' : '',


				'uniform mat4 modelMatrix;',
				'uniform mat4 modelViewMatrix;',
				'uniform mat4 projectionMatrix;',
				'uniform mat4 viewMatrix;',
				'uniform mat3 normalMatrix;',
				'uniform vec3 cameraPosition;',

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

				'#ifdef USE_COLOR',

				'	attribute vec3 color;',

				'#endif',

				'#ifdef USE_MORPHTARGETS',

				'	attribute vec3 morphTarget0;',
				'	attribute vec3 morphTarget1;',
				'	attribute vec3 morphTarget2;',
				'	attribute vec3 morphTarget3;',

				'	#ifdef USE_MORPHNORMALS',

				'		attribute vec3 morphNormal0;',
				'		attribute vec3 morphNormal1;',
				'		attribute vec3 morphNormal2;',
				'		attribute vec3 morphNormal3;',

				'	#else',

				'		attribute vec3 morphTarget4;',
				'		attribute vec3 morphTarget5;',
				'		attribute vec3 morphTarget6;',
				'		attribute vec3 morphTarget7;',

				'	#endif',

				'#endif',

				'#ifdef USE_SKINNING',

				'	attribute vec4 skinIndex;',
				'	attribute vec4 skinWeight;',

				'#endif',

				'\n'

			].filter( filterEmptyLine ).join( '\n' );

			prefixFragment = [

				customExtensions,

				'precision ' + parameters.precision + ' float;',
				'precision ' + parameters.precision + ' int;',

				'#define SHADER_NAME ' + material.__webglShader.name,

				customDefines,

				parameters.alphaTest ? '#define ALPHATEST ' + parameters.alphaTest : '',

				'#define GAMMA_FACTOR ' + gammaFactorDefine,

				( parameters.useFog && parameters.fog ) ? '#define USE_FOG' : '',
				( parameters.useFog && parameters.fogExp ) ? '#define FOG_EXP2' : '',

				parameters.map ? '#define USE_MAP' : '',
				parameters.envMap ? '#define USE_ENVMAP' : '',
				parameters.envMap ? '#define ' + envMapTypeDefine : '',
				parameters.envMap ? '#define ' + envMapModeDefine : '',
				parameters.envMap ? '#define ' + envMapBlendingDefine : '',
				parameters.lightMap ? '#define USE_LIGHTMAP' : '',
				parameters.aoMap ? '#define USE_AOMAP' : '',
				parameters.emissiveMap ? '#define USE_EMISSIVEMAP' : '',
				parameters.bumpMap ? '#define USE_BUMPMAP' : '',
				parameters.normalMap ? '#define USE_NORMALMAP' : '',
				parameters.specularMap ? '#define USE_SPECULARMAP' : '',
				parameters.roughnessMap ? '#define USE_ROUGHNESSMAP' : '',
				parameters.metalnessMap ? '#define USE_METALNESSMAP' : '',
				parameters.alphaMap ? '#define USE_ALPHAMAP' : '',
				parameters.vertexColors ? '#define USE_COLOR' : '',

				parameters.flatShading ? '#define FLAT_SHADED' : '',

				parameters.doubleSided ? '#define DOUBLE_SIDED' : '',
				parameters.flipSided ? '#define FLIP_SIDED' : '',

				parameters.shadowMapEnabled ? '#define USE_SHADOWMAP' : '',
				parameters.shadowMapEnabled ? '#define ' + shadowMapTypeDefine : '',

				parameters.premultipliedAlpha ? "#define PREMULTIPLIED_ALPHA" : '',

				parameters.physicallyCorrectLights ? "#define PHYSICALLY_CORRECT_LIGHTS" : '',

				parameters.logarithmicDepthBuffer ? '#define USE_LOGDEPTHBUF' : '',
				parameters.logarithmicDepthBuffer && renderer.extensions.get( 'EXT_frag_depth' ) ? '#define USE_LOGDEPTHBUF_EXT' : '',

				parameters.envMap && renderer.extensions.get( 'EXT_shader_texture_lod' ) ? '#define TEXTURE_LOD_EXT' : '',

				'uniform mat4 viewMatrix;',
				'uniform vec3 cameraPosition;',

				( parameters.toneMapping !== THREE.NoToneMapping ) ? "#define TONE_MAPPING" : '',
				( parameters.toneMapping !== THREE.NoToneMapping ) ? THREE.ShaderChunk[ 'tonemapping_pars_fragment' ] : '',  // this code is required here because it is used by the toneMapping() function defined below
				( parameters.toneMapping !== THREE.NoToneMapping ) ? getToneMappingFunction( "toneMapping", parameters.toneMapping ) : '',

				( parameters.outputEncoding || parameters.mapEncoding || parameters.envMapEncoding || parameters.emissiveMapEncoding ) ? THREE.ShaderChunk[ 'encodings_pars_fragment' ] : '', // this code is required here because it is used by the various encoding/decoding function defined below
				parameters.mapEncoding ? getTexelDecodingFunction( 'mapTexelToLinear', parameters.mapEncoding ) : '',
				parameters.envMapEncoding ? getTexelDecodingFunction( 'envMapTexelToLinear', parameters.envMapEncoding ) : '',
				parameters.emissiveMapEncoding ? getTexelDecodingFunction( 'emissiveMapTexelToLinear', parameters.emissiveMapEncoding ) : '',
				parameters.outputEncoding ? getTexelEncodingFunction( "linearToOutputTexel", parameters.outputEncoding ) : '',

				'\n'

			].filter( filterEmptyLine ).join( '\n' );

		}

		vertexShader = parseIncludes( vertexShader, parameters );
		vertexShader = replaceLightNums( vertexShader, parameters );

		fragmentShader = parseIncludes( fragmentShader, parameters );
		fragmentShader = replaceLightNums( fragmentShader, parameters );

		if ( material instanceof THREE.ShaderMaterial === false ) {

			vertexShader = unrollLoops( vertexShader );
			fragmentShader = unrollLoops( fragmentShader );

		}

		var vertexGlsl = prefixVertex + vertexShader;
		var fragmentGlsl = prefixFragment + fragmentShader;

		// console.log( '*VERTEX*', vertexGlsl );
		// console.log( '*FRAGMENT*', fragmentGlsl );

		var glVertexShader = THREE.WebGLShader( gl, gl.VERTEX_SHADER, vertexGlsl );
		var glFragmentShader = THREE.WebGLShader( gl, gl.FRAGMENT_SHADER, fragmentGlsl );

		gl.attachShader( program, glVertexShader );
		gl.attachShader( program, glFragmentShader );

		// Force a particular attribute to index 0.

		if ( material.index0AttributeName !== undefined ) {

			gl.bindAttribLocation( program, 0, material.index0AttributeName );

		} else if ( parameters.morphTargets === true ) {

			// programs with morphTargets displace position out of attribute 0
			gl.bindAttribLocation( program, 0, 'position' );

		}

		gl.linkProgram( program );

		var programLog = gl.getProgramInfoLog( program );
		var vertexLog = gl.getShaderInfoLog( glVertexShader );
		var fragmentLog = gl.getShaderInfoLog( glFragmentShader );

		var runnable = true;
		var haveDiagnostics = true;

		// console.log( '**VERTEX**', gl.getExtension( 'WEBGL_debug_shaders' ).getTranslatedShaderSource( glVertexShader ) );
		// console.log( '**FRAGMENT**', gl.getExtension( 'WEBGL_debug_shaders' ).getTranslatedShaderSource( glFragmentShader ) );

		if ( gl.getProgramParameter( program, gl.LINK_STATUS ) === false ) {

			runnable = false;

			console.error( 'THREE.WebGLProgram: shader error: ', gl.getError(), 'gl.VALIDATE_STATUS', gl.getProgramParameter( program, gl.VALIDATE_STATUS ), 'gl.getProgramInfoLog', programLog, vertexLog, fragmentLog );

		} else if ( programLog !== '' ) {

			console.warn( 'THREE.WebGLProgram: gl.getProgramInfoLog()', programLog );

		} else if ( vertexLog === '' || fragmentLog === '' ) {

			haveDiagnostics = false;

		}

		if ( haveDiagnostics ) {

			this.diagnostics = {

				runnable: runnable,
				material: material,

				programLog: programLog,

				vertexShader: {

					log: vertexLog,
					prefix: prefixVertex

				},

				fragmentShader: {

					log: fragmentLog,
					prefix: prefixFragment

				}

			};

		}

		// clean up

		gl.deleteShader( glVertexShader );
		gl.deleteShader( glFragmentShader );

		// set up caching for uniform locations

		var cachedUniforms;

		this.getUniforms = function() {

			if ( cachedUniforms === undefined ) {

				cachedUniforms = fetchUniformLocations( gl, program );

			}

			return cachedUniforms;

		};

		// set up caching for attribute locations

		var cachedAttributes;

		this.getAttributes = function() {

			if ( cachedAttributes === undefined ) {

				cachedAttributes = fetchAttributeLocations( gl, program );

			}

			return cachedAttributes;

		};

		// free resource

		this.destroy = function() {

			gl.deleteProgram( program );
			this.program = undefined;

		};

		// DEPRECATED

		Object.defineProperties( this, {

			uniforms: {
				get: function() {

					console.warn( 'THREE.WebGLProgram: .uniforms is now .getUniforms().' );
					return this.getUniforms();

				}
			},

			attributes: {
				get: function() {

					console.warn( 'THREE.WebGLProgram: .attributes is now .getAttributes().' );
					return this.getAttributes();

				}
			}

		} );


		//

		this.id = programIdCount ++;
		this.code = code;
		this.usedTimes = 1;
		this.program = program;
		this.vertexShader = glVertexShader;
		this.fragmentShader = glFragmentShader;

		return this;

	};

} )();