WebGLRenderer.js

import { REVISION, MaxEquation, MinEquation, RGB_ETC1_Format, RGBA_PVRTC_2BPPV1_Format, RGBA_PVRTC_4BPPV1_Format, RGB_PVRTC_2BPPV1_Format, RGB_PVRTC_4BPPV1_Format, RGBA_S3TC_DXT5_Format, RGBA_S3TC_DXT3_Format, RGBA_S3TC_DXT1_Format, RGB_S3TC_DXT1_Format, SrcAlphaSaturateFactor, OneMinusDstColorFactor, DstColorFactor, OneMinusDstAlphaFactor, DstAlphaFactor, OneMinusSrcAlphaFactor, SrcAlphaFactor, OneMinusSrcColorFactor, SrcColorFactor, OneFactor, ZeroFactor, ReverseSubtractEquation, SubtractEquation, AddEquation, DepthFormat, DepthStencilFormat, LuminanceAlphaFormat, LuminanceFormat, RGBAFormat, RGBFormat, AlphaFormat, HalfFloatType, FloatType, UnsignedIntType, IntType, UnsignedShortType, ShortType, ByteType, UnsignedInt248Type, UnsignedShort565Type, UnsignedShort5551Type, UnsignedShort4444Type, UnsignedByteType, LinearMipMapLinearFilter, LinearMipMapNearestFilter, LinearFilter, NearestMipMapLinearFilter, NearestMipMapNearestFilter, NearestFilter, MirroredRepeatWrapping, ClampToEdgeWrapping, RepeatWrapping, FrontFaceDirectionCW, NoBlending, BackSide, DoubleSide, TriangleFanDrawMode, TriangleStripDrawMode, TrianglesDrawMode, NoColors, FlatShading, LinearToneMapping } from '../constants';
import { Matrix4 } from '../math/Matrix4';
import { WebGLUniforms } from './webgl/WebGLUniforms';
import { UniformsUtils } from './shaders/UniformsUtils';
import { ShaderLib } from './shaders/ShaderLib';
import { LensFlarePlugin } from './webgl/plugins/LensFlarePlugin';
import { SpritePlugin } from './webgl/plugins/SpritePlugin';
import { WebGLShadowMap } from './webgl/WebGLShadowMap';
import { ShaderMaterial } from '../materials/ShaderMaterial';
import { Mesh } from '../objects/Mesh';
import { BoxBufferGeometry } from '../geometries/BoxGeometry';
import { PlaneBufferGeometry } from '../geometries/PlaneGeometry';
import { MeshBasicMaterial } from '../materials/MeshBasicMaterial';
import { PerspectiveCamera } from '../cameras/PerspectiveCamera';
import { OrthographicCamera } from '../cameras/OrthographicCamera';
import { WebGLAttributes } from './webgl/WebGLAttributes';
import { WebGLIndexedBufferRenderer } from './webgl/WebGLIndexedBufferRenderer';
import { WebGLBufferRenderer } from './webgl/WebGLBufferRenderer';
import { WebGLGeometries } from './webgl/WebGLGeometries';
import { WebGLLights } from './webgl/WebGLLights';
import { WebGLObjects } from './webgl/WebGLObjects';
import { WebGLPrograms } from './webgl/WebGLPrograms';
import { WebGLTextures } from './webgl/WebGLTextures';
import { WebGLProperties } from './webgl/WebGLProperties';
import { WebGLState } from './webgl/WebGLState';
import { WebGLCapabilities } from './webgl/WebGLCapabilities';
import { BufferGeometry } from '../core/BufferGeometry';
import { WebGLExtensions } from './webgl/WebGLExtensions';
import { Vector3 } from '../math/Vector3';
// import { Sphere } from '../math/Sphere';
import { WebGLClipping } from './webgl/WebGLClipping';
import { Frustum } from '../math/Frustum';
import { Vector4 } from '../math/Vector4';
import { Color } from '../math/Color';

/**
 * @author supereggbert / http://www.paulbrunt.co.uk/
 * @author mrdoob / http://mrdoob.com/
 * @author alteredq / http://alteredqualia.com/
 * @author szimek / https://github.com/szimek/
 * @author tschw
 */

function WebGLRenderer( parameters ) {

	console.log( 'THREE.WebGLRenderer', REVISION );

	parameters = parameters || {};

	var _canvas = parameters.canvas !== undefined ? parameters.canvas : document.createElementNS( 'http://www.w3.org/1999/xhtml', 'canvas' ),
		_context = parameters.context !== undefined ? parameters.context : null,

		_alpha = parameters.alpha !== undefined ? parameters.alpha : false,
		_depth = parameters.depth !== undefined ? parameters.depth : true,
		_stencil = parameters.stencil !== undefined ? parameters.stencil : true,
		_antialias = parameters.antialias !== undefined ? parameters.antialias : false,
		_premultipliedAlpha = parameters.premultipliedAlpha !== undefined ? parameters.premultipliedAlpha : true,
		_preserveDrawingBuffer = parameters.preserveDrawingBuffer !== undefined ? parameters.preserveDrawingBuffer : false;

	var lights = [];

	var opaqueObjects = [];
	var opaqueObjectsLastIndex = - 1;
	var transparentObjects = [];
	var transparentObjectsLastIndex = - 1;

	var morphInfluences = new Float32Array( 8 );

	var sprites = [];
	var lensFlares = [];

	// public properties

	this.domElement = _canvas;
	this.context = null;

	// clearing

	this.autoClear = true;
	this.autoClearColor = true;
	this.autoClearDepth = true;
	this.autoClearStencil = true;

	// scene graph

	this.sortObjects = true;

	// user-defined clipping

	this.clippingPlanes = [];
	this.localClippingEnabled = false;

	// physically based shading

	this.gammaFactor = 2.0;	// for backwards compatibility
	this.gammaInput = false;
	this.gammaOutput = false;

	// physical lights

	this.physicallyCorrectLights = false;

	// tone mapping

	this.toneMapping = LinearToneMapping;
	this.toneMappingExposure = 1.0;
	this.toneMappingWhitePoint = 1.0;

	// morphs

	this.maxMorphTargets = 8;
	this.maxMorphNormals = 4;

	// internal properties

	var _this = this,

		// internal state cache

		_currentProgram = null,
		_currentRenderTarget = null,
		_currentFramebuffer = null,
		_currentMaterialId = - 1,
		_currentGeometryProgram = '',
		_currentCamera = null,

		_currentScissor = new Vector4(),
		_currentScissorTest = null,

		_currentViewport = new Vector4(),

		//

		_usedTextureUnits = 0,

		//

		_clearColor = new Color( 0x000000 ),
		_clearAlpha = 0,

		_width = _canvas.width,
		_height = _canvas.height,

		_pixelRatio = 1,

		_scissor = new Vector4( 0, 0, _width, _height ),
		_scissorTest = false,

		_viewport = new Vector4( 0, 0, _width, _height ),

		// frustum

		_frustum = new Frustum(),

		// clipping

		_clipping = new WebGLClipping(),
		_clippingEnabled = false,
		_localClippingEnabled = false,

		// camera matrices cache

		_projScreenMatrix = new Matrix4(),

		_vector3 = new Vector3(),
		_matrix4 = new Matrix4(),
		_matrix42 = new Matrix4(),

		// light arrays cache

		_lights = {

			hash: '',

			ambient: [ 0, 0, 0 ],
			directional: [],
			directionalShadowMap: [],
			directionalShadowMatrix: [],
			spot: [],
			spotShadowMap: [],
			spotShadowMatrix: [],
			rectArea: [],
			point: [],
			pointShadowMap: [],
			pointShadowMatrix: [],
			hemi: [],

			shadows: []

		},

		// info

		_infoMemory = {
			geometries: 0,
			textures: 0
		},

		_infoRender = {

			frame: 0,
			calls: 0,
			vertices: 0,
			faces: 0,
			points: 0

		};

	this.info = {

		render: _infoRender,
		memory: _infoMemory,
		programs: null

	};


	// initialize

	var _gl;

	try {

		var contextAttributes = {
			alpha: _alpha,
			depth: _depth,
			stencil: _stencil,
			antialias: _antialias,
			premultipliedAlpha: _premultipliedAlpha,
			preserveDrawingBuffer: _preserveDrawingBuffer
		};

		_gl = _context || _canvas.getContext( 'webgl', contextAttributes ) || _canvas.getContext( 'experimental-webgl', contextAttributes );

		if ( _gl === null ) {

			if ( _canvas.getContext( 'webgl' ) !== null ) {

				throw 'Error creating WebGL context with your selected attributes.';

			} else {

				throw 'Error creating WebGL context.';

			}

		}

		// Some experimental-webgl implementations do not have getShaderPrecisionFormat

		if ( _gl.getShaderPrecisionFormat === undefined ) {

			_gl.getShaderPrecisionFormat = function () {

				return { 'rangeMin': 1, 'rangeMax': 1, 'precision': 1 };

			};

		}

		_canvas.addEventListener( 'webglcontextlost', onContextLost, false );

	} catch ( error ) {

		console.error( 'THREE.WebGLRenderer: ' + error );

	}

	var extensions = new WebGLExtensions( _gl );

	extensions.get( 'WEBGL_depth_texture' );
	extensions.get( 'OES_texture_float' );
	extensions.get( 'OES_texture_float_linear' );
	extensions.get( 'OES_texture_half_float' );
	extensions.get( 'OES_texture_half_float_linear' );
	extensions.get( 'OES_standard_derivatives' );
	extensions.get( 'ANGLE_instanced_arrays' );

	if ( extensions.get( 'OES_element_index_uint' ) ) {

		BufferGeometry.MaxIndex = 4294967296;

	}

	var capabilities = new WebGLCapabilities( _gl, extensions, parameters );

	var state = new WebGLState( _gl, extensions, paramThreeToGL );

	var properties = new WebGLProperties();
	var textures = new WebGLTextures( _gl, extensions, state, properties, capabilities, paramThreeToGL, _infoMemory );
	var attributes = new WebGLAttributes( _gl );
	var geometries = new WebGLGeometries( _gl, attributes, _infoMemory );
	var objects = new WebGLObjects( _gl, geometries, _infoRender );
	var programCache = new WebGLPrograms( this, capabilities );
	var lightCache = new WebGLLights();

	this.info.programs = programCache.programs;

	var bufferRenderer = new WebGLBufferRenderer( _gl, extensions, _infoRender );
	var indexedBufferRenderer = new WebGLIndexedBufferRenderer( _gl, extensions, _infoRender );

	//

	var backgroundPlaneCamera, backgroundPlaneMesh;
	var backgroundBoxCamera, backgroundBoxMesh;

	//

	function getTargetPixelRatio() {

		return _currentRenderTarget === null ? _pixelRatio : 1;

	}

	function setDefaultGLState() {

		state.init();

		state.scissor( _currentScissor.copy( _scissor ).multiplyScalar( _pixelRatio ) );
		state.viewport( _currentViewport.copy( _viewport ).multiplyScalar( _pixelRatio ) );

		state.buffers.color.setClear( _clearColor.r, _clearColor.g, _clearColor.b, _clearAlpha, _premultipliedAlpha );

	}

	function resetGLState() {

		_currentProgram = null;
		_currentCamera = null;

		_currentGeometryProgram = '';
		_currentMaterialId = - 1;

		state.reset();

	}

	setDefaultGLState();

	this.context = _gl;
	this.capabilities = capabilities;
	this.extensions = extensions;
	this.properties = properties;
	this.state = state;

	// shadow map

	var shadowMap = new WebGLShadowMap( this, _lights, objects, capabilities );

	this.shadowMap = shadowMap;


	// Plugins

	var spritePlugin = new SpritePlugin( this, sprites );
	var lensFlarePlugin = new LensFlarePlugin( this, lensFlares );

	// API

	this.getContext = function () {

		return _gl;

	};

	this.getContextAttributes = function () {

		return _gl.getContextAttributes();

	};

	this.forceContextLoss = function () {

		extensions.get( 'WEBGL_lose_context' ).loseContext();

	};

	this.getMaxAnisotropy = function () {

		return capabilities.getMaxAnisotropy();

	};

	this.getPrecision = function () {

		return capabilities.precision;

	};

	this.getPixelRatio = function () {

		return _pixelRatio;

	};

	this.setPixelRatio = function ( value ) {

		if ( value === undefined ) return;

		_pixelRatio = value;

		this.setSize( _viewport.z, _viewport.w, false );

	};

	this.getSize = function () {

		return {
			width: _width,
			height: _height
		};

	};

	this.setSize = function ( width, height, updateStyle ) {

		_width = width;
		_height = height;

		_canvas.width = width * _pixelRatio;
		_canvas.height = height * _pixelRatio;

		if ( updateStyle !== false ) {

			_canvas.style.width = width + 'px';
			_canvas.style.height = height + 'px';

		}

		this.setViewport( 0, 0, width, height );

	};

	this.setViewport = function ( x, y, width, height ) {

		state.viewport( _viewport.set( x, y, width, height ) );

	};

	this.setScissor = function ( x, y, width, height ) {

		state.scissor( _scissor.set( x, y, width, height ) );

	};

	this.setScissorTest = function ( boolean ) {

		state.setScissorTest( _scissorTest = boolean );

	};

	// Clearing

	this.getClearColor = function () {

		return _clearColor;

	};

	this.setClearColor = function ( color, alpha ) {

		_clearColor.set( color );

		_clearAlpha = alpha !== undefined ? alpha : 1;

		state.buffers.color.setClear( _clearColor.r, _clearColor.g, _clearColor.b, _clearAlpha, _premultipliedAlpha );

	};

	this.getClearAlpha = function () {

		return _clearAlpha;

	};

	this.setClearAlpha = function ( alpha ) {

		_clearAlpha = alpha;

		state.buffers.color.setClear( _clearColor.r, _clearColor.g, _clearColor.b, _clearAlpha, _premultipliedAlpha );

	};

	this.clear = function ( color, depth, stencil ) {

		var bits = 0;

		if ( color === undefined || color ) bits |= _gl.COLOR_BUFFER_BIT;
		if ( depth === undefined || depth ) bits |= _gl.DEPTH_BUFFER_BIT;
		if ( stencil === undefined || stencil ) bits |= _gl.STENCIL_BUFFER_BIT;

		_gl.clear( bits );

	};

	this.clearColor = function () {

		this.clear( true, false, false );

	};

	this.clearDepth = function () {

		this.clear( false, true, false );

	};

	this.clearStencil = function () {

		this.clear( false, false, true );

	};

	this.clearTarget = function ( renderTarget, color, depth, stencil ) {

		this.setRenderTarget( renderTarget );
		this.clear( color, depth, stencil );

	};

	// Reset

	this.resetGLState = resetGLState;

	this.dispose = function () {

		transparentObjects = [];
		transparentObjectsLastIndex = - 1;
		opaqueObjects = [];
		opaqueObjectsLastIndex = - 1;

		_canvas.removeEventListener( 'webglcontextlost', onContextLost, false );

	};

	// Events

	function onContextLost( event ) {

		event.preventDefault();

		resetGLState();
		setDefaultGLState();

		properties.clear();

	}

	function onMaterialDispose( event ) {

		var material = event.target;

		material.removeEventListener( 'dispose', onMaterialDispose );

		deallocateMaterial( material );

	}

	// Buffer deallocation

	function deallocateMaterial( material ) {

		releaseMaterialProgramReference( material );

		properties.remove( material );

	}


	function releaseMaterialProgramReference( material ) {

		var programInfo = properties.get( material ).program;

		material.program = undefined;

		if ( programInfo !== undefined ) {

			programCache.releaseProgram( programInfo );

		}

	}

	// Buffer rendering

	function renderObjectImmediate( object, program, material ) {

		object.render( function ( object ) {

			_this.renderBufferImmediate( object, program, material );

		} );

	}

	this.renderBufferImmediate = function ( object, program, material ) {

		state.initAttributes();

		var buffers = properties.get( object );

		if ( object.hasPositions && ! buffers.position ) buffers.position = _gl.createBuffer();
		if ( object.hasNormals && ! buffers.normal ) buffers.normal = _gl.createBuffer();
		if ( object.hasUvs && ! buffers.uv ) buffers.uv = _gl.createBuffer();
		if ( object.hasColors && ! buffers.color ) buffers.color = _gl.createBuffer();

		var programAttributes = program.getAttributes();

		if ( object.hasPositions ) {

			_gl.bindBuffer( _gl.ARRAY_BUFFER, buffers.position );
			_gl.bufferData( _gl.ARRAY_BUFFER, object.positionArray, _gl.DYNAMIC_DRAW );

			state.enableAttribute( programAttributes.position );
			_gl.vertexAttribPointer( programAttributes.position, 3, _gl.FLOAT, false, 0, 0 );

		}

		if ( object.hasNormals ) {

			_gl.bindBuffer( _gl.ARRAY_BUFFER, buffers.normal );

			if ( ! material.isMeshPhongMaterial &&
				! material.isMeshStandardMaterial &&
				! material.isMeshNormalMaterial &&
				material.shading === FlatShading ) {

				for ( var i = 0, l = object.count * 3; i < l; i += 9 ) {

					var array = object.normalArray;

					var nx = ( array[ i + 0 ] + array[ i + 3 ] + array[ i + 6 ] ) / 3;
					var ny = ( array[ i + 1 ] + array[ i + 4 ] + array[ i + 7 ] ) / 3;
					var nz = ( array[ i + 2 ] + array[ i + 5 ] + array[ i + 8 ] ) / 3;

					array[ i + 0 ] = nx;
					array[ i + 1 ] = ny;
					array[ i + 2 ] = nz;

					array[ i + 3 ] = nx;
					array[ i + 4 ] = ny;
					array[ i + 5 ] = nz;

					array[ i + 6 ] = nx;
					array[ i + 7 ] = ny;
					array[ i + 8 ] = nz;

				}

			}

			_gl.bufferData( _gl.ARRAY_BUFFER, object.normalArray, _gl.DYNAMIC_DRAW );

			state.enableAttribute( programAttributes.normal );

			_gl.vertexAttribPointer( programAttributes.normal, 3, _gl.FLOAT, false, 0, 0 );

		}

		if ( object.hasUvs && material.map ) {

			_gl.bindBuffer( _gl.ARRAY_BUFFER, buffers.uv );
			_gl.bufferData( _gl.ARRAY_BUFFER, object.uvArray, _gl.DYNAMIC_DRAW );

			state.enableAttribute( programAttributes.uv );

			_gl.vertexAttribPointer( attributes.uv, 2, _gl.FLOAT, false, 0, 0 );

		}

		if ( object.hasColors && material.vertexColors !== NoColors ) {

			_gl.bindBuffer( _gl.ARRAY_BUFFER, buffers.color );
			_gl.bufferData( _gl.ARRAY_BUFFER, object.colorArray, _gl.DYNAMIC_DRAW );

			state.enableAttribute( programAttributes.color );

			_gl.vertexAttribPointer( programAttributes.color, 3, _gl.FLOAT, false, 0, 0 );

		}

		state.disableUnusedAttributes();

		_gl.drawArrays( _gl.TRIANGLES, 0, object.count );

		object.count = 0;

	};

	var program, geometryProgram, updateBuffers;

	this.renderBufferDirect = function ( camera, fog, geometry, material, object, group ) {

		setMaterial( material );

		program = setProgram( camera, fog, material, object );
		geometryProgram = geometry.id + '_' + program.id + '_' + material.wireframe;

		updateBuffers = false;

		if ( geometryProgram !== _currentGeometryProgram ) {

			_currentGeometryProgram = geometryProgram;
			updateBuffers = true;

		}

		// morph targets

		var morphTargetInfluences = object.morphTargetInfluences;

		if ( morphTargetInfluences !== undefined ) {

			// TODO Remove allocations

			var activeInfluences = [];

			for ( var i = 0, l = morphTargetInfluences.length; i < l; i ++ ) {

				var influence = morphTargetInfluences[ i ];
				activeInfluences.push( [ influence, i ] );

			}

			activeInfluences.sort( absNumericalSort );

			if ( activeInfluences.length > 8 ) {

				activeInfluences.length = 8;

			}

			var morphAttributes = geometry.morphAttributes;

			for ( var i = 0, l = activeInfluences.length; i < l; i ++ ) {

				var influence = activeInfluences[ i ];
				morphInfluences[ i ] = influence[ 0 ];

				if ( influence[ 0 ] !== 0 ) {

					var index = influence[ 1 ];

					if ( material.morphTargets === true && morphAttributes.position ) geometry.addAttribute( 'morphTarget' + i, morphAttributes.position[ index ] );
					if ( material.morphNormals === true && morphAttributes.normal ) geometry.addAttribute( 'morphNormal' + i, morphAttributes.normal[ index ] );

				} else {

					if ( material.morphTargets === true ) geometry.removeAttribute( 'morphTarget' + i );
					if ( material.morphNormals === true ) geometry.removeAttribute( 'morphNormal' + i );

				}

			}

			for ( var i = activeInfluences.length, il = morphInfluences.length; i < il; i ++ ) {

				morphInfluences[ i ] = 0.0;

			}

			program.getUniforms().setValue( _gl, 'morphTargetInfluences', morphInfluences );

			updateBuffers = true;

		}

		//

		var index = geometry.index;
		var position = geometry.attributes.position;
		var rangeFactor = 1;

		if ( material.wireframe === true ) {

			index = geometries.getWireframeAttribute( geometry );
			rangeFactor = 2;

		}

		var renderer = bufferRenderer;

		if ( index !== null ) {

			renderer = indexedBufferRenderer;
			renderer.setIndex( index );

		}

		if ( updateBuffers ) {

			setupVertexAttributes( material, program, geometry );

			if ( index !== null ) {

				_gl.bindBuffer( _gl.ELEMENT_ARRAY_BUFFER, attributes.get( index ).buffer );

			}

		}

		//

		var dataCount = 0;

		if ( index !== null ) {

			dataCount = index.count;

		} else if ( position !== undefined ) {

			dataCount = position.count;

		}

		var rangeStart = geometry.drawRange.start * rangeFactor;
		var rangeCount = geometry.drawRange.count * rangeFactor;

		var groupStart = group !== null ? group.start * rangeFactor : 0;
		var groupCount = group !== null ? group.count * rangeFactor : Infinity;

		var drawStart = Math.max( rangeStart, groupStart );
		var drawEnd = Math.min( dataCount, rangeStart + rangeCount, groupStart + groupCount ) - 1;

		var drawCount = Math.max( 0, drawEnd - drawStart + 1 );

		if ( drawCount === 0 ) return;

		//

		if ( object.isMesh ) {

			if ( material.wireframe === true ) {

				state.setLineWidth( material.wireframeLinewidth * getTargetPixelRatio() );
				renderer.setMode( _gl.LINES );

			} else {

				switch ( object.drawMode ) {

					case TrianglesDrawMode:
						renderer.setMode( _gl.TRIANGLES );
						break;

					case TriangleStripDrawMode:
						renderer.setMode( _gl.TRIANGLE_STRIP );
						break;

					case TriangleFanDrawMode:
						renderer.setMode( _gl.TRIANGLE_FAN );
						break;

				}

			}


		} else if ( object.isLine ) {

			var lineWidth = material.linewidth;

			if ( lineWidth === undefined ) lineWidth = 1; // Not using Line*Material

			state.setLineWidth( lineWidth * getTargetPixelRatio() );

			if ( object.isLineSegments ) {

				renderer.setMode( _gl.LINES );

			} else if ( object.isLineLoop ) {

				renderer.setMode( _gl.LINE_LOOP );

			} else {

				renderer.setMode( _gl.LINE_STRIP );

			}

		} else if ( object.isPoints ) {

			renderer.setMode( _gl.POINTS );

		}

		if ( geometry && geometry.isInstancedBufferGeometry ) {

			if ( geometry.maxInstancedCount > 0 ) {

				renderer.renderInstances( geometry, drawStart, drawCount );

			}

		} else {

			renderer.render( drawStart, drawCount );

		}

	};

	function setupVertexAttributes( material, program, geometry, startIndex ) {

		var extension;

		if ( geometry && geometry.isInstancedBufferGeometry ) {

			extension = extensions.get( 'ANGLE_instanced_arrays' );

			if ( extension === null ) {

				console.error( 'THREE.WebGLRenderer.setupVertexAttributes: using THREE.InstancedBufferGeometry but hardware does not support extension ANGLE_instanced_arrays.' );
				return;

			}

		}

		if ( startIndex === undefined ) startIndex = 0;

		state.initAttributes();

		var geometryAttributes = geometry.attributes;

		var programAttributes = program.getAttributes();

		var materialDefaultAttributeValues = material.defaultAttributeValues;

		for ( var name in programAttributes ) {

			var programAttribute = programAttributes[ name ];

			if ( programAttribute >= 0 ) {

				var geometryAttribute = geometryAttributes[ name ];

				if ( geometryAttribute !== undefined ) {

					var normalized = geometryAttribute.normalized;
					var size = geometryAttribute.itemSize;

					var attributeProperties = attributes.get( geometryAttribute );

					var buffer = attributeProperties.buffer;
					var type = attributeProperties.type;
					var bytesPerElement = attributeProperties.bytesPerElement;

					if ( geometryAttribute.isInterleavedBufferAttribute ) {

						var data = geometryAttribute.data;
						var stride = data.stride;
						var offset = geometryAttribute.offset;

						if ( data && data.isInstancedInterleavedBuffer ) {

							state.enableAttributeAndDivisor( programAttribute, data.meshPerAttribute, extension );

							if ( geometry.maxInstancedCount === undefined ) {

								geometry.maxInstancedCount = data.meshPerAttribute * data.count;

							}

						} else {

							state.enableAttribute( programAttribute );

						}

						_gl.bindBuffer( _gl.ARRAY_BUFFER, buffer );
						_gl.vertexAttribPointer( programAttribute, size, type, normalized, stride * bytesPerElement, ( startIndex * stride + offset ) * bytesPerElement );

					} else {

						if ( geometryAttribute.isInstancedBufferAttribute ) {

							state.enableAttributeAndDivisor( programAttribute, geometryAttribute.meshPerAttribute, extension );

							if ( geometry.maxInstancedCount === undefined ) {

								geometry.maxInstancedCount = geometryAttribute.meshPerAttribute * geometryAttribute.count;

							}

						} else {

							state.enableAttribute( programAttribute );

						}

						_gl.bindBuffer( _gl.ARRAY_BUFFER, buffer );
						_gl.vertexAttribPointer( programAttribute, size, type, normalized, 0, startIndex * size * bytesPerElement );

					}

				} else if ( materialDefaultAttributeValues !== undefined ) {

					var value = materialDefaultAttributeValues[ name ];

					if ( value !== undefined ) {

						switch ( value.length ) {

							case 2:
								_gl.vertexAttrib2fv( programAttribute, value );
								break;

							case 3:
								_gl.vertexAttrib3fv( programAttribute, value );
								break;

							case 4:
								_gl.vertexAttrib4fv( programAttribute, value );
								break;

							default:
								_gl.vertexAttrib1fv( programAttribute, value );

						}

					}

				}

			}

		}

		state.disableUnusedAttributes();

	}

	// Sorting

	function absNumericalSort( a, b ) {

		return Math.abs( b[ 0 ] ) - Math.abs( a[ 0 ] );

	}

	function painterSortStable( a, b ) {

		if ( a.object.renderOrder !== b.object.renderOrder ) {

			return a.object.renderOrder - b.object.renderOrder;

		} else if ( a.material.program && b.material.program && a.material.program !== b.material.program ) {

			return a.material.program.id - b.material.program.id;

		} else if ( a.material.id !== b.material.id ) {

			return a.material.id - b.material.id;

		} else if ( a.z !== b.z ) {

			return a.z - b.z;

		} else {

			return a.id - b.id;

		}

	}

	function reversePainterSortStable( a, b ) {

		if ( a.object.renderOrder !== b.object.renderOrder ) {

			return a.object.renderOrder - b.object.renderOrder;

		} if ( a.z !== b.z ) {

			return b.z - a.z;

		} else {

			return a.id - b.id;

		}

	}

	// Rendering

	this.render = function ( scene, camera, renderTarget, forceClear ) {

		if ( camera !== undefined && camera.isCamera !== true ) {

			console.error( 'THREE.WebGLRenderer.render: camera is not an instance of THREE.Camera.' );
			return;

		}

		// reset caching for this frame

		_currentGeometryProgram = '';
		_currentMaterialId = - 1;
		_currentCamera = null;

		// update scene graph

		if ( scene.autoUpdate === true ) scene.updateMatrixWorld();

		// update camera matrices and frustum

		if ( camera.parent === null ) camera.updateMatrixWorld();

		camera.matrixWorldInverse.getInverse( camera.matrixWorld );

		_projScreenMatrix.multiplyMatrices( camera.projectionMatrix, camera.matrixWorldInverse );
		_frustum.setFromMatrix( _projScreenMatrix );

		lights.length = 0;

		opaqueObjectsLastIndex = - 1;
		transparentObjectsLastIndex = - 1;

		sprites.length = 0;
		lensFlares.length = 0;

		_localClippingEnabled = this.localClippingEnabled;
		_clippingEnabled = _clipping.init( this.clippingPlanes, _localClippingEnabled, camera );

		projectObject( scene, camera, _this.sortObjects );

		opaqueObjects.length = opaqueObjectsLastIndex + 1;
		transparentObjects.length = transparentObjectsLastIndex + 1;

		if ( _this.sortObjects === true ) {

			opaqueObjects.sort( painterSortStable );
			transparentObjects.sort( reversePainterSortStable );

		}

		//

		if ( _clippingEnabled ) _clipping.beginShadows();

		setupShadows( lights );

		shadowMap.render( scene, camera );

		setupLights( lights, camera );

		if ( _clippingEnabled ) _clipping.endShadows();

		//

		_infoRender.frame ++;
		_infoRender.calls = 0;
		_infoRender.vertices = 0;
		_infoRender.faces = 0;
		_infoRender.points = 0;

		if ( renderTarget === undefined ) {

			renderTarget = null;

		}

		this.setRenderTarget( renderTarget );

		//

		var background = scene.background;

		if ( background === null ) {

			state.buffers.color.setClear( _clearColor.r, _clearColor.g, _clearColor.b, _clearAlpha, _premultipliedAlpha );

		} else if ( background && background.isColor ) {

			state.buffers.color.setClear( background.r, background.g, background.b, 1, _premultipliedAlpha );
			forceClear = true;

		}

		if ( this.autoClear || forceClear ) {

			this.clear( this.autoClearColor, this.autoClearDepth, this.autoClearStencil );

		}

		if ( background && background.isCubeTexture ) {

			if ( backgroundBoxCamera === undefined ) {

				backgroundBoxCamera = new PerspectiveCamera();

				backgroundBoxMesh = new Mesh(
					new BoxBufferGeometry( 5, 5, 5 ),
					new ShaderMaterial( {
						uniforms: ShaderLib.cube.uniforms,
						vertexShader: ShaderLib.cube.vertexShader,
						fragmentShader: ShaderLib.cube.fragmentShader,
						side: BackSide,
						depthTest: false,
						depthWrite: false,
						fog: false
					} )
				);

			}

			backgroundBoxCamera.projectionMatrix.copy( camera.projectionMatrix );

			backgroundBoxCamera.matrixWorld.extractRotation( camera.matrixWorld );
			backgroundBoxCamera.matrixWorldInverse.getInverse( backgroundBoxCamera.matrixWorld );


			backgroundBoxMesh.material.uniforms[ "tCube" ].value = background;
			backgroundBoxMesh.modelViewMatrix.multiplyMatrices( backgroundBoxCamera.matrixWorldInverse, backgroundBoxMesh.matrixWorld );

			objects.update( backgroundBoxMesh );

			_this.renderBufferDirect( backgroundBoxCamera, null, backgroundBoxMesh.geometry, backgroundBoxMesh.material, backgroundBoxMesh, null );

		} else if ( background && background.isTexture ) {

			if ( backgroundPlaneCamera === undefined ) {

				backgroundPlaneCamera = new OrthographicCamera( - 1, 1, 1, - 1, 0, 1 );

				backgroundPlaneMesh = new Mesh(
					new PlaneBufferGeometry( 2, 2 ),
					new MeshBasicMaterial( { depthTest: false, depthWrite: false, fog: false } )
				);

			}

			backgroundPlaneMesh.material.map = background;

			objects.update( backgroundPlaneMesh );

			_this.renderBufferDirect( backgroundPlaneCamera, null, backgroundPlaneMesh.geometry, backgroundPlaneMesh.material, backgroundPlaneMesh, null );

		}

		//

		if ( scene.overrideMaterial ) {

			var overrideMaterial = scene.overrideMaterial;

			renderObjects( opaqueObjects, scene, camera, overrideMaterial );
			renderObjects( transparentObjects, scene, camera, overrideMaterial );

		} else {

			// opaque pass (front-to-back order)

			state.setBlending( NoBlending );
			renderObjects( opaqueObjects, scene, camera );

			// transparent pass (back-to-front order)

			renderObjects( transparentObjects, scene, camera );

		}

		// custom render plugins (post pass)

		spritePlugin.render( scene, camera );
		lensFlarePlugin.render( scene, camera, _currentViewport );

		// Generate mipmap if we're using any kind of mipmap filtering

		if ( renderTarget ) {

			textures.updateRenderTargetMipmap( renderTarget );

		}

		// Ensure depth buffer writing is enabled so it can be cleared on next render

		state.setDepthTest( true );
		state.setDepthWrite( true );
		state.setColorWrite( true );

		// _gl.finish();

	};

	function pushRenderItem( object, geometry, material, z, group ) {

		var array, index;

		// allocate the next position in the appropriate array

		if ( material.transparent ) {

			array = transparentObjects;
			index = ++ transparentObjectsLastIndex;

		} else {

			array = opaqueObjects;
			index = ++ opaqueObjectsLastIndex;

		}

		// recycle existing render item or grow the array

		var renderItem = array[ index ];

		if ( renderItem ) {

			renderItem.id = object.id;
			renderItem.object = object;
			renderItem.geometry = geometry;
			renderItem.material = material;
			renderItem.z = _vector3.z;
			renderItem.group = group;

		} else {

			renderItem = {
				id: object.id,
				object: object,
				geometry: geometry,
				material: material,
				z: _vector3.z,
				group: group
			};

			// assert( index === array.length );
			array.push( renderItem );

		}

	}

	/*
	// TODO Duplicated code (Frustum)

	var _sphere = new Sphere();

	function isObjectViewable( object ) {

		var geometry = object.geometry;

		if ( geometry.boundingSphere === null )
			geometry.computeBoundingSphere();

		_sphere.copy( geometry.boundingSphere ).
		applyMatrix4( object.matrixWorld );

		return isSphereViewable( _sphere );

	}

	function isSpriteViewable( sprite ) {

		_sphere.center.set( 0, 0, 0 );
		_sphere.radius = 0.7071067811865476;
		_sphere.applyMatrix4( sprite.matrixWorld );

		return isSphereViewable( _sphere );

	}

	function isSphereViewable( sphere ) {

		if ( ! _frustum.intersectsSphere( sphere ) ) return false;

		var numPlanes = _clipping.numPlanes;

		if ( numPlanes === 0 ) return true;

		var planes = _this.clippingPlanes,

			center = sphere.center,
			negRad = - sphere.radius,
			i = 0;

		do {

			// out when deeper than radius in the negative halfspace
			if ( planes[ i ].distanceToPoint( center ) < negRad ) return false;

		} while ( ++ i !== numPlanes );

		return true;

	}
	*/

	function projectObject( object, camera, sortObjects ) {

		if ( ! object.visible ) return;

		var visible = object.layers.test( camera.layers );

		if ( visible ) {

			if ( object.isLight ) {

				lights.push( object );

			} else if ( object.isSprite ) {

				if ( ! object.frustumCulled || _frustum.intersectsSprite( object ) ) {

					sprites.push( object );

				}

			} else if ( object.isLensFlare ) {

				lensFlares.push( object );

			} else if ( object.isImmediateRenderObject ) {

				if ( sortObjects ) {

					_vector3.setFromMatrixPosition( object.matrixWorld )
						.applyMatrix4( _projScreenMatrix );

				}

				pushRenderItem( object, null, object.material, _vector3.z, null );

			} else if ( object.isMesh || object.isLine || object.isPoints ) {

				if ( object.isSkinnedMesh ) {

					object.skeleton.update();

				}

				if ( ! object.frustumCulled || _frustum.intersectsObject( object ) ) {

					if ( sortObjects ) {

						_vector3.setFromMatrixPosition( object.matrixWorld )
							.applyMatrix4( _projScreenMatrix );

					}

					var geometry = objects.update( object );
					var material = object.material;

					if ( Array.isArray( material ) ) {

						var groups = geometry.groups;

						for ( var i = 0, l = groups.length; i < l; i ++ ) {

							var group = groups[ i ];
							var groupMaterial = material[ group.materialIndex ];

							if ( groupMaterial && groupMaterial.visible ) {

								pushRenderItem( object, geometry, groupMaterial, _vector3.z, group );

							}

						}

					} else if ( material.visible ) {

						pushRenderItem( object, geometry, material, _vector3.z, null );

					}

				}

			}

		}

		var children = object.children;

		for ( var i = 0, l = children.length; i < l; i ++ ) {

			projectObject( children[ i ], camera, sortObjects );

		}

	}

	function renderObjects( renderList, scene, camera, overrideMaterial ) {

		for ( var i = 0, l = renderList.length; i < l; i ++ ) {

			var renderItem = renderList[ i ];

			var object = renderItem.object;
			var geometry = renderItem.geometry;
			var material = overrideMaterial === undefined ? renderItem.material : overrideMaterial;
			var group = renderItem.group;

			object.modelViewMatrix.multiplyMatrices( camera.matrixWorldInverse, object.matrixWorld );
			object.normalMatrix.getNormalMatrix( object.modelViewMatrix );

			object.onBeforeRender( _this, scene, camera, geometry, material, group );

			if ( object.isImmediateRenderObject ) {

				setMaterial( material );

				var program = setProgram( camera, scene.fog, material, object );

				_currentGeometryProgram = '';

				renderObjectImmediate( object, program, material );

			} else {

				_this.renderBufferDirect( camera, scene.fog, geometry, material, object, group );

			}

			object.onAfterRender( _this, scene, camera, geometry, material, group );


		}

	}

	function initMaterial( material, fog, object ) {

		var materialProperties = properties.get( material );

		var parameters = programCache.getParameters(
			material, _lights, fog, _clipping.numPlanes, _clipping.numIntersection, object );

		var code = programCache.getProgramCode( material, parameters );

		var program = materialProperties.program;
		var programChange = true;

		if ( program === undefined ) {

			// new material
			material.addEventListener( 'dispose', onMaterialDispose );

		} else if ( program.code !== code ) {

			// changed glsl or parameters
			releaseMaterialProgramReference( material );

		} else if ( parameters.shaderID !== undefined ) {

			// same glsl and uniform list
			return;

		} else {

			// only rebuild uniform list
			programChange = false;

		}

		if ( programChange ) {

			if ( parameters.shaderID ) {

				var shader = ShaderLib[ parameters.shaderID ];

				materialProperties.__webglShader = {
					name: material.type,
					uniforms: UniformsUtils.clone( shader.uniforms ),
					vertexShader: shader.vertexShader,
					fragmentShader: shader.fragmentShader
				};

			} else {

				materialProperties.__webglShader = {
					name: material.type,
					uniforms: material.uniforms,
					vertexShader: material.vertexShader,
					fragmentShader: material.fragmentShader
				};

			}

			material.__webglShader = materialProperties.__webglShader;

			program = programCache.acquireProgram( material, parameters, code );

			materialProperties.program = program;
			material.program = program;

		}

		var programAttributes = program.getAttributes();

		if ( material.morphTargets ) {

			material.numSupportedMorphTargets = 0;

			for ( var i = 0; i < _this.maxMorphTargets; i ++ ) {

				if ( programAttributes[ 'morphTarget' + i ] >= 0 ) {

					material.numSupportedMorphTargets ++;

				}

			}

		}

		if ( material.morphNormals ) {

			material.numSupportedMorphNormals = 0;

			for ( var i = 0; i < _this.maxMorphNormals; i ++ ) {

				if ( programAttributes[ 'morphNormal' + i ] >= 0 ) {

					material.numSupportedMorphNormals ++;

				}

			}

		}

		var uniforms = materialProperties.__webglShader.uniforms;

		if ( ! material.isShaderMaterial &&
			! material.isRawShaderMaterial ||
			material.clipping === true ) {

			materialProperties.numClippingPlanes = _clipping.numPlanes;
			materialProperties.numIntersection = _clipping.numIntersection;
			uniforms.clippingPlanes = _clipping.uniform;

		}

		materialProperties.fog = fog;

		// store the light setup it was created for

		materialProperties.lightsHash = _lights.hash;

		if ( material.lights ) {

			// wire up the material to this renderer's lighting state

			uniforms.ambientLightColor.value = _lights.ambient;
			uniforms.directionalLights.value = _lights.directional;
			uniforms.spotLights.value = _lights.spot;
			uniforms.rectAreaLights.value = _lights.rectArea;
			uniforms.pointLights.value = _lights.point;
			uniforms.hemisphereLights.value = _lights.hemi;

			uniforms.directionalShadowMap.value = _lights.directionalShadowMap;
			uniforms.directionalShadowMatrix.value = _lights.directionalShadowMatrix;
			uniforms.spotShadowMap.value = _lights.spotShadowMap;
			uniforms.spotShadowMatrix.value = _lights.spotShadowMatrix;
			uniforms.pointShadowMap.value = _lights.pointShadowMap;
			uniforms.pointShadowMatrix.value = _lights.pointShadowMatrix;
			// TODO (abelnation): add area lights shadow info to uniforms

		}

		var progUniforms = materialProperties.program.getUniforms(),
			uniformsList =
				WebGLUniforms.seqWithValue( progUniforms.seq, uniforms );

		materialProperties.uniformsList = uniformsList;

	}

	function setMaterial( material ) {

		material.side === DoubleSide
			? state.disable( _gl.CULL_FACE )
			: state.enable( _gl.CULL_FACE );

		state.setFlipSided( material.side === BackSide );

		material.transparent === true
			? state.setBlending( material.blending, material.blendEquation, material.blendSrc, material.blendDst, material.blendEquationAlpha, material.blendSrcAlpha, material.blendDstAlpha, material.premultipliedAlpha )
			: state.setBlending( NoBlending );

		state.setDepthFunc( material.depthFunc );
		state.setDepthTest( material.depthTest );
		state.setDepthWrite( material.depthWrite );
		state.setColorWrite( material.colorWrite );
		state.setPolygonOffset( material.polygonOffset, material.polygonOffsetFactor, material.polygonOffsetUnits );

	}

	function setProgram( camera, fog, material, object ) {

		_usedTextureUnits = 0;

		var materialProperties = properties.get( material );

		if ( _clippingEnabled ) {

			if ( _localClippingEnabled || camera !== _currentCamera ) {

				var useCache =
					camera === _currentCamera &&
					material.id === _currentMaterialId;

				// we might want to call this function with some ClippingGroup
				// object instead of the material, once it becomes feasible
				// (#8465, #8379)
				_clipping.setState(
					material.clippingPlanes, material.clipIntersection, material.clipShadows,
					camera, materialProperties, useCache );

			}

		}

		if ( material.needsUpdate === false ) {

			if ( materialProperties.program === undefined ) {

				material.needsUpdate = true;

			} else if ( material.fog && materialProperties.fog !== fog ) {

				material.needsUpdate = true;

			} else if ( material.lights && materialProperties.lightsHash !== _lights.hash ) {

				material.needsUpdate = true;

			} else if ( materialProperties.numClippingPlanes !== undefined &&
				( materialProperties.numClippingPlanes !== _clipping.numPlanes ||
				materialProperties.numIntersection !== _clipping.numIntersection ) ) {

				material.needsUpdate = true;

			}

		}

		if ( material.needsUpdate ) {

			initMaterial( material, fog, object );
			material.needsUpdate = false;

		}

		var refreshProgram = false;
		var refreshMaterial = false;
		var refreshLights = false;

		var program = materialProperties.program,
			p_uniforms = program.getUniforms(),
			m_uniforms = materialProperties.__webglShader.uniforms;

		if ( program.id !== _currentProgram ) {

			_gl.useProgram( program.program );
			_currentProgram = program.id;

			refreshProgram = true;
			refreshMaterial = true;
			refreshLights = true;

		}

		if ( material.id !== _currentMaterialId ) {

			_currentMaterialId = material.id;

			refreshMaterial = true;

		}

		if ( refreshProgram || camera !== _currentCamera ) {

			p_uniforms.set( _gl, camera, 'projectionMatrix' );

			if ( capabilities.logarithmicDepthBuffer ) {

				p_uniforms.setValue( _gl, 'logDepthBufFC',
					2.0 / ( Math.log( camera.far + 1.0 ) / Math.LN2 ) );

			}


			if ( camera !== _currentCamera ) {

				_currentCamera = camera;

				// lighting uniforms depend on the camera so enforce an update
				// now, in case this material supports lights - or later, when
				// the next material that does gets activated:

				refreshMaterial = true;		// set to true on material change
				refreshLights = true;		// remains set until update done

			}

			// load material specific uniforms
			// (shader material also gets them for the sake of genericity)

			if ( material.isShaderMaterial ||
				material.isMeshPhongMaterial ||
				material.isMeshStandardMaterial ||
				material.envMap ) {

				var uCamPos = p_uniforms.map.cameraPosition;

				if ( uCamPos !== undefined ) {

					uCamPos.setValue( _gl,
						_vector3.setFromMatrixPosition( camera.matrixWorld ) );

				}

			}

			if ( material.isMeshPhongMaterial ||
				material.isMeshLambertMaterial ||
				material.isMeshBasicMaterial ||
				material.isMeshStandardMaterial ||
				material.isShaderMaterial ||
				object.isSkinnedMesh ) {

				p_uniforms.setValue( _gl, 'viewMatrix', camera.matrixWorldInverse );

			}

			p_uniforms.set( _gl, _this, 'toneMappingExposure' );
			p_uniforms.set( _gl, _this, 'toneMappingWhitePoint' );

		}

		// skinning uniforms must be set even if material didn't change
		// auto-setting of texture unit for bone texture must go before other textures
		// not sure why, but otherwise weird things happen

		if ( object.isSkinnedMesh ) {

			p_uniforms.setOptional( _gl, object, 'bindMatrix' );
			p_uniforms.setOptional( _gl, object, 'bindMatrixInverse' );

			var skeleton = object.skeleton;

			if ( skeleton ) {

				if ( capabilities.floatVertexTextures ) {

					p_uniforms.set( _gl, skeleton, 'boneTexture' );
					p_uniforms.set( _gl, skeleton, 'boneTextureSize' );

				} else {

					p_uniforms.setOptional( _gl, skeleton, 'boneMatrices' );

				}

			}

		}

		if ( refreshMaterial ) {

			if ( material.lights ) {

				// the current material requires lighting info

				// note: all lighting uniforms are always set correctly
				// they simply reference the renderer's state for their
				// values
				//
				// use the current material's .needsUpdate flags to set
				// the GL state when required

				markUniformsLightsNeedsUpdate( m_uniforms, refreshLights );

			}

			// refresh uniforms common to several materials

			if ( fog && material.fog ) {

				refreshUniformsFog( m_uniforms, fog );

			}

			if ( material.isMeshBasicMaterial ||
				material.isMeshLambertMaterial ||
				material.isMeshPhongMaterial ||
				material.isMeshStandardMaterial ||
				material.isMeshNormalMaterial ||
				material.isMeshDepthMaterial ) {

				refreshUniformsCommon( m_uniforms, material );

			}

			// refresh single material specific uniforms

			if ( material.isLineBasicMaterial ) {

				refreshUniformsLine( m_uniforms, material );

			} else if ( material.isLineDashedMaterial ) {

				refreshUniformsLine( m_uniforms, material );
				refreshUniformsDash( m_uniforms, material );

			} else if ( material.isPointsMaterial ) {

				refreshUniformsPoints( m_uniforms, material );

			} else if ( material.isMeshLambertMaterial ) {

				refreshUniformsLambert( m_uniforms, material );

			} else if ( material.isMeshToonMaterial ) {

				refreshUniformsToon( m_uniforms, material );

			} else if ( material.isMeshPhongMaterial ) {

				refreshUniformsPhong( m_uniforms, material );

			} else if ( material.isMeshPhysicalMaterial ) {

				refreshUniformsPhysical( m_uniforms, material );

			} else if ( material.isMeshStandardMaterial ) {

				refreshUniformsStandard( m_uniforms, material );

			} else if ( material.isMeshDepthMaterial ) {

				if ( material.displacementMap ) {

					m_uniforms.displacementMap.value = material.displacementMap;
					m_uniforms.displacementScale.value = material.displacementScale;
					m_uniforms.displacementBias.value = material.displacementBias;

				}

			} else if ( material.isMeshNormalMaterial ) {

				refreshUniformsNormal( m_uniforms, material );

			}

			// RectAreaLight Texture
			// TODO (mrdoob): Find a nicer implementation

			if ( m_uniforms.ltcMat !== undefined ) m_uniforms.ltcMat.value = THREE.UniformsLib.LTC_MAT_TEXTURE;
			if ( m_uniforms.ltcMag !== undefined ) m_uniforms.ltcMag.value = THREE.UniformsLib.LTC_MAG_TEXTURE;

			WebGLUniforms.upload(
				_gl, materialProperties.uniformsList, m_uniforms, _this );

		}


		// common matrices

		p_uniforms.set( _gl, object, 'modelViewMatrix' );
		p_uniforms.set( _gl, object, 'normalMatrix' );
		p_uniforms.setValue( _gl, 'modelMatrix', object.matrixWorld );

		return program;

	}

	// Uniforms (refresh uniforms objects)

	function refreshUniformsCommon( uniforms, material ) {

		uniforms.opacity.value = material.opacity;

		uniforms.diffuse.value = material.color;

		if ( material.emissive ) {

			uniforms.emissive.value.copy( material.emissive ).multiplyScalar( material.emissiveIntensity );

		}

		uniforms.map.value = material.map;
		uniforms.specularMap.value = material.specularMap;
		uniforms.alphaMap.value = material.alphaMap;

		if ( material.lightMap ) {

			uniforms.lightMap.value = material.lightMap;
			uniforms.lightMapIntensity.value = material.lightMapIntensity;

		}

		if ( material.aoMap ) {

			uniforms.aoMap.value = material.aoMap;
			uniforms.aoMapIntensity.value = material.aoMapIntensity;

		}

		// uv repeat and offset setting priorities
		// 1. color map
		// 2. specular map
		// 3. normal map
		// 4. bump map
		// 5. alpha map
		// 6. emissive map

		var uvScaleMap;

		if ( material.map ) {

			uvScaleMap = material.map;

		} else if ( material.specularMap ) {

			uvScaleMap = material.specularMap;

		} else if ( material.displacementMap ) {

			uvScaleMap = material.displacementMap;

		} else if ( material.normalMap ) {

			uvScaleMap = material.normalMap;

		} else if ( material.bumpMap ) {

			uvScaleMap = material.bumpMap;

		} else if ( material.roughnessMap ) {

			uvScaleMap = material.roughnessMap;

		} else if ( material.metalnessMap ) {

			uvScaleMap = material.metalnessMap;

		} else if ( material.alphaMap ) {

			uvScaleMap = material.alphaMap;

		} else if ( material.emissiveMap ) {

			uvScaleMap = material.emissiveMap;

		}

		if ( uvScaleMap !== undefined ) {

			// backwards compatibility
			if ( uvScaleMap.isWebGLRenderTarget ) {

				uvScaleMap = uvScaleMap.texture;

			}

			var offset = uvScaleMap.offset;
			var repeat = uvScaleMap.repeat;

			uniforms.offsetRepeat.value.set( offset.x, offset.y, repeat.x, repeat.y );

		}

		uniforms.envMap.value = material.envMap;

		// don't flip CubeTexture envMaps, flip everything else:
		//  WebGLRenderTargetCube will be flipped for backwards compatibility
		//  WebGLRenderTargetCube.texture will be flipped because it's a Texture and NOT a CubeTexture
		// this check must be handled differently, or removed entirely, if WebGLRenderTargetCube uses a CubeTexture in the future
		uniforms.flipEnvMap.value = ( ! ( material.envMap && material.envMap.isCubeTexture ) ) ? 1 : - 1;

		uniforms.reflectivity.value = material.reflectivity;
		uniforms.refractionRatio.value = material.refractionRatio;

	}

	function refreshUniformsLine( uniforms, material ) {

		uniforms.diffuse.value = material.color;
		uniforms.opacity.value = material.opacity;

	}

	function refreshUniformsDash( uniforms, material ) {

		uniforms.dashSize.value = material.dashSize;
		uniforms.totalSize.value = material.dashSize + material.gapSize;
		uniforms.scale.value = material.scale;

	}

	function refreshUniformsPoints( uniforms, material ) {

		uniforms.diffuse.value = material.color;
		uniforms.opacity.value = material.opacity;
		uniforms.size.value = material.size * _pixelRatio;
		uniforms.scale.value = _height * 0.5;

		uniforms.map.value = material.map;

		if ( material.map !== null ) {

			var offset = material.map.offset;
			var repeat = material.map.repeat;

			uniforms.offsetRepeat.value.set( offset.x, offset.y, repeat.x, repeat.y );

		}

	}

	function refreshUniformsFog( uniforms, fog ) {

		uniforms.fogColor.value = fog.color;

		if ( fog.isFog ) {

			uniforms.fogNear.value = fog.near;
			uniforms.fogFar.value = fog.far;

		} else if ( fog.isFogExp2 ) {

			uniforms.fogDensity.value = fog.density;

		}

	}

	function refreshUniformsLambert( uniforms, material ) {

		if ( material.emissiveMap ) {

			uniforms.emissiveMap.value = material.emissiveMap;

		}

	}

	function refreshUniformsPhong( uniforms, material ) {

		uniforms.specular.value = material.specular;
		uniforms.shininess.value = Math.max( material.shininess, 1e-4 ); // to prevent pow( 0.0, 0.0 )

		if ( material.emissiveMap ) {

			uniforms.emissiveMap.value = material.emissiveMap;

		}

		if ( material.bumpMap ) {

			uniforms.bumpMap.value = material.bumpMap;
			uniforms.bumpScale.value = material.bumpScale;

		}

		if ( material.normalMap ) {

			uniforms.normalMap.value = material.normalMap;
			uniforms.normalScale.value.copy( material.normalScale );

		}

		if ( material.displacementMap ) {

			uniforms.displacementMap.value = material.displacementMap;
			uniforms.displacementScale.value = material.displacementScale;
			uniforms.displacementBias.value = material.displacementBias;

		}

	}

	function refreshUniformsToon( uniforms, material ) {

		refreshUniformsPhong( uniforms, material );

		if ( material.gradientMap ) {

			uniforms.gradientMap.value = material.gradientMap;

		}

	}

	function refreshUniformsStandard( uniforms, material ) {

		uniforms.roughness.value = material.roughness;
		uniforms.metalness.value = material.metalness;

		if ( material.roughnessMap ) {

			uniforms.roughnessMap.value = material.roughnessMap;

		}

		if ( material.metalnessMap ) {

			uniforms.metalnessMap.value = material.metalnessMap;

		}

		if ( material.emissiveMap ) {

			uniforms.emissiveMap.value = material.emissiveMap;

		}

		if ( material.bumpMap ) {

			uniforms.bumpMap.value = material.bumpMap;
			uniforms.bumpScale.value = material.bumpScale;

		}

		if ( material.normalMap ) {

			uniforms.normalMap.value = material.normalMap;
			uniforms.normalScale.value.copy( material.normalScale );

		}

		if ( material.displacementMap ) {

			uniforms.displacementMap.value = material.displacementMap;
			uniforms.displacementScale.value = material.displacementScale;
			uniforms.displacementBias.value = material.displacementBias;

		}

		if ( material.envMap ) {

			//uniforms.envMap.value = material.envMap; // part of uniforms common
			uniforms.envMapIntensity.value = material.envMapIntensity;

		}

	}

	function refreshUniformsPhysical( uniforms, material ) {

		uniforms.clearCoat.value = material.clearCoat;
		uniforms.clearCoatRoughness.value = material.clearCoatRoughness;

		refreshUniformsStandard( uniforms, material );

	}

	function refreshUniformsNormal( uniforms, material ) {

		if ( material.bumpMap ) {

			uniforms.bumpMap.value = material.bumpMap;
			uniforms.bumpScale.value = material.bumpScale;

		}

		if ( material.normalMap ) {

			uniforms.normalMap.value = material.normalMap;
			uniforms.normalScale.value.copy( material.normalScale );

		}

		if ( material.displacementMap ) {

			uniforms.displacementMap.value = material.displacementMap;
			uniforms.displacementScale.value = material.displacementScale;
			uniforms.displacementBias.value = material.displacementBias;

		}

	}

	// If uniforms are marked as clean, they don't need to be loaded to the GPU.

	function markUniformsLightsNeedsUpdate( uniforms, value ) {

		uniforms.ambientLightColor.needsUpdate = value;

		uniforms.directionalLights.needsUpdate = value;
		uniforms.pointLights.needsUpdate = value;
		uniforms.spotLights.needsUpdate = value;
		uniforms.rectAreaLights.needsUpdate = value;
		uniforms.hemisphereLights.needsUpdate = value;

	}

	// Lighting

	function setupShadows( lights ) {

		var lightShadowsLength = 0;

		for ( var i = 0, l = lights.length; i < l; i ++ ) {

			var light = lights[ i ];

			if ( light.castShadow ) {

				_lights.shadows[ lightShadowsLength ] = light;
				lightShadowsLength ++;

			}

		}

		_lights.shadows.length = lightShadowsLength;

	}

	function setupLights( lights, camera ) {

		var l, ll, light, shadow,
			r = 0, g = 0, b = 0,
			color,
			intensity,
			distance,
			shadowMap,

			viewMatrix = camera.matrixWorldInverse,

			directionalLength = 0,
			pointLength = 0,
			spotLength = 0,
			rectAreaLength = 0,
			hemiLength = 0;

		for ( l = 0, ll = lights.length; l < ll; l ++ ) {

			light = lights[ l ];

			color = light.color;
			intensity = light.intensity;
			distance = light.distance;

			shadowMap = ( light.shadow && light.shadow.map ) ? light.shadow.map.texture : null;

			if ( light.isAmbientLight ) {

				r += color.r * intensity;
				g += color.g * intensity;
				b += color.b * intensity;

			} else if ( light.isDirectionalLight ) {

				var uniforms = lightCache.get( light );

				uniforms.color.copy( light.color ).multiplyScalar( light.intensity );
				uniforms.direction.setFromMatrixPosition( light.matrixWorld );
				_vector3.setFromMatrixPosition( light.target.matrixWorld );
				uniforms.direction.sub( _vector3 );
				uniforms.direction.transformDirection( viewMatrix );

				uniforms.shadow = light.castShadow;

				if ( light.castShadow ) {

					shadow = light.shadow;

					uniforms.shadowBias = shadow.bias;
					uniforms.shadowRadius = shadow.radius;
					uniforms.shadowMapSize = shadow.mapSize;

				}

				_lights.directionalShadowMap[ directionalLength ] = shadowMap;
				_lights.directionalShadowMatrix[ directionalLength ] = light.shadow.matrix;
				_lights.directional[ directionalLength ] = uniforms;

				directionalLength ++;

			} else if ( light.isSpotLight ) {

				var uniforms = lightCache.get( light );

				uniforms.position.setFromMatrixPosition( light.matrixWorld );
				uniforms.position.applyMatrix4( viewMatrix );

				uniforms.color.copy( color ).multiplyScalar( intensity );
				uniforms.distance = distance;

				uniforms.direction.setFromMatrixPosition( light.matrixWorld );
				_vector3.setFromMatrixPosition( light.target.matrixWorld );
				uniforms.direction.sub( _vector3 );
				uniforms.direction.transformDirection( viewMatrix );

				uniforms.coneCos = Math.cos( light.angle );
				uniforms.penumbraCos = Math.cos( light.angle * ( 1 - light.penumbra ) );
				uniforms.decay = ( light.distance === 0 ) ? 0.0 : light.decay;

				uniforms.shadow = light.castShadow;

				if ( light.castShadow ) {

					shadow = light.shadow;

					uniforms.shadowBias = shadow.bias;
					uniforms.shadowRadius = shadow.radius;
					uniforms.shadowMapSize = shadow.mapSize;

				}

				_lights.spotShadowMap[ spotLength ] = shadowMap;
				_lights.spotShadowMatrix[ spotLength ] = light.shadow.matrix;
				_lights.spot[ spotLength ] = uniforms;

				spotLength ++;

			} else if ( light.isRectAreaLight ) {

				var uniforms = lightCache.get( light );

				// (a) intensity controls irradiance of entire light
				uniforms.color
					.copy( color )
					.multiplyScalar( intensity / ( light.width * light.height ) );

				// (b) intensity controls the radiance per light area
				// uniforms.color.copy( color ).multiplyScalar( intensity );

				uniforms.position.setFromMatrixPosition( light.matrixWorld );
				uniforms.position.applyMatrix4( viewMatrix );

				// extract local rotation of light to derive width/height half vectors
				_matrix42.identity();
				_matrix4.copy( light.matrixWorld );
				_matrix4.premultiply( viewMatrix );
				_matrix42.extractRotation( _matrix4 );

				uniforms.halfWidth.set( light.width * 0.5,                0.0, 0.0 );
				uniforms.halfHeight.set(              0.0, light.height * 0.5, 0.0 );

				uniforms.halfWidth.applyMatrix4( _matrix42 );
				uniforms.halfHeight.applyMatrix4( _matrix42 );

				// TODO (abelnation): RectAreaLight distance?
				// uniforms.distance = distance;

				_lights.rectArea[ rectAreaLength ] = uniforms;

				rectAreaLength ++;

			} else if ( light.isPointLight ) {

				var uniforms = lightCache.get( light );

				uniforms.position.setFromMatrixPosition( light.matrixWorld );
				uniforms.position.applyMatrix4( viewMatrix );

				uniforms.color.copy( light.color ).multiplyScalar( light.intensity );
				uniforms.distance = light.distance;
				uniforms.decay = ( light.distance === 0 ) ? 0.0 : light.decay;

				uniforms.shadow = light.castShadow;

				if ( light.castShadow ) {

					shadow = light.shadow;

					uniforms.shadowBias = shadow.bias;
					uniforms.shadowRadius = shadow.radius;
					uniforms.shadowMapSize = shadow.mapSize;

				}

				_lights.pointShadowMap[ pointLength ] = shadowMap;

				if ( _lights.pointShadowMatrix[ pointLength ] === undefined ) {

					_lights.pointShadowMatrix[ pointLength ] = new Matrix4();

				}

				// for point lights we set the shadow matrix to be a translation-only matrix
				// equal to inverse of the light's position
				_vector3.setFromMatrixPosition( light.matrixWorld ).negate();
				_lights.pointShadowMatrix[ pointLength ].identity().setPosition( _vector3 );

				_lights.point[ pointLength ] = uniforms;

				pointLength ++;

			} else if ( light.isHemisphereLight ) {

				var uniforms = lightCache.get( light );

				uniforms.direction.setFromMatrixPosition( light.matrixWorld );
				uniforms.direction.transformDirection( viewMatrix );
				uniforms.direction.normalize();

				uniforms.skyColor.copy( light.color ).multiplyScalar( intensity );
				uniforms.groundColor.copy( light.groundColor ).multiplyScalar( intensity );

				_lights.hemi[ hemiLength ] = uniforms;

				hemiLength ++;

			}

		}

		_lights.ambient[ 0 ] = r;
		_lights.ambient[ 1 ] = g;
		_lights.ambient[ 2 ] = b;

		_lights.directional.length = directionalLength;
		_lights.spot.length = spotLength;
		_lights.rectArea.length = rectAreaLength;
		_lights.point.length = pointLength;
		_lights.hemi.length = hemiLength;

		// TODO (sam-g-steel) why aren't we using join
		_lights.hash = directionalLength + ',' + pointLength + ',' + spotLength + ',' + rectAreaLength + ',' + hemiLength + ',' + _lights.shadows.length;

	}

	// GL state setting

	this.setFaceCulling = function ( cullFace, frontFaceDirection ) {

		state.setCullFace( cullFace );
		state.setFlipSided( frontFaceDirection === FrontFaceDirectionCW );

	};

	// Textures

	function allocTextureUnit() {

		var textureUnit = _usedTextureUnits;

		if ( textureUnit >= capabilities.maxTextures ) {

			console.warn( 'WebGLRenderer: trying to use ' + textureUnit + ' texture units while this GPU supports only ' + capabilities.maxTextures );

		}

		_usedTextureUnits += 1;

		return textureUnit;

	}

	this.allocTextureUnit = allocTextureUnit;

	// this.setTexture2D = setTexture2D;
	this.setTexture2D = ( function () {

		var warned = false;

		// backwards compatibility: peel texture.texture
		return function setTexture2D( texture, slot ) {

			if ( texture && texture.isWebGLRenderTarget ) {

				if ( ! warned ) {

					console.warn( "THREE.WebGLRenderer.setTexture2D: don't use render targets as textures. Use their .texture property instead." );
					warned = true;

				}

				texture = texture.texture;

			}

			textures.setTexture2D( texture, slot );

		};

	}() );

	this.setTexture = ( function () {

		var warned = false;

		return function setTexture( texture, slot ) {

			if ( ! warned ) {

				console.warn( "THREE.WebGLRenderer: .setTexture is deprecated, use setTexture2D instead." );
				warned = true;

			}

			textures.setTexture2D( texture, slot );

		};

	}() );

	this.setTextureCube = ( function () {

		var warned = false;

		return function setTextureCube( texture, slot ) {

			// backwards compatibility: peel texture.texture
			if ( texture && texture.isWebGLRenderTargetCube ) {

				if ( ! warned ) {

					console.warn( "THREE.WebGLRenderer.setTextureCube: don't use cube render targets as textures. Use their .texture property instead." );
					warned = true;

				}

				texture = texture.texture;

			}

			// currently relying on the fact that WebGLRenderTargetCube.texture is a Texture and NOT a CubeTexture
			// TODO: unify these code paths
			if ( ( texture && texture.isCubeTexture ) ||
				( Array.isArray( texture.image ) && texture.image.length === 6 ) ) {

				// CompressedTexture can have Array in image :/

				// this function alone should take care of cube textures
				textures.setTextureCube( texture, slot );

			} else {

				// assumed: texture property of THREE.WebGLRenderTargetCube

				textures.setTextureCubeDynamic( texture, slot );

			}

		};

	}() );

	this.getCurrentRenderTarget = function () {

		return _currentRenderTarget;

	};

	this.setRenderTarget = function ( renderTarget ) {

		_currentRenderTarget = renderTarget;

		if ( renderTarget && properties.get( renderTarget ).__webglFramebuffer === undefined ) {

			textures.setupRenderTarget( renderTarget );

		}

		var isCube = ( renderTarget && renderTarget.isWebGLRenderTargetCube );
		var framebuffer;

		if ( renderTarget ) {

			var renderTargetProperties = properties.get( renderTarget );

			if ( isCube ) {

				framebuffer = renderTargetProperties.__webglFramebuffer[ renderTarget.activeCubeFace ];

			} else {

				framebuffer = renderTargetProperties.__webglFramebuffer;

			}

			_currentScissor.copy( renderTarget.scissor );
			_currentScissorTest = renderTarget.scissorTest;

			_currentViewport.copy( renderTarget.viewport );

		} else {

			framebuffer = null;

			_currentScissor.copy( _scissor ).multiplyScalar( _pixelRatio );
			_currentScissorTest = _scissorTest;

			_currentViewport.copy( _viewport ).multiplyScalar( _pixelRatio );

		}

		if ( _currentFramebuffer !== framebuffer ) {

			_gl.bindFramebuffer( _gl.FRAMEBUFFER, framebuffer );
			_currentFramebuffer = framebuffer;

		}

		state.scissor( _currentScissor );
		state.setScissorTest( _currentScissorTest );

		state.viewport( _currentViewport );

		if ( isCube ) {

			var textureProperties = properties.get( renderTarget.texture );
			_gl.framebufferTexture2D( _gl.FRAMEBUFFER, _gl.COLOR_ATTACHMENT0, _gl.TEXTURE_CUBE_MAP_POSITIVE_X + renderTarget.activeCubeFace, textureProperties.__webglTexture, renderTarget.activeMipMapLevel );

		}

	};

	this.readRenderTargetPixels = function ( renderTarget, x, y, width, height, buffer ) {

		if ( ( renderTarget && renderTarget.isWebGLRenderTarget ) === false ) {

			console.error( 'THREE.WebGLRenderer.readRenderTargetPixels: renderTarget is not THREE.WebGLRenderTarget.' );
			return;

		}

		var framebuffer = properties.get( renderTarget ).__webglFramebuffer;

		if ( framebuffer ) {

			var restore = false;

			if ( framebuffer !== _currentFramebuffer ) {

				_gl.bindFramebuffer( _gl.FRAMEBUFFER, framebuffer );

				restore = true;

			}

			try {

				var texture = renderTarget.texture;
				var textureFormat = texture.format;
				var textureType = texture.type;

				if ( textureFormat !== RGBAFormat && paramThreeToGL( textureFormat ) !== _gl.getParameter( _gl.IMPLEMENTATION_COLOR_READ_FORMAT ) ) {

					console.error( 'THREE.WebGLRenderer.readRenderTargetPixels: renderTarget is not in RGBA or implementation defined format.' );
					return;

				}

				if ( textureType !== UnsignedByteType && paramThreeToGL( textureType ) !== _gl.getParameter( _gl.IMPLEMENTATION_COLOR_READ_TYPE ) && // IE11, Edge and Chrome Mac < 52 (#9513)
					! ( textureType === FloatType && ( extensions.get( 'OES_texture_float' ) || extensions.get( 'WEBGL_color_buffer_float' ) ) ) && // Chrome Mac >= 52 and Firefox
					! ( textureType === HalfFloatType && extensions.get( 'EXT_color_buffer_half_float' ) ) ) {

					console.error( 'THREE.WebGLRenderer.readRenderTargetPixels: renderTarget is not in UnsignedByteType or implementation defined type.' );
					return;

				}

				if ( _gl.checkFramebufferStatus( _gl.FRAMEBUFFER ) === _gl.FRAMEBUFFER_COMPLETE ) {

					// the following if statement ensures valid read requests (no out-of-bounds pixels, see #8604)

					if ( ( x >= 0 && x <= ( renderTarget.width - width ) ) && ( y >= 0 && y <= ( renderTarget.height - height ) ) ) {

						_gl.readPixels( x, y, width, height, paramThreeToGL( textureFormat ), paramThreeToGL( textureType ), buffer );

					}

				} else {

					console.error( 'THREE.WebGLRenderer.readRenderTargetPixels: readPixels from renderTarget failed. Framebuffer not complete.' );

				}

			} finally {

				if ( restore ) {

					_gl.bindFramebuffer( _gl.FRAMEBUFFER, _currentFramebuffer );

				}

			}

		}

	};

	// Map three.js constants to WebGL constants

	function paramThreeToGL( p ) {

		var extension;

		if ( p === RepeatWrapping ) return _gl.REPEAT;
		if ( p === ClampToEdgeWrapping ) return _gl.CLAMP_TO_EDGE;
		if ( p === MirroredRepeatWrapping ) return _gl.MIRRORED_REPEAT;

		if ( p === NearestFilter ) return _gl.NEAREST;
		if ( p === NearestMipMapNearestFilter ) return _gl.NEAREST_MIPMAP_NEAREST;
		if ( p === NearestMipMapLinearFilter ) return _gl.NEAREST_MIPMAP_LINEAR;

		if ( p === LinearFilter ) return _gl.LINEAR;
		if ( p === LinearMipMapNearestFilter ) return _gl.LINEAR_MIPMAP_NEAREST;
		if ( p === LinearMipMapLinearFilter ) return _gl.LINEAR_MIPMAP_LINEAR;

		if ( p === UnsignedByteType ) return _gl.UNSIGNED_BYTE;
		if ( p === UnsignedShort4444Type ) return _gl.UNSIGNED_SHORT_4_4_4_4;
		if ( p === UnsignedShort5551Type ) return _gl.UNSIGNED_SHORT_5_5_5_1;
		if ( p === UnsignedShort565Type ) return _gl.UNSIGNED_SHORT_5_6_5;

		if ( p === ByteType ) return _gl.BYTE;
		if ( p === ShortType ) return _gl.SHORT;
		if ( p === UnsignedShortType ) return _gl.UNSIGNED_SHORT;
		if ( p === IntType ) return _gl.INT;
		if ( p === UnsignedIntType ) return _gl.UNSIGNED_INT;
		if ( p === FloatType ) return _gl.FLOAT;

		if ( p === HalfFloatType ) {

			extension = extensions.get( 'OES_texture_half_float' );

			if ( extension !== null ) return extension.HALF_FLOAT_OES;

		}

		if ( p === AlphaFormat ) return _gl.ALPHA;
		if ( p === RGBFormat ) return _gl.RGB;
		if ( p === RGBAFormat ) return _gl.RGBA;
		if ( p === LuminanceFormat ) return _gl.LUMINANCE;
		if ( p === LuminanceAlphaFormat ) return _gl.LUMINANCE_ALPHA;
		if ( p === DepthFormat ) return _gl.DEPTH_COMPONENT;
		if ( p === DepthStencilFormat ) return _gl.DEPTH_STENCIL;

		if ( p === AddEquation ) return _gl.FUNC_ADD;
		if ( p === SubtractEquation ) return _gl.FUNC_SUBTRACT;
		if ( p === ReverseSubtractEquation ) return _gl.FUNC_REVERSE_SUBTRACT;

		if ( p === ZeroFactor ) return _gl.ZERO;
		if ( p === OneFactor ) return _gl.ONE;
		if ( p === SrcColorFactor ) return _gl.SRC_COLOR;
		if ( p === OneMinusSrcColorFactor ) return _gl.ONE_MINUS_SRC_COLOR;
		if ( p === SrcAlphaFactor ) return _gl.SRC_ALPHA;
		if ( p === OneMinusSrcAlphaFactor ) return _gl.ONE_MINUS_SRC_ALPHA;
		if ( p === DstAlphaFactor ) return _gl.DST_ALPHA;
		if ( p === OneMinusDstAlphaFactor ) return _gl.ONE_MINUS_DST_ALPHA;

		if ( p === DstColorFactor ) return _gl.DST_COLOR;
		if ( p === OneMinusDstColorFactor ) return _gl.ONE_MINUS_DST_COLOR;
		if ( p === SrcAlphaSaturateFactor ) return _gl.SRC_ALPHA_SATURATE;

		if ( p === RGB_S3TC_DXT1_Format || p === RGBA_S3TC_DXT1_Format ||
			p === RGBA_S3TC_DXT3_Format || p === RGBA_S3TC_DXT5_Format ) {

			extension = extensions.get( 'WEBGL_compressed_texture_s3tc' );

			if ( extension !== null ) {

				if ( p === RGB_S3TC_DXT1_Format ) return extension.COMPRESSED_RGB_S3TC_DXT1_EXT;
				if ( p === RGBA_S3TC_DXT1_Format ) return extension.COMPRESSED_RGBA_S3TC_DXT1_EXT;
				if ( p === RGBA_S3TC_DXT3_Format ) return extension.COMPRESSED_RGBA_S3TC_DXT3_EXT;
				if ( p === RGBA_S3TC_DXT5_Format ) return extension.COMPRESSED_RGBA_S3TC_DXT5_EXT;

			}

		}

		if ( p === RGB_PVRTC_4BPPV1_Format || p === RGB_PVRTC_2BPPV1_Format ||
			p === RGBA_PVRTC_4BPPV1_Format || p === RGBA_PVRTC_2BPPV1_Format ) {

			extension = extensions.get( 'WEBGL_compressed_texture_pvrtc' );

			if ( extension !== null ) {

				if ( p === RGB_PVRTC_4BPPV1_Format ) return extension.COMPRESSED_RGB_PVRTC_4BPPV1_IMG;
				if ( p === RGB_PVRTC_2BPPV1_Format ) return extension.COMPRESSED_RGB_PVRTC_2BPPV1_IMG;
				if ( p === RGBA_PVRTC_4BPPV1_Format ) return extension.COMPRESSED_RGBA_PVRTC_4BPPV1_IMG;
				if ( p === RGBA_PVRTC_2BPPV1_Format ) return extension.COMPRESSED_RGBA_PVRTC_2BPPV1_IMG;

			}

		}

		if ( p === RGB_ETC1_Format ) {

			extension = extensions.get( 'WEBGL_compressed_texture_etc1' );

			if ( extension !== null ) return extension.COMPRESSED_RGB_ETC1_WEBGL;

		}

		if ( p === MinEquation || p === MaxEquation ) {

			extension = extensions.get( 'EXT_blend_minmax' );

			if ( extension !== null ) {

				if ( p === MinEquation ) return extension.MIN_EXT;
				if ( p === MaxEquation ) return extension.MAX_EXT;

			}

		}

		if ( p === UnsignedInt248Type ) {

			extension = extensions.get( 'WEBGL_depth_texture' );

			if ( extension !== null ) return extension.UNSIGNED_INT_24_8_WEBGL;

		}

		return 0;

	}

}


export { WebGLRenderer };