import {
	REVISION,
	BackSide,
	DoubleSide,
	FrontSide,
	RGBAFormat,
	HalfFloatType,
	FloatType,
	UnsignedByteType,
	LinearEncoding,
	NoToneMapping,
	LinearMipmapLinearFilter,
	NearestFilter,
	ClampToEdgeWrapping,
} from '../constants.js';
import { Frustum } from '../math/Frustum.js';
import { Matrix4 } from '../math/Matrix4.js';
import { Vector3 } from '../math/Vector3.js';
import { Vector4 } from '../math/Vector4.js';
import { WebGLAnimation } from './webgl/WebGLAnimation.js';
import { WebGLAttributes } from './webgl/WebGLAttributes.js';
import { WebGLBackground } from './webgl/WebGLBackground.js';
import { WebGLBindingStates } from './webgl/WebGLBindingStates.js';
import { WebGLBufferRenderer } from './webgl/WebGLBufferRenderer.js';
import { WebGLCapabilities } from './webgl/WebGLCapabilities.js';
import { WebGLClipping } from './webgl/WebGLClipping.js';
import { WebGLCubeMaps } from './webgl/WebGLCubeMaps.js';
import { WebGLCubeUVMaps } from './webgl/WebGLCubeUVMaps.js';
import { WebGLExtensions } from './webgl/WebGLExtensions.js';
import { WebGLGeometries } from './webgl/WebGLGeometries.js';
import { WebGLIndexedBufferRenderer } from './webgl/WebGLIndexedBufferRenderer.js';
import { WebGLInfo } from './webgl/WebGLInfo.js';
import { WebGLMorphtargets } from './webgl/WebGLMorphtargets.js';
import { WebGLMultisampleRenderTarget } from './WebGLMultisampleRenderTarget.js';
import { WebGLObjects } from './webgl/WebGLObjects.js';
import { WebGLPrograms } from './webgl/WebGLPrograms.js';
import { WebGLProperties } from './webgl/WebGLProperties.js';
import { WebGLRenderLists } from './webgl/WebGLRenderLists.js';
import { WebGLRenderStates } from './webgl/WebGLRenderStates.js';
import { WebGLRenderTarget } from './WebGLRenderTarget.js';
import { WebGLShadowMap } from './webgl/WebGLShadowMap.js';
import { WebGLState } from './webgl/WebGLState.js';
import { WebGLTextures } from './webgl/WebGLTextures.js';
import { WebGLUniforms } from './webgl/WebGLUniforms.js';
import { WebGLUtils } from './webgl/WebGLUtils.js';
import { WebXRManager } from './webxr/WebXRManager.js';
import { WebGLMaterials } from './webgl/WebGLMaterials.js';
import { createElementNS } from '../utils.js';

function createCanvasElement() {
	const canvas = createElementNS('canvas');
	canvas.style.display = 'block';
	return canvas;
}

function WebGLRenderer(parameters = {}) {
	const _canvas = parameters.canvas !== undefined ? parameters.canvas : createCanvasElement(),
		_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,
		_powerPreference = parameters.powerPreference !== undefined ? parameters.powerPreference : 'default',
		_failIfMajorPerformanceCaveat = parameters.failIfMajorPerformanceCaveat !== undefined ? parameters.failIfMajorPerformanceCaveat : false;

	let currentRenderList = null;
	let currentRenderState = null;

	// render() can be called from within a callback triggered by another render.
	// We track this so that the nested render call gets its list and state isolated from the parent render call.

	const renderListStack = [];
	const renderStateStack = [];

	// public properties

	this.domElement = _canvas;

	// Debug configuration container
	this.debug = {
		/**
		 * Enables error checking and reporting when shader programs are being compiled
		 * @type {boolean}
		 */
		checkShaderErrors: true,
	};

	// 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.outputEncoding = LinearEncoding;

	// physical lights

	this.physicallyCorrectLights = false;

	// tone mapping

	this.toneMapping = NoToneMapping;
	this.toneMappingExposure = 1.0;

	// internal properties

	const _this = this;

	let _isContextLost = false;

	// internal state cache

	let _currentActiveCubeFace = 0;
	let _currentActiveMipmapLevel = 0;
	let _currentRenderTarget = null;
	let _currentMaterialId = -1;

	let _currentCamera = null;

	const _currentViewport = new Vector4();
	const _currentScissor = new Vector4();
	let _currentScissorTest = null;

	//

	let _width = _canvas.width;
	let _height = _canvas.height;

	let _pixelRatio = 1;
	let _opaqueSort = null;
	let _transparentSort = null;

	const _viewport = new Vector4(0, 0, _width, _height);
	const _scissor = new Vector4(0, 0, _width, _height);
	let _scissorTest = false;

	// frustum

	const _frustum = new Frustum();

	// clipping

	let _clippingEnabled = false;
	let _localClippingEnabled = false;

	// transmission

	let _transmissionRenderTarget = null;

	// camera matrices cache

	const _projScreenMatrix = new Matrix4();

	const _vector3 = new Vector3();

	const _emptyScene = { background: null, fog: null, environment: null, overrideMaterial: null, isScene: true };

	function getTargetPixelRatio() {
		return _currentRenderTarget === null ? _pixelRatio : 1;
	}

	// initialize

	let _gl = _context;

	function getContext(contextNames, contextAttributes) {
		for (let i = 0; i < contextNames.length; i++) {
			const contextName = contextNames[i];
			const context = _canvas.getContext(contextName, contextAttributes);
			if (context !== null) return context;
		}

		return null;
	}

	try {
		const contextAttributes = {
			alpha: true,
			depth: _depth,
			stencil: _stencil,
			antialias: _antialias,
			premultipliedAlpha: _premultipliedAlpha,
			preserveDrawingBuffer: _preserveDrawingBuffer,
			powerPreference: _powerPreference,
			failIfMajorPerformanceCaveat: _failIfMajorPerformanceCaveat,
		};

		// OffscreenCanvas does not have setAttribute, see #22811
		if ('setAttribute' in _canvas) _canvas.setAttribute('data-engine', `three.js r${REVISION}`);

		// event listeners must be registered before WebGL context is created, see #12753
		_canvas.addEventListener('webglcontextlost', onContextLost, false);
		_canvas.addEventListener('webglcontextrestored', onContextRestore, false);

		if (_gl === null) {
			const contextNames = ['webgl2', 'webgl', 'experimental-webgl'];

			if (_this.isWebGL1Renderer === true) {
				contextNames.shift();
			}

			_gl = getContext(contextNames, contextAttributes);

			if (_gl === null) {
				if (getContext(contextNames)) {
					throw new Error('Error creating WebGL context with your selected attributes.');
				} else {
					throw new Error('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 };
			};
		}
	} catch (error) {
		console.error('THREE.WebGLRenderer: ' + error.message);
		throw error;
	}

	let extensions, capabilities, state, info;
	let properties, textures, cubemaps, cubeuvmaps, attributes, geometries, objects;
	let programCache, materials, renderLists, renderStates, clipping, shadowMap;

	let background, morphtargets, bufferRenderer, indexedBufferRenderer;

	let utils, bindingStates;

	function initGLContext() {
		extensions = new WebGLExtensions(_gl);

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

		extensions.init(capabilities);

		utils = new WebGLUtils(_gl, extensions, capabilities);

		state = new WebGLState(_gl, extensions, capabilities);

		info = new WebGLInfo(_gl);
		properties = new WebGLProperties();
		textures = new WebGLTextures(_gl, extensions, state, properties, capabilities, utils, info);
		cubemaps = new WebGLCubeMaps(_this);
		cubeuvmaps = new WebGLCubeUVMaps(_this);
		attributes = new WebGLAttributes(_gl, capabilities);
		bindingStates = new WebGLBindingStates(_gl, extensions, attributes, capabilities);
		geometries = new WebGLGeometries(_gl, attributes, info, bindingStates);
		objects = new WebGLObjects(_gl, geometries, attributes, info);
		morphtargets = new WebGLMorphtargets(_gl, capabilities, textures);
		clipping = new WebGLClipping(properties);
		programCache = new WebGLPrograms(_this, cubemaps, cubeuvmaps, extensions, capabilities, bindingStates, clipping);
		materials = new WebGLMaterials(properties);
		renderLists = new WebGLRenderLists();
		renderStates = new WebGLRenderStates(extensions, capabilities);
		background = new WebGLBackground(_this, cubemaps, state, objects, _alpha, _premultipliedAlpha);
		shadowMap = new WebGLShadowMap(_this, objects, capabilities);

		bufferRenderer = new WebGLBufferRenderer(_gl, extensions, info, capabilities);
		indexedBufferRenderer = new WebGLIndexedBufferRenderer(_gl, extensions, info, capabilities);

		info.programs = programCache.programs;

		_this.capabilities = capabilities;
		_this.extensions = extensions;
		_this.properties = properties;
		_this.renderLists = renderLists;
		_this.shadowMap = shadowMap;
		_this.state = state;
		_this.info = info;
	}

	initGLContext();

	// xr

	const xr = new WebXRManager(_this, _gl);

	this.xr = xr;

	// API

	this.getContext = function () {
		return _gl;
	};

	this.getContextAttributes = function () {
		return _gl.getContextAttributes();
	};

	this.forceContextLoss = function () {
		const extension = extensions.get('WEBGL_lose_context');
		if (extension) extension.loseContext();
	};

	this.forceContextRestore = function () {
		const extension = extensions.get('WEBGL_lose_context');
		if (extension) extension.restoreContext();
	};

	this.getPixelRatio = function () {
		return _pixelRatio;
	};

	this.setPixelRatio = function (value) {
		if (value === undefined) return;

		_pixelRatio = value;

		this.setSize(_width, _height, false);
	};

	this.getSize = function (target) {
		return target.set(_width, _height);
	};

	this.setSize = function (width, height, updateStyle) {
		if (xr.isPresenting) {
			console.warn("THREE.WebGLRenderer: Can't change size while VR device is presenting.");
			return;
		}

		_width = width;
		_height = height;

		_canvas.width = Math.floor(width * _pixelRatio);
		_canvas.height = Math.floor(height * _pixelRatio);

		if (updateStyle !== false) {
			_canvas.style.width = width + 'px';
			_canvas.style.height = height + 'px';
		}

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

	this.getDrawingBufferSize = function (target) {
		return target.set(_width * _pixelRatio, _height * _pixelRatio).floor();
	};

	this.setDrawingBufferSize = function (width, height, pixelRatio) {
		_width = width;
		_height = height;

		_pixelRatio = pixelRatio;

		_canvas.width = Math.floor(width * pixelRatio);
		_canvas.height = Math.floor(height * pixelRatio);

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

	this.getCurrentViewport = function (target) {
		return target.copy(_currentViewport);
	};

	this.getViewport = function (target) {
		return target.copy(_viewport);
	};

	this.setViewport = function (x, y, width, height) {
		if (x.isVector4) {
			_viewport.set(x.x, x.y, x.z, x.w);
		} else {
			_viewport.set(x, y, width, height);
		}

		state.viewport(_currentViewport.copy(_viewport).multiplyScalar(_pixelRatio).floor());
	};

	this.getScissor = function (target) {
		return target.copy(_scissor);
	};

	this.setScissor = function (x, y, width, height) {
		if (x.isVector4) {
			_scissor.set(x.x, x.y, x.z, x.w);
		} else {
			_scissor.set(x, y, width, height);
		}

		state.scissor(_currentScissor.copy(_scissor).multiplyScalar(_pixelRatio).floor());
	};

	this.getScissorTest = function () {
		return _scissorTest;
	};

	this.setScissorTest = function (boolean) {
		state.setScissorTest((_scissorTest = boolean));
	};

	this.setOpaqueSort = function (method) {
		_opaqueSort = method;
	};

	this.setTransparentSort = function (method) {
		_transparentSort = method;
	};

	// Clearing

	this.getClearColor = function (target) {
		return target.copy(background.getClearColor());
	};

	this.setClearColor = function () {
		background.setClearColor.apply(background, arguments);
	};

	this.getClearAlpha = function () {
		return background.getClearAlpha();
	};

	this.setClearAlpha = function () {
		background.setClearAlpha.apply(background, arguments);
	};

	this.clear = function (color, depth, stencil) {
		let 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.dispose = function () {
		_canvas.removeEventListener('webglcontextlost', onContextLost, false);
		_canvas.removeEventListener('webglcontextrestored', onContextRestore, false);

		renderLists.dispose();
		renderStates.dispose();
		properties.dispose();
		cubemaps.dispose();
		cubeuvmaps.dispose();
		objects.dispose();
		bindingStates.dispose();
		programCache.dispose();

		xr.dispose();

		xr.removeEventListener('sessionstart', onXRSessionStart);
		xr.removeEventListener('sessionend', onXRSessionEnd);

		if (_transmissionRenderTarget) {
			_transmissionRenderTarget.dispose();
			_transmissionRenderTarget = null;
		}

		animation.stop();
	};

	// Events

	function onContextLost(event) {
		event.preventDefault();

		console.log('THREE.WebGLRenderer: Context Lost.');

		_isContextLost = true;
	}

	function onContextRestore(/* event */) {
		console.log('THREE.WebGLRenderer: Context Restored.');

		_isContextLost = false;

		const infoAutoReset = info.autoReset;
		const shadowMapEnabled = shadowMap.enabled;
		const shadowMapAutoUpdate = shadowMap.autoUpdate;
		const shadowMapNeedsUpdate = shadowMap.needsUpdate;
		const shadowMapType = shadowMap.type;

		initGLContext();

		info.autoReset = infoAutoReset;
		shadowMap.enabled = shadowMapEnabled;
		shadowMap.autoUpdate = shadowMapAutoUpdate;
		shadowMap.needsUpdate = shadowMapNeedsUpdate;
		shadowMap.type = shadowMapType;
	}

	function onMaterialDispose(event) {
		const material = event.target;

		material.removeEventListener('dispose', onMaterialDispose);

		deallocateMaterial(material);
	}

	// Buffer deallocation

	function deallocateMaterial(material) {
		releaseMaterialProgramReferences(material);

		properties.remove(material);
	}

	function releaseMaterialProgramReferences(material) {
		const programs = properties.get(material).programs;

		if (programs !== undefined) {
			programs.forEach(function (program) {
				programCache.releaseProgram(program);
			});

			if (material.isShaderMaterial) {
				programCache.releaseShaderCache(material);
			}
		}
	}

	// Buffer rendering

	this.renderBufferDirect = function (camera, scene, geometry, material, object, group) {
		if (scene === null) scene = _emptyScene; // renderBufferDirect second parameter used to be fog (could be null)

		const frontFaceCW = object.isMesh && object.matrixWorld.determinant() < 0;

		const program = setProgram(camera, scene, geometry, material, object);

		state.setMaterial(material, frontFaceCW);

		//

		let index = geometry.index;
		const position = geometry.attributes.position;

		//

		if (index === null) {
			if (position === undefined || position.count === 0) return;
		} else if (index.count === 0) {
			return;
		}

		//

		let rangeFactor = 1;

		if (material.wireframe === true) {
			index = geometries.getWireframeAttribute(geometry);
			rangeFactor = 2;
		}

		bindingStates.setup(object, material, program, geometry, index);

		let attribute;
		let renderer = bufferRenderer;

		if (index !== null) {
			attribute = attributes.get(index);

			renderer = indexedBufferRenderer;
			renderer.setIndex(attribute);
		}

		//

		const dataCount = index !== null ? index.count : position.count;

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

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

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

		const 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 {
				renderer.setMode(_gl.TRIANGLES);
			}
		} else if (object.isLine) {
			let 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);
		} else if (object.isSprite) {
			renderer.setMode(_gl.TRIANGLES);
		}

		if (object.isInstancedMesh) {
			renderer.renderInstances(drawStart, drawCount, object.count);
		} else if (geometry.isInstancedBufferGeometry) {
			const instanceCount = Math.min(geometry.instanceCount, geometry._maxInstanceCount);

			renderer.renderInstances(drawStart, drawCount, instanceCount);
		} else {
			renderer.render(drawStart, drawCount);
		}
	};

	// Compile

	this.compile = function (scene, camera) {
		currentRenderState = renderStates.get(scene);
		currentRenderState.init();

		renderStateStack.push(currentRenderState);

		scene.traverseVisible(function (object) {
			if (object.isLight && object.layers.test(camera.layers)) {
				currentRenderState.pushLight(object);

				if (object.castShadow) {
					currentRenderState.pushShadow(object);
				}
			}
		});

		currentRenderState.setupLights(_this.physicallyCorrectLights);

		scene.traverse(function (object) {
			const material = object.material;

			if (material) {
				if (Array.isArray(material)) {
					for (let i = 0; i < material.length; i++) {
						const material2 = material[i];

						getProgram(material2, scene, object);
					}
				} else {
					getProgram(material, scene, object);
				}
			}
		});

		renderStateStack.pop();
		currentRenderState = null;
	};

	// Animation Loop

	let onAnimationFrameCallback = null;

	function onAnimationFrame(time) {
		if (onAnimationFrameCallback) onAnimationFrameCallback(time);
	}

	function onXRSessionStart() {
		animation.stop();
	}

	function onXRSessionEnd() {
		animation.start();
	}

	const animation = new WebGLAnimation();
	animation.setAnimationLoop(onAnimationFrame);

	if (typeof window !== 'undefined') animation.setContext(window);

	this.setAnimationLoop = function (callback) {
		onAnimationFrameCallback = callback;
		xr.setAnimationLoop(callback);

		callback === null ? animation.stop() : animation.start();
	};

	xr.addEventListener('sessionstart', onXRSessionStart);
	xr.addEventListener('sessionend', onXRSessionEnd);

	// Rendering

	this.render = function (scene, camera) {
		if (camera !== undefined && camera.isCamera !== true) {
			console.error('THREE.WebGLRenderer.render: camera is not an instance of THREE.Camera.');
			return;
		}

		if (_isContextLost === true) return;

		// update scene graph

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

		// update camera matrices and frustum

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

		if (xr.enabled === true && xr.isPresenting === true) {
			if (xr.cameraAutoUpdate === true) xr.updateCamera(camera);

			camera = xr.getCamera(); // use XR camera for rendering
		}

		//
		if (scene.isScene === true) scene.onBeforeRender(_this, scene, camera, _currentRenderTarget);

		currentRenderState = renderStates.get(scene, renderStateStack.length);
		currentRenderState.init();

		renderStateStack.push(currentRenderState);

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

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

		currentRenderList = renderLists.get(scene, renderListStack.length);
		currentRenderList.init();

		renderListStack.push(currentRenderList);

		projectObject(scene, camera, 0, _this.sortObjects);

		currentRenderList.finish();

		if (_this.sortObjects === true) {
			currentRenderList.sort(_opaqueSort, _transparentSort);
		}

		//

		if (_clippingEnabled === true) clipping.beginShadows();

		const shadowsArray = currentRenderState.state.shadowsArray;

		shadowMap.render(shadowsArray, scene, camera);

		if (_clippingEnabled === true) clipping.endShadows();

		//

		if (this.info.autoReset === true) this.info.reset();

		//

		background.render(currentRenderList, scene);

		// render scene

		currentRenderState.setupLights(_this.physicallyCorrectLights);

		if (camera.isArrayCamera) {
			const cameras = camera.cameras;

			for (let i = 0, l = cameras.length; i < l; i++) {
				const camera2 = cameras[i];

				renderScene(currentRenderList, scene, camera2, camera2.viewport);
			}
		} else {
			renderScene(currentRenderList, scene, camera);
		}

		//

		if (_currentRenderTarget !== null) {
			// resolve multisample renderbuffers to a single-sample texture if necessary

			textures.updateMultisampleRenderTarget(_currentRenderTarget);

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

			textures.updateRenderTargetMipmap(_currentRenderTarget);
		}

		//

		if (scene.isScene === true) scene.onAfterRender(_this, scene, camera);

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

		state.buffers.depth.setTest(true);
		state.buffers.depth.setMask(true);
		state.buffers.color.setMask(true);

		state.setPolygonOffset(false);

		// _gl.finish();

		bindingStates.resetDefaultState();
		_currentMaterialId = -1;
		_currentCamera = null;

		renderStateStack.pop();

		if (renderStateStack.length > 0) {
			currentRenderState = renderStateStack[renderStateStack.length - 1];
		} else {
			currentRenderState = null;
		}

		renderListStack.pop();

		if (renderListStack.length > 0) {
			currentRenderList = renderListStack[renderListStack.length - 1];
		} else {
			currentRenderList = null;
		}
	};

	function projectObject(object, camera, groupOrder, sortObjects) {
		if (object.visible === false) return;

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

		if (visible) {
			if (object.isGroup) {
				groupOrder = object.renderOrder;
			} else if (object.isLOD) {
				if (object.autoUpdate === true) object.update(camera);
			} else if (object.isLight) {
				currentRenderState.pushLight(object);

				if (object.castShadow) {
					currentRenderState.pushShadow(object);
				}
			} else if (object.isSprite) {
				if (!object.frustumCulled || _frustum.intersectsSprite(object)) {
					if (sortObjects) {
						_vector3.setFromMatrixPosition(object.matrixWorld).applyMatrix4(_projScreenMatrix);
					}

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

					if (material.visible) {
						currentRenderList.push(object, geometry, material, groupOrder, _vector3.z, null);
					}
				}
			} else if (object.isMesh || object.isLine || object.isPoints) {
				if (object.isSkinnedMesh) {
					// update skeleton only once in a frame

					if (object.skeleton.frame !== info.render.frame) {
						object.skeleton.update();
						object.skeleton.frame = info.render.frame;
					}
				}

				if (!object.frustumCulled || _frustum.intersectsObject(object)) {
					if (sortObjects) {
						_vector3.setFromMatrixPosition(object.matrixWorld).applyMatrix4(_projScreenMatrix);
					}

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

					if (Array.isArray(material)) {
						const groups = geometry.groups;

						for (let i = 0, l = groups.length; i < l; i++) {
							const group = groups[i];
							const groupMaterial = material[group.materialIndex];

							if (groupMaterial && groupMaterial.visible) {
								currentRenderList.push(object, geometry, groupMaterial, groupOrder, _vector3.z, group);
							}
						}
					} else if (material.visible) {
						currentRenderList.push(object, geometry, material, groupOrder, _vector3.z, null);
					}
				}
			}
		}

		const children = object.children;

		for (let i = 0, l = children.length; i < l; i++) {
			projectObject(children[i], camera, groupOrder, sortObjects);
		}
	}

	function renderScene(currentRenderList, scene, camera, viewport) {
		const opaqueObjects = currentRenderList.opaque;
		const transmissiveObjects = currentRenderList.transmissive;
		const transparentObjects = currentRenderList.transparent;

		currentRenderState.setupLightsView(camera);

		if (transmissiveObjects.length > 0) renderTransmissionPass(opaqueObjects, scene, camera);

		if (viewport) state.viewport(_currentViewport.copy(viewport));

		if (opaqueObjects.length > 0) renderObjects(opaqueObjects, scene, camera);
		if (transmissiveObjects.length > 0) renderObjects(transmissiveObjects, scene, camera);
		if (transparentObjects.length > 0) renderObjects(transparentObjects, scene, camera);
	}

	function renderTransmissionPass(opaqueObjects, scene, camera) {
		if (_transmissionRenderTarget === null) {
			const needsAntialias = _antialias === true && capabilities.isWebGL2 === true;
			const renderTargetType = needsAntialias ? WebGLMultisampleRenderTarget : WebGLRenderTarget;

			_transmissionRenderTarget = new renderTargetType(1024, 1024, {
				generateMipmaps: true,
				type: utils.convert(HalfFloatType) !== null ? HalfFloatType : UnsignedByteType,
				minFilter: LinearMipmapLinearFilter,
				magFilter: NearestFilter,
				wrapS: ClampToEdgeWrapping,
				wrapT: ClampToEdgeWrapping,
				useRenderToTexture: extensions.has('WEBGL_multisampled_render_to_texture'),
			});
		}

		const currentRenderTarget = _this.getRenderTarget();
		_this.setRenderTarget(_transmissionRenderTarget);
		_this.clear();

		// Turn off the features which can affect the frag color for opaque objects pass.
		// Otherwise they are applied twice in opaque objects pass and transmission objects pass.
		const currentToneMapping = _this.toneMapping;
		_this.toneMapping = NoToneMapping;

		renderObjects(opaqueObjects, scene, camera);

		_this.toneMapping = currentToneMapping;

		textures.updateMultisampleRenderTarget(_transmissionRenderTarget);
		textures.updateRenderTargetMipmap(_transmissionRenderTarget);

		_this.setRenderTarget(currentRenderTarget);
	}

	function renderObjects(renderList, scene, camera) {
		const overrideMaterial = scene.isScene === true ? scene.overrideMaterial : null;

		for (let i = 0, l = renderList.length; i < l; i++) {
			const renderItem = renderList[i];

			const object = renderItem.object;
			const geometry = renderItem.geometry;
			const material = overrideMaterial === null ? renderItem.material : overrideMaterial;
			const group = renderItem.group;

			if (object.layers.test(camera.layers)) {
				renderObject(object, scene, camera, geometry, material, group);
			}
		}
	}

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

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

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

		if (material.transparent === true && material.side === DoubleSide) {
			material.side = BackSide;
			material.needsUpdate = true;
			_this.renderBufferDirect(camera, scene, geometry, material, object, group);

			material.side = FrontSide;
			material.needsUpdate = true;
			_this.renderBufferDirect(camera, scene, geometry, material, object, group);

			material.side = DoubleSide;
		} else {
			_this.renderBufferDirect(camera, scene, geometry, material, object, group);
		}

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

	function getProgram(material, scene, object) {
		if (scene.isScene !== true) scene = _emptyScene; // scene could be a Mesh, Line, Points, ...

		const materialProperties = properties.get(material);

		const lights = currentRenderState.state.lights;
		const shadowsArray = currentRenderState.state.shadowsArray;

		const lightsStateVersion = lights.state.version;

		const parameters = programCache.getParameters(material, lights.state, shadowsArray, scene, object);
		const programCacheKey = programCache.getProgramCacheKey(parameters);

		let programs = materialProperties.programs;

		// always update environment and fog - changing these trigger an getProgram call, but it's possible that the program doesn't change

		materialProperties.environment = material.isMeshStandardMaterial ? scene.environment : null;
		materialProperties.fog = scene.fog;
		materialProperties.envMap = (material.isMeshStandardMaterial ? cubeuvmaps : cubemaps).get(material.envMap || materialProperties.environment);

		if (programs === undefined) {
			// new material

			material.addEventListener('dispose', onMaterialDispose);

			programs = new Map();
			materialProperties.programs = programs;
		}

		let program = programs.get(programCacheKey);

		if (program !== undefined) {
			// early out if program and light state is identical

			if (materialProperties.currentProgram === program && materialProperties.lightsStateVersion === lightsStateVersion) {
				updateCommonMaterialProperties(material, parameters);

				return program;
			}
		} else {
			parameters.uniforms = programCache.getUniforms(material);

			material.onBuild(object, parameters, _this);

			material.onBeforeCompile(parameters, _this);

			program = programCache.acquireProgram(parameters, programCacheKey);
			programs.set(programCacheKey, program);

			materialProperties.uniforms = parameters.uniforms;
		}

		const uniforms = materialProperties.uniforms;

		if ((!material.isShaderMaterial && !material.isRawShaderMaterial) || material.clipping === true) {
			uniforms.clippingPlanes = clipping.uniform;
		}

		updateCommonMaterialProperties(material, parameters);

		// store the light setup it was created for

		materialProperties.needsLights = materialNeedsLights(material);
		materialProperties.lightsStateVersion = lightsStateVersion;

		if (materialProperties.needsLights) {
			// wire up the material to this renderer's lighting state

			uniforms.ambientLightColor.value = lights.state.ambient;
			uniforms.lightProbe.value = lights.state.probe;
			uniforms.directionalLights.value = lights.state.directional;
			uniforms.directionalLightShadows.value = lights.state.directionalShadow;
			uniforms.spotLights.value = lights.state.spot;
			uniforms.spotLightShadows.value = lights.state.spotShadow;
			uniforms.rectAreaLights.value = lights.state.rectArea;
			uniforms.ltc_1.value = lights.state.rectAreaLTC1;
			uniforms.ltc_2.value = lights.state.rectAreaLTC2;
			uniforms.pointLights.value = lights.state.point;
			uniforms.pointLightShadows.value = lights.state.pointShadow;
			uniforms.hemisphereLights.value = lights.state.hemi;

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

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

		materialProperties.currentProgram = program;
		materialProperties.uniformsList = uniformsList;

		return program;
	}

	function updateCommonMaterialProperties(material, parameters) {
		const materialProperties = properties.get(material);

		materialProperties.outputEncoding = parameters.outputEncoding;
		materialProperties.instancing = parameters.instancing;
		materialProperties.skinning = parameters.skinning;
		materialProperties.morphTargets = parameters.morphTargets;
		materialProperties.morphNormals = parameters.morphNormals;
		materialProperties.morphTargetsCount = parameters.morphTargetsCount;
		materialProperties.numClippingPlanes = parameters.numClippingPlanes;
		materialProperties.numIntersection = parameters.numClipIntersection;
		materialProperties.vertexAlphas = parameters.vertexAlphas;
		materialProperties.vertexTangents = parameters.vertexTangents;
		materialProperties.toneMapping = parameters.toneMapping;
	}

	function setProgram(camera, scene, geometry, material, object) {
		if (scene.isScene !== true) scene = _emptyScene; // scene could be a Mesh, Line, Points, ...

		textures.resetTextureUnits();

		const fog = scene.fog;
		const environment = material.isMeshStandardMaterial ? scene.environment : null;
		const encoding = _currentRenderTarget === null ? _this.outputEncoding : LinearEncoding;
		const envMap = (material.isMeshStandardMaterial ? cubeuvmaps : cubemaps).get(material.envMap || environment);
		const vertexAlphas = material.vertexColors === true && !!geometry.attributes.color && geometry.attributes.color.itemSize === 4;
		const vertexTangents = !!material.normalMap && !!geometry.attributes.tangent;
		const morphTargets = !!geometry.morphAttributes.position;
		const morphNormals = !!geometry.morphAttributes.normal;
		const morphTargetsCount = !!geometry.morphAttributes.position ? geometry.morphAttributes.position.length : 0;
		const toneMapping = material.toneMapped ? _this.toneMapping : NoToneMapping;

		const materialProperties = properties.get(material);
		const lights = currentRenderState.state.lights;

		if (_clippingEnabled === true) {
			if (_localClippingEnabled === true || camera !== _currentCamera) {
				const 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, camera, useCache);
			}
		}

		//

		let needsProgramChange = false;

		if (material.version === materialProperties.__version) {
			if (materialProperties.needsLights && materialProperties.lightsStateVersion !== lights.state.version) {
				needsProgramChange = true;
			} else if (materialProperties.outputEncoding !== encoding) {
				needsProgramChange = true;
			} else if (object.isInstancedMesh && materialProperties.instancing === false) {
				needsProgramChange = true;
			} else if (!object.isInstancedMesh && materialProperties.instancing === true) {
				needsProgramChange = true;
			} else if (object.isSkinnedMesh && materialProperties.skinning === false) {
				needsProgramChange = true;
			} else if (!object.isSkinnedMesh && materialProperties.skinning === true) {
				needsProgramChange = true;
			} else if (materialProperties.envMap !== envMap) {
				needsProgramChange = true;
			} else if (material.fog && materialProperties.fog !== fog) {
				needsProgramChange = true;
			} else if (
				materialProperties.numClippingPlanes !== undefined &&
				(materialProperties.numClippingPlanes !== clipping.numPlanes || materialProperties.numIntersection !== clipping.numIntersection)
			) {
				needsProgramChange = true;
			} else if (materialProperties.vertexAlphas !== vertexAlphas) {
				needsProgramChange = true;
			} else if (materialProperties.vertexTangents !== vertexTangents) {
				needsProgramChange = true;
			} else if (materialProperties.morphTargets !== morphTargets) {
				needsProgramChange = true;
			} else if (materialProperties.morphNormals !== morphNormals) {
				needsProgramChange = true;
			} else if (materialProperties.toneMapping !== toneMapping) {
				needsProgramChange = true;
			} else if (capabilities.isWebGL2 === true && materialProperties.morphTargetsCount !== morphTargetsCount) {
				needsProgramChange = true;
			}
		} else {
			needsProgramChange = true;
			materialProperties.__version = material.version;
		}

		//

		let program = materialProperties.currentProgram;

		if (needsProgramChange === true) {
			program = getProgram(material, scene, object);
		}

		let refreshProgram = false;
		let refreshMaterial = false;
		let refreshLights = false;

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

		if (state.useProgram(program.program)) {
			refreshProgram = true;
			refreshMaterial = true;
			refreshLights = true;
		}

		if (material.id !== _currentMaterialId) {
			_currentMaterialId = material.id;

			refreshMaterial = true;
		}

		if (refreshProgram || _currentCamera !== camera) {
			p_uniforms.setValue(_gl, 'projectionMatrix', camera.projectionMatrix);

			if (capabilities.logarithmicDepthBuffer) {
				p_uniforms.setValue(_gl, 'logDepthBufFC', 2.0 / (Math.log(camera.far + 1.0) / Math.LN2));
			}

			if (_currentCamera !== camera) {
				_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.isMeshToonMaterial ||
				material.isMeshStandardMaterial ||
				material.envMap
			) {
				const uCamPos = p_uniforms.map.cameraPosition;

				if (uCamPos !== undefined) {
					uCamPos.setValue(_gl, _vector3.setFromMatrixPosition(camera.matrixWorld));
				}
			}

			if (
				material.isMeshPhongMaterial ||
				material.isMeshToonMaterial ||
				material.isMeshLambertMaterial ||
				material.isMeshBasicMaterial ||
				material.isMeshStandardMaterial ||
				material.isShaderMaterial
			) {
				p_uniforms.setValue(_gl, 'isOrthographic', camera.isOrthographicCamera === true);
			}

			if (
				material.isMeshPhongMaterial ||
				material.isMeshToonMaterial ||
				material.isMeshLambertMaterial ||
				material.isMeshBasicMaterial ||
				material.isMeshStandardMaterial ||
				material.isShaderMaterial ||
				material.isShadowMaterial ||
				object.isSkinnedMesh
			) {
				p_uniforms.setValue(_gl, 'viewMatrix', camera.matrixWorldInverse);
			}
		}

		// skinning and morph target uniforms must be set even if material didn't change
		// auto-setting of texture unit for bone and morph texture must go before other textures
		// otherwise textures used for skinning and morphing can take over texture units reserved for other material textures

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

			const skeleton = object.skeleton;

			if (skeleton) {
				if (capabilities.floatVertexTextures) {
					if (skeleton.boneTexture === null) skeleton.computeBoneTexture();

					p_uniforms.setValue(_gl, 'boneTexture', skeleton.boneTexture, textures);
					p_uniforms.setValue(_gl, 'boneTextureSize', skeleton.boneTextureSize);
				} else {
					p_uniforms.setOptional(_gl, skeleton, 'boneMatrices');
				}
			}
		}

		if (!!geometry && (geometry.morphAttributes.position !== undefined || geometry.morphAttributes.normal !== undefined)) {
			morphtargets.update(object, geometry, material, program);
		}

		if (refreshMaterial || materialProperties.receiveShadow !== object.receiveShadow) {
			materialProperties.receiveShadow = object.receiveShadow;
			p_uniforms.setValue(_gl, 'receiveShadow', object.receiveShadow);
		}

		if (refreshMaterial) {
			p_uniforms.setValue(_gl, 'toneMappingExposure', _this.toneMappingExposure);

			if (materialProperties.needsLights) {
				// 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) {
				materials.refreshFogUniforms(m_uniforms, fog);
			}

			materials.refreshMaterialUniforms(m_uniforms, material, _pixelRatio, _height, _transmissionRenderTarget);

			WebGLUniforms.upload(_gl, materialProperties.uniformsList, m_uniforms, textures);
		}

		if (material.isShaderMaterial && material.uniformsNeedUpdate === true) {
			WebGLUniforms.upload(_gl, materialProperties.uniformsList, m_uniforms, textures);
			material.uniformsNeedUpdate = false;
		}

		if (material.isSpriteMaterial) {
			p_uniforms.setValue(_gl, 'center', object.center);
		}

		// common matrices

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

		return program;
	}

	// 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.lightProbe.needsUpdate = value;

		uniforms.directionalLights.needsUpdate = value;
		uniforms.directionalLightShadows.needsUpdate = value;
		uniforms.pointLights.needsUpdate = value;
		uniforms.pointLightShadows.needsUpdate = value;
		uniforms.spotLights.needsUpdate = value;
		uniforms.spotLightShadows.needsUpdate = value;
		uniforms.rectAreaLights.needsUpdate = value;
		uniforms.hemisphereLights.needsUpdate = value;
	}

	function materialNeedsLights(material) {
		return (
			material.isMeshLambertMaterial ||
			material.isMeshToonMaterial ||
			material.isMeshPhongMaterial ||
			material.isMeshStandardMaterial ||
			material.isShadowMaterial ||
			(material.isShaderMaterial && material.lights === true)
		);
	}

	this.getActiveCubeFace = function () {
		return _currentActiveCubeFace;
	};

	this.getActiveMipmapLevel = function () {
		return _currentActiveMipmapLevel;
	};

	this.getRenderTarget = function () {
		return _currentRenderTarget;
	};

	this.setRenderTargetTextures = function (renderTarget, colorTexture, depthTexture) {
		properties.get(renderTarget.texture).__webglTexture = colorTexture;
		properties.get(renderTarget.depthTexture).__webglTexture = depthTexture;

		const renderTargetProperties = properties.get(renderTarget);
		renderTargetProperties.__hasExternalTextures = true;

		if (renderTargetProperties.__hasExternalTextures) {
			renderTargetProperties.__autoAllocateDepthBuffer = depthTexture === undefined;

			if (!renderTargetProperties.__autoAllocateDepthBuffer) {
				// The multisample_render_to_texture extension doesn't work properly if there
				// are midframe flushes and an external depth buffer. Disable use of the extension.
				if (renderTarget.useRenderToTexture) {
					console.warn('render-to-texture extension was disabled because an external texture was provided');
					renderTarget.useRenderToTexture = false;
					renderTarget.useRenderbuffer = true;
				}
			}
		}
	};

	this.setRenderTargetFramebuffer = function (renderTarget, defaultFramebuffer) {
		const renderTargetProperties = properties.get(renderTarget);
		renderTargetProperties.__webglFramebuffer = defaultFramebuffer;
		renderTargetProperties.__useDefaultFramebuffer = defaultFramebuffer === undefined;
	};

	this.setRenderTarget = function (renderTarget, activeCubeFace = 0, activeMipmapLevel = 0) {
		_currentRenderTarget = renderTarget;
		_currentActiveCubeFace = activeCubeFace;
		_currentActiveMipmapLevel = activeMipmapLevel;
		let useDefaultFramebuffer = true;

		if (renderTarget) {
			const renderTargetProperties = properties.get(renderTarget);

			if (renderTargetProperties.__useDefaultFramebuffer !== undefined) {
				// We need to make sure to rebind the framebuffer.
				state.bindFramebuffer(_gl.FRAMEBUFFER, null);
				useDefaultFramebuffer = false;
			} else if (renderTargetProperties.__webglFramebuffer === undefined) {
				textures.setupRenderTarget(renderTarget);
			} else if (renderTargetProperties.__hasExternalTextures) {
				// Color and depth texture must be rebound in order for the swapchain to update.
				textures.rebindTextures(
					renderTarget,
					properties.get(renderTarget.texture).__webglTexture,
					properties.get(renderTarget.depthTexture).__webglTexture
				);
			}
		}

		let framebuffer = null;
		let isCube = false;
		let isRenderTarget3D = false;

		if (renderTarget) {
			const texture = renderTarget.texture;

			if (texture.isDataTexture3D || texture.isDataTexture2DArray) {
				isRenderTarget3D = true;
			}

			const __webglFramebuffer = properties.get(renderTarget).__webglFramebuffer;

			if (renderTarget.isWebGLCubeRenderTarget) {
				framebuffer = __webglFramebuffer[activeCubeFace];
				isCube = true;
			} else if (renderTarget.useRenderbuffer) {
				framebuffer = properties.get(renderTarget).__webglMultisampledFramebuffer;
			} else {
				framebuffer = __webglFramebuffer;
			}

			_currentViewport.copy(renderTarget.viewport);
			_currentScissor.copy(renderTarget.scissor);
			_currentScissorTest = renderTarget.scissorTest;
		} else {
			_currentViewport.copy(_viewport).multiplyScalar(_pixelRatio).floor();
			_currentScissor.copy(_scissor).multiplyScalar(_pixelRatio).floor();
			_currentScissorTest = _scissorTest;
		}

		const framebufferBound = state.bindFramebuffer(_gl.FRAMEBUFFER, framebuffer);

		if (framebufferBound && capabilities.drawBuffers && useDefaultFramebuffer) {
			state.drawBuffers(renderTarget, framebuffer);
		}

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

		if (isCube) {
			const textureProperties = properties.get(renderTarget.texture);
			_gl.framebufferTexture2D(
				_gl.FRAMEBUFFER,
				_gl.COLOR_ATTACHMENT0,
				_gl.TEXTURE_CUBE_MAP_POSITIVE_X + activeCubeFace,
				textureProperties.__webglTexture,
				activeMipmapLevel
			);
		} else if (isRenderTarget3D) {
			const textureProperties = properties.get(renderTarget.texture);
			const layer = activeCubeFace || 0;
			_gl.framebufferTextureLayer(_gl.FRAMEBUFFER, _gl.COLOR_ATTACHMENT0, textureProperties.__webglTexture, activeMipmapLevel || 0, layer);
		}

		_currentMaterialId = -1; // reset current material to ensure correct uniform bindings
	};

	this.readRenderTargetPixels = function (renderTarget, x, y, width, height, buffer, activeCubeFaceIndex) {
		if (!(renderTarget && renderTarget.isWebGLRenderTarget)) {
			console.error('THREE.WebGLRenderer.readRenderTargetPixels: renderTarget is not THREE.WebGLRenderTarget.');
			return;
		}

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

		if (renderTarget.isWebGLCubeRenderTarget && activeCubeFaceIndex !== undefined) {
			framebuffer = framebuffer[activeCubeFaceIndex];
		}

		if (framebuffer) {
			state.bindFramebuffer(_gl.FRAMEBUFFER, framebuffer);

			try {
				const texture = renderTarget.texture;
				const textureFormat = texture.format;
				const textureType = texture.type;

				if (textureFormat !== RGBAFormat && utils.convert(textureFormat) !== _gl.getParameter(_gl.IMPLEMENTATION_COLOR_READ_FORMAT)) {
					console.error('THREE.WebGLRenderer.readRenderTargetPixels: renderTarget is not in RGBA or implementation defined format.');
					return;
				}

				const halfFloatSupportedByExt =
					textureType === HalfFloatType &&
					(extensions.has('EXT_color_buffer_half_float') || (capabilities.isWebGL2 && extensions.has('EXT_color_buffer_float')));

				if (
					textureType !== UnsignedByteType &&
					utils.convert(textureType) !== _gl.getParameter(_gl.IMPLEMENTATION_COLOR_READ_TYPE) && // Edge and Chrome Mac < 52 (#9513)
					!(
						textureType === FloatType &&
						(capabilities.isWebGL2 || extensions.has('OES_texture_float') || extensions.has('WEBGL_color_buffer_float'))
					) && // Chrome Mac >= 52 and Firefox
					!halfFloatSupportedByExt
				) {
					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, utils.convert(textureFormat), utils.convert(textureType), buffer);
					}
				} else {
					console.error('THREE.WebGLRenderer.readRenderTargetPixels: readPixels from renderTarget failed. Framebuffer not complete.');
				}
			} finally {
				// restore framebuffer of current render target if necessary

				const framebuffer = _currentRenderTarget !== null ? properties.get(_currentRenderTarget).__webglFramebuffer : null;
				state.bindFramebuffer(_gl.FRAMEBUFFER, framebuffer);
			}
		}
	};

	this.copyFramebufferToTexture = function (position, texture, level = 0) {
		if (texture.isFramebufferTexture !== true) {
			console.error('THREE.WebGLRenderer: copyFramebufferToTexture() can only be used with FramebufferTexture.');
			return;
		}

		const levelScale = Math.pow(2, -level);
		const width = Math.floor(texture.image.width * levelScale);
		const height = Math.floor(texture.image.height * levelScale);

		textures.setTexture2D(texture, 0);

		_gl.copyTexSubImage2D(_gl.TEXTURE_2D, level, 0, 0, position.x, position.y, width, height);

		state.unbindTexture();
	};

	this.copyTextureToTexture = function (position, srcTexture, dstTexture, level = 0) {
		const width = srcTexture.image.width;
		const height = srcTexture.image.height;
		const glFormat = utils.convert(dstTexture.format);
		const glType = utils.convert(dstTexture.type);

		textures.setTexture2D(dstTexture, 0);

		// As another texture upload may have changed pixelStorei
		// parameters, make sure they are correct for the dstTexture
		_gl.pixelStorei(_gl.UNPACK_FLIP_Y_WEBGL, dstTexture.flipY);
		_gl.pixelStorei(_gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, dstTexture.premultiplyAlpha);
		_gl.pixelStorei(_gl.UNPACK_ALIGNMENT, dstTexture.unpackAlignment);

		if (srcTexture.isDataTexture) {
			_gl.texSubImage2D(_gl.TEXTURE_2D, level, position.x, position.y, width, height, glFormat, glType, srcTexture.image.data);
		} else {
			if (srcTexture.isCompressedTexture) {
				_gl.compressedTexSubImage2D(
					_gl.TEXTURE_2D,
					level,
					position.x,
					position.y,
					srcTexture.mipmaps[0].width,
					srcTexture.mipmaps[0].height,
					glFormat,
					srcTexture.mipmaps[0].data
				);
			} else {
				_gl.texSubImage2D(_gl.TEXTURE_2D, level, position.x, position.y, glFormat, glType, srcTexture.image);
			}
		}

		// Generate mipmaps only when copying level 0
		if (level === 0 && dstTexture.generateMipmaps) _gl.generateMipmap(_gl.TEXTURE_2D);

		state.unbindTexture();
	};

	this.copyTextureToTexture3D = function (sourceBox, position, srcTexture, dstTexture, level = 0) {
		if (_this.isWebGL1Renderer) {
			console.warn('THREE.WebGLRenderer.copyTextureToTexture3D: can only be used with WebGL2.');
			return;
		}

		const width = sourceBox.max.x - sourceBox.min.x + 1;
		const height = sourceBox.max.y - sourceBox.min.y + 1;
		const depth = sourceBox.max.z - sourceBox.min.z + 1;
		const glFormat = utils.convert(dstTexture.format);
		const glType = utils.convert(dstTexture.type);
		let glTarget;

		if (dstTexture.isDataTexture3D) {
			textures.setTexture3D(dstTexture, 0);
			glTarget = _gl.TEXTURE_3D;
		} else if (dstTexture.isDataTexture2DArray) {
			textures.setTexture2DArray(dstTexture, 0);
			glTarget = _gl.TEXTURE_2D_ARRAY;
		} else {
			console.warn('THREE.WebGLRenderer.copyTextureToTexture3D: only supports THREE.DataTexture3D and THREE.DataTexture2DArray.');
			return;
		}

		_gl.pixelStorei(_gl.UNPACK_FLIP_Y_WEBGL, dstTexture.flipY);
		_gl.pixelStorei(_gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, dstTexture.premultiplyAlpha);
		_gl.pixelStorei(_gl.UNPACK_ALIGNMENT, dstTexture.unpackAlignment);

		const unpackRowLen = _gl.getParameter(_gl.UNPACK_ROW_LENGTH);
		const unpackImageHeight = _gl.getParameter(_gl.UNPACK_IMAGE_HEIGHT);
		const unpackSkipPixels = _gl.getParameter(_gl.UNPACK_SKIP_PIXELS);
		const unpackSkipRows = _gl.getParameter(_gl.UNPACK_SKIP_ROWS);
		const unpackSkipImages = _gl.getParameter(_gl.UNPACK_SKIP_IMAGES);

		const image = srcTexture.isCompressedTexture ? srcTexture.mipmaps[0] : srcTexture.image;

		_gl.pixelStorei(_gl.UNPACK_ROW_LENGTH, image.width);
		_gl.pixelStorei(_gl.UNPACK_IMAGE_HEIGHT, image.height);
		_gl.pixelStorei(_gl.UNPACK_SKIP_PIXELS, sourceBox.min.x);
		_gl.pixelStorei(_gl.UNPACK_SKIP_ROWS, sourceBox.min.y);
		_gl.pixelStorei(_gl.UNPACK_SKIP_IMAGES, sourceBox.min.z);

		if (srcTexture.isDataTexture || srcTexture.isDataTexture3D) {
			_gl.texSubImage3D(glTarget, level, position.x, position.y, position.z, width, height, depth, glFormat, glType, image.data);
		} else {
			if (srcTexture.isCompressedTexture) {
				console.warn('THREE.WebGLRenderer.copyTextureToTexture3D: untested support for compressed srcTexture.');
				_gl.compressedTexSubImage3D(glTarget, level, position.x, position.y, position.z, width, height, depth, glFormat, image.data);
			} else {
				_gl.texSubImage3D(glTarget, level, position.x, position.y, position.z, width, height, depth, glFormat, glType, image);
			}
		}

		_gl.pixelStorei(_gl.UNPACK_ROW_LENGTH, unpackRowLen);
		_gl.pixelStorei(_gl.UNPACK_IMAGE_HEIGHT, unpackImageHeight);
		_gl.pixelStorei(_gl.UNPACK_SKIP_PIXELS, unpackSkipPixels);
		_gl.pixelStorei(_gl.UNPACK_SKIP_ROWS, unpackSkipRows);
		_gl.pixelStorei(_gl.UNPACK_SKIP_IMAGES, unpackSkipImages);

		// Generate mipmaps only when copying level 0
		if (level === 0 && dstTexture.generateMipmaps) _gl.generateMipmap(glTarget);

		state.unbindTexture();
	};

	this.initTexture = function (texture) {
		textures.setTexture2D(texture, 0);

		state.unbindTexture();
	};

	this.resetState = function () {
		_currentActiveCubeFace = 0;
		_currentActiveMipmapLevel = 0;
		_currentRenderTarget = null;

		state.reset();
		bindingStates.reset();
	};

	if (typeof __THREE_DEVTOOLS__ !== 'undefined') {
		__THREE_DEVTOOLS__.dispatchEvent(new CustomEvent('observe', { detail: this }));
	}
}

WebGLRenderer.prototype.isWebGLRenderer = true;

export { WebGLRenderer };