three
Version:
JavaScript 3D library
2,007 lines (1,166 loc) • 56.3 kB
JavaScript
import {
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 { 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';
function createCanvasElement() {
const canvas = document.createElementNS( 'http://www.w3.org/1999/xhtml', '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.gammaFactor = 2.0; // for backwards compatibility
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;
//
const _currentDrawBuffers = [];
// 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: _alpha,
depth: _depth,
stencil: _stencil,
antialias: _antialias,
premultipliedAlpha: _premultipliedAlpha,
preserveDrawingBuffer: _preserveDrawingBuffer,
powerPreference: _powerPreference,
failIfMajorPerformanceCaveat: _failIfMajorPerformanceCaveat
};
// 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, 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 );
_currentDrawBuffers[ 0 ] = _gl.BACK;
info = new WebGLInfo( _gl );
properties = new WebGLProperties();
textures = new WebGLTextures( _gl, extensions, state, properties, capabilities, utils, info );
cubemaps = new WebGLCubeMaps( _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 );
clipping = new WebGLClipping( properties );
programCache = new WebGLPrograms( _this, cubemaps, extensions, capabilities, bindingStates, clipping );
materials = new WebGLMaterials( properties );
renderLists = new WebGLRenderLists( properties );
renderStates = new WebGLRenderStates( extensions, capabilities );
background = new WebGLBackground( _this, cubemaps, state, objects, _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();
objects.dispose();
bindingStates.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 );
} );
}
}
// Buffer rendering
function renderObjectImmediate( object, program ) {
object.render( function ( object ) {
_this.renderBufferImmediate( object, program );
} );
}
this.renderBufferImmediate = function ( object, program ) {
bindingStates.initAttributes();
const 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();
const programAttributes = program.getAttributes();
if ( object.hasPositions ) {
_gl.bindBuffer( _gl.ARRAY_BUFFER, buffers.position );
_gl.bufferData( _gl.ARRAY_BUFFER, object.positionArray, _gl.DYNAMIC_DRAW );
bindingStates.enableAttribute( programAttributes.position );
_gl.vertexAttribPointer( programAttributes.position, 3, _gl.FLOAT, false, 0, 0 );
}
if ( object.hasNormals ) {
_gl.bindBuffer( _gl.ARRAY_BUFFER, buffers.normal );
_gl.bufferData( _gl.ARRAY_BUFFER, object.normalArray, _gl.DYNAMIC_DRAW );
bindingStates.enableAttribute( programAttributes.normal );
_gl.vertexAttribPointer( programAttributes.normal, 3, _gl.FLOAT, false, 0, 0 );
}
if ( object.hasUvs ) {
_gl.bindBuffer( _gl.ARRAY_BUFFER, buffers.uv );
_gl.bufferData( _gl.ARRAY_BUFFER, object.uvArray, _gl.DYNAMIC_DRAW );
bindingStates.enableAttribute( programAttributes.uv );
_gl.vertexAttribPointer( programAttributes.uv, 2, _gl.FLOAT, false, 0, 0 );
}
if ( object.hasColors ) {
_gl.bindBuffer( _gl.ARRAY_BUFFER, buffers.color );
_gl.bufferData( _gl.ARRAY_BUFFER, object.colorArray, _gl.DYNAMIC_DRAW );
bindingStates.enableAttribute( programAttributes.color );
_gl.vertexAttribPointer( programAttributes.color, 3, _gl.FLOAT, false, 0, 0 );
}
bindingStates.disableUnusedAttributes();
_gl.drawArrays( _gl.TRIANGLES, 0, object.count );
object.count = 0;
};
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, 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;
}
if ( material.morphTargets || material.morphNormals ) {
morphtargets.update( object, geometry, material, program );
}
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();
scene.traverseVisible( function ( object ) {
if ( object.isLight && object.layers.test( camera.layers ) ) {
currentRenderState.pushLight( object );
if ( object.castShadow ) {
currentRenderState.pushShadow( object );
}
}
} );
currentRenderState.setupLights();
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 );
}
}
} );
};
// 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 );
currentRenderState.setupLights();
currentRenderState.setupLightsView( camera );
if ( _clippingEnabled === true ) clipping.endShadows();
//
if ( this.info.autoReset === true ) this.info.reset();
//
background.render( currentRenderList, scene );
// render scene
const opaqueObjects = currentRenderList.opaque;
const transmissiveObjects = currentRenderList.transmissive;
const transparentObjects = currentRenderList.transparent;
if ( opaqueObjects.length > 0 ) renderObjects( opaqueObjects, scene, camera );
if ( transmissiveObjects.length > 0 ) renderTransmissiveObjects( opaqueObjects, transmissiveObjects, scene, camera );
if ( transparentObjects.length > 0 ) renderObjects( transparentObjects, 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.isImmediateRenderObject ) {
if ( sortObjects ) {
_vector3.setFromMatrixPosition( object.matrixWorld )
.applyMatrix4( _projScreenMatrix );
}
currentRenderList.push( object, null, object.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 renderTransmissiveObjects( opaqueObjects, transmissiveObjects, 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
} );
}
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 );
renderObjects( transmissiveObjects, scene, camera );
}
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 ( camera.isArrayCamera ) {
const cameras = camera.cameras;
for ( let j = 0, jl = cameras.length; j < jl; j ++ ) {
const camera2 = cameras[ j ];
if ( object.layers.test( camera2.layers ) ) {
state.viewport( _currentViewport.copy( camera2.viewport ) );
currentRenderState.setupLightsView( camera2 );
renderObject( object, scene, camera2, geometry, material, group );
}
}
} else {
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 );
if ( object.isImmediateRenderObject ) {
const program = setProgram( camera, scene, material, object );
state.setMaterial( material );
bindingStates.reset();
renderObjectImmediate( object, program );
} else {
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 = 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( 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.numClippingPlanes = parameters.numClippingPlanes;
materialProperties.numIntersection = parameters.numClipIntersection;
materialProperties.vertexAlphas = parameters.vertexAlphas;
}
function setProgram( camera, scene, 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 : _currentRenderTarget.texture.encoding;
const envMap = cubemaps.get( material.envMap || environment );
const vertexAlphas = material.vertexColors === true && object.geometry && object.geometry.attributes.color && object.geometry.attributes.color.itemSize === 4;
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 {
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 uniforms must be set even if material didn't change
// auto-setting of texture unit for bone texture must go before other textures
// otherwise textures used for skinning 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 ( 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.setRenderTarget = function ( renderTarget, activeCubeFace = 0, activeMipmapLevel = 0 ) {
_currentRenderTarget = renderTarget;
_currentActiveCubeFace = activeCubeFace;
_currentActiveMipmapLevel = activeMipmapLevel;
if ( renderTarget && properties.get( renderTarget ).__webglFramebuffer === undefined ) {
textures.setupRenderTarget( renderTarget );
}
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.isWebGLMultisampleRenderTarget ) {
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 ) {
let needsUpdate = false;
if ( renderTarget ) {
if ( renderTarget.isWebGLMultipleRenderTargets ) {
const textures = renderTarget.texture;
if ( _currentDrawBuffers.length !== textures.length || _currentDrawBuffers[ 0 ] !== _gl.COLOR_ATTACHMENT0 ) {
for ( let i = 0, il = textures.length; i < il; i ++ ) {
_currentDrawBuffers[ i ] = _gl.COLOR_ATTACHMENT0 + i;
}
_currentDrawBuffers.length = textures.length;
needsUpdate = true;
}
} else {
if ( _currentDrawBuffers.length !== 1 || _currentDrawBuffers[ 0 ] !== _gl.COLOR_ATTACHMENT0 ) {
_currentDrawBuffers[ 0 ] = _gl.COLOR_ATTACHMENT0;
_currentDrawBuffers.length = 1;
needsUpdate = true;
}
}
} else {
if ( _currentDrawBuffers.length !== 1 || _currentDrawBuffers[ 0 ] !== _gl.BACK ) {
_currentDrawBuffers[ 0 ] = _gl.BACK;
_currentDrawBuffers.length = 1;
needsUpdate = true;
}
}
if ( needsUpdate ) {
if ( capabilities.isWebGL2 ) {
_gl.drawBuffers( _currentDrawBuffers );
} else {
extensions.get( 'WEBGL_draw_buffers' ).drawBuffersWEBGL( _currentDrawBuffers );
}
}
}
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 );
}
};
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)