threejs/examples/js/renderers/Projector.js

( function () {

	class RenderableObject {

		constructor() {

			this.id = 0;
			this.object = null;
			this.z = 0;
			this.renderOrder = 0;

		}

	}

	//

	class RenderableFace {

		constructor() {

			this.id = 0;
			this.v1 = new RenderableVertex();
			this.v2 = new RenderableVertex();
			this.v3 = new RenderableVertex();
			this.normalModel = new THREE.Vector3();
			this.vertexNormalsModel = [ new THREE.Vector3(), new THREE.Vector3(), new THREE.Vector3() ];
			this.vertexNormalsLength = 0;
			this.color = new THREE.Color();
			this.material = null;
			this.uvs = [ new THREE.Vector2(), new THREE.Vector2(), new THREE.Vector2() ];
			this.z = 0;
			this.renderOrder = 0;

		}

	}

	//

	class RenderableVertex {

		constructor() {

			this.position = new THREE.Vector3();
			this.positionWorld = new THREE.Vector3();
			this.positionScreen = new THREE.Vector4();
			this.visible = true;

		}
		copy( vertex ) {

			this.positionWorld.copy( vertex.positionWorld );
			this.positionScreen.copy( vertex.positionScreen );

		}

	}

	//

	class RenderableLine {

		constructor() {

			this.id = 0;
			this.v1 = new RenderableVertex();
			this.v2 = new RenderableVertex();
			this.vertexColors = [ new THREE.Color(), new THREE.Color() ];
			this.material = null;
			this.z = 0;
			this.renderOrder = 0;

		}

	}

	//

	class RenderableSprite {

		constructor() {

			this.id = 0;
			this.object = null;
			this.x = 0;
			this.y = 0;
			this.z = 0;
			this.rotation = 0;
			this.scale = new THREE.Vector2();
			this.material = null;
			this.renderOrder = 0;

		}

	}

	//

	class Projector {

		constructor() {

			let _object,
				_objectCount,
				_objectPoolLength = 0,
				_vertex,
				_vertexCount,
				_vertexPoolLength = 0,
				_face,
				_faceCount,
				_facePoolLength = 0,
				_line,
				_lineCount,
				_linePoolLength = 0,
				_sprite,
				_spriteCount,
				_spritePoolLength = 0,
				_modelMatrix;
			const _renderData = {
					objects: [],
					lights: [],
					elements: []
				},
				_vector3 = new THREE.Vector3(),
				_vector4 = new THREE.Vector4(),
				_clipBox = new THREE.Box3( new THREE.Vector3( - 1, - 1, - 1 ), new THREE.Vector3( 1, 1, 1 ) ),
				_boundingBox = new THREE.Box3(),
				_points3 = new Array( 3 ),
				_viewMatrix = new THREE.Matrix4(),
				_viewProjectionMatrix = new THREE.Matrix4(),
				_modelViewProjectionMatrix = new THREE.Matrix4(),
				_frustum = new THREE.Frustum(),
				_objectPool = [],
				_vertexPool = [],
				_facePool = [],
				_linePool = [],
				_spritePool = [];

			//

			function RenderList() {

				const normals = [];
				const colors = [];
				const uvs = [];
				let object = null;
				const normalMatrix = new THREE.Matrix3();
				function setObject( value ) {

					object = value;
					normalMatrix.getNormalMatrix( object.matrixWorld );
					normals.length = 0;
					colors.length = 0;
					uvs.length = 0;

				}

				function projectVertex( vertex ) {

					const position = vertex.position;
					const positionWorld = vertex.positionWorld;
					const positionScreen = vertex.positionScreen;
					positionWorld.copy( position ).applyMatrix4( _modelMatrix );
					positionScreen.copy( positionWorld ).applyMatrix4( _viewProjectionMatrix );
					const invW = 1 / positionScreen.w;
					positionScreen.x *= invW;
					positionScreen.y *= invW;
					positionScreen.z *= invW;
					vertex.visible = positionScreen.x >= - 1 && positionScreen.x <= 1 && positionScreen.y >= - 1 && positionScreen.y <= 1 && positionScreen.z >= - 1 && positionScreen.z <= 1;

				}

				function pushVertex( x, y, z ) {

					_vertex = getNextVertexInPool();
					_vertex.position.set( x, y, z );
					projectVertex( _vertex );

				}

				function pushNormal( x, y, z ) {

					normals.push( x, y, z );

				}

				function pushColor( r, g, b ) {

					colors.push( r, g, b );

				}

				function pushUv( x, y ) {

					uvs.push( x, y );

				}

				function checkTriangleVisibility( v1, v2, v3 ) {

					if ( v1.visible === true || v2.visible === true || v3.visible === true ) return true;
					_points3[ 0 ] = v1.positionScreen;
					_points3[ 1 ] = v2.positionScreen;
					_points3[ 2 ] = v3.positionScreen;
					return _clipBox.intersectsBox( _boundingBox.setFromPoints( _points3 ) );

				}

				function checkBackfaceCulling( v1, v2, v3 ) {

					return ( v3.positionScreen.x - v1.positionScreen.x ) * ( v2.positionScreen.y - v1.positionScreen.y ) - ( v3.positionScreen.y - v1.positionScreen.y ) * ( v2.positionScreen.x - v1.positionScreen.x ) < 0;

				}

				function pushLine( a, b ) {

					const v1 = _vertexPool[ a ];
					const v2 = _vertexPool[ b ];

					// Clip

					v1.positionScreen.copy( v1.position ).applyMatrix4( _modelViewProjectionMatrix );
					v2.positionScreen.copy( v2.position ).applyMatrix4( _modelViewProjectionMatrix );
					if ( clipLine( v1.positionScreen, v2.positionScreen ) === true ) {

						// Perform the perspective divide
						v1.positionScreen.multiplyScalar( 1 / v1.positionScreen.w );
						v2.positionScreen.multiplyScalar( 1 / v2.positionScreen.w );
						_line = getNextLineInPool();
						_line.id = object.id;
						_line.v1.copy( v1 );
						_line.v2.copy( v2 );
						_line.z = Math.max( v1.positionScreen.z, v2.positionScreen.z );
						_line.renderOrder = object.renderOrder;
						_line.material = object.material;
						if ( object.material.vertexColors ) {

							_line.vertexColors[ 0 ].fromArray( colors, a * 3 );
							_line.vertexColors[ 1 ].fromArray( colors, b * 3 );

						}

						_renderData.elements.push( _line );

					}

				}

				function pushTriangle( a, b, c, material ) {

					const v1 = _vertexPool[ a ];
					const v2 = _vertexPool[ b ];
					const v3 = _vertexPool[ c ];
					if ( checkTriangleVisibility( v1, v2, v3 ) === false ) return;
					if ( material.side === THREE.DoubleSide || checkBackfaceCulling( v1, v2, v3 ) === true ) {

						_face = getNextFaceInPool();
						_face.id = object.id;
						_face.v1.copy( v1 );
						_face.v2.copy( v2 );
						_face.v3.copy( v3 );
						_face.z = ( v1.positionScreen.z + v2.positionScreen.z + v3.positionScreen.z ) / 3;
						_face.renderOrder = object.renderOrder;

						// face normal
						_vector3.subVectors( v3.position, v2.position );
						_vector4.subVectors( v1.position, v2.position );
						_vector3.cross( _vector4 );
						_face.normalModel.copy( _vector3 );
						_face.normalModel.applyMatrix3( normalMatrix ).normalize();
						for ( let i = 0; i < 3; i ++ ) {

							const normal = _face.vertexNormalsModel[ i ];
							normal.fromArray( normals, arguments[ i ] * 3 );
							normal.applyMatrix3( normalMatrix ).normalize();
							const uv = _face.uvs[ i ];
							uv.fromArray( uvs, arguments[ i ] * 2 );

						}

						_face.vertexNormalsLength = 3;
						_face.material = material;
						if ( material.vertexColors ) {

							_face.color.fromArray( colors, a * 3 );

						}

						_renderData.elements.push( _face );

					}

				}

				return {
					setObject: setObject,
					projectVertex: projectVertex,
					checkTriangleVisibility: checkTriangleVisibility,
					checkBackfaceCulling: checkBackfaceCulling,
					pushVertex: pushVertex,
					pushNormal: pushNormal,
					pushColor: pushColor,
					pushUv: pushUv,
					pushLine: pushLine,
					pushTriangle: pushTriangle
				};

			}

			const renderList = new RenderList();
			function projectObject( object ) {

				if ( object.visible === false ) return;
				if ( object.isLight ) {

					_renderData.lights.push( object );

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

					if ( object.material.visible === false ) return;
					if ( object.frustumCulled === true && _frustum.intersectsObject( object ) === false ) return;
					addObject( object );

				} else if ( object.isSprite ) {

					if ( object.material.visible === false ) return;
					if ( object.frustumCulled === true && _frustum.intersectsSprite( object ) === false ) return;
					addObject( object );

				}

				const children = object.children;
				for ( let i = 0, l = children.length; i < l; i ++ ) {

					projectObject( children[ i ] );

				}

			}

			function addObject( object ) {

				_object = getNextObjectInPool();
				_object.id = object.id;
				_object.object = object;
				_vector3.setFromMatrixPosition( object.matrixWorld );
				_vector3.applyMatrix4( _viewProjectionMatrix );
				_object.z = _vector3.z;
				_object.renderOrder = object.renderOrder;
				_renderData.objects.push( _object );

			}

			this.projectScene = function ( scene, camera, sortObjects, sortElements ) {

				_faceCount = 0;
				_lineCount = 0;
				_spriteCount = 0;
				_renderData.elements.length = 0;
				if ( scene.matrixWorldAutoUpdate === true ) scene.updateMatrixWorld();
				if ( camera.parent === null && camera.matrixWorldAutoUpdate === true ) camera.updateMatrixWorld();
				_viewMatrix.copy( camera.matrixWorldInverse );
				_viewProjectionMatrix.multiplyMatrices( camera.projectionMatrix, _viewMatrix );
				_frustum.setFromProjectionMatrix( _viewProjectionMatrix );

				//

				_objectCount = 0;
				_renderData.objects.length = 0;
				_renderData.lights.length = 0;
				projectObject( scene );
				if ( sortObjects === true ) {

					_renderData.objects.sort( painterSort );

				}

				//

				const objects = _renderData.objects;
				for ( let o = 0, ol = objects.length; o < ol; o ++ ) {

					const object = objects[ o ].object;
					const geometry = object.geometry;
					renderList.setObject( object );
					_modelMatrix = object.matrixWorld;
					_vertexCount = 0;
					if ( object.isMesh ) {

						let material = object.material;
						const isMultiMaterial = Array.isArray( material );
						const attributes = geometry.attributes;
						const groups = geometry.groups;
						if ( attributes.position === undefined ) continue;
						const positions = attributes.position.array;
						for ( let i = 0, l = positions.length; i < l; i += 3 ) {

							let x = positions[ i ];
							let y = positions[ i + 1 ];
							let z = positions[ i + 2 ];
							const morphTargets = geometry.morphAttributes.position;
							if ( morphTargets !== undefined ) {

								const morphTargetsRelative = geometry.morphTargetsRelative;
								const morphInfluences = object.morphTargetInfluences;
								for ( let t = 0, tl = morphTargets.length; t < tl; t ++ ) {

									const influence = morphInfluences[ t ];
									if ( influence === 0 ) continue;
									const target = morphTargets[ t ];
									if ( morphTargetsRelative ) {

										x += target.getX( i / 3 ) * influence;
										y += target.getY( i / 3 ) * influence;
										z += target.getZ( i / 3 ) * influence;

									} else {

										x += ( target.getX( i / 3 ) - positions[ i ] ) * influence;
										y += ( target.getY( i / 3 ) - positions[ i + 1 ] ) * influence;
										z += ( target.getZ( i / 3 ) - positions[ i + 2 ] ) * influence;

									}

								}

							}

							renderList.pushVertex( x, y, z );

						}

						if ( attributes.normal !== undefined ) {

							const normals = attributes.normal.array;
							for ( let i = 0, l = normals.length; i < l; i += 3 ) {

								renderList.pushNormal( normals[ i ], normals[ i + 1 ], normals[ i + 2 ] );

							}

						}

						if ( attributes.color !== undefined ) {

							const colors = attributes.color.array;
							for ( let i = 0, l = colors.length; i < l; i += 3 ) {

								renderList.pushColor( colors[ i ], colors[ i + 1 ], colors[ i + 2 ] );

							}

						}

						if ( attributes.uv !== undefined ) {

							const uvs = attributes.uv.array;
							for ( let i = 0, l = uvs.length; i < l; i += 2 ) {

								renderList.pushUv( uvs[ i ], uvs[ i + 1 ] );

							}

						}

						if ( geometry.index !== null ) {

							const indices = geometry.index.array;
							if ( groups.length > 0 ) {

								for ( let g = 0; g < groups.length; g ++ ) {

									const group = groups[ g ];
									material = isMultiMaterial === true ? object.material[ group.materialIndex ] : object.material;
									if ( material === undefined ) continue;
									for ( let i = group.start, l = group.start + group.count; i < l; i += 3 ) {

										renderList.pushTriangle( indices[ i ], indices[ i + 1 ], indices[ i + 2 ], material );

									}

								}

							} else {

								for ( let i = 0, l = indices.length; i < l; i += 3 ) {

									renderList.pushTriangle( indices[ i ], indices[ i + 1 ], indices[ i + 2 ], material );

								}

							}

						} else {

							if ( groups.length > 0 ) {

								for ( let g = 0; g < groups.length; g ++ ) {

									const group = groups[ g ];
									material = isMultiMaterial === true ? object.material[ group.materialIndex ] : object.material;
									if ( material === undefined ) continue;
									for ( let i = group.start, l = group.start + group.count; i < l; i += 3 ) {

										renderList.pushTriangle( i, i + 1, i + 2, material );

									}

								}

							} else {

								for ( let i = 0, l = positions.length / 3; i < l; i += 3 ) {

									renderList.pushTriangle( i, i + 1, i + 2, material );

								}

							}

						}

					} else if ( object.isLine ) {

						_modelViewProjectionMatrix.multiplyMatrices( _viewProjectionMatrix, _modelMatrix );
						const attributes = geometry.attributes;
						if ( attributes.position !== undefined ) {

							const positions = attributes.position.array;
							for ( let i = 0, l = positions.length; i < l; i += 3 ) {

								renderList.pushVertex( positions[ i ], positions[ i + 1 ], positions[ i + 2 ] );

							}

							if ( attributes.color !== undefined ) {

								const colors = attributes.color.array;
								for ( let i = 0, l = colors.length; i < l; i += 3 ) {

									renderList.pushColor( colors[ i ], colors[ i + 1 ], colors[ i + 2 ] );

								}

							}

							if ( geometry.index !== null ) {

								const indices = geometry.index.array;
								for ( let i = 0, l = indices.length; i < l; i += 2 ) {

									renderList.pushLine( indices[ i ], indices[ i + 1 ] );

								}

							} else {

								const step = object.isLineSegments ? 2 : 1;
								for ( let i = 0, l = positions.length / 3 - 1; i < l; i += step ) {

									renderList.pushLine( i, i + 1 );

								}

							}

						}

					} else if ( object.isPoints ) {

						_modelViewProjectionMatrix.multiplyMatrices( _viewProjectionMatrix, _modelMatrix );
						const attributes = geometry.attributes;
						if ( attributes.position !== undefined ) {

							const positions = attributes.position.array;
							for ( let i = 0, l = positions.length; i < l; i += 3 ) {

								_vector4.set( positions[ i ], positions[ i + 1 ], positions[ i + 2 ], 1 );
								_vector4.applyMatrix4( _modelViewProjectionMatrix );
								pushPoint( _vector4, object, camera );

							}

						}

					} else if ( object.isSprite ) {

						object.modelViewMatrix.multiplyMatrices( camera.matrixWorldInverse, object.matrixWorld );
						_vector4.set( _modelMatrix.elements[ 12 ], _modelMatrix.elements[ 13 ], _modelMatrix.elements[ 14 ], 1 );
						_vector4.applyMatrix4( _viewProjectionMatrix );
						pushPoint( _vector4, object, camera );

					}

				}

				if ( sortElements === true ) {

					_renderData.elements.sort( painterSort );

				}

				return _renderData;

			};

			function pushPoint( _vector4, object, camera ) {

				const invW = 1 / _vector4.w;
				_vector4.z *= invW;
				if ( _vector4.z >= - 1 && _vector4.z <= 1 ) {

					_sprite = getNextSpriteInPool();
					_sprite.id = object.id;
					_sprite.x = _vector4.x * invW;
					_sprite.y = _vector4.y * invW;
					_sprite.z = _vector4.z;
					_sprite.renderOrder = object.renderOrder;
					_sprite.object = object;
					_sprite.rotation = object.rotation;
					_sprite.scale.x = object.scale.x * Math.abs( _sprite.x - ( _vector4.x + camera.projectionMatrix.elements[ 0 ] ) / ( _vector4.w + camera.projectionMatrix.elements[ 12 ] ) );
					_sprite.scale.y = object.scale.y * Math.abs( _sprite.y - ( _vector4.y + camera.projectionMatrix.elements[ 5 ] ) / ( _vector4.w + camera.projectionMatrix.elements[ 13 ] ) );
					_sprite.material = object.material;
					_renderData.elements.push( _sprite );

				}

			}

			// Pools

			function getNextObjectInPool() {

				if ( _objectCount === _objectPoolLength ) {

					const object = new RenderableObject();
					_objectPool.push( object );
					_objectPoolLength ++;
					_objectCount ++;
					return object;

				}

				return _objectPool[ _objectCount ++ ];

			}

			function getNextVertexInPool() {

				if ( _vertexCount === _vertexPoolLength ) {

					const vertex = new RenderableVertex();
					_vertexPool.push( vertex );
					_vertexPoolLength ++;
					_vertexCount ++;
					return vertex;

				}

				return _vertexPool[ _vertexCount ++ ];

			}

			function getNextFaceInPool() {

				if ( _faceCount === _facePoolLength ) {

					const face = new RenderableFace();
					_facePool.push( face );
					_facePoolLength ++;
					_faceCount ++;
					return face;

				}

				return _facePool[ _faceCount ++ ];

			}

			function getNextLineInPool() {

				if ( _lineCount === _linePoolLength ) {

					const line = new RenderableLine();
					_linePool.push( line );
					_linePoolLength ++;
					_lineCount ++;
					return line;

				}

				return _linePool[ _lineCount ++ ];

			}

			function getNextSpriteInPool() {

				if ( _spriteCount === _spritePoolLength ) {

					const sprite = new RenderableSprite();
					_spritePool.push( sprite );
					_spritePoolLength ++;
					_spriteCount ++;
					return sprite;

				}

				return _spritePool[ _spriteCount ++ ];

			}

			//

			function painterSort( a, b ) {

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

					return a.renderOrder - b.renderOrder;

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

					return b.z - a.z;

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

					return a.id - b.id;

				} else {

					return 0;

				}

			}

			function clipLine( s1, s2 ) {

				let alpha1 = 0,
					alpha2 = 1;

				// Calculate the boundary coordinate of each vertex for the near and far clip planes,
				// Z = -1 and Z = +1, respectively.

				const bc1near = s1.z + s1.w,
					bc2near = s2.z + s2.w,
					bc1far = - s1.z + s1.w,
					bc2far = - s2.z + s2.w;
				if ( bc1near >= 0 && bc2near >= 0 && bc1far >= 0 && bc2far >= 0 ) {

					// Both vertices lie entirely within all clip planes.
					return true;

				} else if ( bc1near < 0 && bc2near < 0 || bc1far < 0 && bc2far < 0 ) {

					// Both vertices lie entirely outside one of the clip planes.
					return false;

				} else {

					// The line segment spans at least one clip plane.

					if ( bc1near < 0 ) {

						// v1 lies outside the near plane, v2 inside
						alpha1 = Math.max( alpha1, bc1near / ( bc1near - bc2near ) );

					} else if ( bc2near < 0 ) {

						// v2 lies outside the near plane, v1 inside
						alpha2 = Math.min( alpha2, bc1near / ( bc1near - bc2near ) );

					}

					if ( bc1far < 0 ) {

						// v1 lies outside the far plane, v2 inside
						alpha1 = Math.max( alpha1, bc1far / ( bc1far - bc2far ) );

					} else if ( bc2far < 0 ) {

						// v2 lies outside the far plane, v2 inside
						alpha2 = Math.min( alpha2, bc1far / ( bc1far - bc2far ) );

					}

					if ( alpha2 < alpha1 ) {

						// The line segment spans two boundaries, but is outside both of them.
						// (This can't happen when we're only clipping against just near/far but good
						//  to leave the check here for future usage if other clip planes are added.)
						return false;

					} else {

						// Update the s1 and s2 vertices to match the clipped line segment.
						s1.lerp( s2, alpha1 );
						s2.lerp( s1, 1 - alpha2 );
						return true;

					}

				}

			}

		}

	}

	THREE.Projector = Projector;
	THREE.RenderableFace = RenderableFace;
	THREE.RenderableLine = RenderableLine;
	THREE.RenderableObject = RenderableObject;
	THREE.RenderableSprite = RenderableSprite;
	THREE.RenderableVertex = RenderableVertex;

} )();