Accueil / npm / three@0.186.1 / examples / jsm / renderers / Projector.js
Projector.js
import {
Box3,
Color,
DoubleSide,
Frustum,
Matrix3,
Matrix4,
Vector2,
Vector3,
Vector4
} from 'three';
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 Vector3();
this.vertexNormalsModel = [ new Vector3(), new Vector3(), new Vector3() ];
this.vertexNormalsLength = 0;
this.color = new Color();
this.material = null;
this.uvs = [ new Vector2(), new Vector2(), new Vector2() ];
this.z = 0;
this.renderOrder = 0;
}
}
//
class RenderableVertex {
constructor() {
this.position = new Vector3();
this.positionWorld = new Vector3();
this.positionScreen = new 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 Color(), new 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 Vector2();
this.material = null;
this.renderOrder = 0;
}
}
/**
* This class can project a given scene in 3D space into a 2D representation
* used for rendering with a 2D API. `Projector` is currently used by {@link SVGRenderer}
* and was previously used by the legacy `CanvasRenderer`.
*
* @three_import import { Projector } from 'three/addons/renderers/Projector.js';
*/
class Projector {
/**
* Constructs a new projector.
*/
constructor() {
let _object, _objectCount, _objectPoolLength = 0,
_vertex, _vertexCount, _vertexPoolLength = 0,
_face, _faceCount, _facePoolLength = 0,
_line, _lineCount, _linePoolLength = 0,
_sprite, _spriteCount, _spritePoolLength = 0,
_modelMatrix, _clipInput = [], _clipOutput = [];
const
_renderData = { objects: [], lights: [], elements: [] },
_vector3 = new Vector3(),
_vector4 = new Vector4(),
_clipBox = new Box3( new Vector3( - 1, - 1, - 1 ), new Vector3( 1, 1, 1 ) ),
_boundingBox = new Box3(),
_points3 = new Array( 3 ),
_viewMatrix = new Matrix4(),
_viewProjectionMatrix = new Matrix4(),
_modelViewProjectionMatrix = new Matrix4(),
_frustum = new Frustum(),
_objectPool = [], _vertexPool = [], _facePool = [], _linePool = [], _spritePool = [],
_clipVertexPool = [],
_clipPos1 = new Vector4(),
_clipPos2 = new Vector4(),
_clipPos3 = new Vector4(),
_screenVertexPool = [],
_clipInputVertices = [ null, null, null ],
_clipPlanes = [
{ sign: + 1 },
{ sign: - 1 }
];
//
function RenderList() {
const normals = [];
const colors = [];
const uvs = [];
let object = null;
const normalMatrix = new 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 ];
// Derive near/far clip distances from NDC z and stored clip-space w
// (projectVertex already computed positionScreen = clipPos / w, with w preserved)
const w1 = v1.positionScreen.w;
const w2 = v2.positionScreen.w;
const w3 = v3.positionScreen.w;
const nearDist1 = w1 * ( v1.positionScreen.z + 1 );
const nearDist2 = w2 * ( v2.positionScreen.z + 1 );
const nearDist3 = w3 * ( v3.positionScreen.z + 1 );
const farDist1 = w1 * ( 1 - v1.positionScreen.z );
const farDist2 = w2 * ( 1 - v2.positionScreen.z );
const farDist3 = w3 * ( 1 - v3.positionScreen.z );
// Check if completely outside
if ( ( nearDist1 < 0 && nearDist2 < 0 && nearDist3 < 0 ) ||
( farDist1 < 0 && farDist2 < 0 && farDist3 < 0 ) ) {
return; // Triangle completely clipped
}
// Check if completely inside (no clipping needed)
if ( nearDist1 >= 0 && nearDist2 >= 0 && nearDist3 >= 0 &&
farDist1 >= 0 && farDist2 >= 0 && farDist3 >= 0 ) {
// No clipping needed - use original path
if ( checkTriangleVisibility( v1, v2, v3 ) === false ) return;
if ( material.side === 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;
}
// Triangle needs clipping - reconstruct clip-space positions from NDC + w
_clipPos1.set( v1.positionScreen.x * w1, v1.positionScreen.y * w1, v1.positionScreen.z * w1, w1 );
_clipPos2.set( v2.positionScreen.x * w2, v2.positionScreen.y * w2, v2.positionScreen.z * w2, w2 );
_clipPos3.set( v3.positionScreen.x * w3, v3.positionScreen.y * w3, v3.positionScreen.z * w3, w3 );
_clipInputVertices[ 0 ] = _clipPos1;
_clipInputVertices[ 1 ] = _clipPos2;
_clipInputVertices[ 2 ] = _clipPos3;
const clippedCount = clipTriangle( _clipInputVertices );
if ( clippedCount < 3 ) return; // Triangle completely clipped
// Perform perspective divide on clipped vertices and create screen vertices
for ( let i = 0; i < clippedCount; i ++ ) {
const cv = _clipInput[ i ];
// Get or create renderable vertex from pool
let sv = _screenVertexPool[ i ];
if ( ! sv ) {
sv = new RenderableVertex();
_screenVertexPool[ i ] = sv;
}
// Perform perspective divide
const invW = 1 / cv.w;
sv.positionScreen.set( cv.x * invW, cv.y * invW, cv.z * invW, 1 );
// Interpolate world position (simplified - using weighted average based on barycentric-like coords)
// For a proper implementation, we'd need to track interpolation weights
sv.positionWorld.copy( v1.positionWorld );
sv.visible = true;
}
// Triangulate the clipped polygon (simple fan triangulation)
for ( let i = 1; i < clippedCount - 1; i ++ ) {
const tv1 = _screenVertexPool[ 0 ];
const tv2 = _screenVertexPool[ i ];
const tv3 = _screenVertexPool[ i + 1 ];
if ( material.side === DoubleSide || checkBackfaceCulling( tv1, tv2, tv3 ) === true ) {
_face = getNextFaceInPool();
_face.id = object.id;
_face.v1.copy( tv1 );
_face.v2.copy( tv2 );
_face.v3.copy( tv3 );
_face.z = ( tv1.positionScreen.z + tv2.positionScreen.z + tv3.positionScreen.z ) / 3;
_face.renderOrder = object.renderOrder;
// face normal - use original triangle's 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();
// Use original vertex normals and UVs (simplified - proper impl would interpolate)
for ( let j = 0; j < 3; j ++ ) {
const normal = _face.vertexNormalsModel[ j ];
normal.fromArray( normals, arguments[ j ] * 3 );
normal.applyMatrix3( normalMatrix ).normalize();
const uv = _face.uvs[ j ];
uv.fromArray( uvs, arguments[ j ] * 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 );
}
/**
* Projects the given scene in 3D space into a 2D representation. The result
* is an object with renderable items.
*
* @param {Object3D} scene - A scene or any other type of 3D object.
* @param {Camera} camera - The camera.
* @param {boolean} sortObjects - Whether to sort objects or not.
* @param {boolean} sortElements - Whether to sort elements (faces, lines and sprites) or not.
* @return {{objects:Array<Objects>,lights:Array<Objects>,elements:Array<Objects>}} The projected scene as renderable objects.
*/
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;
}
}
// Sutherland-Hodgman triangle clipping in homogeneous clip space
// Returns count of vertices in clipped polygon (0 if completely clipped, 3+ if partially clipped)
// Result vertices are in _clipInput array
function clipTriangle( vertices ) {
// Initialize input with the three input vertices
_clipInput[ 0 ] = vertices[ 0 ];
_clipInput[ 1 ] = vertices[ 1 ];
_clipInput[ 2 ] = vertices[ 2 ];
let inputCount = 3;
let outputCount = 0;
for ( let p = 0; p < _clipPlanes.length; p ++ ) {
const plane = _clipPlanes[ p ];
outputCount = 0;
if ( inputCount === 0 ) break;
for ( let i = 0; i < inputCount; i ++ ) {
const v1 = _clipInput[ i ];
const v2 = _clipInput[ ( i + 1 ) % inputCount ];
const d1 = plane.sign * v1.z + v1.w;
const d2 = plane.sign * v2.z + v2.w;
const v1Inside = d1 >= 0;
const v2Inside = d2 >= 0;
if ( v1Inside && v2Inside ) {
// Both inside - add v1
_clipOutput[ outputCount ++ ] = v1;
} else if ( v1Inside && ! v2Inside ) {
// v1 inside, v2 outside - add v1 and intersection
_clipOutput[ outputCount ++ ] = v1;
const t = d1 / ( d1 - d2 );
let intersection = _clipVertexPool[ outputCount ];
if ( ! intersection ) {
intersection = new Vector4();
_clipVertexPool[ outputCount ] = intersection;
}
intersection.lerpVectors( v1, v2, t );
_clipOutput[ outputCount ++ ] = intersection;
} else if ( ! v1Inside && v2Inside ) {
// v1 outside, v2 inside - add intersection only
const t = d1 / ( d1 - d2 );
let intersection = _clipVertexPool[ outputCount ];
if ( ! intersection ) {
intersection = new Vector4();
_clipVertexPool[ outputCount ] = intersection;
}
intersection.lerpVectors( v1, v2, t );
_clipOutput[ outputCount ++ ] = intersection;
}
// Both outside - add nothing
}
// Swap input/output
const temp = _clipInput;
_clipInput = _clipOutput;
_clipOutput = temp;
inputCount = outputCount;
}
return inputCount;
}
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;
}
}
}
}
}
export { RenderableObject, RenderableFace, RenderableVertex, RenderableLine, RenderableSprite, Projector };