three 基础库
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import {
Box3,
InstancedInterleavedBuffer,
InterleavedBufferAttribute,
Line3,
MathUtils,
Matrix4,
Mesh,
Sphere,
Vector3,
Vector4
} from '../../../build/three.module.js';
import { LineSegmentsGeometry } from '../lines/LineSegmentsGeometry.js';
import { LineMaterial } from '../lines/LineMaterial.js';
const _start = new Vector3();
const _end = new Vector3();
const _start4 = new Vector4();
const _end4 = new Vector4();
const _ssOrigin = new Vector4();
const _ssOrigin3 = new Vector3();
const _mvMatrix = new Matrix4();
const _line = new Line3();
const _closestPoint = new Vector3();
const _box = new Box3();
const _sphere = new Sphere();
const _clipToWorldVector = new Vector4();
class LineSegments2 extends Mesh {
constructor( geometry = new LineSegmentsGeometry(), material = new LineMaterial( { color: Math.random() * 0xffffff } ) ) {
super( geometry, material );
this.type = 'LineSegments2';
}
// for backwards-compatability, but could be a method of LineSegmentsGeometry...
computeLineDistances() {
const geometry = this.geometry;
const instanceStart = geometry.attributes.instanceStart;
const instanceEnd = geometry.attributes.instanceEnd;
const lineDistances = new Float32Array( 2 * instanceStart.count );
for ( let i = 0, j = 0, l = instanceStart.count; i < l; i ++, j += 2 ) {
_start.fromBufferAttribute( instanceStart, i );
_end.fromBufferAttribute( instanceEnd, i );
lineDistances[ j ] = ( j === 0 ) ? 0 : lineDistances[ j - 1 ];
lineDistances[ j + 1 ] = lineDistances[ j ] + _start.distanceTo( _end );
}
const instanceDistanceBuffer = new InstancedInterleavedBuffer( lineDistances, 2, 1 ); // d0, d1
geometry.setAttribute( 'instanceDistanceStart', new InterleavedBufferAttribute( instanceDistanceBuffer, 1, 0 ) ); // d0
geometry.setAttribute( 'instanceDistanceEnd', new InterleavedBufferAttribute( instanceDistanceBuffer, 1, 1 ) ); // d1
return this;
}
raycast( raycaster, intersects ) {
if ( raycaster.camera === null ) {
console.error( 'LineSegments2: "Raycaster.camera" needs to be set in order to raycast against LineSegments2.' );
}
const threshold = ( raycaster.params.Line2 !== undefined ) ? raycaster.params.Line2.threshold || 0 : 0;
const ray = raycaster.ray;
const camera = raycaster.camera;
const projectionMatrix = camera.projectionMatrix;
const matrixWorld = this.matrixWorld;
const geometry = this.geometry;
const material = this.material;
const resolution = material.resolution;
const lineWidth = material.linewidth + threshold;
const instanceStart = geometry.attributes.instanceStart;
const instanceEnd = geometry.attributes.instanceEnd;
// camera forward is negative
const near = - camera.near;
// clip space is [ - 1, 1 ] so multiply by two to get the full
// width in clip space
const ssMaxWidth = 2.0 * Math.max( lineWidth / resolution.width, lineWidth / resolution.height );
//
// check if we intersect the sphere bounds
if ( geometry.boundingSphere === null ) {
geometry.computeBoundingSphere();
}
_sphere.copy( geometry.boundingSphere ).applyMatrix4( matrixWorld );
const distanceToSphere = Math.max( camera.near, _sphere.distanceToPoint( ray.origin ) );
// get the w component to scale the world space line width
_clipToWorldVector.set( 0, 0, - distanceToSphere, 1.0 ).applyMatrix4( camera.projectionMatrix );
_clipToWorldVector.multiplyScalar( 1.0 / _clipToWorldVector.w );
_clipToWorldVector.applyMatrix4( camera.projectionMatrixInverse );
// increase the sphere bounds by the worst case line screen space width
const sphereMargin = Math.abs( ssMaxWidth / _clipToWorldVector.w ) * 0.5;
_sphere.radius += sphereMargin;
if ( raycaster.ray.intersectsSphere( _sphere ) === false ) {
return;
}
//
// check if we intersect the box bounds
if ( geometry.boundingBox === null ) {
geometry.computeBoundingBox();
}
_box.copy( geometry.boundingBox ).applyMatrix4( matrixWorld );
const distanceToBox = Math.max( camera.near, _box.distanceToPoint( ray.origin ) );
// get the w component to scale the world space line width
_clipToWorldVector.set( 0, 0, - distanceToBox, 1.0 ).applyMatrix4( camera.projectionMatrix );
_clipToWorldVector.multiplyScalar( 1.0 / _clipToWorldVector.w );
_clipToWorldVector.applyMatrix4( camera.projectionMatrixInverse );
// increase the sphere bounds by the worst case line screen space width
const boxMargin = Math.abs( ssMaxWidth / _clipToWorldVector.w ) * 0.5;
_box.max.x += boxMargin;
_box.max.y += boxMargin;
_box.max.z += boxMargin;
_box.min.x -= boxMargin;
_box.min.y -= boxMargin;
_box.min.z -= boxMargin;
if ( raycaster.ray.intersectsBox( _box ) === false ) {
return;
}
//
// pick a point 1 unit out along the ray to avoid the ray origin
// sitting at the camera origin which will cause "w" to be 0 when
// applying the projection matrix.
ray.at( 1, _ssOrigin );
// ndc space [ - 1.0, 1.0 ]
_ssOrigin.w = 1;
_ssOrigin.applyMatrix4( camera.matrixWorldInverse );
_ssOrigin.applyMatrix4( projectionMatrix );
_ssOrigin.multiplyScalar( 1 / _ssOrigin.w );
// screen space
_ssOrigin.x *= resolution.x / 2;
_ssOrigin.y *= resolution.y / 2;
_ssOrigin.z = 0;
_ssOrigin3.copy( _ssOrigin );
_mvMatrix.multiplyMatrices( camera.matrixWorldInverse, matrixWorld );
for ( let i = 0, l = instanceStart.count; i < l; i ++ ) {
_start4.fromBufferAttribute( instanceStart, i );
_end4.fromBufferAttribute( instanceEnd, i );
_start4.w = 1;
_end4.w = 1;
// camera space
_start4.applyMatrix4( _mvMatrix );
_end4.applyMatrix4( _mvMatrix );
// skip the segment if it's entirely behind the camera
var isBehindCameraNear = _start4.z > near && _end4.z > near;
if ( isBehindCameraNear ) {
continue;
}
// trim the segment if it extends behind camera near
if ( _start4.z > near ) {
const deltaDist = _start4.z - _end4.z;
const t = ( _start4.z - near ) / deltaDist;
_start4.lerp( _end4, t );
} else if ( _end4.z > near ) {
const deltaDist = _end4.z - _start4.z;
const t = ( _end4.z - near ) / deltaDist;
_end4.lerp( _start4, t );
}
// clip space
_start4.applyMatrix4( projectionMatrix );
_end4.applyMatrix4( projectionMatrix );
// ndc space [ - 1.0, 1.0 ]
_start4.multiplyScalar( 1 / _start4.w );
_end4.multiplyScalar( 1 / _end4.w );
// screen space
_start4.x *= resolution.x / 2;
_start4.y *= resolution.y / 2;
_end4.x *= resolution.x / 2;
_end4.y *= resolution.y / 2;
// create 2d segment
_line.start.copy( _start4 );
_line.start.z = 0;
_line.end.copy( _end4 );
_line.end.z = 0;
// get closest point on ray to segment
const param = _line.closestPointToPointParameter( _ssOrigin3, true );
_line.at( param, _closestPoint );
// check if the intersection point is within clip space
const zPos = MathUtils.lerp( _start4.z, _end4.z, param );
const isInClipSpace = zPos >= - 1 && zPos <= 1;
const isInside = _ssOrigin3.distanceTo( _closestPoint ) < lineWidth * 0.5;
if ( isInClipSpace && isInside ) {
_line.start.fromBufferAttribute( instanceStart, i );
_line.end.fromBufferAttribute( instanceEnd, i );
_line.start.applyMatrix4( matrixWorld );
_line.end.applyMatrix4( matrixWorld );
const pointOnLine = new Vector3();
const point = new Vector3();
ray.distanceSqToSegment( _line.start, _line.end, point, pointOnLine );
intersects.push( {
point: point,
pointOnLine: pointOnLine,
distance: ray.origin.distanceTo( point ),
object: this,
face: null,
faceIndex: i,
uv: null,
uv2: null,
} );
}
}
}
}
LineSegments2.prototype.LineSegments2 = true;
export { LineSegments2 };