Cesium-Examples/examples/cesiumEx/ammolibs/ammo/ex/geometries/ConvexGeometry.js
2025-03-11 17:51:04 +08:00

91 lines
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JavaScript

/**
* @author Mugen87 / https://github.com/Mugen87
*/
( function() {
// ConvexGeometry
function ConvexGeometry( points ) {
THREE.Geometry.call( this );
this.type = 'ConvexGeometry';
this.fromBufferGeometry( new ConvexBufferGeometry( points ) );
this.mergeVertices();
}
ConvexGeometry.prototype = Object.create( THREE.Geometry.prototype );
ConvexGeometry.prototype.constructor = ConvexGeometry;
// ConvexBufferGeometry
function ConvexBufferGeometry( points ) {
THREE.BufferGeometry.call( this );
this.type = 'ConvexBufferGeometry';
// buffers
var vertices = [];
var normals = [];
// execute QuickHull
if ( THREE.QuickHull === undefined ) {
console.error( 'THREE.ConvexBufferGeometry: ConvexBufferGeometry relies on THREE.QuickHull' );
}
var quickHull = new THREE.QuickHull().setFromPoints( points );
// generate vertices and normals
var faces = quickHull.faces;
for ( var i = 0; i < faces.length; i ++ ) {
var face = faces[ i ];
var edge = face.edge;
// we move along a doubly-connected edge list to access all face points (see HalfEdge docs)
do {
var point = edge.head().point;
vertices.push( point.x, point.y, point.z );
normals.push( face.normal.x, face.normal.y, face.normal.z );
edge = edge.next;
} while ( edge !== face.edge );
}
// build geometry
if (THREE.Float32BufferAttribute) {
this.addAttribute('position', new THREE.Float32BufferAttribute(vertices, 3));
this.addAttribute('normal', new THREE.Float32BufferAttribute(normals, 3));
} else {
this.addAttribute('position', new THREE.BufferAttribute(new Float32Array(vertices), 3));
this.addAttribute('normal', new THREE.BufferAttribute(new Float32Array(normals), 3));
}
}
ConvexBufferGeometry.prototype = Object.create( THREE.BufferGeometry.prototype );
ConvexBufferGeometry.prototype.constructor = ConvexBufferGeometry;
// export
THREE.ConvexGeometry = ConvexGeometry;
THREE.ConvexBufferGeometry = ConvexBufferGeometry;
} ) ();