mirror of
https://github.com/jiawanlong/Cesium-Examples.git
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1219 lines
21 KiB
JavaScript
1219 lines
21 KiB
JavaScript
/**
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* @author Mugen87 / https://github.com/Mugen87
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*
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* Ported from: https://github.com/maurizzzio/quickhull3d/ by Mauricio Poppe (https://github.com/maurizzzio)
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*
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*/
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( function() {
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var Visible = 0;
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var Deleted = 1;
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function QuickHull() {
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this.tolerance = - 1;
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this.faces = []; // the generated faces of the convex hull
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this.newFaces = []; // this array holds the faces that are generated within a single iteration
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// the vertex lists work as follows:
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//
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// let 'a' and 'b' be 'Face' instances
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// let 'v' be points wrapped as instance of 'Vertex'
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//
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// [v, v, ..., v, v, v, ...]
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// ^ ^
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// | |
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// a.outside b.outside
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//
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this.assigned = new VertexList();
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this.unassigned = new VertexList();
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this.vertices = []; // vertices of the hull (internal representation of given geometry data)
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}
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Object.assign( QuickHull.prototype, {
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setFromPoints: function ( points ) {
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if ( Array.isArray( points ) !== true ) {
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console.error( 'THREE.QuickHull: Points parameter is not an array.' );
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}
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if ( points.length < 4 ) {
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console.error( 'THREE.QuickHull: The algorithm needs at least four points.' );
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}
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this.makeEmpty();
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for ( var i = 0, l = points.length; i < l; i ++ ) {
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this.vertices.push( new VertexNode( points[ i ] ) );
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}
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this.compute();
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return this;
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},
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setFromObject: function ( object ) {
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var points = [];
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object.updateMatrixWorld( true );
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object.traverse( function ( node ) {
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var i, l, point;
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var geometry = node.geometry;
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if ( geometry !== undefined ) {
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if ( geometry.isGeometry ) {
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var vertices = geometry.vertices;
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for ( i = 0, l = vertices.length; i < l; i ++ ) {
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point = vertices[ i ].clone();
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point.applyMatrix4( node.matrixWorld );
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points.push( point );
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}
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} else if ( geometry.isBufferGeometry ) {
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var attribute = geometry.attributes.position;
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if ( attribute !== undefined ) {
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for ( i = 0, l = attribute.count; i < l; i ++ ) {
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point = new THREE.Vector3();
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point.fromBufferAttribute( attribute, i ).applyMatrix4( node.matrixWorld );
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points.push( point );
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}
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}
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}
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}
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} );
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return this.setFromPoints( points );
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},
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makeEmpty: function () {
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this.faces = [];
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this.vertices = [];
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return this;
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},
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// Adds a vertex to the 'assigned' list of vertices and assigns it to the given face
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addVertexToFace: function ( vertex, face ) {
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vertex.face = face;
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if ( face.outside === null ) {
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this.assigned.append( vertex );
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} else {
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this.assigned.insertBefore( face.outside, vertex );
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}
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face.outside = vertex;
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return this;
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},
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// Removes a vertex from the 'assigned' list of vertices and from the given face
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removeVertexFromFace: function ( vertex, face ) {
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if ( vertex === face.outside ) {
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// fix face.outside link
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if ( vertex.next !== null && vertex.next.face === face ) {
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// face has at least 2 outside vertices, move the 'outside' reference
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face.outside = vertex.next;
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} else {
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// vertex was the only outside vertex that face had
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face.outside = null;
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}
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}
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this.assigned.remove( vertex );
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return this;
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},
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// Removes all the visible vertices that a given face is able to see which are stored in the 'assigned' vertext list
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removeAllVerticesFromFace: function ( face ) {
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if ( face.outside !== null ) {
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// reference to the first and last vertex of this face
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var start = face.outside;
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var end = face.outside;
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while ( end.next !== null && end.next.face === face ) {
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end = end.next;
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}
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this.assigned.removeSubList( start, end );
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// fix references
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start.prev = end.next = null;
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face.outside = null;
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return start;
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}
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},
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// Removes all the visible vertices that 'face' is able to see
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deleteFaceVertices: function ( face, absorbingFace ) {
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var faceVertices = this.removeAllVerticesFromFace( face );
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if ( faceVertices !== undefined ) {
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if ( absorbingFace === undefined ) {
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// mark the vertices to be reassigned to some other face
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this.unassigned.appendChain( faceVertices );
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} else {
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// if there's an absorbing face try to assign as many vertices as possible to it
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var vertex = faceVertices;
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do {
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// we need to buffer the subsequent vertex at this point because the 'vertex.next' reference
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// will be changed by upcoming method calls
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var nextVertex = vertex.next;
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var distance = absorbingFace.distanceToPoint( vertex.point );
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// check if 'vertex' is able to see 'absorbingFace'
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if ( distance > this.tolerance ) {
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this.addVertexToFace( vertex, absorbingFace );
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} else {
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this.unassigned.append( vertex );
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}
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// now assign next vertex
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vertex = nextVertex;
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} while ( vertex !== null );
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}
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}
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return this;
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},
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// Reassigns as many vertices as possible from the unassigned list to the new faces
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resolveUnassignedPoints: function ( newFaces ) {
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if ( this.unassigned.isEmpty() === false ) {
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var vertex = this.unassigned.first();
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do {
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// buffer 'next' reference, see .deleteFaceVertices()
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var nextVertex = vertex.next;
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var maxDistance = this.tolerance;
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var maxFace = null;
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for ( var i = 0; i < newFaces.length; i ++ ) {
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var face = newFaces[ i ];
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if ( face.mark === Visible ) {
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var distance = face.distanceToPoint( vertex.point );
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if ( distance > maxDistance ) {
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maxDistance = distance;
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maxFace = face;
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}
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if ( maxDistance > 1000 * this.tolerance ) break;
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}
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}
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// 'maxFace' can be null e.g. if there are identical vertices
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if ( maxFace !== null ) {
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this.addVertexToFace( vertex, maxFace );
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}
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vertex = nextVertex;
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} while ( vertex !== null );
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}
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return this;
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},
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// Computes the extremes of a simplex which will be the initial hull
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computeExtremes: function () {
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var min = new THREE.Vector3();
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var max = new THREE.Vector3();
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var minVertices = [];
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var maxVertices = [];
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var i, l, j;
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// initially assume that the first vertex is the min/max
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for ( i = 0; i < 3; i ++ ) {
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minVertices[ i ] = maxVertices[ i ] = this.vertices[ 0 ];
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}
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min.copy( this.vertices[ 0 ].point );
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max.copy( this.vertices[ 0 ].point );
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// compute the min/max vertex on all six directions
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for ( i = 0, l = this.vertices.length; i < l ; i ++ ) {
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var vertex = this.vertices[ i ];
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var point = vertex.point;
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// update the min coordinates
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for ( j = 0; j < 3; j ++ ) {
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if ( point.getComponent( j ) < min.getComponent( j ) ) {
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min.setComponent( j, point.getComponent( j ) );
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minVertices[ j ] = vertex;
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}
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}
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// update the max coordinates
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for ( j = 0; j < 3; j ++ ) {
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if ( point.getComponent( j ) > max.getComponent( j ) ) {
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max.setComponent( j, point.getComponent( j ) );
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maxVertices[ j ] = vertex;
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}
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}
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}
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// use min/max vectors to compute an optimal epsilon
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this.tolerance = 3 * Number.EPSILON * (
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Math.max( Math.abs( min.x ), Math.abs( max.x ) ) +
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Math.max( Math.abs( min.y ), Math.abs( max.y ) ) +
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Math.max( Math.abs( min.z ), Math.abs( max.z ) )
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);
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return { min: minVertices, max: maxVertices };
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},
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// Computes the initial simplex assigning to its faces all the points
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// that are candidates to form part of the hull
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computeInitialHull: function () {
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var line3, plane, closestPoint;
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return function computeInitialHull () {
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if ( line3 === undefined ) {
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line3 = new THREE.Line3();
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plane = new THREE.Plane();
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closestPoint = new THREE.Vector3();
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}
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var vertex, vertices = this.vertices;
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var extremes = this.computeExtremes();
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var min = extremes.min;
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var max = extremes.max;
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var v0, v1, v2, v3;
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var i, l, j;
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// 1. Find the two vertices 'v0' and 'v1' with the greatest 1d separation
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// (max.x - min.x)
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// (max.y - min.y)
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// (max.z - min.z)
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var distance, maxDistance = 0;
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var index = 0;
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for ( i = 0; i < 3; i ++ ) {
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distance = max[ i ].point.getComponent( i ) - min[ i ].point.getComponent( i );
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if ( distance > maxDistance ) {
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maxDistance = distance;
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index = i;
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}
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}
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v0 = min[ index ];
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v1 = max[ index ];
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// 2. The next vertex 'v2' is the one farthest to the line formed by 'v0' and 'v1'
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maxDistance = 0;
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line3.set( v0.point, v1.point );
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for ( i = 0, l = this.vertices.length; i < l; i ++ ) {
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vertex = vertices[ i ];
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if ( vertex !== v0 && vertex !== v1 ) {
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line3.closestPointToPoint( vertex.point, true, closestPoint );
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distance = closestPoint.distanceToSquared( vertex.point );
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if ( distance > maxDistance ) {
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maxDistance = distance;
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v2 = vertex;
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}
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}
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}
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// 3. The next vertex 'v3' is the one farthest to the plane 'v0', 'v1', 'v2'
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maxDistance = 0;
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plane.setFromCoplanarPoints( v0.point, v1.point, v2.point );
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for ( i = 0, l = this.vertices.length; i < l; i ++ ) {
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vertex = vertices[ i ];
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if ( vertex !== v0 && vertex !== v1 && vertex !== v2 ) {
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distance = Math.abs( plane.distanceToPoint( vertex.point ) );
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if ( distance > maxDistance ) {
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maxDistance = distance;
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v3 = vertex;
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}
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}
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}
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var faces = [];
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if ( plane.distanceToPoint( v3.point ) < 0 ) {
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// the face is not able to see the point so 'plane.normal' is pointing outside the tetrahedron
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faces.push(
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Face.create( v0, v1, v2 ),
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Face.create( v3, v1, v0 ),
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Face.create( v3, v2, v1 ),
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Face.create( v3, v0, v2 )
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);
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// set the twin edge
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for ( i = 0; i < 3; i ++ ) {
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j = ( i + 1 ) % 3;
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// join face[ i ] i > 0, with the first face
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faces[ i + 1 ].getEdge( 2 ).setTwin( faces[ 0 ].getEdge( j ) );
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// join face[ i ] with face[ i + 1 ], 1 <= i <= 3
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faces[ i + 1 ].getEdge( 1 ).setTwin( faces[ j + 1 ].getEdge( 0 ) );
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}
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} else {
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// the face is able to see the point so 'plane.normal' is pointing inside the tetrahedron
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faces.push(
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Face.create( v0, v2, v1 ),
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Face.create( v3, v0, v1 ),
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Face.create( v3, v1, v2 ),
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Face.create( v3, v2, v0 )
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);
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// set the twin edge
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for ( i = 0; i < 3; i ++ ) {
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j = ( i + 1 ) % 3;
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// join face[ i ] i > 0, with the first face
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faces[ i + 1 ].getEdge( 2 ).setTwin( faces[ 0 ].getEdge( ( 3 - i ) % 3 ) );
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// join face[ i ] with face[ i + 1 ]
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faces[ i + 1 ].getEdge( 0 ).setTwin( faces[ j + 1 ].getEdge( 1 ) );
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}
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}
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// the initial hull is the tetrahedron
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for ( i = 0; i < 4; i ++ ) {
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this.faces.push( faces[ i ] );
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}
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// initial assignment of vertices to the faces of the tetrahedron
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for ( i = 0, l = vertices.length; i < l; i ++ ) {
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vertex = vertices[i];
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if ( vertex !== v0 && vertex !== v1 && vertex !== v2 && vertex !== v3 ) {
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maxDistance = this.tolerance;
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var maxFace = null;
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for ( j = 0; j < 4; j ++ ) {
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distance = this.faces[ j ].distanceToPoint( vertex.point );
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if ( distance > maxDistance ) {
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maxDistance = distance;
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maxFace = this.faces[ j ];
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}
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}
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if ( maxFace !== null ) {
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this.addVertexToFace( vertex, maxFace );
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}
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}
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}
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return this;
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};
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}(),
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// Removes inactive faces
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reindexFaces: function () {
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var activeFaces = [];
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for ( var i = 0; i < this.faces.length; i ++ ) {
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var face = this.faces[ i ];
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if ( face.mark === Visible ) {
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activeFaces.push( face );
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}
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}
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this.faces = activeFaces;
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return this;
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},
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// Finds the next vertex to create faces with the current hull
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nextVertexToAdd: function () {
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// if the 'assigned' list of vertices is empty, no vertices are left. return with 'undefined'
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if ( this.assigned.isEmpty() === false ) {
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var eyeVertex, maxDistance = 0;
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// grap the first available face and start with the first visible vertex of that face
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var eyeFace = this.assigned.first().face;
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var vertex = eyeFace.outside;
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// now calculate the farthest vertex that face can see
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do {
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var distance = eyeFace.distanceToPoint( vertex.point );
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if ( distance > maxDistance ) {
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maxDistance = distance;
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eyeVertex = vertex;
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}
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vertex = vertex.next;
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} while ( vertex !== null && vertex.face === eyeFace );
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return eyeVertex;
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}
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},
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// Computes a chain of half edges in CCW order called the 'horizon'.
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// For an edge to be part of the horizon it must join a face that can see
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// 'eyePoint' and a face that cannot see 'eyePoint'.
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computeHorizon: function ( eyePoint, crossEdge, face, horizon ) {
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// moves face's vertices to the 'unassigned' vertex list
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this.deleteFaceVertices( face );
|
|
|
|
face.mark = Deleted;
|
|
|
|
var edge;
|
|
|
|
if ( crossEdge === null ) {
|
|
|
|
edge = crossEdge = face.getEdge( 0 );
|
|
|
|
} else {
|
|
|
|
// start from the next edge since 'crossEdge' was already analyzed
|
|
// (actually 'crossEdge.twin' was the edge who called this method recursively)
|
|
|
|
edge = crossEdge.next;
|
|
|
|
}
|
|
|
|
do {
|
|
|
|
var twinEdge = edge.twin;
|
|
var oppositeFace = twinEdge.face;
|
|
|
|
if ( oppositeFace.mark === Visible ) {
|
|
|
|
if ( oppositeFace.distanceToPoint( eyePoint ) > this.tolerance ) {
|
|
|
|
// the opposite face can see the vertex, so proceed with next edge
|
|
|
|
this.computeHorizon( eyePoint, twinEdge, oppositeFace, horizon );
|
|
|
|
} else {
|
|
|
|
// the opposite face can't see the vertex, so this edge is part of the horizon
|
|
|
|
horizon.push( edge );
|
|
|
|
}
|
|
|
|
}
|
|
|
|
edge = edge.next;
|
|
|
|
} while ( edge !== crossEdge );
|
|
|
|
return this;
|
|
|
|
},
|
|
|
|
// Creates a face with the vertices 'eyeVertex.point', 'horizonEdge.tail' and 'horizonEdge.head' in CCW order
|
|
|
|
addAdjoiningFace: function ( eyeVertex, horizonEdge ) {
|
|
|
|
// all the half edges are created in ccw order thus the face is always pointing outside the hull
|
|
|
|
var face = Face.create( eyeVertex, horizonEdge.tail(), horizonEdge.head() );
|
|
|
|
this.faces.push( face );
|
|
|
|
// join face.getEdge( - 1 ) with the horizon's opposite edge face.getEdge( - 1 ) = face.getEdge( 2 )
|
|
|
|
face.getEdge( - 1 ).setTwin( horizonEdge.twin );
|
|
|
|
return face.getEdge( 0 ); // the half edge whose vertex is the eyeVertex
|
|
|
|
|
|
},
|
|
|
|
// Adds 'horizon.length' faces to the hull, each face will be linked with the
|
|
// horizon opposite face and the face on the left/right
|
|
|
|
addNewFaces: function ( eyeVertex, horizon ) {
|
|
|
|
this.newFaces = [];
|
|
|
|
var firstSideEdge = null;
|
|
var previousSideEdge = null;
|
|
|
|
for ( var i = 0; i < horizon.length; i ++ ) {
|
|
|
|
var horizonEdge = horizon[ i ];
|
|
|
|
// returns the right side edge
|
|
|
|
var sideEdge = this.addAdjoiningFace( eyeVertex, horizonEdge );
|
|
|
|
if ( firstSideEdge === null ) {
|
|
|
|
firstSideEdge = sideEdge;
|
|
|
|
} else {
|
|
|
|
// joins face.getEdge( 1 ) with previousFace.getEdge( 0 )
|
|
|
|
sideEdge.next.setTwin( previousSideEdge );
|
|
|
|
}
|
|
|
|
this.newFaces.push( sideEdge.face );
|
|
previousSideEdge = sideEdge;
|
|
|
|
}
|
|
|
|
// perform final join of new faces
|
|
|
|
firstSideEdge.next.setTwin( previousSideEdge );
|
|
|
|
return this;
|
|
|
|
},
|
|
|
|
// Adds a vertex to the hull
|
|
|
|
addVertexToHull: function ( eyeVertex ) {
|
|
|
|
var horizon = [];
|
|
var i, face;
|
|
|
|
this.unassigned.clear();
|
|
|
|
// remove 'eyeVertex' from 'eyeVertex.face' so that it can't be added to the 'unassigned' vertex list
|
|
|
|
this.removeVertexFromFace( eyeVertex, eyeVertex.face );
|
|
|
|
this.computeHorizon( eyeVertex.point, null, eyeVertex.face, horizon );
|
|
|
|
this.addNewFaces( eyeVertex, horizon );
|
|
|
|
// reassign 'unassigned' vertices to the new faces
|
|
|
|
this.resolveUnassignedPoints( this.newFaces );
|
|
|
|
return this;
|
|
|
|
},
|
|
|
|
cleanup: function () {
|
|
|
|
this.assigned.clear();
|
|
this.unassigned.clear();
|
|
this.newFaces = [];
|
|
|
|
return this;
|
|
|
|
},
|
|
|
|
compute: function () {
|
|
|
|
var vertex;
|
|
|
|
this.computeInitialHull();
|
|
|
|
// add all available vertices gradually to the hull
|
|
|
|
while ( ( vertex = this.nextVertexToAdd() ) !== undefined ) {
|
|
|
|
this.addVertexToHull( vertex );
|
|
|
|
}
|
|
|
|
this.reindexFaces();
|
|
|
|
this.cleanup();
|
|
|
|
return this;
|
|
|
|
}
|
|
|
|
} );
|
|
|
|
//
|
|
|
|
function Face() {
|
|
|
|
this.normal = new THREE.Vector3();
|
|
this.midpoint = new THREE.Vector3();
|
|
this.area = 0;
|
|
|
|
this.constant = 0; // signed distance from face to the origin
|
|
this.outside = null; // reference to a vertex in a vertex list this face can see
|
|
this.mark = Visible;
|
|
this.edge = null;
|
|
|
|
}
|
|
|
|
Object.assign( Face, {
|
|
|
|
create: function( a, b, c ) {
|
|
|
|
var face = new Face();
|
|
|
|
var e0 = new HalfEdge( a, face );
|
|
var e1 = new HalfEdge( b, face );
|
|
var e2 = new HalfEdge( c, face );
|
|
|
|
// join edges
|
|
|
|
e0.next = e2.prev = e1;
|
|
e1.next = e0.prev = e2;
|
|
e2.next = e1.prev = e0;
|
|
|
|
// main half edge reference
|
|
|
|
face.edge = e0;
|
|
|
|
return face.compute();
|
|
|
|
}
|
|
|
|
} );
|
|
|
|
Object.assign( Face.prototype, {
|
|
|
|
getEdge: function ( i ) {
|
|
|
|
var edge = this.edge;
|
|
|
|
while ( i > 0 ) {
|
|
|
|
edge = edge.next;
|
|
i --;
|
|
|
|
}
|
|
|
|
while ( i < 0 ) {
|
|
|
|
edge = edge.prev;
|
|
i ++;
|
|
|
|
}
|
|
|
|
return edge;
|
|
|
|
},
|
|
|
|
compute: function () {
|
|
|
|
var triangle;
|
|
|
|
return function compute () {
|
|
|
|
if ( triangle === undefined ) triangle = new THREE.Triangle();
|
|
|
|
var a = this.edge.tail();
|
|
var b = this.edge.head();
|
|
var c = this.edge.next.head();
|
|
|
|
triangle.set( a.point, b.point, c.point );
|
|
|
|
triangle.normal( this.normal );
|
|
triangle.midpoint( this.midpoint );
|
|
this.area = triangle.area();
|
|
|
|
this.constant = this.normal.dot( this.midpoint );
|
|
|
|
return this;
|
|
|
|
};
|
|
|
|
}(),
|
|
|
|
distanceToPoint: function ( point ) {
|
|
|
|
return this.normal.dot( point ) - this.constant;
|
|
|
|
}
|
|
|
|
} );
|
|
|
|
// Entity for a Doubly-Connected Edge List (DCEL).
|
|
|
|
function HalfEdge( vertex, face ) {
|
|
|
|
this.vertex = vertex;
|
|
this.prev = null;
|
|
this.next = null;
|
|
this.twin = null;
|
|
this.face = face;
|
|
|
|
}
|
|
|
|
Object.assign( HalfEdge.prototype, {
|
|
|
|
head: function () {
|
|
|
|
return this.vertex;
|
|
|
|
},
|
|
|
|
tail: function () {
|
|
|
|
return this.prev ? this.prev.vertex : null;
|
|
|
|
},
|
|
|
|
length: function () {
|
|
|
|
var head = this.head();
|
|
var tail = this.tail();
|
|
|
|
if ( tail !== null ) {
|
|
|
|
return tail.point.distanceTo( head.point );
|
|
|
|
}
|
|
|
|
return - 1;
|
|
|
|
},
|
|
|
|
lengthSquared: function () {
|
|
|
|
var head = this.head();
|
|
var tail = this.tail();
|
|
|
|
if ( tail !== null ) {
|
|
|
|
return tail.point.distanceToSquared( head.point );
|
|
|
|
}
|
|
|
|
return - 1;
|
|
|
|
},
|
|
|
|
setTwin: function ( edge ) {
|
|
|
|
this.twin = edge;
|
|
edge.twin = this;
|
|
|
|
return this;
|
|
|
|
}
|
|
|
|
} );
|
|
|
|
// A vertex as a double linked list node.
|
|
|
|
function VertexNode( point ) {
|
|
|
|
this.point = point;
|
|
this.prev = null;
|
|
this.next = null;
|
|
this.face = null; // the face that is able to see this vertex
|
|
|
|
}
|
|
|
|
// A double linked list that contains vertex nodes.
|
|
|
|
function VertexList() {
|
|
|
|
this.head = null;
|
|
this.tail = null;
|
|
|
|
}
|
|
|
|
Object.assign( VertexList.prototype, {
|
|
|
|
first: function () {
|
|
|
|
return this.head;
|
|
|
|
},
|
|
|
|
last: function () {
|
|
|
|
return this.tail;
|
|
|
|
},
|
|
|
|
clear: function () {
|
|
|
|
this.head = this.tail = null;
|
|
|
|
return this;
|
|
|
|
},
|
|
|
|
// Inserts a vertex before the target vertex
|
|
|
|
insertBefore: function ( target, vertex ) {
|
|
|
|
vertex.prev = target.prev;
|
|
vertex.next = target;
|
|
|
|
if ( vertex.prev === null ) {
|
|
|
|
this.head = vertex;
|
|
|
|
} else {
|
|
|
|
vertex.prev.next = vertex;
|
|
|
|
}
|
|
|
|
target.prev = vertex;
|
|
|
|
return this;
|
|
|
|
},
|
|
|
|
// Inserts a vertex after the target vertex
|
|
|
|
insertAfter: function ( target, vertex ) {
|
|
|
|
vertex.prev = target;
|
|
vertex.next = target.next;
|
|
|
|
if ( vertex.next === null ) {
|
|
|
|
this.tail = vertex;
|
|
|
|
} else {
|
|
|
|
vertex.next.prev = vertex;
|
|
|
|
}
|
|
|
|
target.next = vertex;
|
|
|
|
return this;
|
|
|
|
},
|
|
|
|
// Appends a vertex to the end of the linked list
|
|
|
|
append: function ( vertex ) {
|
|
|
|
if ( this.head === null ) {
|
|
|
|
this.head = vertex;
|
|
|
|
} else {
|
|
|
|
this.tail.next = vertex;
|
|
|
|
}
|
|
|
|
vertex.prev = this.tail;
|
|
vertex.next = null; // the tail has no subsequent vertex
|
|
|
|
this.tail = vertex;
|
|
|
|
return this;
|
|
|
|
},
|
|
|
|
// Appends a chain of vertices where 'vertex' is the head.
|
|
|
|
appendChain: function ( vertex ) {
|
|
|
|
if ( this.head === null ) {
|
|
|
|
this.head = vertex;
|
|
|
|
} else {
|
|
|
|
this.tail.next = vertex;
|
|
|
|
}
|
|
|
|
vertex.prev = this.tail;
|
|
|
|
// ensure that the 'tail' reference points to the last vertex of the chain
|
|
|
|
while ( vertex.next !== null ) {
|
|
|
|
vertex = vertex.next;
|
|
|
|
}
|
|
|
|
this.tail = vertex;
|
|
|
|
return this;
|
|
|
|
},
|
|
|
|
// Removes a vertex from the linked list
|
|
|
|
remove: function ( vertex ) {
|
|
|
|
if ( vertex.prev === null ) {
|
|
|
|
this.head = vertex.next;
|
|
|
|
} else {
|
|
|
|
vertex.prev.next = vertex.next;
|
|
|
|
}
|
|
|
|
if ( vertex.next === null ) {
|
|
|
|
this.tail = vertex.prev;
|
|
|
|
} else {
|
|
|
|
vertex.next.prev = vertex.prev;
|
|
|
|
}
|
|
|
|
return this;
|
|
|
|
},
|
|
|
|
// Removes a list of vertices whose 'head' is 'a' and whose 'tail' is b
|
|
|
|
removeSubList: function ( a, b ) {
|
|
|
|
if ( a.prev === null ) {
|
|
|
|
this.head = b.next;
|
|
|
|
} else {
|
|
|
|
a.prev.next = b.next;
|
|
|
|
}
|
|
|
|
if ( b.next === null ) {
|
|
|
|
this.tail = a.prev;
|
|
|
|
} else {
|
|
|
|
b.next.prev = a.prev;
|
|
|
|
}
|
|
|
|
return this;
|
|
|
|
},
|
|
|
|
isEmpty: function() {
|
|
|
|
return this.head === null;
|
|
|
|
}
|
|
|
|
} );
|
|
|
|
// export
|
|
|
|
THREE.QuickHull = QuickHull;
|
|
|
|
|
|
} ) ();
|