Spaces:
Running
Running
| /** | |
| * @author Mugen87 / https://github.com/Mugen87 | |
| * | |
| * Ported from: https://github.com/maurizzzio/quickhull3d/ by Mauricio Poppe (https://github.com/maurizzzio) | |
| * | |
| */ | |
| ( function () { | |
| var Visible = 0; | |
| var Deleted = 1; | |
| function QuickHull() { | |
| this.tolerance = - 1; | |
| this.faces = []; // the generated faces of the convex hull | |
| this.newFaces = []; // this array holds the faces that are generated within a single iteration | |
| // the vertex lists work as follows: | |
| // | |
| // let 'a' and 'b' be 'Face' instances | |
| // let 'v' be points wrapped as instance of 'Vertex' | |
| // | |
| // [v, v, ..., v, v, v, ...] | |
| // ^ ^ | |
| // | | | |
| // a.outside b.outside | |
| // | |
| this.assigned = new VertexList(); | |
| this.unassigned = new VertexList(); | |
| this.vertices = []; // vertices of the hull (internal representation of given geometry data) | |
| } | |
| Object.assign( QuickHull.prototype, { | |
| setFromPoints: function ( points ) { | |
| if ( Array.isArray( points ) !== true ) { | |
| console.error( 'THREE.QuickHull: Points parameter is not an array.' ); | |
| } | |
| if ( points.length < 4 ) { | |
| console.error( 'THREE.QuickHull: The algorithm needs at least four points.' ); | |
| } | |
| this.makeEmpty(); | |
| for ( var i = 0, l = points.length; i < l; i ++ ) { | |
| this.vertices.push( new VertexNode( points[ i ] ) ); | |
| } | |
| this.compute(); | |
| return this; | |
| }, | |
| setFromObject: function ( object ) { | |
| var points = []; | |
| object.updateMatrixWorld( true ); | |
| object.traverse( function ( node ) { | |
| var i, l, point; | |
| var geometry = node.geometry; | |
| if ( geometry !== undefined ) { | |
| if ( geometry.isGeometry ) { | |
| var vertices = geometry.vertices; | |
| for ( i = 0, l = vertices.length; i < l; i ++ ) { | |
| point = vertices[ i ].clone(); | |
| point.applyMatrix4( node.matrixWorld ); | |
| points.push( point ); | |
| } | |
| } else if ( geometry.isBufferGeometry ) { | |
| var attribute = geometry.attributes.position; | |
| if ( attribute !== undefined ) { | |
| for ( i = 0, l = attribute.count; i < l; i ++ ) { | |
| point = new THREE.Vector3(); | |
| point.fromBufferAttribute( attribute, i ).applyMatrix4( node.matrixWorld ); | |
| points.push( point ); | |
| } | |
| } | |
| } | |
| } | |
| } ); | |
| return this.setFromPoints( points ); | |
| }, | |
| makeEmpty: function () { | |
| this.faces = []; | |
| this.vertices = []; | |
| return this; | |
| }, | |
| // Adds a vertex to the 'assigned' list of vertices and assigns it to the given face | |
| addVertexToFace: function ( vertex, face ) { | |
| vertex.face = face; | |
| if ( face.outside === null ) { | |
| this.assigned.append( vertex ); | |
| } else { | |
| this.assigned.insertBefore( face.outside, vertex ); | |
| } | |
| face.outside = vertex; | |
| return this; | |
| }, | |
| // Removes a vertex from the 'assigned' list of vertices and from the given face | |
| removeVertexFromFace: function ( vertex, face ) { | |
| if ( vertex === face.outside ) { | |
| // fix face.outside link | |
| if ( vertex.next !== null && vertex.next.face === face ) { | |
| // face has at least 2 outside vertices, move the 'outside' reference | |
| face.outside = vertex.next; | |
| } else { | |
| // vertex was the only outside vertex that face had | |
| face.outside = null; | |
| } | |
| } | |
| this.assigned.remove( vertex ); | |
| return this; | |
| }, | |
| // Removes all the visible vertices that a given face is able to see which are stored in the 'assigned' vertext list | |
| removeAllVerticesFromFace: function ( face ) { | |
| if ( face.outside !== null ) { | |
| // reference to the first and last vertex of this face | |
| var start = face.outside; | |
| var end = face.outside; | |
| while ( end.next !== null && end.next.face === face ) { | |
| end = end.next; | |
| } | |
| this.assigned.removeSubList( start, end ); | |
| // fix references | |
| start.prev = end.next = null; | |
| face.outside = null; | |
| return start; | |
| } | |
| }, | |
| // Removes all the visible vertices that 'face' is able to see | |
| deleteFaceVertices: function ( face, absorbingFace ) { | |
| var faceVertices = this.removeAllVerticesFromFace( face ); | |
| if ( faceVertices !== undefined ) { | |
| if ( absorbingFace === undefined ) { | |
| // mark the vertices to be reassigned to some other face | |
| this.unassigned.appendChain( faceVertices ); | |
| } else { | |
| // if there's an absorbing face try to assign as many vertices as possible to it | |
| var vertex = faceVertices; | |
| do { | |
| // we need to buffer the subsequent vertex at this point because the 'vertex.next' reference | |
| // will be changed by upcoming method calls | |
| var nextVertex = vertex.next; | |
| var distance = absorbingFace.distanceToPoint( vertex.point ); | |
| // check if 'vertex' is able to see 'absorbingFace' | |
| if ( distance > this.tolerance ) { | |
| this.addVertexToFace( vertex, absorbingFace ); | |
| } else { | |
| this.unassigned.append( vertex ); | |
| } | |
| // now assign next vertex | |
| vertex = nextVertex; | |
| } while ( vertex !== null ); | |
| } | |
| } | |
| return this; | |
| }, | |
| // Reassigns as many vertices as possible from the unassigned list to the new faces | |
| resolveUnassignedPoints: function ( newFaces ) { | |
| if ( this.unassigned.isEmpty() === false ) { | |
| var vertex = this.unassigned.first(); | |
| do { | |
| // buffer 'next' reference, see .deleteFaceVertices() | |
| var nextVertex = vertex.next; | |
| var maxDistance = this.tolerance; | |
| var maxFace = null; | |
| for ( var i = 0; i < newFaces.length; i ++ ) { | |
| var face = newFaces[ i ]; | |
| if ( face.mark === Visible ) { | |
| var distance = face.distanceToPoint( vertex.point ); | |
| if ( distance > maxDistance ) { | |
| maxDistance = distance; | |
| maxFace = face; | |
| } | |
| if ( maxDistance > 1000 * this.tolerance ) break; | |
| } | |
| } | |
| // 'maxFace' can be null e.g. if there are identical vertices | |
| if ( maxFace !== null ) { | |
| this.addVertexToFace( vertex, maxFace ); | |
| } | |
| vertex = nextVertex; | |
| } while ( vertex !== null ); | |
| } | |
| return this; | |
| }, | |
| // Computes the extremes of a simplex which will be the initial hull | |
| computeExtremes: function () { | |
| var min = new THREE.Vector3(); | |
| var max = new THREE.Vector3(); | |
| var minVertices = []; | |
| var maxVertices = []; | |
| var i, l, j; | |
| // initially assume that the first vertex is the min/max | |
| for ( i = 0; i < 3; i ++ ) { | |
| minVertices[ i ] = maxVertices[ i ] = this.vertices[ 0 ]; | |
| } | |
| min.copy( this.vertices[ 0 ].point ); | |
| max.copy( this.vertices[ 0 ].point ); | |
| // compute the min/max vertex on all six directions | |
| for ( i = 0, l = this.vertices.length; i < l; i ++ ) { | |
| var vertex = this.vertices[ i ]; | |
| var point = vertex.point; | |
| // update the min coordinates | |
| for ( j = 0; j < 3; j ++ ) { | |
| if ( point.getComponent( j ) < min.getComponent( j ) ) { | |
| min.setComponent( j, point.getComponent( j ) ); | |
| minVertices[ j ] = vertex; | |
| } | |
| } | |
| // update the max coordinates | |
| for ( j = 0; j < 3; j ++ ) { | |
| if ( point.getComponent( j ) > max.getComponent( j ) ) { | |
| max.setComponent( j, point.getComponent( j ) ); | |
| maxVertices[ j ] = vertex; | |
| } | |
| } | |
| } | |
| // use min/max vectors to compute an optimal epsilon | |
| this.tolerance = 3 * Number.EPSILON * ( | |
| Math.max( Math.abs( min.x ), Math.abs( max.x ) ) + | |
| Math.max( Math.abs( min.y ), Math.abs( max.y ) ) + | |
| Math.max( Math.abs( min.z ), Math.abs( max.z ) ) | |
| ); | |
| return { min: minVertices, max: maxVertices }; | |
| }, | |
| // Computes the initial simplex assigning to its faces all the points | |
| // that are candidates to form part of the hull | |
| computeInitialHull: function () { | |
| var line3, plane, closestPoint; | |
| return function computeInitialHull() { | |
| if ( line3 === undefined ) { | |
| line3 = new THREE.Line3(); | |
| plane = new THREE.Plane(); | |
| closestPoint = new THREE.Vector3(); | |
| } | |
| var vertex, vertices = this.vertices; | |
| var extremes = this.computeExtremes(); | |
| var min = extremes.min; | |
| var max = extremes.max; | |
| var v0, v1, v2, v3; | |
| var i, l, j; | |
| // 1. Find the two vertices 'v0' and 'v1' with the greatest 1d separation | |
| // (max.x - min.x) | |
| // (max.y - min.y) | |
| // (max.z - min.z) | |
| var distance, maxDistance = 0; | |
| var index = 0; | |
| for ( i = 0; i < 3; i ++ ) { | |
| distance = max[ i ].point.getComponent( i ) - min[ i ].point.getComponent( i ); | |
| if ( distance > maxDistance ) { | |
| maxDistance = distance; | |
| index = i; | |
| } | |
| } | |
| v0 = min[ index ]; | |
| v1 = max[ index ]; | |
| // 2. The next vertex 'v2' is the one farthest to the line formed by 'v0' and 'v1' | |
| maxDistance = 0; | |
| line3.set( v0.point, v1.point ); | |
| for ( i = 0, l = this.vertices.length; i < l; i ++ ) { | |
| vertex = vertices[ i ]; | |
| if ( vertex !== v0 && vertex !== v1 ) { | |
| line3.closestPointToPoint( vertex.point, true, closestPoint ); | |
| distance = closestPoint.distanceToSquared( vertex.point ); | |
| if ( distance > maxDistance ) { | |
| maxDistance = distance; | |
| v2 = vertex; | |
| } | |
| } | |
| } | |
| // 3. The next vertex 'v3' is the one farthest to the plane 'v0', 'v1', 'v2' | |
| maxDistance = - 1; | |
| plane.setFromCoplanarPoints( v0.point, v1.point, v2.point ); | |
| for ( i = 0, l = this.vertices.length; i < l; i ++ ) { | |
| vertex = vertices[ i ]; | |
| if ( vertex !== v0 && vertex !== v1 && vertex !== v2 ) { | |
| distance = Math.abs( plane.distanceToPoint( vertex.point ) ); | |
| if ( distance > maxDistance ) { | |
| maxDistance = distance; | |
| v3 = vertex; | |
| } | |
| } | |
| } | |
| var faces = []; | |
| if ( plane.distanceToPoint( v3.point ) < 0 ) { | |
| // the face is not able to see the point so 'plane.normal' is pointing outside the tetrahedron | |
| faces.push( | |
| Face.create( v0, v1, v2 ), | |
| Face.create( v3, v1, v0 ), | |
| Face.create( v3, v2, v1 ), | |
| Face.create( v3, v0, v2 ) | |
| ); | |
| // set the twin edge | |
| for ( i = 0; i < 3; i ++ ) { | |
| j = ( i + 1 ) % 3; | |
| // join face[ i ] i > 0, with the first face | |
| faces[ i + 1 ].getEdge( 2 ).setTwin( faces[ 0 ].getEdge( j ) ); | |
| // join face[ i ] with face[ i + 1 ], 1 <= i <= 3 | |
| faces[ i + 1 ].getEdge( 1 ).setTwin( faces[ j + 1 ].getEdge( 0 ) ); | |
| } | |
| } else { | |
| // the face is able to see the point so 'plane.normal' is pointing inside the tetrahedron | |
| faces.push( | |
| Face.create( v0, v2, v1 ), | |
| Face.create( v3, v0, v1 ), | |
| Face.create( v3, v1, v2 ), | |
| Face.create( v3, v2, v0 ) | |
| ); | |
| // set the twin edge | |
| for ( i = 0; i < 3; i ++ ) { | |
| j = ( i + 1 ) % 3; | |
| // join face[ i ] i > 0, with the first face | |
| faces[ i + 1 ].getEdge( 2 ).setTwin( faces[ 0 ].getEdge( ( 3 - i ) % 3 ) ); | |
| // join face[ i ] with face[ i + 1 ] | |
| faces[ i + 1 ].getEdge( 0 ).setTwin( faces[ j + 1 ].getEdge( 1 ) ); | |
| } | |
| } | |
| // the initial hull is the tetrahedron | |
| for ( i = 0; i < 4; i ++ ) { | |
| this.faces.push( faces[ i ] ); | |
| } | |
| // initial assignment of vertices to the faces of the tetrahedron | |
| for ( i = 0, l = vertices.length; i < l; i ++ ) { | |
| vertex = vertices[ i ]; | |
| if ( vertex !== v0 && vertex !== v1 && vertex !== v2 && vertex !== v3 ) { | |
| maxDistance = this.tolerance; | |
| var maxFace = null; | |
| for ( j = 0; j < 4; j ++ ) { | |
| distance = this.faces[ j ].distanceToPoint( vertex.point ); | |
| if ( distance > maxDistance ) { | |
| maxDistance = distance; | |
| maxFace = this.faces[ j ]; | |
| } | |
| } | |
| if ( maxFace !== null ) { | |
| this.addVertexToFace( vertex, maxFace ); | |
| } | |
| } | |
| } | |
| return this; | |
| }; | |
| }(), | |
| // Removes inactive faces | |
| reindexFaces: function () { | |
| var activeFaces = []; | |
| for ( var i = 0; i < this.faces.length; i ++ ) { | |
| var face = this.faces[ i ]; | |
| if ( face.mark === Visible ) { | |
| activeFaces.push( face ); | |
| } | |
| } | |
| this.faces = activeFaces; | |
| return this; | |
| }, | |
| // Finds the next vertex to create faces with the current hull | |
| nextVertexToAdd: function () { | |
| // if the 'assigned' list of vertices is empty, no vertices are left. return with 'undefined' | |
| if ( this.assigned.isEmpty() === false ) { | |
| var eyeVertex, maxDistance = 0; | |
| // grap the first available face and start with the first visible vertex of that face | |
| var eyeFace = this.assigned.first().face; | |
| var vertex = eyeFace.outside; | |
| // now calculate the farthest vertex that face can see | |
| do { | |
| var distance = eyeFace.distanceToPoint( vertex.point ); | |
| if ( distance > maxDistance ) { | |
| maxDistance = distance; | |
| eyeVertex = vertex; | |
| } | |
| vertex = vertex.next; | |
| } while ( vertex !== null && vertex.face === eyeFace ); | |
| return eyeVertex; | |
| } | |
| }, | |
| // Computes a chain of half edges in CCW order called the 'horizon'. | |
| // For an edge to be part of the horizon it must join a face that can see | |
| // 'eyePoint' and a face that cannot see 'eyePoint'. | |
| computeHorizon: function ( eyePoint, crossEdge, face, horizon ) { | |
| // moves face's vertices to the 'unassigned' vertex list | |
| 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 = []; | |
| 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.getNormal( this.normal ); | |
| triangle.getMidpoint( this.midpoint ); | |
| this.area = triangle.getArea(); | |
| 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; | |
| } )(); | |