Bullet Collision Detection & Physics Library: btConvexHullComputer.h Source File

Bullet Collision Detection & Physics Library

btConvexHullComputer.h
Go to the documentation of this file.
1 /*
2 Copyright (c) 2011 Ole Kniemeyer, MAXON, www.maxon.net
3
4 This software is provided 'as-is', without any express or implied warranty.
5 In no event will the authors be held liable for any damages arising from the use of this software.
6 Permission is granted to anyone to use this software for any purpose,
7 including commercial applications, and to alter it and redistribute it freely,
8 subject to the following restrictions:
9
10 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
11 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
12 3. This notice may not be removed or altered from any source distribution.
13 */
14
15 #ifndef BT_CONVEX_HULL_COMPUTER_H
16 #define BT_CONVEX_HULL_COMPUTER_H
17
18 #include "btVector3.h"
19 #include "btAlignedObjectArray.h"
20
24 class btConvexHullComputer
25 {
26 private:
27 btScalar compute(const void* coords, bool doubleCoords, int stride, int count, btScalar shrink, btScalar shrinkClamp);
28
29 public:
30
31 class Edge
32 {
33 private:
34 int next;
35 int reverse;
36 int targetVertex;
37
38 friend class btConvexHullComputer;
39
40 public:
41 int getSourceVertex() const
42 {
43 return (this + reverse)->targetVertex;
44 }
45
46 int getTargetVertex() const
47 {
48 return targetVertex;
49 }
50
51 const Edge* getNextEdgeOfVertex() const // clockwise list of all edges of a vertex
52 {
53 return this + next;
54 }
55
56 const Edge* getNextEdgeOfFace() const // counter-clockwise list of all edges of a face
57 {
58 return (this + reverse)->getNextEdgeOfVertex();
59 }
60
61 const Edge* getReverseEdge() const
62 {
63 return this + reverse;
64 }
65 };
66
67
68 // Vertices of the output hull
69 btAlignedObjectArray<btVector3> vertices;
70
71 // Edges of the output hull
72 btAlignedObjectArray<Edge> edges;
73
74 // Faces of the convex hull. Each entry is an index into the "edges" array pointing to an edge of the face. Faces are planar n-gons
75 btAlignedObjectArray<int> faces;
76
77 /*
78 Compute convex hull of "count" vertices stored in "coords". "stride" is the difference in bytes
79 between the addresses of consecutive vertices. If "shrink" is positive, the convex hull is shrunken
80 by that amount (each face is moved by "shrink" length units towards the center along its normal).
81 If "shrinkClamp" is positive, "shrink" is clamped to not exceed "shrinkClamp * innerRadius", where "innerRadius"
82 is the minimum distance of a face to the center of the convex hull.
83
84 The returned value is the amount by which the hull has been shrunken. If it is negative, the amount was so large
85 that the resulting convex hull is empty.
86
87 The output convex hull can be found in the member variables "vertices", "edges", "faces".
88 */
89 btScalar compute(const float* coords, int stride, int count, btScalar shrink, btScalar shrinkClamp)
90 {
91 return compute(coords, false, stride, count, shrink, shrinkClamp);
92 }
93
94 // same as above, but double precision
95 btScalar compute(const double* coords, int stride, int count, btScalar shrink, btScalar shrinkClamp)
96 {
97 return compute(coords, true, stride, count, shrink, shrinkClamp);
98 }
99 };
100
101
102 #endif //BT_CONVEX_HULL_COMPUTER_H
103
btConvexHullComputer::edges
btAlignedObjectArray< Edge > edges
Definition: btConvexHullComputer.h:72
btAlignedObjectArray< btVector3 >
btVector3.h
btConvexHullComputer::Edge::next
int next
Definition: btConvexHullComputer.h:34
btConvexHullComputer::Edge::getReverseEdge
const Edge * getReverseEdge() const
Definition: btConvexHullComputer.h:61
btConvexHullComputer
Convex hull implementation based on Preparata and Hong See http://code.google.com/p/bullet/issues/det...
Definition: btConvexHullComputer.h:24
btConvexHullComputer::Edge::getTargetVertex
int getTargetVertex() const
Definition: btConvexHullComputer.h:46
btConvexHullComputer::Edge::getNextEdgeOfVertex
const Edge * getNextEdgeOfVertex() const
Definition: btConvexHullComputer.h:51
btConvexHullComputer::Edge::reverse
int reverse
Definition: btConvexHullComputer.h:35
btConvexHullComputer::compute
btScalar compute(const double *coords, int stride, int count, btScalar shrink, btScalar shrinkClamp)
Definition: btConvexHullComputer.h:95
btConvexHullComputer::vertices
btAlignedObjectArray< btVector3 > vertices
Definition: btConvexHullComputer.h:69
btConvexHullComputer::Edge::getNextEdgeOfFace
const Edge * getNextEdgeOfFace() const
Definition: btConvexHullComputer.h:56
btConvexHullComputer::Edge::targetVertex
int targetVertex
Definition: btConvexHullComputer.h:36
btConvexHullComputer::Edge
Definition: btConvexHullComputer.h:31
btAlignedObjectArray.h
btConvexHullComputer::compute
btScalar compute(const void *coords, bool doubleCoords, int stride, int count, btScalar shrink, btScalar shrinkClamp)
Definition: btConvexHullComputer.cpp:2645
btConvexHullComputer::Edge::getSourceVertex
int getSourceVertex() const
Definition: btConvexHullComputer.h:41
btConvexHullComputer::compute
btScalar compute(const float *coords, int stride, int count, btScalar shrink, btScalar shrinkClamp)
Definition: btConvexHullComputer.h:89
btConvexHullComputer::faces
btAlignedObjectArray< int > faces
Definition: btConvexHullComputer.h:75
btScalar
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:279