1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2009 Erwin Coumans http://bulletphysics.org
4
5 This software is provided 'as-is', without any express or implied warranty.
6 In no event will the authors be held liable for any damages arising from the use of this software.
7 Permission is granted to anyone to use this software for any purpose,
8 including commercial applications, and to alter it and redistribute it freely,
9 subject to the following restrictions:
10
11 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.
12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
13 3. This notice may not be removed or altered from any source distribution.
14 */
15
16 //btShapeHull was implemented by John McCutchan.
17
18
19 #include "btShapeHull.h"
20 #include "LinearMath/btConvexHull.h"
21
22 #define NUM_UNITSPHERE_POINTS 42
23
btShapeHull(const btConvexShape * shape)24 btShapeHull::btShapeHull (const btConvexShape* shape)
25 {
26 m_shape = shape;
27 m_vertices.clear ();
28 m_indices.clear();
29 m_numIndices = 0;
30 }
31
~btShapeHull()32 btShapeHull::~btShapeHull ()
33 {
34 m_indices.clear();
35 m_vertices.clear ();
36 }
37
38 bool
buildHull(btScalar)39 btShapeHull::buildHull (btScalar /*margin*/)
40 {
41 int numSampleDirections = NUM_UNITSPHERE_POINTS;
42 {
43 int numPDA = m_shape->getNumPreferredPenetrationDirections();
44 if (numPDA)
45 {
46 for (int i=0;i<numPDA;i++)
47 {
48 btVector3 norm;
49 m_shape->getPreferredPenetrationDirection(i,norm);
50 getUnitSpherePoints()[numSampleDirections] = norm;
51 numSampleDirections++;
52 }
53 }
54 }
55
56 btVector3 supportPoints[NUM_UNITSPHERE_POINTS+MAX_PREFERRED_PENETRATION_DIRECTIONS*2];
57 int i;
58 for (i = 0; i < numSampleDirections; i++)
59 {
60 supportPoints[i] = m_shape->localGetSupportingVertex(getUnitSpherePoints()[i]);
61 }
62
63 HullDesc hd;
64 hd.mFlags = QF_TRIANGLES;
65 hd.mVcount = static_cast<unsigned int>(numSampleDirections);
66
67 #ifdef BT_USE_DOUBLE_PRECISION
68 hd.mVertices = &supportPoints[0];
69 hd.mVertexStride = sizeof(btVector3);
70 #else
71 hd.mVertices = &supportPoints[0];
72 hd.mVertexStride = sizeof (btVector3);
73 #endif
74
75 HullLibrary hl;
76 HullResult hr;
77 if (hl.CreateConvexHull (hd, hr) == QE_FAIL)
78 {
79 return false;
80 }
81
82 m_vertices.resize (static_cast<int>(hr.mNumOutputVertices));
83
84
85 for (i = 0; i < static_cast<int>(hr.mNumOutputVertices); i++)
86 {
87 m_vertices[i] = hr.m_OutputVertices[i];
88 }
89 m_numIndices = hr.mNumIndices;
90 m_indices.resize(static_cast<int>(m_numIndices));
91 for (i = 0; i < static_cast<int>(m_numIndices); i++)
92 {
93 m_indices[i] = hr.m_Indices[i];
94 }
95
96 // free temporary hull result that we just copied
97 hl.ReleaseResult (hr);
98
99 return true;
100 }
101
102 int
numTriangles() const103 btShapeHull::numTriangles () const
104 {
105 return static_cast<int>(m_numIndices / 3);
106 }
107
108 int
numVertices() const109 btShapeHull::numVertices () const
110 {
111 return m_vertices.size ();
112 }
113
114 int
numIndices() const115 btShapeHull::numIndices () const
116 {
117 return static_cast<int>(m_numIndices);
118 }
119
120
getUnitSpherePoints()121 btVector3* btShapeHull::getUnitSpherePoints()
122 {
123 static btVector3 sUnitSpherePoints[NUM_UNITSPHERE_POINTS+MAX_PREFERRED_PENETRATION_DIRECTIONS*2] =
124 {
125 btVector3(btScalar(0.000000) , btScalar(-0.000000),btScalar(-1.000000)),
126 btVector3(btScalar(0.723608) , btScalar(-0.525725),btScalar(-0.447219)),
127 btVector3(btScalar(-0.276388) , btScalar(-0.850649),btScalar(-0.447219)),
128 btVector3(btScalar(-0.894426) , btScalar(-0.000000),btScalar(-0.447216)),
129 btVector3(btScalar(-0.276388) , btScalar(0.850649),btScalar(-0.447220)),
130 btVector3(btScalar(0.723608) , btScalar(0.525725),btScalar(-0.447219)),
131 btVector3(btScalar(0.276388) , btScalar(-0.850649),btScalar(0.447220)),
132 btVector3(btScalar(-0.723608) , btScalar(-0.525725),btScalar(0.447219)),
133 btVector3(btScalar(-0.723608) , btScalar(0.525725),btScalar(0.447219)),
134 btVector3(btScalar(0.276388) , btScalar(0.850649),btScalar(0.447219)),
135 btVector3(btScalar(0.894426) , btScalar(0.000000),btScalar(0.447216)),
136 btVector3(btScalar(-0.000000) , btScalar(0.000000),btScalar(1.000000)),
137 btVector3(btScalar(0.425323) , btScalar(-0.309011),btScalar(-0.850654)),
138 btVector3(btScalar(-0.162456) , btScalar(-0.499995),btScalar(-0.850654)),
139 btVector3(btScalar(0.262869) , btScalar(-0.809012),btScalar(-0.525738)),
140 btVector3(btScalar(0.425323) , btScalar(0.309011),btScalar(-0.850654)),
141 btVector3(btScalar(0.850648) , btScalar(-0.000000),btScalar(-0.525736)),
142 btVector3(btScalar(-0.525730) , btScalar(-0.000000),btScalar(-0.850652)),
143 btVector3(btScalar(-0.688190) , btScalar(-0.499997),btScalar(-0.525736)),
144 btVector3(btScalar(-0.162456) , btScalar(0.499995),btScalar(-0.850654)),
145 btVector3(btScalar(-0.688190) , btScalar(0.499997),btScalar(-0.525736)),
146 btVector3(btScalar(0.262869) , btScalar(0.809012),btScalar(-0.525738)),
147 btVector3(btScalar(0.951058) , btScalar(0.309013),btScalar(0.000000)),
148 btVector3(btScalar(0.951058) , btScalar(-0.309013),btScalar(0.000000)),
149 btVector3(btScalar(0.587786) , btScalar(-0.809017),btScalar(0.000000)),
150 btVector3(btScalar(0.000000) , btScalar(-1.000000),btScalar(0.000000)),
151 btVector3(btScalar(-0.587786) , btScalar(-0.809017),btScalar(0.000000)),
152 btVector3(btScalar(-0.951058) , btScalar(-0.309013),btScalar(-0.000000)),
153 btVector3(btScalar(-0.951058) , btScalar(0.309013),btScalar(-0.000000)),
154 btVector3(btScalar(-0.587786) , btScalar(0.809017),btScalar(-0.000000)),
155 btVector3(btScalar(-0.000000) , btScalar(1.000000),btScalar(-0.000000)),
156 btVector3(btScalar(0.587786) , btScalar(0.809017),btScalar(-0.000000)),
157 btVector3(btScalar(0.688190) , btScalar(-0.499997),btScalar(0.525736)),
158 btVector3(btScalar(-0.262869) , btScalar(-0.809012),btScalar(0.525738)),
159 btVector3(btScalar(-0.850648) , btScalar(0.000000),btScalar(0.525736)),
160 btVector3(btScalar(-0.262869) , btScalar(0.809012),btScalar(0.525738)),
161 btVector3(btScalar(0.688190) , btScalar(0.499997),btScalar(0.525736)),
162 btVector3(btScalar(0.525730) , btScalar(0.000000),btScalar(0.850652)),
163 btVector3(btScalar(0.162456) , btScalar(-0.499995),btScalar(0.850654)),
164 btVector3(btScalar(-0.425323) , btScalar(-0.309011),btScalar(0.850654)),
165 btVector3(btScalar(-0.425323) , btScalar(0.309011),btScalar(0.850654)),
166 btVector3(btScalar(0.162456) , btScalar(0.499995),btScalar(0.850654))
167 };
168 return sUnitSpherePoints;
169 }
170
171