1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
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
17
18 #ifndef BT_VORONOI_SIMPLEX_SOLVER_H
19 #define BT_VORONOI_SIMPLEX_SOLVER_H
20
21 #include "btSimplexSolverInterface.h"
22
23
24
25 #define VORONOI_SIMPLEX_MAX_VERTS 5
26
27 ///disable next define, or use defaultCollisionConfiguration->getSimplexSolver()->setEqualVertexThreshold(0.f) to disable/configure
28 #define BT_USE_EQUAL_VERTEX_THRESHOLD
29 #define VORONOI_DEFAULT_EQUAL_VERTEX_THRESHOLD 0.0001f
30
31
32 struct btUsageBitfield{
btUsageBitfieldbtUsageBitfield33 btUsageBitfield()
34 {
35 reset();
36 }
37
resetbtUsageBitfield38 void reset()
39 {
40 usedVertexA = false;
41 usedVertexB = false;
42 usedVertexC = false;
43 usedVertexD = false;
44 }
45 unsigned short usedVertexA : 1;
46 unsigned short usedVertexB : 1;
47 unsigned short usedVertexC : 1;
48 unsigned short usedVertexD : 1;
49 unsigned short unused1 : 1;
50 unsigned short unused2 : 1;
51 unsigned short unused3 : 1;
52 unsigned short unused4 : 1;
53 };
54
55
56 struct btSubSimplexClosestResult
57 {
58 btVector3 m_closestPointOnSimplex;
59 //MASK for m_usedVertices
60 //stores the simplex vertex-usage, using the MASK,
61 // if m_usedVertices & MASK then the related vertex is used
62 btUsageBitfield m_usedVertices;
63 btScalar m_barycentricCoords[4];
64 bool m_degenerate;
65
resetbtSubSimplexClosestResult66 void reset()
67 {
68 m_degenerate = false;
69 setBarycentricCoordinates();
70 m_usedVertices.reset();
71 }
isValidbtSubSimplexClosestResult72 bool isValid()
73 {
74 bool valid = (m_barycentricCoords[0] >= btScalar(0.)) &&
75 (m_barycentricCoords[1] >= btScalar(0.)) &&
76 (m_barycentricCoords[2] >= btScalar(0.)) &&
77 (m_barycentricCoords[3] >= btScalar(0.));
78
79
80 return valid;
81 }
82 void setBarycentricCoordinates(btScalar a=btScalar(0.),btScalar b=btScalar(0.),btScalar c=btScalar(0.),btScalar d=btScalar(0.))
83 {
84 m_barycentricCoords[0] = a;
85 m_barycentricCoords[1] = b;
86 m_barycentricCoords[2] = c;
87 m_barycentricCoords[3] = d;
88 }
89
90 };
91
92 /// btVoronoiSimplexSolver is an implementation of the closest point distance algorithm from a 1-4 points simplex to the origin.
93 /// Can be used with GJK, as an alternative to Johnson distance algorithm.
94 #ifdef NO_VIRTUAL_INTERFACE
ATTRIBUTE_ALIGNED16(class)95 ATTRIBUTE_ALIGNED16(class) btVoronoiSimplexSolver
96 #else
97 ATTRIBUTE_ALIGNED16(class) btVoronoiSimplexSolver : public btSimplexSolverInterface
98 #endif
99 {
100 public:
101
102 BT_DECLARE_ALIGNED_ALLOCATOR();
103
104 int m_numVertices;
105
106 btVector3 m_simplexVectorW[VORONOI_SIMPLEX_MAX_VERTS];
107 btVector3 m_simplexPointsP[VORONOI_SIMPLEX_MAX_VERTS];
108 btVector3 m_simplexPointsQ[VORONOI_SIMPLEX_MAX_VERTS];
109
110
111
112 btVector3 m_cachedP1;
113 btVector3 m_cachedP2;
114 btVector3 m_cachedV;
115 btVector3 m_lastW;
116
117 btScalar m_equalVertexThreshold;
118 bool m_cachedValidClosest;
119
120
121 btSubSimplexClosestResult m_cachedBC;
122
123 bool m_needsUpdate;
124
125 void removeVertex(int index);
126 void reduceVertices (const btUsageBitfield& usedVerts);
127 bool updateClosestVectorAndPoints();
128
129 bool closestPtPointTetrahedron(const btVector3& p, const btVector3& a, const btVector3& b, const btVector3& c, const btVector3& d, btSubSimplexClosestResult& finalResult);
130 int pointOutsideOfPlane(const btVector3& p, const btVector3& a, const btVector3& b, const btVector3& c, const btVector3& d);
131 bool closestPtPointTriangle(const btVector3& p, const btVector3& a, const btVector3& b, const btVector3& c,btSubSimplexClosestResult& result);
132
133 public:
134
135 btVoronoiSimplexSolver()
136 : m_equalVertexThreshold(VORONOI_DEFAULT_EQUAL_VERTEX_THRESHOLD)
137 {
138 }
139 void reset();
140
141 void addVertex(const btVector3& w, const btVector3& p, const btVector3& q);
142
143 void setEqualVertexThreshold(btScalar threshold)
144 {
145 m_equalVertexThreshold = threshold;
146 }
147
148 btScalar getEqualVertexThreshold() const
149 {
150 return m_equalVertexThreshold;
151 }
152
153 bool closest(btVector3& v);
154
155 btScalar maxVertex();
156
157 bool fullSimplex() const
158 {
159 return (m_numVertices == 4);
160 }
161
162 int getSimplex(btVector3 *pBuf, btVector3 *qBuf, btVector3 *yBuf) const;
163
164 bool inSimplex(const btVector3& w);
165
166 void backup_closest(btVector3& v) ;
167
168 bool emptySimplex() const ;
169
170 void compute_points(btVector3& p1, btVector3& p2) ;
171
172 int numVertices() const
173 {
174 return m_numVertices;
175 }
176
177
178 };
179
180 #endif //BT_VORONOI_SIMPLEX_SOLVER_H
181
182