2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2006 Erwin Coumans https://bulletphysics.org
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:
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.
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16 #ifndef BT_VORONOI_SIMPLEX_SOLVER_H
17 #define BT_VORONOI_SIMPLEX_SOLVER_H
19 #include "btSimplexSolverInterface.h"
21 #define VORONOI_SIMPLEX_MAX_VERTS 5
23 ///disable next define, or use defaultCollisionConfiguration->getSimplexSolver()->setEqualVertexThreshold(0.f) to disable/configure
24 #define BT_USE_EQUAL_VERTEX_THRESHOLD
26 #ifdef BT_USE_DOUBLE_PRECISION
27 #define VORONOI_DEFAULT_EQUAL_VERTEX_THRESHOLD 1e-12f
29 #define VORONOI_DEFAULT_EQUAL_VERTEX_THRESHOLD 0.0001f
30 #endif //BT_USE_DOUBLE_PRECISION
32 struct btUsageBitfield
46 unsigned short usedVertexA : 1;
47 unsigned short usedVertexB : 1;
48 unsigned short usedVertexC : 1;
49 unsigned short usedVertexD : 1;
50 unsigned short unused1 : 1;
51 unsigned short unused2 : 1;
52 unsigned short unused3 : 1;
53 unsigned short unused4 : 1;
56 struct btSubSimplexClosestResult
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];
69 setBarycentricCoordinates();
70 m_usedVertices.reset();
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.));
81 void setBarycentricCoordinates(btScalar a = btScalar(0.), btScalar b = btScalar(0.), btScalar c = btScalar(0.), btScalar d = btScalar(0.))
83 m_barycentricCoords[0] = a;
84 m_barycentricCoords[1] = b;
85 m_barycentricCoords[2] = c;
86 m_barycentricCoords[3] = d;
90 /// btVoronoiSimplexSolver is an implementation of the closest point distance algorithm from a 1-4 points simplex to the origin.
91 /// Can be used with GJK, as an alternative to Johnson distance algorithm.
92 #ifdef NO_VIRTUAL_INTERFACE
93 ATTRIBUTE_ALIGNED16(class)
94 btVoronoiSimplexSolver
96 ATTRIBUTE_ALIGNED16(class)
97 btVoronoiSimplexSolver : public btSimplexSolverInterface
101 BT_DECLARE_ALIGNED_ALLOCATOR();
105 btVector3 m_simplexVectorW[VORONOI_SIMPLEX_MAX_VERTS];
106 btVector3 m_simplexPointsP[VORONOI_SIMPLEX_MAX_VERTS];
107 btVector3 m_simplexPointsQ[VORONOI_SIMPLEX_MAX_VERTS];
109 btVector3 m_cachedP1;
110 btVector3 m_cachedP2;
114 btScalar m_equalVertexThreshold;
115 bool m_cachedValidClosest;
117 btSubSimplexClosestResult m_cachedBC;
121 void removeVertex(int index);
122 void reduceVertices(const btUsageBitfield& usedVerts);
123 bool updateClosestVectorAndPoints();
125 bool closestPtPointTetrahedron(const btVector3& p, const btVector3& a, const btVector3& b, const btVector3& c, const btVector3& d, btSubSimplexClosestResult& finalResult);
126 int pointOutsideOfPlane(const btVector3& p, const btVector3& a, const btVector3& b, const btVector3& c, const btVector3& d);
127 bool closestPtPointTriangle(const btVector3& p, const btVector3& a, const btVector3& b, const btVector3& c, btSubSimplexClosestResult& result);
130 btVoronoiSimplexSolver()
131 : m_equalVertexThreshold(VORONOI_DEFAULT_EQUAL_VERTEX_THRESHOLD)
136 void addVertex(const btVector3& w, const btVector3& p, const btVector3& q);
138 void setEqualVertexThreshold(btScalar threshold)
140 m_equalVertexThreshold = threshold;
143 btScalar getEqualVertexThreshold() const
145 return m_equalVertexThreshold;
148 bool closest(btVector3 & v);
150 btScalar maxVertex();
152 bool fullSimplex() const
154 return (m_numVertices == 4);
157 int getSimplex(btVector3 * pBuf, btVector3 * qBuf, btVector3 * yBuf) const;
159 bool inSimplex(const btVector3& w);
161 void backup_closest(btVector3 & v);
163 bool emptySimplex() const;
165 void compute_points(btVector3 & p1, btVector3 & p2);
167 int numVertices() const
169 return m_numVertices;
173 #endif //BT_VORONOI_SIMPLEX_SOLVER_H