1/*
2Bullet Continuous Collision Detection and Physics Library
3Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
4
5This software is provided 'as-is', without any express or implied warranty.
6In no event will the authors be held liable for any damages arising from the use of this software.
7Permission is granted to anyone to use this software for any purpose,
8including commercial applications, and to alter it and redistribute it freely,
9subject to the following restrictions:
10
111. 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.
122. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
133. 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
32struct btUsageBitfield{
33	btUsageBitfield()
34	{
35		reset();
36	}
37
38	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
56struct	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
66	void	reset()
67	{
68		m_degenerate = false;
69		setBarycentricCoordinates();
70		m_usedVertices.reset();
71	}
72	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
95ATTRIBUTE_ALIGNED16(class) btVoronoiSimplexSolver
96#else
97ATTRIBUTE_ALIGNED16(class) btVoronoiSimplexSolver : public btSimplexSolverInterface
98#endif
99{
100public:
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
133public:
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