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 #ifndef PERSISTENT_MANIFOLD_H
17 #define PERSISTENT_MANIFOLD_H
18
19
20 #include "LinearMath/btVector3.h"
21 #include "LinearMath/btTransform.h"
22 #include "btManifoldPoint.h"
23 #include "LinearMath/btAlignedAllocator.h"
24
25 struct btCollisionResult;
26
27 ///maximum contact breaking and merging threshold
28 extern btScalar gContactBreakingThreshold;
29
30 typedef bool (*ContactDestroyedCallback)(void* userPersistentData);
31 typedef bool (*ContactProcessedCallback)(btManifoldPoint& cp,void* body0,void* body1);
32 extern ContactDestroyedCallback gContactDestroyedCallback;
33 extern ContactProcessedCallback gContactProcessedCallback;
34
35
36 enum btContactManifoldTypes
37 {
38 BT_PERSISTENT_MANIFOLD_TYPE = 1,
39 MAX_CONTACT_MANIFOLD_TYPE
40 };
41
42 #define MANIFOLD_CACHE_SIZE 4
43
44 ///btPersistentManifold is a contact point cache, it stays persistent as long as objects are overlapping in the broadphase.
45 ///Those contact points are created by the collision narrow phase.
46 ///The cache can be empty, or hold 1,2,3 or 4 points. Some collision algorithms (GJK) might only add one point at a time.
47 ///updates/refreshes old contact points, and throw them away if necessary (distance becomes too large)
48 ///reduces the cache to 4 points, when more then 4 points are added, using following rules:
49 ///the contact point with deepest penetration is always kept, and it tries to maximuze the area covered by the points
50 ///note that some pairs of objects might have more then one contact manifold.
ATTRIBUTE_ALIGNED16(class)51 ATTRIBUTE_ALIGNED16( class) btPersistentManifold : public btTypedObject
52 {
53
54 btManifoldPoint m_pointCache[MANIFOLD_CACHE_SIZE];
55
56 /// this two body pointers can point to the physics rigidbody class.
57 /// void* will allow any rigidbody class
58 void* m_body0;
59 void* m_body1;
60 int m_cachedPoints;
61
62 btScalar m_contactBreakingThreshold;
63 btScalar m_contactProcessingThreshold;
64
65
66 /// sort cached points so most isolated points come first
67 int sortCachedPoints(const btManifoldPoint& pt);
68
69 int findContactPoint(const btManifoldPoint* unUsed, int numUnused,const btManifoldPoint& pt);
70
71 public:
72
73 BT_DECLARE_ALIGNED_ALLOCATOR();
74
75 int m_index1a;
76
77 btPersistentManifold();
78
79 btPersistentManifold(void* body0,void* body1,int , btScalar contactBreakingThreshold,btScalar contactProcessingThreshold)
80 : btTypedObject(BT_PERSISTENT_MANIFOLD_TYPE),
81 m_body0(body0),m_body1(body1),m_cachedPoints(0),
82 m_contactBreakingThreshold(contactBreakingThreshold),
83 m_contactProcessingThreshold(contactProcessingThreshold)
84 {
85 }
86
87 SIMD_FORCE_INLINE void* getBody0() { return m_body0;}
88 SIMD_FORCE_INLINE void* getBody1() { return m_body1;}
89
90 SIMD_FORCE_INLINE const void* getBody0() const { return m_body0;}
91 SIMD_FORCE_INLINE const void* getBody1() const { return m_body1;}
92
93 void setBodies(void* body0,void* body1)
94 {
95 m_body0 = body0;
96 m_body1 = body1;
97 }
98
99 void clearUserCache(btManifoldPoint& pt);
100
101 #ifdef DEBUG_PERSISTENCY
102 void DebugPersistency();
103 #endif //
104
105 SIMD_FORCE_INLINE int getNumContacts() const { return m_cachedPoints;}
106
107 SIMD_FORCE_INLINE const btManifoldPoint& getContactPoint(int index) const
108 {
109 btAssert(index < m_cachedPoints);
110 return m_pointCache[index];
111 }
112
113 SIMD_FORCE_INLINE btManifoldPoint& getContactPoint(int index)
114 {
115 btAssert(index < m_cachedPoints);
116 return m_pointCache[index];
117 }
118
119 ///@todo: get this margin from the current physics / collision environment
120 btScalar getContactBreakingThreshold() const;
121
122 btScalar getContactProcessingThreshold() const
123 {
124 return m_contactProcessingThreshold;
125 }
126
127 int getCacheEntry(const btManifoldPoint& newPoint) const;
128
129 int addManifoldPoint( const btManifoldPoint& newPoint);
130
131 void removeContactPoint (int index)
132 {
133 clearUserCache(m_pointCache[index]);
134
135 int lastUsedIndex = getNumContacts() - 1;
136 // m_pointCache[index] = m_pointCache[lastUsedIndex];
137 if(index != lastUsedIndex)
138 {
139 m_pointCache[index] = m_pointCache[lastUsedIndex];
140 //get rid of duplicated userPersistentData pointer
141 m_pointCache[lastUsedIndex].m_userPersistentData = 0;
142 m_pointCache[lastUsedIndex].m_appliedImpulse = 0.f;
143 m_pointCache[lastUsedIndex].m_lateralFrictionInitialized = false;
144 m_pointCache[lastUsedIndex].m_appliedImpulseLateral1 = 0.f;
145 m_pointCache[lastUsedIndex].m_appliedImpulseLateral2 = 0.f;
146 m_pointCache[lastUsedIndex].m_lifeTime = 0;
147 }
148
149 btAssert(m_pointCache[lastUsedIndex].m_userPersistentData==0);
150 m_cachedPoints--;
151 }
152 void replaceContactPoint(const btManifoldPoint& newPoint,int insertIndex)
153 {
154 btAssert(validContactDistance(newPoint));
155
156 #define MAINTAIN_PERSISTENCY 1
157 #ifdef MAINTAIN_PERSISTENCY
158 int lifeTime = m_pointCache[insertIndex].getLifeTime();
159 btScalar appliedImpulse = m_pointCache[insertIndex].m_appliedImpulse;
160 btScalar appliedLateralImpulse1 = m_pointCache[insertIndex].m_appliedImpulseLateral1;
161 btScalar appliedLateralImpulse2 = m_pointCache[insertIndex].m_appliedImpulseLateral2;
162
163 btAssert(lifeTime>=0);
164 void* cache = m_pointCache[insertIndex].m_userPersistentData;
165
166 m_pointCache[insertIndex] = newPoint;
167
168 m_pointCache[insertIndex].m_userPersistentData = cache;
169 m_pointCache[insertIndex].m_appliedImpulse = appliedImpulse;
170 m_pointCache[insertIndex].m_appliedImpulseLateral1 = appliedLateralImpulse1;
171 m_pointCache[insertIndex].m_appliedImpulseLateral2 = appliedLateralImpulse2;
172
173 m_pointCache[insertIndex].m_lifeTime = lifeTime;
174 #else
175 clearUserCache(m_pointCache[insertIndex]);
176 m_pointCache[insertIndex] = newPoint;
177
178 #endif
179 }
180
181 bool validContactDistance(const btManifoldPoint& pt) const
182 {
183 return pt.m_distance1 <= getContactBreakingThreshold();
184 }
185 /// calculated new worldspace coordinates and depth, and reject points that exceed the collision margin
186 void refreshContactPoints( const btTransform& trA,const btTransform& trB);
187
188
189 SIMD_FORCE_INLINE void clearManifold()
190 {
191 int i;
192 for (i=0;i<m_cachedPoints;i++)
193 {
194 clearUserCache(m_pointCache[i]);
195 }
196 m_cachedPoints = 0;
197 }
198
199
200
201 }
202 ;
203
204
205
206
207
208 #endif //PERSISTENT_MANIFOLD_H
209