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 BT_PERSISTENT_MANIFOLD_H
17 #define BT_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 //the enum starts at 1024 to avoid type conflicts with btTypedConstraint
36 enum btContactManifoldTypes
37 {
38 MIN_CONTACT_MANIFOLD_TYPE = 1024,
39 BT_PERSISTENT_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.
51
52
ATTRIBUTE_ALIGNED128(class)53 ATTRIBUTE_ALIGNED128( class) btPersistentManifold : public btTypedObject
54 //ATTRIBUTE_ALIGNED16( class) btPersistentManifold : public btTypedObject
55 {
56
57 btManifoldPoint m_pointCache[MANIFOLD_CACHE_SIZE];
58
59 /// this two body pointers can point to the physics rigidbody class.
60 /// void* will allow any rigidbody class
61 void* m_body0;
62 void* m_body1;
63
64 int m_cachedPoints;
65
66 btScalar m_contactBreakingThreshold;
67 btScalar m_contactProcessingThreshold;
68
69
70 /// sort cached points so most isolated points come first
71 int sortCachedPoints(const btManifoldPoint& pt);
72
73 int findContactPoint(const btManifoldPoint* unUsed, int numUnused,const btManifoldPoint& pt);
74
75 public:
76
77 BT_DECLARE_ALIGNED_ALLOCATOR();
78
79 int m_companionIdA;
80 int m_companionIdB;
81
82 int m_index1a;
83
84 btPersistentManifold();
85
86 btPersistentManifold(void* body0,void* body1,int , btScalar contactBreakingThreshold,btScalar contactProcessingThreshold)
87 : btTypedObject(BT_PERSISTENT_MANIFOLD_TYPE),
88 m_body0(body0),m_body1(body1),m_cachedPoints(0),
89 m_contactBreakingThreshold(contactBreakingThreshold),
90 m_contactProcessingThreshold(contactProcessingThreshold)
91 {
92 }
93
94 SIMD_FORCE_INLINE void* getBody0() { return m_body0;}
95 SIMD_FORCE_INLINE void* getBody1() { return m_body1;}
96
97 SIMD_FORCE_INLINE const void* getBody0() const { return m_body0;}
98 SIMD_FORCE_INLINE const void* getBody1() const { return m_body1;}
99
100 void setBodies(void* body0,void* body1)
101 {
102 m_body0 = body0;
103 m_body1 = body1;
104 }
105
106 void clearUserCache(btManifoldPoint& pt);
107
108 #ifdef DEBUG_PERSISTENCY
109 void DebugPersistency();
110 #endif //
111
112 SIMD_FORCE_INLINE int getNumContacts() const { return m_cachedPoints;}
113
114 SIMD_FORCE_INLINE const btManifoldPoint& getContactPoint(int index) const
115 {
116 btAssert(index < m_cachedPoints);
117 return m_pointCache[index];
118 }
119
120 SIMD_FORCE_INLINE btManifoldPoint& getContactPoint(int index)
121 {
122 btAssert(index < m_cachedPoints);
123 return m_pointCache[index];
124 }
125
126 ///@todo: get this margin from the current physics / collision environment
127 btScalar getContactBreakingThreshold() const;
128
129 btScalar getContactProcessingThreshold() const
130 {
131 return m_contactProcessingThreshold;
132 }
133
134 int getCacheEntry(const btManifoldPoint& newPoint) const;
135
136 int addManifoldPoint( const btManifoldPoint& newPoint);
137
138 void removeContactPoint (int index)
139 {
140 clearUserCache(m_pointCache[index]);
141
142 int lastUsedIndex = getNumContacts() - 1;
143 // m_pointCache[index] = m_pointCache[lastUsedIndex];
144 if(index != lastUsedIndex)
145 {
146 m_pointCache[index] = m_pointCache[lastUsedIndex];
147 //get rid of duplicated userPersistentData pointer
148 m_pointCache[lastUsedIndex].m_userPersistentData = 0;
149 m_pointCache[lastUsedIndex].mConstraintRow[0].m_accumImpulse = 0.f;
150 m_pointCache[lastUsedIndex].mConstraintRow[1].m_accumImpulse = 0.f;
151 m_pointCache[lastUsedIndex].mConstraintRow[2].m_accumImpulse = 0.f;
152
153 m_pointCache[lastUsedIndex].m_appliedImpulse = 0.f;
154 m_pointCache[lastUsedIndex].m_lateralFrictionInitialized = false;
155 m_pointCache[lastUsedIndex].m_appliedImpulseLateral1 = 0.f;
156 m_pointCache[lastUsedIndex].m_appliedImpulseLateral2 = 0.f;
157 m_pointCache[lastUsedIndex].m_lifeTime = 0;
158 }
159
160 btAssert(m_pointCache[lastUsedIndex].m_userPersistentData==0);
161 m_cachedPoints--;
162 }
163 void replaceContactPoint(const btManifoldPoint& newPoint,int insertIndex)
164 {
165 btAssert(validContactDistance(newPoint));
166
167 #define MAINTAIN_PERSISTENCY 1
168 #ifdef MAINTAIN_PERSISTENCY
169 int lifeTime = m_pointCache[insertIndex].getLifeTime();
170 btScalar appliedImpulse = m_pointCache[insertIndex].mConstraintRow[0].m_accumImpulse;
171 btScalar appliedLateralImpulse1 = m_pointCache[insertIndex].mConstraintRow[1].m_accumImpulse;
172 btScalar appliedLateralImpulse2 = m_pointCache[insertIndex].mConstraintRow[2].m_accumImpulse;
173 // bool isLateralFrictionInitialized = m_pointCache[insertIndex].m_lateralFrictionInitialized;
174
175
176
177 btAssert(lifeTime>=0);
178 void* cache = m_pointCache[insertIndex].m_userPersistentData;
179
180 m_pointCache[insertIndex] = newPoint;
181
182 m_pointCache[insertIndex].m_userPersistentData = cache;
183 m_pointCache[insertIndex].m_appliedImpulse = appliedImpulse;
184 m_pointCache[insertIndex].m_appliedImpulseLateral1 = appliedLateralImpulse1;
185 m_pointCache[insertIndex].m_appliedImpulseLateral2 = appliedLateralImpulse2;
186
187 m_pointCache[insertIndex].mConstraintRow[0].m_accumImpulse = appliedImpulse;
188 m_pointCache[insertIndex].mConstraintRow[1].m_accumImpulse = appliedLateralImpulse1;
189 m_pointCache[insertIndex].mConstraintRow[2].m_accumImpulse = appliedLateralImpulse2;
190
191
192 m_pointCache[insertIndex].m_lifeTime = lifeTime;
193 #else
194 clearUserCache(m_pointCache[insertIndex]);
195 m_pointCache[insertIndex] = newPoint;
196
197 #endif
198 }
199
200 bool validContactDistance(const btManifoldPoint& pt) const
201 {
202 if (pt.m_lifeTime >1)
203 {
204 return pt.m_distance1 <= getContactBreakingThreshold();
205 }
206 return pt.m_distance1 <= getContactProcessingThreshold();
207
208 }
209 /// calculated new worldspace coordinates and depth, and reject points that exceed the collision margin
210 void refreshContactPoints( const btTransform& trA,const btTransform& trB);
211
212
213 SIMD_FORCE_INLINE void clearManifold()
214 {
215 int i;
216 for (i=0;i<m_cachedPoints;i++)
217 {
218 clearUserCache(m_pointCache[i]);
219 }
220 m_cachedPoints = 0;
221 }
222
223
224
225 }
226 ;
227
228
229
230
231
232 #endif //BT_PERSISTENT_MANIFOLD_H
233