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 #include "btManifoldResult.h"
18 #include "BulletCollision/NarrowPhaseCollision/btPersistentManifold.h"
19 #include "BulletCollision/CollisionDispatch/btCollisionObject.h"
20 #include "BulletCollision/CollisionDispatch/btCollisionObjectWrapper.h"
21
22 ///This is to allow MaterialCombiner/Custom Friction/Restitution values
23 ContactAddedCallback gContactAddedCallback=0;
24
25
26
27 ///User can override this material combiner by implementing gContactAddedCallback and setting body0->m_collisionFlags |= btCollisionObject::customMaterialCallback;
calculateCombinedRollingFriction(const btCollisionObject * body0,const btCollisionObject * body1)28 inline btScalar calculateCombinedRollingFriction(const btCollisionObject* body0,const btCollisionObject* body1)
29 {
30 btScalar friction = body0->getRollingFriction() * body1->getRollingFriction();
31
32 const btScalar MAX_FRICTION = btScalar(10.);
33 if (friction < -MAX_FRICTION)
34 friction = -MAX_FRICTION;
35 if (friction > MAX_FRICTION)
36 friction = MAX_FRICTION;
37 return friction;
38
39 }
40
41
42 ///User can override this material combiner by implementing gContactAddedCallback and setting body0->m_collisionFlags |= btCollisionObject::customMaterialCallback;
calculateCombinedFriction(const btCollisionObject * body0,const btCollisionObject * body1)43 btScalar btManifoldResult::calculateCombinedFriction(const btCollisionObject* body0,const btCollisionObject* body1)
44 {
45 btScalar friction = body0->getFriction() * body1->getFriction();
46
47 const btScalar MAX_FRICTION = btScalar(10.);
48 if (friction < -MAX_FRICTION)
49 friction = -MAX_FRICTION;
50 if (friction > MAX_FRICTION)
51 friction = MAX_FRICTION;
52 return friction;
53
54 }
55
calculateCombinedRestitution(const btCollisionObject * body0,const btCollisionObject * body1)56 btScalar btManifoldResult::calculateCombinedRestitution(const btCollisionObject* body0,const btCollisionObject* body1)
57 {
58 return body0->getRestitution() * body1->getRestitution();
59 }
60
61
62
btManifoldResult(const btCollisionObjectWrapper * body0Wrap,const btCollisionObjectWrapper * body1Wrap)63 btManifoldResult::btManifoldResult(const btCollisionObjectWrapper* body0Wrap,const btCollisionObjectWrapper* body1Wrap)
64 :m_manifoldPtr(0),
65 m_body0Wrap(body0Wrap),
66 m_body1Wrap(body1Wrap)
67 #ifdef DEBUG_PART_INDEX
68 ,m_partId0(-1),
69 m_partId1(-1),
70 m_index0(-1),
71 m_index1(-1)
72 #endif //DEBUG_PART_INDEX
73 {
74 }
75
76
addContactPoint(const btVector3 & normalOnBInWorld,const btVector3 & pointInWorld,btScalar depth)77 void btManifoldResult::addContactPoint(const btVector3& normalOnBInWorld,const btVector3& pointInWorld,btScalar depth)
78 {
79 btAssert(m_manifoldPtr);
80 //order in manifold needs to match
81
82 if (depth > m_manifoldPtr->getContactBreakingThreshold())
83 // if (depth > m_manifoldPtr->getContactProcessingThreshold())
84 return;
85
86 bool isSwapped = m_manifoldPtr->getBody0() != m_body0Wrap->getCollisionObject();
87
88 btVector3 pointA = pointInWorld + normalOnBInWorld * depth;
89
90 btVector3 localA;
91 btVector3 localB;
92
93 if (isSwapped)
94 {
95 localA = m_body1Wrap->getCollisionObject()->getWorldTransform().invXform(pointA );
96 localB = m_body0Wrap->getCollisionObject()->getWorldTransform().invXform(pointInWorld);
97 } else
98 {
99 localA = m_body0Wrap->getCollisionObject()->getWorldTransform().invXform(pointA );
100 localB = m_body1Wrap->getCollisionObject()->getWorldTransform().invXform(pointInWorld);
101 }
102
103 btManifoldPoint newPt(localA,localB,normalOnBInWorld,depth);
104 newPt.m_positionWorldOnA = pointA;
105 newPt.m_positionWorldOnB = pointInWorld;
106
107 int insertIndex = m_manifoldPtr->getCacheEntry(newPt);
108
109 newPt.m_combinedFriction = calculateCombinedFriction(m_body0Wrap->getCollisionObject(),m_body1Wrap->getCollisionObject());
110 newPt.m_combinedRestitution = calculateCombinedRestitution(m_body0Wrap->getCollisionObject(),m_body1Wrap->getCollisionObject());
111 newPt.m_combinedRollingFriction = calculateCombinedRollingFriction(m_body0Wrap->getCollisionObject(),m_body1Wrap->getCollisionObject());
112 btPlaneSpace1(newPt.m_normalWorldOnB,newPt.m_lateralFrictionDir1,newPt.m_lateralFrictionDir2);
113
114
115
116 //BP mod, store contact triangles.
117 if (isSwapped)
118 {
119 newPt.m_partId0 = m_partId1;
120 newPt.m_partId1 = m_partId0;
121 newPt.m_index0 = m_index1;
122 newPt.m_index1 = m_index0;
123 } else
124 {
125 newPt.m_partId0 = m_partId0;
126 newPt.m_partId1 = m_partId1;
127 newPt.m_index0 = m_index0;
128 newPt.m_index1 = m_index1;
129 }
130 //printf("depth=%f\n",depth);
131 ///@todo, check this for any side effects
132 if (insertIndex >= 0)
133 {
134 //const btManifoldPoint& oldPoint = m_manifoldPtr->getContactPoint(insertIndex);
135 m_manifoldPtr->replaceContactPoint(newPt,insertIndex);
136 } else
137 {
138 insertIndex = m_manifoldPtr->addManifoldPoint(newPt);
139 }
140
141 //User can override friction and/or restitution
142 if (gContactAddedCallback &&
143 //and if either of the two bodies requires custom material
144 ((m_body0Wrap->getCollisionObject()->getCollisionFlags() & btCollisionObject::CF_CUSTOM_MATERIAL_CALLBACK) ||
145 (m_body1Wrap->getCollisionObject()->getCollisionFlags() & btCollisionObject::CF_CUSTOM_MATERIAL_CALLBACK)))
146 {
147 //experimental feature info, for per-triangle material etc.
148 const btCollisionObjectWrapper* obj0Wrap = isSwapped? m_body1Wrap : m_body0Wrap;
149 const btCollisionObjectWrapper* obj1Wrap = isSwapped? m_body0Wrap : m_body1Wrap;
150 (*gContactAddedCallback)(m_manifoldPtr->getContactPoint(insertIndex),obj0Wrap,newPt.m_partId0,newPt.m_index0,obj1Wrap,newPt.m_partId1,newPt.m_index1);
151 }
152
153 }
154
155