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 bool isNewCollision = m_manifoldPtr->getNumContacts() == 0;
88
89 btVector3 pointA = pointInWorld + normalOnBInWorld * depth;
90
91 btVector3 localA;
92 btVector3 localB;
93
94 if (isSwapped)
95 {
96 localA = m_body1Wrap->getCollisionObject()->getWorldTransform().invXform(pointA );
97 localB = m_body0Wrap->getCollisionObject()->getWorldTransform().invXform(pointInWorld);
98 } else
99 {
100 localA = m_body0Wrap->getCollisionObject()->getWorldTransform().invXform(pointA );
101 localB = m_body1Wrap->getCollisionObject()->getWorldTransform().invXform(pointInWorld);
102 }
103
104 btManifoldPoint newPt(localA,localB,normalOnBInWorld,depth);
105 newPt.m_positionWorldOnA = pointA;
106 newPt.m_positionWorldOnB = pointInWorld;
107
108 int insertIndex = m_manifoldPtr->getCacheEntry(newPt);
109
110 newPt.m_combinedFriction = calculateCombinedFriction(m_body0Wrap->getCollisionObject(),m_body1Wrap->getCollisionObject());
111 newPt.m_combinedRestitution = calculateCombinedRestitution(m_body0Wrap->getCollisionObject(),m_body1Wrap->getCollisionObject());
112 newPt.m_combinedRollingFriction = calculateCombinedRollingFriction(m_body0Wrap->getCollisionObject(),m_body1Wrap->getCollisionObject());
113 btPlaneSpace1(newPt.m_normalWorldOnB,newPt.m_lateralFrictionDir1,newPt.m_lateralFrictionDir2);
114
115
116
117 //BP mod, store contact triangles.
118 if (isSwapped)
119 {
120 newPt.m_partId0 = m_partId1;
121 newPt.m_partId1 = m_partId0;
122 newPt.m_index0 = m_index1;
123 newPt.m_index1 = m_index0;
124 } else
125 {
126 newPt.m_partId0 = m_partId0;
127 newPt.m_partId1 = m_partId1;
128 newPt.m_index0 = m_index0;
129 newPt.m_index1 = m_index1;
130 }
131 //printf("depth=%f\n",depth);
132 ///@todo, check this for any side effects
133 if (insertIndex >= 0)
134 {
135 //const btManifoldPoint& oldPoint = m_manifoldPtr->getContactPoint(insertIndex);
136 m_manifoldPtr->replaceContactPoint(newPt,insertIndex);
137 } else
138 {
139 insertIndex = m_manifoldPtr->addManifoldPoint(newPt);
140 }
141
142 //User can override friction and/or restitution
143 if (gContactAddedCallback &&
144 //and if either of the two bodies requires custom material
145 ((m_body0Wrap->getCollisionObject()->getCollisionFlags() & btCollisionObject::CF_CUSTOM_MATERIAL_CALLBACK) ||
146 (m_body1Wrap->getCollisionObject()->getCollisionFlags() & btCollisionObject::CF_CUSTOM_MATERIAL_CALLBACK)))
147 {
148 //experimental feature info, for per-triangle material etc.
149 const btCollisionObjectWrapper* obj0Wrap = isSwapped? m_body1Wrap : m_body0Wrap;
150 const btCollisionObjectWrapper* obj1Wrap = isSwapped? m_body0Wrap : m_body1Wrap;
151 (*gContactAddedCallback)(m_manifoldPtr->getContactPoint(insertIndex),obj0Wrap,newPt.m_partId0,newPt.m_index0,obj1Wrap,newPt.m_partId1,newPt.m_index1);
152 }
153
154 if (gContactStartedCallback && isNewCollision)
155 {
156 gContactStartedCallback(m_manifoldPtr);
157 }
158 }
159
160