1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2006 Erwin Coumans https://bulletphysics.org
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 #include "btManifoldResult.h"
17 #include "BulletCollision/NarrowPhaseCollision/btPersistentManifold.h"
18 #include "BulletCollision/CollisionDispatch/btCollisionObject.h"
19 #include "BulletCollision/CollisionDispatch/btCollisionObjectWrapper.h"
20
21 ///This is to allow MaterialCombiner/Custom Friction/Restitution values
22 ContactAddedCallback gContactAddedCallback = 0;
23
24 CalculateCombinedCallback gCalculateCombinedRestitutionCallback = &btManifoldResult::calculateCombinedRestitution;
25 CalculateCombinedCallback gCalculateCombinedFrictionCallback = &btManifoldResult::calculateCombinedFriction;
26 CalculateCombinedCallback gCalculateCombinedRollingFrictionCallback = &btManifoldResult::calculateCombinedRollingFriction;
27 CalculateCombinedCallback gCalculateCombinedSpinningFrictionCallback = &btManifoldResult::calculateCombinedSpinningFriction;
28 CalculateCombinedCallback gCalculateCombinedContactDampingCallback = &btManifoldResult::calculateCombinedContactDamping;
29 CalculateCombinedCallback gCalculateCombinedContactStiffnessCallback = &btManifoldResult::calculateCombinedContactStiffness;
30
calculateCombinedRollingFriction(const btCollisionObject * body0,const btCollisionObject * body1)31 btScalar btManifoldResult::calculateCombinedRollingFriction(const btCollisionObject* body0, const btCollisionObject* body1)
32 {
33 btScalar friction = body0->getRollingFriction() * body1->getFriction() + body1->getRollingFriction() * body0->getFriction();
34
35 const btScalar MAX_FRICTION = btScalar(10.);
36 if (friction < -MAX_FRICTION)
37 friction = -MAX_FRICTION;
38 if (friction > MAX_FRICTION)
39 friction = MAX_FRICTION;
40 return friction;
41 }
42
calculateCombinedSpinningFriction(const btCollisionObject * body0,const btCollisionObject * body1)43 btScalar btManifoldResult::calculateCombinedSpinningFriction(const btCollisionObject* body0, const btCollisionObject* body1)
44 {
45 btScalar friction = body0->getSpinningFriction() * body1->getFriction() + body1->getSpinningFriction() * body0->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 ///User can override this material combiner by implementing gContactAddedCallback and setting body0->m_collisionFlags |= btCollisionObject::customMaterialCallback;
calculateCombinedFriction(const btCollisionObject * body0,const btCollisionObject * body1)56 btScalar btManifoldResult::calculateCombinedFriction(const btCollisionObject* body0, const btCollisionObject* body1)
57 {
58 btScalar friction = body0->getFriction() * body1->getFriction();
59
60 const btScalar MAX_FRICTION = btScalar(10.);
61 if (friction < -MAX_FRICTION)
62 friction = -MAX_FRICTION;
63 if (friction > MAX_FRICTION)
64 friction = MAX_FRICTION;
65 return friction;
66 }
67
calculateCombinedRestitution(const btCollisionObject * body0,const btCollisionObject * body1)68 btScalar btManifoldResult::calculateCombinedRestitution(const btCollisionObject* body0, const btCollisionObject* body1)
69 {
70 return body0->getRestitution() * body1->getRestitution();
71 }
72
calculateCombinedContactDamping(const btCollisionObject * body0,const btCollisionObject * body1)73 btScalar btManifoldResult::calculateCombinedContactDamping(const btCollisionObject* body0, const btCollisionObject* body1)
74 {
75 return body0->getContactDamping() + body1->getContactDamping();
76 }
77
calculateCombinedContactStiffness(const btCollisionObject * body0,const btCollisionObject * body1)78 btScalar btManifoldResult::calculateCombinedContactStiffness(const btCollisionObject* body0, const btCollisionObject* body1)
79 {
80 btScalar s0 = body0->getContactStiffness();
81 btScalar s1 = body1->getContactStiffness();
82
83 btScalar tmp0 = btScalar(1) / s0;
84 btScalar tmp1 = btScalar(1) / s1;
85 btScalar combinedStiffness = btScalar(1) / (tmp0 + tmp1);
86 return combinedStiffness;
87 }
88
btManifoldResult(const btCollisionObjectWrapper * body0Wrap,const btCollisionObjectWrapper * body1Wrap)89 btManifoldResult::btManifoldResult(const btCollisionObjectWrapper* body0Wrap, const btCollisionObjectWrapper* body1Wrap)
90 : m_manifoldPtr(0),
91 m_body0Wrap(body0Wrap),
92 m_body1Wrap(body1Wrap)
93 ,
94 m_partId0(-1),
95 m_partId1(-1),
96 m_index0(-1),
97 m_index1(-1)
98 ,
99 m_closestPointDistanceThreshold(0)
100 {
101 }
102
addContactPoint(const btVector3 & normalOnBInWorld,const btVector3 & pointInWorld,btScalar depth)103 void btManifoldResult::addContactPoint(const btVector3& normalOnBInWorld, const btVector3& pointInWorld, btScalar depth)
104 {
105 btAssert(m_manifoldPtr);
106 //order in manifold needs to match
107
108 if (depth > m_manifoldPtr->getContactBreakingThreshold())
109 // if (depth > m_manifoldPtr->getContactProcessingThreshold())
110 return;
111
112 bool isSwapped = m_manifoldPtr->getBody0() != m_body0Wrap->getCollisionObject();
113 bool isNewCollision = m_manifoldPtr->getNumContacts() == 0;
114
115 btVector3 pointA = pointInWorld + normalOnBInWorld * depth;
116
117 btVector3 localA;
118 btVector3 localB;
119
120 if (isSwapped)
121 {
122 localA = m_body1Wrap->getCollisionObject()->getWorldTransform().invXform(pointA);
123 localB = m_body0Wrap->getCollisionObject()->getWorldTransform().invXform(pointInWorld);
124 }
125 else
126 {
127 localA = m_body0Wrap->getCollisionObject()->getWorldTransform().invXform(pointA);
128 localB = m_body1Wrap->getCollisionObject()->getWorldTransform().invXform(pointInWorld);
129 }
130
131 btManifoldPoint newPt(localA, localB, normalOnBInWorld, depth);
132 newPt.m_positionWorldOnA = pointA;
133 newPt.m_positionWorldOnB = pointInWorld;
134
135 int insertIndex = m_manifoldPtr->getCacheEntry(newPt);
136
137 newPt.m_combinedFriction = gCalculateCombinedFrictionCallback(m_body0Wrap->getCollisionObject(), m_body1Wrap->getCollisionObject());
138 newPt.m_combinedRestitution = gCalculateCombinedRestitutionCallback(m_body0Wrap->getCollisionObject(), m_body1Wrap->getCollisionObject());
139 newPt.m_combinedRollingFriction = gCalculateCombinedRollingFrictionCallback(m_body0Wrap->getCollisionObject(), m_body1Wrap->getCollisionObject());
140 newPt.m_combinedSpinningFriction = gCalculateCombinedSpinningFrictionCallback(m_body0Wrap->getCollisionObject(), m_body1Wrap->getCollisionObject());
141
142 if ((m_body0Wrap->getCollisionObject()->getCollisionFlags() & btCollisionObject::CF_HAS_CONTACT_STIFFNESS_DAMPING) ||
143 (m_body1Wrap->getCollisionObject()->getCollisionFlags() & btCollisionObject::CF_HAS_CONTACT_STIFFNESS_DAMPING))
144 {
145 newPt.m_combinedContactDamping1 = gCalculateCombinedContactDampingCallback(m_body0Wrap->getCollisionObject(), m_body1Wrap->getCollisionObject());
146 newPt.m_combinedContactStiffness1 = gCalculateCombinedContactStiffnessCallback(m_body0Wrap->getCollisionObject(), m_body1Wrap->getCollisionObject());
147 newPt.m_contactPointFlags |= BT_CONTACT_FLAG_CONTACT_STIFFNESS_DAMPING;
148 }
149
150 if ((m_body0Wrap->getCollisionObject()->getCollisionFlags() & btCollisionObject::CF_HAS_FRICTION_ANCHOR) ||
151 (m_body1Wrap->getCollisionObject()->getCollisionFlags() & btCollisionObject::CF_HAS_FRICTION_ANCHOR))
152 {
153 newPt.m_contactPointFlags |= BT_CONTACT_FLAG_FRICTION_ANCHOR;
154 }
155
156 btPlaneSpace1(newPt.m_normalWorldOnB, newPt.m_lateralFrictionDir1, newPt.m_lateralFrictionDir2);
157
158 //BP mod, store contact triangles.
159 if (isSwapped)
160 {
161 newPt.m_partId0 = m_partId1;
162 newPt.m_partId1 = m_partId0;
163 newPt.m_index0 = m_index1;
164 newPt.m_index1 = m_index0;
165 }
166 else
167 {
168 newPt.m_partId0 = m_partId0;
169 newPt.m_partId1 = m_partId1;
170 newPt.m_index0 = m_index0;
171 newPt.m_index1 = m_index1;
172 }
173 //printf("depth=%f\n",depth);
174 ///@todo, check this for any side effects
175 if (insertIndex >= 0)
176 {
177 //const btManifoldPoint& oldPoint = m_manifoldPtr->getContactPoint(insertIndex);
178 m_manifoldPtr->replaceContactPoint(newPt, insertIndex);
179 }
180 else
181 {
182 insertIndex = m_manifoldPtr->addManifoldPoint(newPt);
183 }
184
185 //User can override friction and/or restitution
186 if (gContactAddedCallback &&
187 //and if either of the two bodies requires custom material
188 ((m_body0Wrap->getCollisionObject()->getCollisionFlags() & btCollisionObject::CF_CUSTOM_MATERIAL_CALLBACK) ||
189 (m_body1Wrap->getCollisionObject()->getCollisionFlags() & btCollisionObject::CF_CUSTOM_MATERIAL_CALLBACK)))
190 {
191 //experimental feature info, for per-triangle material etc.
192 const btCollisionObjectWrapper* obj0Wrap = isSwapped ? m_body1Wrap : m_body0Wrap;
193 const btCollisionObjectWrapper* obj1Wrap = isSwapped ? m_body0Wrap : m_body1Wrap;
194 (*gContactAddedCallback)(m_manifoldPtr->getContactPoint(insertIndex), obj0Wrap, newPt.m_partId0, newPt.m_index0, obj1Wrap, newPt.m_partId1, newPt.m_index1);
195 }
196
197 if (gContactStartedCallback && isNewCollision)
198 {
199 gContactStartedCallback(m_manifoldPtr);
200 }
201 }
202