Blender  V3.3
btManifoldResult.cpp
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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 #include "btManifoldResult.h"
20 
23 
30 
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 
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 
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 
69 {
70  return body0->getRestitution() * body1->getRestitution();
71 }
72 
74 {
75  return body0->getContactDamping() + body1->getContactDamping();
76 }
77 
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 
90  : m_manifoldPtr(0),
91  m_body0Wrap(body0Wrap),
92  m_body1Wrap(body1Wrap)
93 #ifdef DEBUG_PART_INDEX
94  ,
95  m_partId0(-1),
96  m_partId1(-1),
97  m_index0(-1),
98  m_index1(-1)
99 #endif //DEBUG_PART_INDEX
100  ,
101  m_closestPointDistanceThreshold(0)
102 {
103 }
104 
105 void btManifoldResult::addContactPoint(const btVector3& normalOnBInWorld, const btVector3& pointInWorld, btScalar depth)
106 {
108  //order in manifold needs to match
109 
110  if (depth > m_manifoldPtr->getContactBreakingThreshold())
111  // if (depth > m_manifoldPtr->getContactProcessingThreshold())
112  return;
113 
114  bool isSwapped = m_manifoldPtr->getBody0() != m_body0Wrap->getCollisionObject();
115  bool isNewCollision = m_manifoldPtr->getNumContacts() == 0;
116 
117  btVector3 pointA = pointInWorld + normalOnBInWorld * depth;
118 
119  btVector3 localA;
120  btVector3 localB;
121 
122  if (isSwapped)
123  {
124  localA = m_body1Wrap->getCollisionObject()->getWorldTransform().invXform(pointA);
125  localB = m_body0Wrap->getCollisionObject()->getWorldTransform().invXform(pointInWorld);
126  }
127  else
128  {
129  localA = m_body0Wrap->getCollisionObject()->getWorldTransform().invXform(pointA);
130  localB = m_body1Wrap->getCollisionObject()->getWorldTransform().invXform(pointInWorld);
131  }
132 
133  btManifoldPoint newPt(localA, localB, normalOnBInWorld, depth);
134  newPt.m_positionWorldOnA = pointA;
135  newPt.m_positionWorldOnB = pointInWorld;
136 
137  int insertIndex = m_manifoldPtr->getCacheEntry(newPt);
138 
143 
146  {
150  }
151 
154  {
156  }
157 
159 
160  //BP mod, store contact triangles.
161  if (isSwapped)
162  {
163  newPt.m_partId0 = m_partId1;
164  newPt.m_partId1 = m_partId0;
165  newPt.m_index0 = m_index1;
166  newPt.m_index1 = m_index0;
167  }
168  else
169  {
170  newPt.m_partId0 = m_partId0;
171  newPt.m_partId1 = m_partId1;
172  newPt.m_index0 = m_index0;
173  newPt.m_index1 = m_index1;
174  }
175  //printf("depth=%f\n",depth);
177  if (insertIndex >= 0)
178  {
179  //const btManifoldPoint& oldPoint = m_manifoldPtr->getContactPoint(insertIndex);
180  m_manifoldPtr->replaceContactPoint(newPt, insertIndex);
181  }
182  else
183  {
184  insertIndex = m_manifoldPtr->addManifoldPoint(newPt);
185  }
186 
187  //User can override friction and/or restitution
188  if (gContactAddedCallback &&
189  //and if either of the two bodies requires custom material
192  {
193  //experimental feature info, for per-triangle material etc.
194  const btCollisionObjectWrapper* obj0Wrap = isSwapped ? m_body1Wrap : m_body0Wrap;
195  const btCollisionObjectWrapper* obj1Wrap = isSwapped ? m_body0Wrap : m_body1Wrap;
196  (*gContactAddedCallback)(m_manifoldPtr->getContactPoint(insertIndex), obj0Wrap, newPt.m_partId0, newPt.m_index0, obj1Wrap, newPt.m_partId1, newPt.m_index1);
197  }
198 
199  if (gContactStartedCallback && isNewCollision)
200  {
202  }
203 }
btCollisionObject
@ CF_HAS_CONTACT_STIFFNESS_DAMPING
@ CF_HAS_FRICTION_ANCHOR
@ CF_CUSTOM_MATERIAL_CALLBACK
btPersistentManifold * m_manifoldPtr
@ BT_CONTACT_FLAG_CONTACT_STIFFNESS_DAMPING
@ BT_CONTACT_FLAG_FRICTION_ANCHOR
CalculateCombinedCallback gCalculateCombinedContactStiffnessCallback
CalculateCombinedCallback gCalculateCombinedContactDampingCallback
ContactAddedCallback gContactAddedCallback
This is to allow MaterialCombiner/Custom Friction/Restitution values.
CalculateCombinedCallback gCalculateCombinedSpinningFrictionCallback
CalculateCombinedCallback gCalculateCombinedFrictionCallback
CalculateCombinedCallback gCalculateCombinedRollingFrictionCallback
CalculateCombinedCallback gCalculateCombinedRestitutionCallback
bool(* ContactAddedCallback)(btManifoldPoint &cp, const btCollisionObjectWrapper *colObj0Wrap, int partId0, int index0, const btCollisionObjectWrapper *colObj1Wrap, int partId1, int index1)
btScalar(* CalculateCombinedCallback)(const btCollisionObject *body0, const btCollisionObject *body1)
These callbacks are used to customize the algorith that combine restitution, friction,...
ContactStartedCallback gContactStartedCallback
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:314
#define btAssert(x)
Definition: btScalar.h:295
SIMD_FORCE_INLINE void btPlaneSpace1(const T &n, T &p, T &q)
Definition: btVector3.h:1251
btVector3
btVector3 can be used to represent 3D points and vectors. It has an un-used w component to suit 16-by...
Definition: btVector3.h:82
btScalar m_combinedSpinningFriction
btScalar m_combinedRollingFriction
btScalar m_combinedContactStiffness1
btScalar m_combinedRestitution
btVector3 m_lateralFrictionDir2
btVector3 m_positionWorldOnA
m_positionWorldOnA is redundant information, see getPositionWorldOnA(), but for clarity
btScalar m_combinedContactDamping1
btVector3 m_normalWorldOnB
btScalar m_combinedFriction
btVector3 m_positionWorldOnB
btVector3 m_lateralFrictionDir1
const btCollisionObjectWrapper * m_body0Wrap
static btScalar calculateCombinedFriction(const btCollisionObject *body0, const btCollisionObject *body1)
User can override this material combiner by implementing gContactAddedCallback and setting body0->m_c...
static btScalar calculateCombinedContactDamping(const btCollisionObject *body0, const btCollisionObject *body1)
const btCollisionObjectWrapper * m_body1Wrap
static btScalar calculateCombinedContactStiffness(const btCollisionObject *body0, const btCollisionObject *body1)
static btScalar calculateCombinedSpinningFriction(const btCollisionObject *body0, const btCollisionObject *body1)
static btScalar calculateCombinedRollingFriction(const btCollisionObject *body0, const btCollisionObject *body1)
static btScalar calculateCombinedRestitution(const btCollisionObject *body0, const btCollisionObject *body1)
in the future we can let the user override the methods to combine restitution and friction
btPersistentManifold * m_manifoldPtr
virtual void addContactPoint(const btVector3 &normalOnBInWorld, const btVector3 &pointInWorld, btScalar depth)
SIMD_FORCE_INLINE const btCollisionObject * getCollisionObject() const