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 "btCollisionDispatcherMt.h"
17 #include "LinearMath/btQuickprof.h"
18 
19 #include "BulletCollision/BroadphaseCollision/btCollisionAlgorithm.h"
20 
21 #include "BulletCollision/CollisionShapes/btCollisionShape.h"
22 #include "BulletCollision/CollisionDispatch/btCollisionObject.h"
23 #include "BulletCollision/BroadphaseCollision/btOverlappingPairCache.h"
24 #include "LinearMath/btPoolAllocator.h"
25 #include "BulletCollision/CollisionDispatch/btCollisionConfiguration.h"
26 #include "BulletCollision/CollisionDispatch/btCollisionObjectWrapper.h"
27 
btCollisionDispatcherMt(btCollisionConfiguration * config,int grainSize)28 btCollisionDispatcherMt::btCollisionDispatcherMt(btCollisionConfiguration* config, int grainSize)
29 	: btCollisionDispatcher(config)
30 {
31 	m_batchManifoldsPtr.resize(btGetTaskScheduler()->getNumThreads());
32 	m_batchReleasePtr.resize(btGetTaskScheduler()->getNumThreads());
33 
34 	m_batchUpdating = false;
35 	m_grainSize = grainSize;  // iterations per task
36 }
37 
getNewManifold(const btCollisionObject * body0,const btCollisionObject * body1)38 btPersistentManifold* btCollisionDispatcherMt::getNewManifold(const btCollisionObject* body0, const btCollisionObject* body1)
39 {
40 	//optional relative contact breaking threshold, turned on by default (use setDispatcherFlags to switch off feature for improved performance)
41 
42 	btScalar contactBreakingThreshold = (m_dispatcherFlags & btCollisionDispatcher::CD_USE_RELATIVE_CONTACT_BREAKING_THRESHOLD) ? btMin(body0->getCollisionShape()->getContactBreakingThreshold(gContactBreakingThreshold), body1->getCollisionShape()->getContactBreakingThreshold(gContactBreakingThreshold))
43 																																: gContactBreakingThreshold;
44 
45 	btScalar contactProcessingThreshold = btMin(body0->getContactProcessingThreshold(), body1->getContactProcessingThreshold());
46 
47 	void* mem = m_persistentManifoldPoolAllocator->allocate(sizeof(btPersistentManifold));
48 	if (NULL == mem)
49 	{
50 		//we got a pool memory overflow, by default we fallback to dynamically allocate memory. If we require a contiguous contact pool then assert.
51 		if ((m_dispatcherFlags & CD_DISABLE_CONTACTPOOL_DYNAMIC_ALLOCATION) == 0)
52 		{
53 			mem = btAlignedAlloc(sizeof(btPersistentManifold), 16);
54 		}
55 		else
56 		{
57 			btAssert(0);
58 			//make sure to increase the m_defaultMaxPersistentManifoldPoolSize in the btDefaultCollisionConstructionInfo/btDefaultCollisionConfiguration
59 			return 0;
60 		}
61 	}
62 	btPersistentManifold* manifold = new (mem) btPersistentManifold(body0, body1, 0, contactBreakingThreshold, contactProcessingThreshold);
63 	if (!m_batchUpdating)
64 	{
65 		// batch updater will update manifold pointers array after finishing, so
66 		// only need to update array when not batch-updating
67 		//btAssert( !btThreadsAreRunning() );
68 		manifold->m_index1a = m_manifoldsPtr.size();
69 		m_manifoldsPtr.push_back(manifold);
70 	}
71 	else
72 	{
73 		m_batchManifoldsPtr[btGetCurrentThreadIndex()].push_back(manifold);
74 	}
75 
76 	return manifold;
77 }
78 
releaseManifold(btPersistentManifold * manifold)79 void btCollisionDispatcherMt::releaseManifold(btPersistentManifold* manifold)
80 {
81 	//btAssert( !btThreadsAreRunning() );
82 
83 	if (!m_batchUpdating)
84 	{
85 		clearManifold(manifold);
86 		// batch updater will update manifold pointers array after finishing, so
87 		// only need to update array when not batch-updating
88 		int findIndex = manifold->m_index1a;
89 		btAssert(findIndex < m_manifoldsPtr.size());
90 		m_manifoldsPtr.swap(findIndex, m_manifoldsPtr.size() - 1);
91 		m_manifoldsPtr[findIndex]->m_index1a = findIndex;
92 		m_manifoldsPtr.pop_back();
93 	} else {
94 		m_batchReleasePtr[btGetCurrentThreadIndex()].push_back(manifold);
95 		return;
96 	}
97 
98 	manifold->~btPersistentManifold();
99 	if (m_persistentManifoldPoolAllocator->validPtr(manifold))
100 	{
101 		m_persistentManifoldPoolAllocator->freeMemory(manifold);
102 	}
103 	else
104 	{
105 		btAlignedFree(manifold);
106 	}
107 }
108 
109 struct CollisionDispatcherUpdater : public btIParallelForBody
110 {
111 	btBroadphasePair* mPairArray;
112 	btNearCallback mCallback;
113 	btCollisionDispatcher* mDispatcher;
114 	const btDispatcherInfo* mInfo;
115 
CollisionDispatcherUpdaterCollisionDispatcherUpdater116 	CollisionDispatcherUpdater()
117 	{
118 		mPairArray = NULL;
119 		mCallback = NULL;
120 		mDispatcher = NULL;
121 		mInfo = NULL;
122 	}
forLoopCollisionDispatcherUpdater123 	void forLoop(int iBegin, int iEnd) const
124 	{
125 		for (int i = iBegin; i < iEnd; ++i)
126 		{
127 			btBroadphasePair* pair = &mPairArray[i];
128 			mCallback(*pair, *mDispatcher, *mInfo);
129 		}
130 	}
131 };
132 
dispatchAllCollisionPairs(btOverlappingPairCache * pairCache,const btDispatcherInfo & info,btDispatcher * dispatcher)133 void btCollisionDispatcherMt::dispatchAllCollisionPairs(btOverlappingPairCache* pairCache, const btDispatcherInfo& info, btDispatcher* dispatcher)
134 {
135 	const int pairCount = pairCache->getNumOverlappingPairs();
136 	if (pairCount == 0)
137 	{
138 		return;
139 	}
140 	CollisionDispatcherUpdater updater;
141 	updater.mCallback = getNearCallback();
142 	updater.mPairArray = pairCache->getOverlappingPairArrayPtr();
143 	updater.mDispatcher = this;
144 	updater.mInfo = &info;
145 
146 	m_batchUpdating = true;
147 	btParallelFor(0, pairCount, m_grainSize, updater);
148 	m_batchUpdating = false;
149 
150 	// merge new manifolds, if any
151 	for (int i = 0; i < m_batchManifoldsPtr.size(); ++i)
152 	{
153 		btAlignedObjectArray<btPersistentManifold*>& batchManifoldsPtr = m_batchManifoldsPtr[i];
154 
155 		for (int j = 0; j < batchManifoldsPtr.size(); ++j)
156 		{
157 			m_manifoldsPtr.push_back(batchManifoldsPtr[j]);
158 		}
159 
160 		batchManifoldsPtr.resizeNoInitialize(0);
161 	}
162 
163 	// remove batched remove manifolds.
164 	for (int i = 0; i < m_batchReleasePtr.size(); ++i)
165 	{
166 		btAlignedObjectArray<btPersistentManifold*>& batchManifoldsPtr = m_batchReleasePtr[i];
167 		for (int j = 0; j < batchManifoldsPtr.size(); ++j)
168 		{
169 			releaseManifold(batchManifoldsPtr[j]);
170 		}
171 		batchManifoldsPtr.resizeNoInitialize(0);
172 	}
173 
174 	// update the indices (used when releasing manifolds)
175 	for (int i = 0; i < m_manifoldsPtr.size(); ++i)
176 	{
177 		m_manifoldsPtr[i]->m_index1a = i;
178 	}
179 }
180