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Diffstat (limited to 'extern/bullet2/src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolverMt.h')
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diff --git a/extern/bullet2/src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolverMt.h b/extern/bullet2/src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolverMt.h new file mode 100644 index 00000000000..1861ddd7d76 --- /dev/null +++ b/extern/bullet2/src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolverMt.h @@ -0,0 +1,150 @@ +/* +Bullet Continuous Collision Detection and Physics Library +Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/ + +This software is provided 'as-is', without any express or implied warranty. +In no event will the authors be held liable for any damages arising from the use of this software. +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it freely, +subject to the following restrictions: + +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. +2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. +3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef BT_SEQUENTIAL_IMPULSE_CONSTRAINT_SOLVER_MT_H +#define BT_SEQUENTIAL_IMPULSE_CONSTRAINT_SOLVER_MT_H + +#include "btSequentialImpulseConstraintSolver.h" +#include "btBatchedConstraints.h" +#include "LinearMath/btThreads.h" + +/// +/// btSequentialImpulseConstraintSolverMt +/// +/// A multithreaded variant of the sequential impulse constraint solver. The constraints to be solved are grouped into +/// batches and phases where each batch of constraints within a given phase can be solved in parallel with the rest. +/// Ideally we want as few phases as possible, and each phase should have many batches, and all of the batches should +/// have about the same number of constraints. +/// This method works best on a large island of many constraints. +/// +/// Supports all of the features of the normal sequential impulse solver such as: +/// - split penetration impulse +/// - rolling friction +/// - interleaving constraints +/// - warmstarting +/// - 2 friction directions +/// - randomized constraint ordering +/// - early termination when leastSquaresResidualThreshold is satisfied +/// +/// When the SOLVER_INTERLEAVE_CONTACT_AND_FRICTION_CONSTRAINTS flag is enabled, unlike the normal SequentialImpulse solver, +/// the rolling friction is interleaved as well. +/// Interleaving the contact penetration constraints with friction reduces the number of parallel loops that need to be done, +/// which reduces threading overhead so it can be a performance win, however, it does seem to produce a less stable simulation, +/// at least on stacks of blocks. +/// +/// When the SOLVER_RANDMIZE_ORDER flag is enabled, the ordering of phases, and the ordering of constraints within each batch +/// is randomized, however it does not swap constraints between batches. +/// This is to avoid regenerating the batches for each solver iteration which would be quite costly in performance. +/// +/// Note that a non-zero leastSquaresResidualThreshold could possibly affect the determinism of the simulation +/// if the task scheduler's parallelSum operation is non-deterministic. The parallelSum operation can be non-deterministic +/// because floating point addition is not associative due to rounding errors. +/// The task scheduler can and should ensure that the result of any parallelSum operation is deterministic. +/// +ATTRIBUTE_ALIGNED16(class) +btSequentialImpulseConstraintSolverMt : public btSequentialImpulseConstraintSolver +{ +public: + virtual void solveGroupCacheFriendlySplitImpulseIterations(btCollisionObject * *bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* debugDrawer) BT_OVERRIDE; + virtual btScalar solveSingleIteration(int iteration, btCollisionObject** bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* debugDrawer) BT_OVERRIDE; + virtual btScalar solveGroupCacheFriendlySetup(btCollisionObject * *bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* debugDrawer) BT_OVERRIDE; + virtual btScalar solveGroupCacheFriendlyFinish(btCollisionObject * *bodies, int numBodies, const btContactSolverInfo& infoGlobal) BT_OVERRIDE; + + // temp struct used to collect info from persistent manifolds into a cache-friendly struct using multiple threads + struct btContactManifoldCachedInfo + { + static const int MAX_NUM_CONTACT_POINTS = 4; + + int numTouchingContacts; + int solverBodyIds[2]; + int contactIndex; + int rollingFrictionIndex; + bool contactHasRollingFriction[MAX_NUM_CONTACT_POINTS]; + btManifoldPoint* contactPoints[MAX_NUM_CONTACT_POINTS]; + }; + // temp struct used for setting up joint constraints in parallel + struct JointParams + { + int m_solverConstraint; + int m_solverBodyA; + int m_solverBodyB; + }; + void internalInitMultipleJoints(btTypedConstraint * *constraints, int iBegin, int iEnd); + void internalConvertMultipleJoints(const btAlignedObjectArray<JointParams>& jointParamsArray, btTypedConstraint** constraints, int iBegin, int iEnd, const btContactSolverInfo& infoGlobal); + + // parameters to control batching + static bool s_allowNestedParallelForLoops; // whether to allow nested parallel operations + static int s_minimumContactManifoldsForBatching; // don't even try to batch if fewer manifolds than this + static btBatchedConstraints::BatchingMethod s_contactBatchingMethod; + static btBatchedConstraints::BatchingMethod s_jointBatchingMethod; + static int s_minBatchSize; // desired number of constraints per batch + static int s_maxBatchSize; + +protected: + static const int CACHE_LINE_SIZE = 64; + + btBatchedConstraints m_batchedContactConstraints; + btBatchedConstraints m_batchedJointConstraints; + int m_numFrictionDirections; + bool m_useBatching; + bool m_useObsoleteJointConstraints; + btAlignedObjectArray<btContactManifoldCachedInfo> m_manifoldCachedInfoArray; + btAlignedObjectArray<int> m_rollingFrictionIndexTable; // lookup table mapping contact index to rolling friction index + btSpinMutex m_bodySolverArrayMutex; + char m_antiFalseSharingPadding[CACHE_LINE_SIZE]; // padding to keep mutexes in separate cachelines + btSpinMutex m_kinematicBodyUniqueIdToSolverBodyTableMutex; + btAlignedObjectArray<char> m_scratchMemory; + + virtual void randomizeConstraintOrdering(int iteration, int numIterations); + virtual btScalar resolveAllJointConstraints(int iteration); + virtual btScalar resolveAllContactConstraints(); + virtual btScalar resolveAllContactFrictionConstraints(); + virtual btScalar resolveAllContactConstraintsInterleaved(); + virtual btScalar resolveAllRollingFrictionConstraints(); + + virtual void setupBatchedContactConstraints(); + virtual void setupBatchedJointConstraints(); + virtual void convertJoints(btTypedConstraint * *constraints, int numConstraints, const btContactSolverInfo& infoGlobal) BT_OVERRIDE; + virtual void convertContacts(btPersistentManifold * *manifoldPtr, int numManifolds, const btContactSolverInfo& infoGlobal) BT_OVERRIDE; + virtual void convertBodies(btCollisionObject * *bodies, int numBodies, const btContactSolverInfo& infoGlobal) BT_OVERRIDE; + + int getOrInitSolverBodyThreadsafe(btCollisionObject & body, btScalar timeStep); + void allocAllContactConstraints(btPersistentManifold * *manifoldPtr, int numManifolds, const btContactSolverInfo& infoGlobal); + void setupAllContactConstraints(const btContactSolverInfo& infoGlobal); + void randomizeBatchedConstraintOrdering(btBatchedConstraints * batchedConstraints); + +public: + BT_DECLARE_ALIGNED_ALLOCATOR(); + + btSequentialImpulseConstraintSolverMt(); + virtual ~btSequentialImpulseConstraintSolverMt(); + + btScalar resolveMultipleJointConstraints(const btAlignedObjectArray<int>& consIndices, int batchBegin, int batchEnd, int iteration); + btScalar resolveMultipleContactConstraints(const btAlignedObjectArray<int>& consIndices, int batchBegin, int batchEnd); + btScalar resolveMultipleContactSplitPenetrationImpulseConstraints(const btAlignedObjectArray<int>& consIndices, int batchBegin, int batchEnd); + btScalar resolveMultipleContactFrictionConstraints(const btAlignedObjectArray<int>& consIndices, int batchBegin, int batchEnd); + btScalar resolveMultipleContactRollingFrictionConstraints(const btAlignedObjectArray<int>& consIndices, int batchBegin, int batchEnd); + btScalar resolveMultipleContactConstraintsInterleaved(const btAlignedObjectArray<int>& contactIndices, int batchBegin, int batchEnd); + + void internalCollectContactManifoldCachedInfo(btContactManifoldCachedInfo * cachedInfoArray, btPersistentManifold * *manifoldPtr, int numManifolds, const btContactSolverInfo& infoGlobal); + void internalAllocContactConstraints(const btContactManifoldCachedInfo* cachedInfoArray, int numManifolds); + void internalSetupContactConstraints(int iContactConstraint, const btContactSolverInfo& infoGlobal); + void internalConvertBodies(btCollisionObject * *bodies, int iBegin, int iEnd, const btContactSolverInfo& infoGlobal); + void internalWriteBackContacts(int iBegin, int iEnd, const btContactSolverInfo& infoGlobal); + void internalWriteBackJoints(int iBegin, int iEnd, const btContactSolverInfo& infoGlobal); + void internalWriteBackBodies(int iBegin, int iEnd, const btContactSolverInfo& infoGlobal); +}; + +#endif //BT_SEQUENTIAL_IMPULSE_CONSTRAINT_SOLVER_MT_H |