Added preparation for GPU hardware accelerated solvers for BulletSoftBody (OpenCL and DirectCompute backends will follow)

Added assert to check for positive masses in btCompoundShape::calculatePrincipalAxisTransform, see Issue 399
Fixes for LLVM/GCC compilation issue in btSequentialImpulseConstraintSolver
(Untested) fix for Linux 64bit compilation Issue 409

CMakeLists.txt

@@ -7,6 +7,11 @@ SET(MSVC_INCREMENTAL_DEFAULT ON)
 PROJECT(BULLET_PHYSICS)
 SET(BULLET_VERSION 2.76)
 
+IF(COMMAND cmake_policy)
+   cmake_policy(SET CMP0003 NEW)
+ENDIF(COMMAND cmake_policy)
+
+
 IF (NOT CMAKE_BUILD_TYPE)
 # SET(CMAKE_BUILD_TYPE "Debug")
  SET(CMAKE_BUILD_TYPE "Release")
@@ -157,6 +162,8 @@ IF (USE_GLUT AND MSVC)
         remove_definitions(-D_WINDOWS )
 ENDIF()
 
+
+
 ELSE(WIN32)
 OPTION(USE_GLUT "Use Glut"	ON)
 ENDIF(WIN32)

Demos/Benchmarks/BenchmarkDemo.cpp

@@ -41,12 +41,40 @@ subject to the following restrictions:
 #ifdef USE_PARALLEL_DISPATCHER_BENCHMARK
 #include "BulletMultiThreaded/Win32ThreadSupport.h"
 #include "BulletMultiThreaded/SpuGatheringCollisionDispatcher.h"
+#include "BulletMultiThreaded/btParallelConstraintSolver.h"
+
+
+
+
+btThreadSupportInterface* createSolverThreadSupport(int maxNumThreads)
+{
+//#define SEQUENTIAL
+#ifdef SEQUENTIAL
+	SequentialThreadSupport::SequentialThreadConstructionInfo tci("solverThreads",SolverThreadFunc,SolverlsMemoryFunc);
+	SequentialThreadSupport* threadSupport = new SequentialThreadSupport(tci);
+	threadSupport->startSPU();
+#else
+
+#ifdef _WIN32
+	Win32ThreadSupport::Win32ThreadConstructionInfo threadConstructionInfo("solverThreads",SolverThreadFunc,SolverlsMemoryFunc,maxNumThreads);
+	Win32ThreadSupport* threadSupport = new Win32ThreadSupport(threadConstructionInfo);
+	threadSupport->startSPU();
+#elif defined (USE_PTHREADS)
+	PosixThreadSupport::ThreadConstructionInfo solverConstructionInfo("solver", SolverThreadFunc,
+																	  SolverlsMemoryFunc, maxNumThreads);
+	
+	PosixThreadSupport* threadSupport = new PosixThreadSupport(solverConstructionInfo);
+	
+#else
+	SequentialThreadSupport::SequentialThreadConstructionInfo tci("solverThreads",SolverThreadFunc,SolverlsMemoryFunc);
+	SequentialThreadSupport* threadSupport = new SequentialThreadSupport(tci);
+	threadSupport->startSPU();
+#endif
 	
 #endif
 
-#undef USE_PARALLEL_SOLVER_BENCHMARK
+	return threadSupport;
-#ifdef USE_PARALLEL_SOLVER_BENCHMARK
+}
-#include "BulletMultiThreaded/btParallelConstraintSolver.h"
 #endif
 
 class btRaycastBar2
@@ -319,8 +347,10 @@ void	BenchmarkDemo::initPhysics()
 	
 
 	///the default constraint solver. For parallel processing you can use a different solver (see Extras/BulletMultiThreaded)
-#ifdef USE_PARALLEL_SOLVER_BENCHMARK
+#ifdef USE_PARALLEL_DISPATCHER_BENCHMARK
-	btConstraintSolver* sol = new btParallelConstraintSolver;
+
+	btThreadSupportInterface* thread = createSolverThreadSupport(4);
+	btConstraintSolver* sol = new btParallelConstraintSolver(thread);
 #else
 	btSequentialImpulseConstraintSolver* sol = new btSequentialImpulseConstraintSolver;
 #endif //USE_PARALLEL_DISPATCHER_BENCHMARK
@@ -331,9 +361,13 @@ void	BenchmarkDemo::initPhysics()
 	btDiscreteDynamicsWorld* dynamicsWorld;
 	m_dynamicsWorld = dynamicsWorld = new btDiscreteDynamicsWorld(m_dispatcher,m_overlappingPairCache,m_solver,m_collisionConfiguration);
 	
+#ifdef USE_PARALLEL_DISPATCHER_BENCHMARK
+	dynamicsWorld->getSimulationIslandManager()->setSplitIslands(false);
+#endif //USE_PARALLEL_DISPATCHER_BENCHMARK
+
 	///the following 3 lines increase the performance dramatically, with a little bit of loss of quality
 	m_dynamicsWorld->getSolverInfo().m_solverMode |=SOLVER_ENABLE_FRICTION_DIRECTION_CACHING; //don't recalculate friction values each frame
-	dynamicsWorld->getSolverInfo().m_numIterations = 4; //few solver iterations 
+	dynamicsWorld->getSolverInfo().m_numIterations = 5; //few solver iterations 
 	m_defaultContactProcessingThreshold = 0.f;//used when creating bodies: body->setContactProcessingThreshold(...);
 	
 
@@ -494,8 +528,8 @@ void BenchmarkDemo::createWall(const btVector3& offsetPosition,int stackSize,con
 
 void BenchmarkDemo::createPyramid(const btVector3& offsetPosition,int stackSize,const btVector3& boxSize)
 {
+	btScalar space = 0.0001f;
 	
-	btScalar space = 0.000f;
 	btVector3 pos(0.0f, boxSize[1], 0.0f);
 
 	btBoxShape* blockShape = new btBoxShape(btVector3(boxSize[0]-COLLISION_RADIUS,boxSize[1]-COLLISION_RADIUS,boxSize[2]-COLLISION_RADIUS));
@@ -507,9 +541,9 @@ void BenchmarkDemo::createPyramid(const btVector3& offsetPosition,int stackSize,
 	blockShape->calculateLocalInertia(mass,localInertia);
 
 	
-	btScalar diffX = boxSize[0];
+	btScalar diffX = boxSize[0]*1.02f;
-	btScalar diffY = boxSize[1];
+	btScalar diffY = boxSize[1]*1.02f;
-	btScalar diffZ = boxSize[2];
+	btScalar diffZ = boxSize[2]*1.02f;
 	
 	btScalar offsetX = -stackSize * (diffX * 2.0f + space) * 0.5f;
 	btScalar offsetZ = -stackSize * (diffZ * 2.0f + space) * 0.5f;

Demos/CMakeLists.txt

@@ -3,7 +3,7 @@ IF (USE_GLUT)
 
 IF(BUILD_CPU_DEMOS)
 	SET(SharedDemoSubdirs
-		OpenGL AllBulletDemos  ConvexDecompositionDemo Benchmarks HelloWorld
+		OpenGL AllBulletDemos  ConvexDecompositionDemo HelloWorld
 		CcdPhysicsDemo ConstraintDemo SliderConstraintDemo GenericJointDemo Raytracer
 		RagdollDemo ForkLiftDemo BasicDemo Box2dDemo BspDemo MovingConcaveDemo VehicleDemo
 		UserCollisionAlgorithm CharacterDemo SoftDemo HeightFieldFluidDemo
@@ -19,6 +19,7 @@ ELSE()
 ENDIF()
 
 	SUBDIRS( 		${SharedDemoSubdirs}
+	Benchmarks
 		ThreadingDemo
 		MultiThreadedDemo
 		VectorAdd_OpenCL

Demos/ParticlesOpenCL/Apple/CMakeLists.txt

@@ -64,8 +64,6 @@ IF (CMAKE_CL_64)
 					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/glut64.dll ${CMAKE_CURRENT_BINARY_DIR}	)
 		ADD_CUSTOM_COMMAND(	TARGET AppParticlesOCL_Apple	POST_BUILD
 					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/GLEW64.DLL ${CMAKE_CURRENT_BINARY_DIR})
-		ADD_CUSTOM_COMMAND(	TARGET AppParticlesOCL_Apple	POST_BUILD
-					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/Demos/ParticlesOpenCL/ParticlesOCL.cl ${CMAKE_CURRENT_BINARY_DIR})
 	ENDIF()
 ELSE(CMAKE_CL_64)
 	IF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
@@ -73,12 +71,14 @@ ELSE(CMAKE_CL_64)
 					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/GLUT32.DLL ${CMAKE_CURRENT_BINARY_DIR})
 		ADD_CUSTOM_COMMAND(	TARGET AppParticlesOCL_Apple	POST_BUILD
 					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/GLEW32.DLL ${CMAKE_CURRENT_BINARY_DIR})
-		ADD_CUSTOM_COMMAND(	TARGET AppParticlesOCL_Apple	POST_BUILD
-					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/Demos/ParticlesOpenCL/ParticlesOCL.cl ${CMAKE_CURRENT_BINARY_DIR})
 	ENDIF()
 ENDIF(CMAKE_CL_64)
 ENDIF(WIN32)
 
+ADD_CUSTOM_COMMAND(     TARGET AppParticlesOCL_Apple    POST_BUILD
+                                        COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/Demos/ParticlesOpenCL/ParticlesOCL.cl ${CMAKE_CURRENT_BINARY_DIR})
+
+
 IF (UNIX)
   TARGET_LINK_LIBRARIES(AppParticlesOCL_Apple pthread)
 ENDIF(UNIX)

Demos/ParticlesOpenCL/MiniCL/CMakeLists.txt

@@ -62,8 +62,6 @@ IF (CMAKE_CL_64)
 					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/glut64.dll ${CMAKE_CURRENT_BINARY_DIR}	)
 		ADD_CUSTOM_COMMAND(	TARGET AppParticlesOCL_Mini	POST_BUILD
 					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/GLEW64.DLL ${CMAKE_CURRENT_BINARY_DIR})
-		ADD_CUSTOM_COMMAND(	TARGET AppParticlesOCL_Mini	POST_BUILD
-					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/Demos/ParticlesOpenCL/ParticlesOCL.cl ${CMAKE_CURRENT_BINARY_DIR})
 	ENDIF()
 ELSE(CMAKE_CL_64)
 	IF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
@@ -71,12 +69,14 @@ ELSE(CMAKE_CL_64)
 					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/GLUT32.DLL ${CMAKE_CURRENT_BINARY_DIR})
 		ADD_CUSTOM_COMMAND(	TARGET AppParticlesOCL_Mini	POST_BUILD
 					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/GLEW32.DLL ${CMAKE_CURRENT_BINARY_DIR})
-		ADD_CUSTOM_COMMAND(	TARGET AppParticlesOCL_Mini	POST_BUILD
-					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/Demos/ParticlesOpenCL/ParticlesOCL.cl ${CMAKE_CURRENT_BINARY_DIR})
 	ENDIF()
 ENDIF(CMAKE_CL_64)
 ENDIF(WIN32)
 
+ADD_CUSTOM_COMMAND(     TARGET AppParticlesOCL_Mini     POST_BUILD
+                                        COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/Demos/ParticlesOpenCL/ParticlesOCL.cl ${CMAKE_CURRENT_BINARY_DIR})
+ 
+
 IF (UNIX)
   TARGET_LINK_LIBRARIES(AppParticlesOCL_Mini pthread)
 ENDIF(UNIX)

src/BulletCollision/CollisionShapes/btCompoundShape.cpp

@@ -219,9 +219,13 @@ void btCompoundShape::calculatePrincipalAxisTransform(btScalar* masses, btTransf
 
 	for (k = 0; k < n; k++)
 	{
+		btAssert(masses[k]>0);
 		center += m_children[k].m_transform.getOrigin() * masses[k];
 		totalMass += masses[k];
 	}
+
+	btAssert(totalMass>0);
+
 	center /= totalMass;
 	principal.setOrigin(center);
 

src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.cpp

@@ -539,7 +539,7 @@ void btSequentialImpulseConstraintSolver::setupContactConstraint(btSolverConstra
 					if (rb0)
 						rb0->internalApplyImpulse(solverConstraint.m_contactNormal*rb0->getInvMass()*rb0->getLinearFactor(),solverConstraint.m_angularComponentA,solverConstraint.m_appliedImpulse);
 					if (rb1)
-						rb1->internalApplyImpulse(solverConstraint.m_contactNormal*rb1->getInvMass()*rb1->getLinearFactor(),-solverConstraint.m_angularComponentB,-solverConstraint.m_appliedImpulse);
+						rb1->internalApplyImpulse(solverConstraint.m_contactNormal*rb1->getInvMass()*rb1->getLinearFactor(),-solverConstraint.m_angularComponentB,-(btScalar)solverConstraint.m_appliedImpulse);
 				} else
 				{
 					solverConstraint.m_appliedImpulse = 0.f;
@@ -598,7 +598,7 @@ void btSequentialImpulseConstraintSolver::setFrictionConstraintImpulse( btSolver
 								if (rb0)
 									rb0->internalApplyImpulse(frictionConstraint1.m_contactNormal*rb0->getInvMass()*rb0->getLinearFactor(),frictionConstraint1.m_angularComponentA,frictionConstraint1.m_appliedImpulse);
 								if (rb1)
-									rb1->internalApplyImpulse(frictionConstraint1.m_contactNormal*rb1->getInvMass()*rb1->getLinearFactor(),-frictionConstraint1.m_angularComponentB,-frictionConstraint1.m_appliedImpulse);
+									rb1->internalApplyImpulse(frictionConstraint1.m_contactNormal*rb1->getInvMass()*rb1->getLinearFactor(),-frictionConstraint1.m_angularComponentB,-(btScalar)frictionConstraint1.m_appliedImpulse);
 							} else
 							{
 								frictionConstraint1.m_appliedImpulse = 0.f;
@@ -614,7 +614,7 @@ void btSequentialImpulseConstraintSolver::setFrictionConstraintImpulse( btSolver
 								if (rb0)
 									rb0->internalApplyImpulse(frictionConstraint2.m_contactNormal*rb0->getInvMass(),frictionConstraint2.m_angularComponentA,frictionConstraint2.m_appliedImpulse);
 								if (rb1)
-									rb1->internalApplyImpulse(frictionConstraint2.m_contactNormal*rb1->getInvMass(),-frictionConstraint2.m_angularComponentB,-frictionConstraint2.m_appliedImpulse);
+									rb1->internalApplyImpulse(frictionConstraint2.m_contactNormal*rb1->getInvMass(),-frictionConstraint2.m_angularComponentB,-(btScalar)frictionConstraint2.m_appliedImpulse);
 							} else
 							{
 								frictionConstraint2.m_appliedImpulse = 0.f;

src/BulletMultiThreaded/CMakeLists.txt

@@ -5,6 +5,7 @@ INCLUDE_DIRECTORIES(
 
 ADD_LIBRARY(BulletMultiThreaded
 		PlatformDefinitions.h
+		PpuAddressSpace.h
 		SpuFakeDma.cpp
 		SpuFakeDma.h
 		SpuDoubleBuffer.h

src/BulletMultiThreaded/PpuAddressSpace.h

@@ -1,3 +1,19 @@
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2003-2010 Erwin Coumans  http://bulletphysics.org
+
+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 __PPU_ADDRESS_SPACE_H
 #define __PPU_ADDRESS_SPACE_H
 
@@ -9,13 +25,13 @@
 #endif //_WIN32
 
 
-#if defined(_WIN64) || defined(__LP64__) || defined(__x86_64__)
+#if defined(_WIN64)
-typedef unsigned __int64 ppu_address_t;
+	typedef unsigned __int64 ppu_address_t;
+#elif defined(__LP64__) || defined(__x86_64__)
+	typedef uint64_t ppu_address_t;
 #else
+	typedef uint32_t ppu_address_t;
+#endif //defined(_WIN64)
 
-typedef uint32_t ppu_address_t;
+#endif //__PPU_ADDRESS_SPACE_H
-
-#endif
-
-#endif
 

src/BulletMultiThreaded/SpuNarrowPhaseCollisionTask/SpuGatheringCollisionTask.cpp

@@ -1216,7 +1216,7 @@ void	processCollisionTask(void* userPtr, void* lsMemPtr)
 #endif											
 										)
 										{
-#define USE_PE_BOX_BOX 1
+//#define USE_PE_BOX_BOX 1
 #ifdef USE_PE_BOX_BOX
 											{
 

src/BulletSoftBody/CMakeLists.txt

@@ -1,8 +1,11 @@
 
 INCLUDE_DIRECTORIES(
 ${BULLET_PHYSICS_SOURCE_DIR}/src
+	
 )
 
+#SUBDIRS( Solvers )
+
 SET(BulletSoftBody_SRCS
 	btSoftBody.cpp
 	btSoftBodyConcaveCollisionAlgorithm.cpp
@@ -11,6 +14,8 @@ SET(BulletSoftBody_SRCS
 	btSoftRigidCollisionAlgorithm.cpp
 	btSoftRigidDynamicsWorld.cpp
 	btSoftSoftCollisionAlgorithm.cpp
+	btDefaultSoftBodySolver.cpp
+
 )
 
 SET(BulletSoftBody_HDRS
@@ -22,6 +27,11 @@ SET(BulletSoftBody_HDRS
 	btSoftRigidDynamicsWorld.h
 	btSoftSoftCollisionAlgorithm.h
 	btSparseSDF.h
+
+	btSoftBodySolvers.h
+	btDefaultSoftBodySolver.h
+
+	btSoftBodySolverVertexBuffer.h
 )
 
 

src/BulletSoftBody/btDefaultSoftBodySolver.cpp

@@ -0,0 +1,128 @@
+/*
+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.
+*/
+
+#include "BulletCollision/CollisionShapes/btTriangleIndexVertexArray.h"
+#include "BulletCollision/CollisionDispatch/btCollisionObject.h"
+#include "BulletCollision/CollisionShapes/btCollisionShape.h"
+
+#include "btDefaultSoftBodySolver.h"
+#include "BulletCollision/CollisionShapes/btCapsuleShape.h"
+#include "BulletSoftBody/btSoftBody.h"
+
+
+btDefaultSoftBodySolver::btDefaultSoftBodySolver()
+{
+	// Initial we will clearly need to update solver constants
+	// For now this is global for the cloths linked with this solver - we should probably make this body specific 
+	// for performance in future once we understand more clearly when constants need to be updated
+	m_updateSolverConstants = true;
+}
+
+btDefaultSoftBodySolver::~btDefaultSoftBodySolver()
+{
+}
+
+
+
+
+void btDefaultSoftBodySolver::optimize( btAlignedObjectArray< btSoftBody * > &softBodies )
+{
+	m_softBodySet.copyFromArray( softBodies );
+}
+
+void btDefaultSoftBodySolver::updateSoftBodies( )
+{
+	for ( int i=0; i < m_softBodySet.size(); i++)
+	{
+		btSoftBody*	psb=(btSoftBody*)m_softBodySet[i];
+		psb->integrateMotion();	
+	}
+} // updateSoftBodies
+
+bool btDefaultSoftBodySolver::checkInitialized()
+{
+	return true;
+}
+
+void btDefaultSoftBodySolver::solveConstraints( float solverdt )
+{
+	// Solve constraints for non-solver softbodies
+	for(int i=0; i < m_softBodySet.size(); ++i)
+	{
+		btSoftBody*	psb = static_cast<btSoftBody*>(m_softBodySet[i]);
+		psb->solveConstraints();
+	}	
+} // btDefaultSoftBodySolver::solveConstraints
+
+
+void btDefaultSoftBodySolver::copySoftBodyToVertexBuffer( const btSoftBody *const softBody, btVertexBufferDescriptor *vertexBuffer )
+{
+	// Currently only support CPU output buffers
+	// TODO: check for DX11 buffers. Take all offsets into the same DX11 buffer
+	// and use them together on a single kernel call if possible by setting up a
+	// per-cloth target buffer array for the copy kernel.
+
+	if( vertexBuffer->getBufferType() == btVertexBufferDescriptor::CPU_BUFFER )
+	{
+		const btAlignedObjectArray<btSoftBody::Node> &clothVertices( softBody->m_nodes );
+		int numVertices = clothVertices.size();
+
+		const btCPUVertexBufferDescriptor *cpuVertexBuffer = static_cast< btCPUVertexBufferDescriptor* >(vertexBuffer);						
+		float *basePointer = cpuVertexBuffer->getBasePointer();						
+
+		if( vertexBuffer->hasVertexPositions() )
+		{
+			const int vertexOffset = cpuVertexBuffer->getVertexOffset();
+			const int vertexStride = cpuVertexBuffer->getVertexStride();
+			float *vertexPointer = basePointer + vertexOffset;
+
+			for( int vertexIndex = 0; vertexIndex < numVertices; ++vertexIndex )
+			{
+				btVector3 position = clothVertices[vertexIndex].m_x;
+				*(vertexPointer + 0) = position.getX();
+				*(vertexPointer + 1) = position.getY();
+				*(vertexPointer + 2) = position.getZ();
+				vertexPointer += vertexStride;
+			}
+		}
+		if( vertexBuffer->hasNormals() )
+		{
+			const int normalOffset = cpuVertexBuffer->getNormalOffset();
+			const int normalStride = cpuVertexBuffer->getNormalStride();
+			float *normalPointer = basePointer + normalOffset;
+
+			for( int vertexIndex = 0; vertexIndex < numVertices; ++vertexIndex )
+			{
+				btVector3 normal = clothVertices[vertexIndex].m_n;
+				*(normalPointer + 0) = normal.getX();
+				*(normalPointer + 1) = normal.getY();
+				*(normalPointer + 2) = normal.getZ();
+				normalPointer += normalStride;
+			}
+		}
+	}
+} // btDefaultSoftBodySolver::copySoftBodyToVertexBuffer
+
+
+void btDefaultSoftBodySolver::predictMotion( float timeStep )
+{
+	for ( int i=0; i < m_softBodySet.size(); ++i)
+	{
+		btSoftBody*	psb = m_softBodySet[i];
+
+		psb->predictMotion(timeStep);		
+	}
+}
+

src/BulletSoftBody/btDefaultSoftBodySolver.h

@@ -0,0 +1,51 @@
+/*
+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_SOFT_BODY_DEFAULT_SOLVER_H
+#define BT_SOFT_BODY_DEFAULT_SOLVER_H
+
+
+#include "BulletSoftBody/btSoftBodySolvers.h"
+#include "btSoftBodySolverVertexBuffer.h"
+
+
+class btDefaultSoftBodySolver : public btSoftBodySolver
+{
+protected:		
+	/** Variable to define whether we need to update solver constants on the next iteration */
+	bool m_updateSolverConstants;
+
+	btAlignedObjectArray< btSoftBody * > m_softBodySet;
+
+
+public:
+	btDefaultSoftBodySolver();
+	
+	virtual ~btDefaultSoftBodySolver();
+
+	virtual bool checkInitialized();
+
+	virtual void updateSoftBodies( );
+
+	virtual void optimize( btAlignedObjectArray< btSoftBody * > &softBodies );
+
+	virtual void solveConstraints( float solverdt );
+
+	virtual void predictMotion( float solverdt );
+
+	virtual void copySoftBodyToVertexBuffer( const btSoftBody *const softBody, btVertexBufferDescriptor *vertexBuffer );
+};
+
+#endif // #ifndef BT_ACCELERATED_SOFT_BODY_CPU_SOLVER_H

src/BulletSoftBody/btSoftBody.cpp

@@ -15,6 +15,7 @@ subject to the following restrictions:
 ///btSoftBody implementation by Nathanael Presson
 
 #include "btSoftBodyInternals.h"
+#include "BulletSoftBody/btSoftBodySolvers.h"
 
 //
 btSoftBody::btSoftBody(btSoftBodyWorldInfo*	worldInfo,int node_count,  const btVector3* x,  const btScalar* m)
@@ -88,6 +89,8 @@ btSoftBody::btSoftBody(btSoftBodyWorldInfo*	worldInfo,int node_count,  const btV
 	updateBounds();	
 
 	m_initialWorldTransform.setIdentity();
+
+	m_windVelocity = btVector3(0,0,0);
 }
 
 //
@@ -606,6 +609,7 @@ void			btSoftBody::rotate(	const btQuaternion& rot)
 //
 void			btSoftBody::scale(const btVector3& scl)
 {
+
 	const btScalar	margin=getCollisionShape()->getMargin();
 	ATTRIBUTE_ALIGNED16(btDbvtVolume)	vol;
 	
@@ -1488,6 +1492,7 @@ void			btSoftBody::setSolver(eSolverPresets::_ preset)
 //
 void			btSoftBody::predictMotion(btScalar dt)
 {
+
 	int i,ni;
 
 	/* Update				*/ 
@@ -1579,6 +1584,7 @@ void			btSoftBody::predictMotion(btScalar dt)
 //
 void			btSoftBody::solveConstraints()
 {
+
 	/* Apply clusters		*/ 
 	applyClusters(false);
 	/* Prepare links		*/ 
@@ -1948,20 +1954,21 @@ bool				btSoftBody::checkContact(	btCollisionObject* colObj,
 											 btScalar margin,
 											 btSoftBody::sCti& cti) const
 {
-	btVector3			nrm;
+	btVector3 nrm;
-	btCollisionShape*	shp=colObj->getCollisionShape();
+	btCollisionShape *shp = colObj->getCollisionShape();
-	btRigidBody* tmpRigid = btRigidBody::upcast(colObj);
+	btRigidBody *tmpRigid = btRigidBody::upcast(colObj);
-	const btTransform&	wtr=tmpRigid? tmpRigid->getInterpolationWorldTransform() : colObj->getWorldTransform();
+	const btTransform &wtr = tmpRigid ? tmpRigid->getInterpolationWorldTransform() : colObj->getWorldTransform();
-	btScalar			dst=m_worldInfo->m_sparsesdf.Evaluate(	wtr.invXform(x),
+	btScalar dst = 
-		shp,
+		m_worldInfo->m_sparsesdf.Evaluate(	
-		nrm,
+			wtr.invXform(x),
-		margin);
+			shp,
+			nrm,
+			margin);
 	if(dst<0)
 	{
-		cti.m_colObj		=	colObj;
+		cti.m_colObj = colObj;
-		cti.m_normal	=	wtr.getBasis()*nrm;
+		cti.m_normal = wtr.getBasis()*nrm;
-		cti.m_offset	=	-btDot(	cti.m_normal,
+		cti.m_offset = -btDot( cti.m_normal, x - cti.m_normal * dst );
-			x-cti.m_normal*dst);
 		return(true);
 	}
 	return(false);
@@ -1970,6 +1977,7 @@ bool				btSoftBody::checkContact(	btCollisionObject* colObj,
 //
 void					btSoftBody::updateNormals()
 {
+
 	const btVector3	zv(0,0,0);
 	int i,ni;
 
@@ -1998,29 +2006,42 @@ void					btSoftBody::updateNormals()
 //
 void					btSoftBody::updateBounds()
 {
-	if(m_ndbvt.m_root)
+	/*if( m_acceleratedSoftBody )
 	{
-		const btVector3&	mins=m_ndbvt.m_root->volume.Mins();
+		// If we have an accelerated softbody we need to obtain the bounds correctly
-		const btVector3&	maxs=m_ndbvt.m_root->volume.Maxs();
+		// For now (slightly hackily) just have a very large AABB
-		const btScalar		csm=getCollisionShape()->getMargin();
+		// TODO: Write get bounds kernel
-		const btVector3		mrg=btVector3(	csm,
+		// If that is updating in place, atomic collisions might be low (when the cloth isn't perfectly aligned to an axis) and we could
-			csm,
+		// probably do a test and exchange reasonably efficiently.
-			csm)*1; // ??? to investigate...
+
-		m_bounds[0]=mins-mrg;
+		m_bounds[0] = btVector3(-1000, -1000, -1000);
-		m_bounds[1]=maxs+mrg;
+		m_bounds[1] = btVector3(1000, 1000, 1000);
-		if(0!=getBroadphaseHandle())
+
+	} else {*/
+		if(m_ndbvt.m_root)
 		{
-			m_worldInfo->m_broadphase->setAabb(	getBroadphaseHandle(),
+			const btVector3&	mins=m_ndbvt.m_root->volume.Mins();
-				m_bounds[0],
+			const btVector3&	maxs=m_ndbvt.m_root->volume.Maxs();
-				m_bounds[1],
+			const btScalar		csm=getCollisionShape()->getMargin();
-				m_worldInfo->m_dispatcher);
+			const btVector3		mrg=btVector3(	csm,
+				csm,
+				csm)*1; // ??? to investigate...
+			m_bounds[0]=mins-mrg;
+			m_bounds[1]=maxs+mrg;
+			if(0!=getBroadphaseHandle())
+			{					
+				m_worldInfo->m_broadphase->setAabb(	getBroadphaseHandle(),
+					m_bounds[0],
+					m_bounds[1],
+					m_worldInfo->m_dispatcher);
+			}
 		}
-	}
+		else
-	else
+		{
-	{
+			m_bounds[0]=
-		m_bounds[0]=
+				m_bounds[1]=btVector3(0,0,0);
-			m_bounds[1]=btVector3(0,0,0);
+		}		
-	}		
+	//}
 }
 
 
@@ -2571,27 +2592,27 @@ void				btSoftBody::applyForces()
 {
 
 	BT_PROFILE("SoftBody applyForces");
-	const btScalar					dt=m_sst.sdt;
+	const btScalar					dt =			m_sst.sdt;
-	const btScalar					kLF=m_cfg.kLF;
+	const btScalar					kLF =			m_cfg.kLF;
-	const btScalar					kDG=m_cfg.kDG;
+	const btScalar					kDG =			m_cfg.kDG;
-	const btScalar					kPR=m_cfg.kPR;
+	const btScalar					kPR =			m_cfg.kPR;
-	const btScalar					kVC=m_cfg.kVC;
+	const btScalar					kVC =			m_cfg.kVC;
-	const bool						as_lift=kLF>0;
+	const bool						as_lift =		kLF>0;
-	const bool						as_drag=kDG>0;
+	const bool						as_drag =		kDG>0;
-	const bool						as_pressure=kPR!=0;
+	const bool						as_pressure =	kPR!=0;
-	const bool						as_volume=kVC>0;
+	const bool						as_volume =		kVC>0;
-	const bool						as_aero=	as_lift		||
+	const bool						as_aero =		as_lift	||
-		as_drag		;
+													as_drag		;
-	const bool						as_vaero=	as_aero		&&
+	const bool						as_vaero =		as_aero	&&
-		(m_cfg.aeromodel<btSoftBody::eAeroModel::F_TwoSided);
+													(m_cfg.aeromodel < btSoftBody::eAeroModel::F_TwoSided);
-	const bool						as_faero=	as_aero		&&
+	const bool						as_faero =		as_aero	&&
-		(m_cfg.aeromodel>=btSoftBody::eAeroModel::F_TwoSided);
+													(m_cfg.aeromodel >= btSoftBody::eAeroModel::F_TwoSided);
-	const bool						use_medium=	as_aero;
+	const bool						use_medium =	as_aero;
-	const bool						use_volume=	as_pressure	||
+	const bool						use_volume =	as_pressure	||
 		as_volume	;
-	btScalar						volume=0;
+	btScalar						volume =		0;
-	btScalar						ivolumetp=0;
+	btScalar						ivolumetp =		0;
-	btScalar						dvolumetv=0;
+	btScalar						dvolumetv =		0;
 	btSoftBody::sMedium	medium;
 	if(use_volume)
 	{
@@ -2609,36 +2630,41 @@ void				btSoftBody::applyForces()
 		{
 			if(use_medium)
 			{
-				EvaluateMedium(m_worldInfo,n.m_x,medium);
+				EvaluateMedium(m_worldInfo, n.m_x, medium);
+				medium.m_velocity = m_windVelocity;
+				medium.m_density = m_worldInfo->air_density;
+
 				/* Aerodynamics			*/ 
 				if(as_vaero)
 				{				
-					const btVector3	rel_v=n.m_v-medium.m_velocity;
+					const btVector3	rel_v = n.m_v - medium.m_velocity;
-					const btScalar	rel_v2=rel_v.length2();
+					const btScalar	rel_v2 = rel_v.length2();
 					if(rel_v2>SIMD_EPSILON)
 					{
-						btVector3	nrm=n.m_n;
+						btVector3	nrm = n.m_n;
 						/* Setup normal		*/ 
 						switch(m_cfg.aeromodel)
 						{
 						case	btSoftBody::eAeroModel::V_Point:
-							nrm=NormalizeAny(rel_v);break;
+							nrm = NormalizeAny(rel_v);
+							break;
 						case	btSoftBody::eAeroModel::V_TwoSided:
-							nrm*=(btScalar)(btDot(nrm,rel_v)<0?-1:+1);break;
+							nrm *= (btScalar)( (btDot(nrm,rel_v) < 0) ? -1 : +1);
-							default:
+							break;							
+						default:
 							{
 							}
 						}
-						const btScalar	dvn=btDot(rel_v,nrm);
+						const btScalar dvn = btDot(rel_v,nrm);
 						/* Compute forces	*/ 
 						if(dvn>0)
 						{
 							btVector3		force(0,0,0);
-							const btScalar	c0	=	n.m_area*dvn*rel_v2/2;
+							const btScalar	c0	=	n.m_area * dvn * rel_v2/2;
-							const btScalar	c1	=	c0*medium.m_density;
+							const btScalar	c1	=	c0 * medium.m_density;
 							force	+=	nrm*(-c1*kLF);
-							force	+=	rel_v.normalized()*(-c1*kDG);
+							force	+=	rel_v.normalized() * (-c1 * kDG);
-							ApplyClampedForce(n,force,dt);
+							ApplyClampedForce(n, force, dt);
 						}
 					}
 				}
@@ -2716,26 +2742,27 @@ void				btSoftBody::PSolve_Anchors(btSoftBody* psb,btScalar kst,btScalar ti)
 }
 
 //
-void				btSoftBody::PSolve_RContacts(btSoftBody* psb,btScalar kst,btScalar ti)
+void btSoftBody::PSolve_RContacts(btSoftBody* psb, btScalar kst, btScalar ti)
 {
-	const btScalar	dt=psb->m_sst.sdt;
+	const btScalar	dt = psb->m_sst.sdt;
-	const btScalar	mrg=psb->getCollisionShape()->getMargin();
+	const btScalar	mrg = psb->getCollisionShape()->getMargin();
 	for(int i=0,ni=psb->m_rcontacts.size();i<ni;++i)
 	{
-		const RContact&		c=psb->m_rcontacts[i];
+		const RContact&		c = psb->m_rcontacts[i];
-		const sCti&			cti=c.m_cti;	
+		const sCti&			cti = c.m_cti;	
 		btRigidBody* tmpRigid = btRigidBody::upcast(cti.m_colObj);
 
-		const btVector3		va=tmpRigid ? tmpRigid->getVelocityInLocalPoint(c.m_c1)*dt : btVector3(0,0,0);
+		const btVector3		va = tmpRigid ? tmpRigid->getVelocityInLocalPoint(c.m_c1)*dt : btVector3(0,0,0);
-		const btVector3		vb=c.m_node->m_x-c.m_node->m_q;	
+		const btVector3		vb = c.m_node->m_x-c.m_node->m_q;	
-		const btVector3		vr=vb-va;
+		const btVector3		vr = vb-va;
-		const btScalar		dn=btDot(vr,cti.m_normal);		
+		const btScalar		dn = btDot(vr, cti.m_normal);		
 		if(dn<=SIMD_EPSILON)
 		{
-			const btScalar		dp=btMin(btDot(c.m_node->m_x,cti.m_normal)+cti.m_offset,mrg);
+			const btScalar		dp = btMin( (btDot(c.m_node->m_x, cti.m_normal) + cti.m_offset), mrg );
-			const btVector3		fv=vr-cti.m_normal*dn;
+			const btVector3		fv = vr - (cti.m_normal * dn);
-			const btVector3		impulse=c.m_c0*((vr-fv*c.m_c3+cti.m_normal*(dp*c.m_c4))*kst);
+			// c0 is the impulse matrix, c3 is 1 - the friction coefficient or 0, c4 is the contact hardness coefficient
-			c.m_node->m_x-=impulse*c.m_c2;
+			const btVector3		impulse = c.m_c0 * ( (vr - (fv * c.m_c3) + (cti.m_normal * (dp * c.m_c4))) * kst );
+			c.m_node->m_x -= impulse * c.m_c2;
 			if (tmpRigid)
 				tmpRigid->applyImpulse(impulse,c.m_c1);
 		}
@@ -2844,41 +2871,58 @@ btSoftBody::vsolver_t	btSoftBody::getSolver(eVSolver::_ solver)
 //
 void			btSoftBody::defaultCollisionHandler(btCollisionObject* pco)
 {
-	switch(m_cfg.collisions&fCollision::RVSmask)
+#if 0
+	// If we have a solver, skip this work.
+	// It will have been done within the solver.
+	// TODO: In the case of the collision handler we need to ensure that we're
+	// updating the data structures correctly and in here we generate the 
+	// collision lists to deal with in the solver
+	if( this->m_acceleratedSoftBody )
 	{
-	case	fCollision::SDF_RS:
+		// We need to pass the collision data through to the solver collision engine
+		// Note that we only add the collision object here, we are not applying the collision or dealing with 
+		// an impulse response.
+		m_acceleratedSoftBody->addCollisionObject(pco);
+	} else {
+#endif
+		switch(m_cfg.collisions&fCollision::RVSmask)
 		{
-			btSoftColliders::CollideSDF_RS	docollide;		
+		case	fCollision::SDF_RS:
-			btRigidBody*		prb1=btRigidBody::upcast(pco);
+			{
-			btTransform	wtr=prb1 ? prb1->getInterpolationWorldTransform() : pco->getWorldTransform();
+				btSoftColliders::CollideSDF_RS	docollide;		
+				btRigidBody*		prb1=btRigidBody::upcast(pco);
+				btTransform	wtr=prb1 ? prb1->getInterpolationWorldTransform() : pco->getWorldTransform();
 
-			const btTransform	ctr=pco->getWorldTransform();
+				const btTransform	ctr=pco->getWorldTransform();
-			const btScalar		timemargin=(wtr.getOrigin()-ctr.getOrigin()).length();
+				const btScalar		timemargin=(wtr.getOrigin()-ctr.getOrigin()).length();
-			const btScalar		basemargin=getCollisionShape()->getMargin();
+				const btScalar		basemargin=getCollisionShape()->getMargin();
-			btVector3			mins;
+				btVector3			mins;
-			btVector3			maxs;
+				btVector3			maxs;
-			ATTRIBUTE_ALIGNED16(btDbvtVolume)		volume;
+				ATTRIBUTE_ALIGNED16(btDbvtVolume)		volume;
-			pco->getCollisionShape()->getAabb(	pco->getInterpolationWorldTransform(),
+				pco->getCollisionShape()->getAabb(	pco->getInterpolationWorldTransform(),
-				mins,
+					mins,
-				maxs);
+					maxs);
-			volume=btDbvtVolume::FromMM(mins,maxs);
+				volume=btDbvtVolume::FromMM(mins,maxs);
-			volume.Expand(btVector3(basemargin,basemargin,basemargin));		
+				volume.Expand(btVector3(basemargin,basemargin,basemargin));		
-			docollide.psb		=	this;
+				docollide.psb		=	this;
-			docollide.m_colObj1 = pco;
+				docollide.m_colObj1 = pco;
-			docollide.m_rigidBody = prb1;
+				docollide.m_rigidBody = prb1;
 
-			docollide.dynmargin	=	basemargin+timemargin;
+				docollide.dynmargin	=	basemargin+timemargin;
-			docollide.stamargin	=	basemargin;
+				docollide.stamargin	=	basemargin;
-			m_ndbvt.collideTV(m_ndbvt.m_root,volume,docollide);
+				m_ndbvt.collideTV(m_ndbvt.m_root,volume,docollide);
+			}
+			break;
+		case	fCollision::CL_RS:
+			{
+				btSoftColliders::CollideCL_RS	collider;
+				collider.Process(this,pco);
+			}
+			break;
 		}
-		break;
+#if 0
-	case	fCollision::CL_RS:
-		{
-			btSoftColliders::CollideCL_RS	collider;
-			collider.Process(this,pco);
-		}
-		break;
 	}
+#endif
 }
 
 //
@@ -2929,3 +2973,16 @@ void			btSoftBody::defaultCollisionHandler(btSoftBody* psb)
 		}
 	}
 }
+
+
+
+void btSoftBody::setWindVelocity( const btVector3 &velocity )
+{
+	m_windVelocity = velocity;
+}
+
+
+const btVector3& btSoftBody::getWindVelocity()
+{
+	return m_windVelocity;
+}

src/BulletSoftBody/btSoftBody.h

@@ -30,6 +30,7 @@ subject to the following restrictions:
 class btBroadphaseInterface;
 class btDispatcher;
 
+
 /* btSoftBodyWorldInfo	*/ 
 struct	btSoftBodyWorldInfo
 {
@@ -589,7 +590,7 @@ public:
 	};
 
 	//
-	// Typedef's
+	// Typedefs
 	//
 
 	typedef void								(*psolver_t)(btSoftBody*,btScalar,btScalar);
@@ -639,6 +640,7 @@ public:
 
 	btTransform			m_initialWorldTransform;
 
+	btVector3			m_windVelocity;
 	//
 	// Api
 	//
@@ -827,6 +829,24 @@ public:
 	void				defaultCollisionHandler(btCollisionObject* pco);
 	void				defaultCollisionHandler(btSoftBody* psb);
 
+
+
+	//
+	// Functionality to deal with new accelerated solvers.
+	//
+
+	/**
+	 * Set a wind velocity for interaction with the air.
+	 */
+	void setWindVelocity( const btVector3 &velocity );
+
+
+	/**
+	 * Return the wind velocity for interaction with the air.
+	 */
+	const btVector3& getWindVelocity();
+
+
 	//
 	// Cast
 	//

src/BulletSoftBody/btSoftBodySolverVertexBuffer.h

@@ -0,0 +1,165 @@
+/*
+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_SOFT_BODY_SOLVER_VERTEX_BUFFER_H
+#define BT_SOFT_BODY_SOLVER_VERTEX_BUFFER_H
+
+
+class btVertexBufferDescriptor
+{
+public:
+	enum BufferTypes
+	{
+		CPU_BUFFER,
+		DX11_BUFFER,
+		OPENGL_BUFFER
+	};
+
+protected:	
+
+	bool m_hasVertexPositions;
+	bool m_hasNormals;
+
+	int m_vertexOffset;
+	int m_vertexStride;
+
+	int m_normalOffset;
+	int m_normalStride;
+
+public:
+	btVertexBufferDescriptor()
+	{
+		m_hasVertexPositions = false;
+		m_hasNormals = false;
+		m_vertexOffset = 0;
+		m_vertexStride = 0;
+		m_normalOffset = 0;
+		m_normalStride = 0;
+	}
+
+	virtual ~btVertexBufferDescriptor()
+	{
+
+	}
+
+	virtual bool hasVertexPositions() const
+	{
+		return m_hasVertexPositions;
+	}
+
+	virtual bool hasNormals() const
+	{
+		return m_hasNormals;
+	}
+
+	/**
+	 * Return the type of the vertex buffer descriptor.
+	 */
+	virtual BufferTypes getBufferType() const = 0;
+
+	/**
+	 * Return the vertex offset in floats from the base pointer.
+	 */
+	virtual int getVertexOffset() const
+	{
+		return m_vertexOffset;
+	}
+
+	/**
+	 * Return the vertex stride in number of floats between vertices.
+	 */
+	virtual int getVertexStride() const
+	{
+		return m_vertexStride;
+	}
+
+	/**
+	 * Return the vertex offset in floats from the base pointer.
+	 */
+	virtual int getNormalOffset() const
+	{
+		return m_normalOffset;
+	}
+
+	/**
+	 * Return the vertex stride in number of floats between vertices.
+	 */
+	virtual int getNormalStride() const
+	{
+		return m_normalStride;
+	}
+};
+
+
+class btCPUVertexBufferDescriptor : public btVertexBufferDescriptor
+{
+protected:
+	float *m_basePointer;
+
+public:
+	/**
+	 * vertexBasePointer is pointer to beginning of the buffer.
+	 * vertexOffset is the offset in floats to the first vertex.
+	 * vertexStride is the stride in floats between vertices.
+	 */
+	btCPUVertexBufferDescriptor( float *basePointer, int vertexOffset, int vertexStride )
+	{
+		m_basePointer = basePointer;
+		m_vertexOffset = vertexOffset;
+		m_vertexStride = vertexStride;
+		m_hasVertexPositions = true;
+	}
+
+	/**
+	 * vertexBasePointer is pointer to beginning of the buffer.
+	 * vertexOffset is the offset in floats to the first vertex.
+	 * vertexStride is the stride in floats between vertices.
+	 */
+	btCPUVertexBufferDescriptor( float *basePointer, int vertexOffset, int vertexStride, int normalOffset, int normalStride )
+	{
+		m_basePointer = basePointer;
+
+		m_vertexOffset = vertexOffset;
+		m_vertexStride = vertexStride;
+		m_hasVertexPositions = true;
+
+		m_normalOffset = normalOffset;
+		m_normalStride = normalStride;
+		m_hasNormals = true;
+	}
+
+	virtual ~btCPUVertexBufferDescriptor()
+	{
+
+	}
+
+	/**
+	 * Return the type of the vertex buffer descriptor.
+	 */
+	virtual BufferTypes getBufferType() const
+	{
+		return CPU_BUFFER;
+	}
+
+	/**
+	 * Return the base pointer in memory to the first vertex.
+	 */
+	virtual float *getBasePointer() const
+	{
+		return m_basePointer;
+	}
+};
+
+#endif // #ifndef BT_SOFT_BODY_SOLVER_VERTEX_BUFFER_H

src/BulletSoftBody/btSoftBodySolvers.h

@@ -0,0 +1,143 @@
+/*
+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_SOFT_BODY_SOLVERS_H
+#define BT_SOFT_BODY_SOLVERS_H
+
+#include "BulletCollision/CollisionShapes/btTriangleIndexVertexArray.h"
+
+
+class btSoftBodyTriangleData;
+class btSoftBodyLinkData;
+class btSoftBodyVertexData;
+class btVertexBufferDescriptor;
+class btAcceleratedSoftBodyInterface;
+class btCollisionObject;
+class btSoftBody;
+
+
+class btSoftBodySolver
+{
+
+protected:
+	int m_numberOfPositionIterations;
+	int m_numberOfVelocityIterations;
+	// Simulation timescale
+	float m_timeScale;
+	
+public:
+	btSoftBodySolver() :
+		m_numberOfPositionIterations( 10 ),
+		m_timeScale( 1 )
+	{
+		m_numberOfVelocityIterations = 0;
+		m_numberOfPositionIterations = 5;
+	}
+
+	virtual ~btSoftBodySolver()
+	{
+	}
+
+#if 0
+	/** Acceleration for all cloths in the solver. Can be used to efficiently apply gravity. */
+	virtual void setPerClothAcceleration( int clothIdentifier, Vectormath::Aos::Vector3 acceleration ) = 0;
+
+	/** A wind velocity applied normal to the cloth for all cloths in the solver. */
+	virtual void setPerClothWindVelocity( int clothIdentifier, Vectormath::Aos::Vector3 windVelocity ) = 0;
+
+	/** Set the density of the medium a given cloth is situated in. This could be air or possibly water. */
+	virtual void setPerClothMediumDensity( int clothIdentifier, float mediumDensity ) = 0;		
+
+	/** A damping factor specific to each cloth applied for all cloths. */
+	virtual void setPerClothDampingFactor( int clothIdentifier, float dampingFactor ) = 0;
+
+	/** A damping factor specific to each cloth applied for all cloths. */
+	virtual void setPerClothVelocityCorrectionCoefficient( int clothIdentifier, float velocityCorrectionCoefficient ) = 0;
+
+	/** Lift parameter for wind action on cloth. */
+	virtual void setPerClothLiftFactor( int clothIdentifier, float liftFactor ) = 0;
+
+	/** Drag parameter for wind action on cloth. */
+	virtual void setPerClothDragFactor( int clothIdentifier, float dragFactor ) = 0;
+
+	/**
+	 * Add a velocity to all soft bodies in the solver - useful for doing world-wide velocities such as a change due to gravity 
+	 * Only add a velocity to nodes with a non-zero inverse mass.
+	 */
+	virtual void addVelocity( Vectormath::Aos::Vector3 velocity ) = 0;
+#endif
+
+
+
+	/** Ensure that this solver is initialized. */
+	virtual bool checkInitialized() = 0;
+
+	/** Optimize soft bodies in this solver. */
+	virtual void optimize( btAlignedObjectArray< btSoftBody * > &softBodies ) = 0;
+
+	/** Predict motion of soft bodies into next timestep */
+	virtual void predictMotion( float solverdt ) = 0;
+
+	/** Solve constraints for a set of soft bodies */
+	virtual void solveConstraints( float solverdt ) = 0;
+
+	/** Perform necessary per-step updates of soft bodies such as recomputing normals and bounding boxes */
+	virtual void updateSoftBodies() = 0;
+
+	/** Output current computed vertex data to the vertex buffers for all cloths in the solver. */
+	virtual void copySoftBodyToVertexBuffer( const btSoftBody * const softBody, btVertexBufferDescriptor *vertexBuffer ) = 0;
+
+
+
+	/** Set the number of velocity constraint solver iterations this solver uses. */
+	virtual void setNumberOfPositionIterations( int iterations )
+	{
+		m_numberOfPositionIterations = iterations;
+	}
+
+	/** Get the number of velocity constraint solver iterations this solver uses. */
+	virtual int getNumberOfPositionIterations()
+	{
+		return m_numberOfPositionIterations;
+	}
+
+	/** Set the number of velocity constraint solver iterations this solver uses. */
+	virtual void setNumberOfVelocityIterations( int iterations )
+	{
+		m_numberOfVelocityIterations = iterations;
+	}
+
+	/** Get the number of velocity constraint solver iterations this solver uses. */
+	virtual int getNumberOfVelocityIterations()
+	{
+		return m_numberOfVelocityIterations;
+	}
+
+	/** Return the timescale that the simulation is using */
+	float getTimeScale()
+	{
+		return m_timeScale;
+	}
+
+#if 0
+	/**
+	 * Add a collision object to be used by the indicated softbody.
+	 */
+	virtual void addCollisionObjectForSoftBody( int clothIdentifier, btCollisionObject *collisionObject ) = 0;
+#endif
+};
+
+
+#endif // #ifndef BT_SOFT_BODY_SOLVERS_H

src/BulletSoftBody/btSoftRigidDynamicsWorld.cpp

@@ -20,14 +20,28 @@ subject to the following restrictions:
 //softbody & helpers
 #include "btSoftBody.h"
 #include "btSoftBodyHelpers.h"
+#include "btSoftBodySolvers.h"
+#include "btDefaultSoftBodySolver.h"
 
 
 
-
+btSoftRigidDynamicsWorld::btSoftRigidDynamicsWorld(
-
+	btDispatcher* dispatcher,
-btSoftRigidDynamicsWorld::btSoftRigidDynamicsWorld(btDispatcher* dispatcher,btBroadphaseInterface* pairCache,btConstraintSolver* constraintSolver,btCollisionConfiguration* collisionConfiguration)
+	btBroadphaseInterface* pairCache,
-:btDiscreteDynamicsWorld(dispatcher,pairCache,constraintSolver,collisionConfiguration)
+	btConstraintSolver* constraintSolver,
+	btCollisionConfiguration* collisionConfiguration,
+	btSoftBodySolver *softBodySolver ) : 
+		btDiscreteDynamicsWorld(dispatcher,pairCache,constraintSolver,collisionConfiguration),
+		m_softBodySolver( softBodySolver ),
+		m_ownsSolver(false)
 {
+	if( !m_softBodySolver )
+	{
+		void* ptr = btAlignedAlloc(sizeof(btDefaultSoftBodySolver),16);
+		m_softBodySolver = new(ptr) btDefaultSoftBodySolver();
+		m_ownsSolver = true;
+	}
+
 	m_drawFlags			=	fDrawFlags::Std;
 	m_drawNodeTree		=	true;
 	m_drawFaceTree		=	false;
@@ -41,27 +55,34 @@ btSoftRigidDynamicsWorld::btSoftRigidDynamicsWorld(btDispatcher* dispatcher,btBr
 
 btSoftRigidDynamicsWorld::~btSoftRigidDynamicsWorld()
 {
-
+	if (m_ownsSolver)
+	{
+		m_softBodySolver->~btSoftBodySolver();
+		btAlignedFree(m_softBodySolver);
+	}
 }
 
 void	btSoftRigidDynamicsWorld::predictUnconstraintMotion(btScalar timeStep)
 {
-	btDiscreteDynamicsWorld::predictUnconstraintMotion( timeStep);
+	btDiscreteDynamicsWorld::predictUnconstraintMotion( timeStep );
 
-	for ( int i=0;i<m_softBodies.size();++i)
+	m_softBodySolver->predictMotion( timeStep );
-	{
-		btSoftBody*	psb= m_softBodies[i];
-
-		psb->predictMotion(timeStep);		
-	}
 }
 
-void	btSoftRigidDynamicsWorld::internalSingleStepSimulation( btScalar timeStep)
+void	btSoftRigidDynamicsWorld::internalSingleStepSimulation( btScalar timeStep )
 {
+	if( !m_softBodySolver->checkInitialized() )
+	{
+		btAssert( "Solver initialization failed\n" );
+	}
+
+	// Let the solver grab the soft bodies and if necessary optimize for it
+	m_softBodySolver->optimize( getSoftBodyArray() );
+
 	btDiscreteDynamicsWorld::internalSingleStepSimulation( timeStep );
 
 	///solve soft bodies constraints
-	solveSoftBodiesConstraints();
+	solveSoftBodiesConstraints( timeStep );
 
 	//self collisions
 	for ( int i=0;i<m_softBodies.size();i++)
@@ -71,22 +92,14 @@ void	btSoftRigidDynamicsWorld::internalSingleStepSimulation( btScalar timeStep)
 	}
 
 	///update soft bodies
-	updateSoftBodies();
+	m_softBodySolver->updateSoftBodies( );
+	
+	// End solver-wise simulation step
+	// ///////////////////////////////
 
 }
 
-void	btSoftRigidDynamicsWorld::updateSoftBodies()
+void	btSoftRigidDynamicsWorld::solveSoftBodiesConstraints( btScalar timeStep )
-{
-	BT_PROFILE("updateSoftBodies");
-
-	for ( int i=0;i<m_softBodies.size();i++)
-	{
-		btSoftBody*	psb=(btSoftBody*)m_softBodies[i];
-		psb->integrateMotion();	
-	}
-}
-
-void	btSoftRigidDynamicsWorld::solveSoftBodiesConstraints()
 {
 	BT_PROFILE("solveSoftConstraints");
 
@@ -95,11 +108,9 @@ void	btSoftRigidDynamicsWorld::solveSoftBodiesConstraints()
 		btSoftBody::solveClusters(m_softBodies);
 	}
 
-	for(int i=0;i<m_softBodies.size();++i)
+	// Solve constraints solver-wise
-	{
+	m_softBodySolver->solveConstraints( timeStep * m_softBodySolver->getTimeScale() );
-		btSoftBody*	psb=(btSoftBody*)m_softBodies[i];
+
-		psb->solveConstraints();
-	}	
 }
 
 void	btSoftRigidDynamicsWorld::addSoftBody(btSoftBody* body,short int collisionFilterGroup,short int collisionFilterMask)

src/BulletSoftBody/btSoftRigidDynamicsWorld.h

@@ -21,6 +21,8 @@ subject to the following restrictions:
 
 typedef	btAlignedObjectArray<btSoftBody*> btSoftBodyArray;
 
+class btSoftBodySolver;
+
 class btSoftRigidDynamicsWorld : public btDiscreteDynamicsWorld
 {
 
@@ -30,6 +32,9 @@ class btSoftRigidDynamicsWorld : public btDiscreteDynamicsWorld
 	bool			m_drawFaceTree;
 	bool			m_drawClusterTree;
 	btSoftBodyWorldInfo m_sbi;
+	///Solver classes that encapsulate multiple soft bodies for solving
+	btSoftBodySolver *m_softBodySolver;
+	bool			m_ownsSolver;
 
 protected:
 
@@ -37,14 +42,12 @@ protected:
 
 	virtual void	internalSingleStepSimulation( btScalar timeStep);
 
-	void	updateSoftBodies();
+	void	solveSoftBodiesConstraints( btScalar timeStep );
-
-	void	solveSoftBodiesConstraints();
 
 
 public:
 
-	btSoftRigidDynamicsWorld(btDispatcher* dispatcher,btBroadphaseInterface* pairCache,btConstraintSolver* constraintSolver,btCollisionConfiguration* collisionConfiguration);
+	btSoftRigidDynamicsWorld(btDispatcher* dispatcher,btBroadphaseInterface* pairCache,btConstraintSolver* constraintSolver, btCollisionConfiguration* collisionConfiguration, btSoftBodySolver *softBodySolver = 0 );
 
 	virtual ~btSoftRigidDynamicsWorld();
 
@@ -92,6 +95,7 @@ public:
 					  const btTransform& colObjWorldTransform,
 					  RayResultCallback& resultCallback);
 
+
 };
 
 #endif //BT_SOFT_RIGID_DYNAMICS_WORLD_H

src/LinearMath/btAlignedObjectArray.h

@@ -459,6 +459,13 @@ class btAlignedObjectArray
 		m_capacity = capacity;
 	}
 
+	void copyFromArray(const btAlignedObjectArray& otherArray)
+	{
+		int otherSize = otherArray.size();
+		resize (otherSize);
+		otherArray.copy(0, otherSize, m_data);
+	}
+
 };
 
 #endif //BT_OBJECT_ARRAY__

src/MiniCL/cl_MiniCL_Defs.h

@@ -22,7 +22,7 @@ subject to the following restrictions:
 
 #define __kernel
 #define __global
-#define __local static
+#define __local
 #define get_global_id(a)	__guid_arg
 #define get_local_id(a)		((__guid_arg) % gMiniCLNumOutstandingTasks)
 #define get_local_size(a)	(gMiniCLNumOutstandingTasks)