btDiscreteDynamicsWorld.cpp

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/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2009 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.
*/


#include "btDiscreteDynamicsWorld.h"

//collision detection
#include "BulletCollision/CollisionDispatch/btCollisionDispatcher.h"
#include "BulletCollision/BroadphaseCollision/btSimpleBroadphase.h"
#include "BulletCollision/BroadphaseCollision/btCollisionAlgorithm.h"
#include "BulletCollision/CollisionShapes/btCollisionShape.h"
#include "BulletCollision/CollisionDispatch/btSimulationIslandManager.h"
#include "LinearMath/btTransformUtil.h"
#include "LinearMath/btQuickprof.h"

//rigidbody & constraints
#include "BulletDynamics/Dynamics/btRigidBody.h"
#include "BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.h"
#include "BulletDynamics/ConstraintSolver/btContactSolverInfo.h"
#include "BulletDynamics/ConstraintSolver/btTypedConstraint.h"
#include "BulletDynamics/ConstraintSolver/btPoint2PointConstraint.h"
#include "BulletDynamics/ConstraintSolver/btHingeConstraint.h"
#include "BulletDynamics/ConstraintSolver/btConeTwistConstraint.h"
#include "BulletDynamics/ConstraintSolver/btGeneric6DofConstraint.h"
#include "BulletDynamics/ConstraintSolver/btSliderConstraint.h"

#include "LinearMath/btIDebugDraw.h"
#include "BulletCollision/CollisionShapes/btSphereShape.h"


#include "BulletDynamics/Dynamics/btActionInterface.h"
#include "LinearMath/btQuickprof.h"
#include "LinearMath/btMotionState.h"

#include "LinearMath/btSerializer.h"



btDiscreteDynamicsWorld::btDiscreteDynamicsWorld(btDispatcher* dispatcher,btBroadphaseInterface* pairCache,btConstraintSolver* constraintSolver, btCollisionConfiguration* collisionConfiguration)
:btDynamicsWorld(dispatcher,pairCache,collisionConfiguration),
m_constraintSolver(constraintSolver),
m_gravity(0,-10,0),
m_localTime(0),
m_synchronizeAllMotionStates(false),
m_profileTimings(0)
{
    if (!m_constraintSolver)
    {
        void* mem = btAlignedAlloc(sizeof(btSequentialImpulseConstraintSolver),16);
        m_constraintSolver = new (mem) btSequentialImpulseConstraintSolver;
        m_ownsConstraintSolver = true;
    } else
    {
        m_ownsConstraintSolver = false;
    }

    {
        void* mem = btAlignedAlloc(sizeof(btSimulationIslandManager),16);
        m_islandManager = new (mem) btSimulationIslandManager();
    }

    m_ownsIslandManager = true;
}


btDiscreteDynamicsWorld::~btDiscreteDynamicsWorld()
{
    //only delete it when we created it
    if (m_ownsIslandManager)
    {
        m_islandManager->~btSimulationIslandManager();
        btAlignedFree( m_islandManager);
    }
    if (m_ownsConstraintSolver)
    {

        m_constraintSolver->~btConstraintSolver();
        btAlignedFree(m_constraintSolver);
    }
}

void    btDiscreteDynamicsWorld::saveKinematicState(btScalar timeStep)
{
    for (int i=0;i<m_collisionObjects.size();i++)
    {
        btCollisionObject* colObj = m_collisionObjects[i];
        btRigidBody* body = btRigidBody::upcast(colObj);
        if (body && body->getActivationState() != ISLAND_SLEEPING)
        {
            if (body->isKinematicObject())
            {
                //to calculate velocities next frame
                body->saveKinematicState(timeStep);
            }
        }
    }

}

void    btDiscreteDynamicsWorld::debugDrawWorld()
{
    BT_PROFILE("debugDrawWorld");

    btCollisionWorld::debugDrawWorld();

    bool drawConstraints = false;
    if (getDebugDrawer())
    {
        int mode = getDebugDrawer()->getDebugMode();
        if(mode  & (btIDebugDraw::DBG_DrawConstraints | btIDebugDraw::DBG_DrawConstraintLimits))
        {
            drawConstraints = true;
        }
    }
    if(drawConstraints)
    {
        for(int i = getNumConstraints()-1; i>=0 ;i--)
        {
            btTypedConstraint* constraint = getConstraint(i);
            debugDrawConstraint(constraint);
        }
    }



    if (getDebugDrawer() && getDebugDrawer()->getDebugMode() & (btIDebugDraw::DBG_DrawWireframe | btIDebugDraw::DBG_DrawAabb))
    {
        int i;

        if (getDebugDrawer() && getDebugDrawer()->getDebugMode())
        {
            for (i=0;i<m_actions.size();i++)
            {
                m_actions[i]->debugDraw(m_debugDrawer);
            }
        }
    }
}

void    btDiscreteDynamicsWorld::clearForces()
{
    for ( int i=0;i<m_nonStaticRigidBodies.size();i++)
    {
        btRigidBody* body = m_nonStaticRigidBodies[i];
        //need to check if next line is ok
        //it might break backward compatibility (people applying forces on sleeping objects get never cleared and accumulate on wake-up
        body->clearForces();
    }
}   

void    btDiscreteDynamicsWorld::applyGravity()
{
    for ( int i=0;i<m_nonStaticRigidBodies.size();i++)
    {
        btRigidBody* body = m_nonStaticRigidBodies[i];
        if (body->isActive())
        {
            body->applyGravity();
        }
    }
}


void    btDiscreteDynamicsWorld::synchronizeSingleMotionState(btRigidBody* body)
{
    btAssert(body);

    if (body->getMotionState() && !body->isStaticOrKinematicObject())
    {
        //we need to call the update at least once, even for sleeping objects
        //otherwise the 'graphics' transform never updates properly
        //if (body->getActivationState() != ISLAND_SLEEPING)
        {
            btTransform interpolatedTransform;
            btTransformUtil::integrateTransform(body->getInterpolationWorldTransform(),
                body->getInterpolationLinearVelocity(),body->getInterpolationAngularVelocity(),m_localTime*body->getHitFraction(),interpolatedTransform);
            body->getMotionState()->setWorldTransform(interpolatedTransform);
        }
    }
}


void    btDiscreteDynamicsWorld::synchronizeMotionStates()
{
    BT_PROFILE("synchronizeMotionStates");
    if (m_synchronizeAllMotionStates)
    {
        //iterate  over all collision objects
        for ( int i=0;i<m_collisionObjects.size();i++)
        {
            btCollisionObject* colObj = m_collisionObjects[i];
            btRigidBody* body = btRigidBody::upcast(colObj);
            if (body)
                synchronizeSingleMotionState(body);
        }
    } else
    {
        //iterate over all active rigid bodies
        for ( int i=0;i<m_nonStaticRigidBodies.size();i++)
        {
            btRigidBody* body = m_nonStaticRigidBodies[i];
            if (body->isActive())
                synchronizeSingleMotionState(body);
        }
    }
}


int btDiscreteDynamicsWorld::stepSimulation( btScalar timeStep,int maxSubSteps, btScalar fixedTimeStep)
{
    startProfiling(timeStep);

    BT_PROFILE("stepSimulation");

    int numSimulationSubSteps = 0;

    if (maxSubSteps)
    {
        //fixed timestep with interpolation
        m_localTime += timeStep;
        if (m_localTime >= fixedTimeStep)
        {
            numSimulationSubSteps = int( m_localTime / fixedTimeStep);
            m_localTime -= numSimulationSubSteps * fixedTimeStep;
        }
    } else
    {
        //variable timestep
        fixedTimeStep = timeStep;
        m_localTime = timeStep;
        if (btFuzzyZero(timeStep))
        {
            numSimulationSubSteps = 0;
            maxSubSteps = 0;
        } else
        {
            numSimulationSubSteps = 1;
            maxSubSteps = 1;
        }
    }

    //process some debugging flags
    if (getDebugDrawer())
    {
        btIDebugDraw* debugDrawer = getDebugDrawer ();
        gDisableDeactivation = (debugDrawer->getDebugMode() & btIDebugDraw::DBG_NoDeactivation) != 0;
    }
    if (numSimulationSubSteps)
    {

        //clamp the number of substeps, to prevent simulation grinding spiralling down to a halt
        int clampedSimulationSteps = (numSimulationSubSteps > maxSubSteps)? maxSubSteps : numSimulationSubSteps;

        saveKinematicState(fixedTimeStep*clampedSimulationSteps);

        applyGravity();

        

        for (int i=0;i<clampedSimulationSteps;i++)
        {
            internalSingleStepSimulation(fixedTimeStep);
            synchronizeMotionStates();
        }

    } else
    {
        synchronizeMotionStates();
    }

    clearForces();

#ifndef BT_NO_PROFILE
    CProfileManager::Increment_Frame_Counter();
#endif //BT_NO_PROFILE
    
    return numSimulationSubSteps;
}

void    btDiscreteDynamicsWorld::internalSingleStepSimulation(btScalar timeStep)
{
    
    BT_PROFILE("internalSingleStepSimulation");

    if(0 != m_internalPreTickCallback) {
        (*m_internalPreTickCallback)(this, timeStep);
    }   

    predictUnconstraintMotion(timeStep);

    btDispatcherInfo& dispatchInfo = getDispatchInfo();

    dispatchInfo.m_timeStep = timeStep;
    dispatchInfo.m_stepCount = 0;
    dispatchInfo.m_debugDraw = getDebugDrawer();

    performDiscreteCollisionDetection();

    calculateSimulationIslands();

    
    getSolverInfo().m_timeStep = timeStep;
    


    solveConstraints(getSolverInfo());
    

    integrateTransforms(timeStep);

    updateActions(timeStep);
    
    updateActivationState( timeStep );

    if(0 != m_internalTickCallback) {
        (*m_internalTickCallback)(this, timeStep);
    }   
}

void    btDiscreteDynamicsWorld::setGravity(const btVector3& gravity)
{
    m_gravity = gravity;
    for ( int i=0;i<m_nonStaticRigidBodies.size();i++)
    {
        btRigidBody* body = m_nonStaticRigidBodies[i];
        if (body->isActive() && !(body->getFlags() &BT_DISABLE_WORLD_GRAVITY))
        {
            body->setGravity(gravity);
        }
    }
}

btVector3 btDiscreteDynamicsWorld::getGravity () const
{
    return m_gravity;
}

void    btDiscreteDynamicsWorld::addCollisionObject(btCollisionObject* collisionObject,short int collisionFilterGroup,short int collisionFilterMask)
{
    btCollisionWorld::addCollisionObject(collisionObject,collisionFilterGroup,collisionFilterMask);
}

void    btDiscreteDynamicsWorld::removeCollisionObject(btCollisionObject* collisionObject)
{
    btRigidBody* body = btRigidBody::upcast(collisionObject);
    if (body)
        removeRigidBody(body);
    else
        btCollisionWorld::removeCollisionObject(collisionObject);
}

void    btDiscreteDynamicsWorld::removeRigidBody(btRigidBody* body)
{
    m_nonStaticRigidBodies.remove(body);
    btCollisionWorld::removeCollisionObject(body);
}


void    btDiscreteDynamicsWorld::addRigidBody(btRigidBody* body)
{
    if (!body->isStaticOrKinematicObject() && !(body->getFlags() &BT_DISABLE_WORLD_GRAVITY))
    {
        body->setGravity(m_gravity);
    }

    if (body->getCollisionShape())
    {
        if (!body->isStaticObject())
        {
            m_nonStaticRigidBodies.push_back(body);
        } else
        {
            body->setActivationState(ISLAND_SLEEPING);
        }

        bool isDynamic = !(body->isStaticObject() || body->isKinematicObject());
        short collisionFilterGroup = isDynamic? short(btBroadphaseProxy::DefaultFilter) : short(btBroadphaseProxy::StaticFilter);
        short collisionFilterMask = isDynamic?  short(btBroadphaseProxy::AllFilter) :   short(btBroadphaseProxy::AllFilter ^ btBroadphaseProxy::StaticFilter);

        addCollisionObject(body,collisionFilterGroup,collisionFilterMask);
    }
}

void    btDiscreteDynamicsWorld::addRigidBody(btRigidBody* body, short group, short mask)
{
    if (!body->isStaticOrKinematicObject() && !(body->getFlags() &BT_DISABLE_WORLD_GRAVITY))
    {
        body->setGravity(m_gravity);
    }

    if (body->getCollisionShape())
    {
        if (!body->isStaticObject())
        {
            m_nonStaticRigidBodies.push_back(body);
        }
         else
        {
            body->setActivationState(ISLAND_SLEEPING);
        }
        addCollisionObject(body,group,mask);
    }
}


void    btDiscreteDynamicsWorld::updateActions(btScalar timeStep)
{
    BT_PROFILE("updateActions");
    
    for ( int i=0;i<m_actions.size();i++)
    {
        m_actions[i]->updateAction( this, timeStep);
    }
}
    
    
void    btDiscreteDynamicsWorld::updateActivationState(btScalar timeStep)
{
    BT_PROFILE("updateActivationState");

    for ( int i=0;i<m_nonStaticRigidBodies.size();i++)
    {
        btRigidBody* body = m_nonStaticRigidBodies[i];
        if (body)
        {
            body->updateDeactivation(timeStep);

            if (body->wantsSleeping())
            {
                if (body->isStaticOrKinematicObject())
                {
                    body->setActivationState(ISLAND_SLEEPING);
                } else
                {
                    if (body->getActivationState() == ACTIVE_TAG)
                        body->setActivationState( WANTS_DEACTIVATION );
                    if (body->getActivationState() == ISLAND_SLEEPING) 
                    {
                        body->setAngularVelocity(btVector3(0,0,0));
                        body->setLinearVelocity(btVector3(0,0,0));
                    }

                }
            } else
            {
                if (body->getActivationState() != DISABLE_DEACTIVATION)
                    body->setActivationState( ACTIVE_TAG );
            }
        }
    }
}

void    btDiscreteDynamicsWorld::addConstraint(btTypedConstraint* constraint,bool disableCollisionsBetweenLinkedBodies)
{
    m_constraints.push_back(constraint);
    if (disableCollisionsBetweenLinkedBodies)
    {
        constraint->getRigidBodyA().addConstraintRef(constraint);
        constraint->getRigidBodyB().addConstraintRef(constraint);
    }
}

void    btDiscreteDynamicsWorld::removeConstraint(btTypedConstraint* constraint)
{
    m_constraints.remove(constraint);
    constraint->getRigidBodyA().removeConstraintRef(constraint);
    constraint->getRigidBodyB().removeConstraintRef(constraint);
}

void    btDiscreteDynamicsWorld::addAction(btActionInterface* action)
{
    m_actions.push_back(action);
}

void    btDiscreteDynamicsWorld::removeAction(btActionInterface* action)
{
    m_actions.remove(action);
}


void    btDiscreteDynamicsWorld::addVehicle(btActionInterface* vehicle)
{
    addAction(vehicle);
}

void    btDiscreteDynamicsWorld::removeVehicle(btActionInterface* vehicle)
{
    removeAction(vehicle);
}

void    btDiscreteDynamicsWorld::addCharacter(btActionInterface* character)
{
    addAction(character);
}

void    btDiscreteDynamicsWorld::removeCharacter(btActionInterface* character)
{
    removeAction(character);
}


SIMD_FORCE_INLINE   int btGetConstraintIslandId(const btTypedConstraint* lhs)
{
    int islandId;
    
    const btCollisionObject& rcolObj0 = lhs->getRigidBodyA();
    const btCollisionObject& rcolObj1 = lhs->getRigidBodyB();
    islandId= rcolObj0.getIslandTag()>=0?rcolObj0.getIslandTag():rcolObj1.getIslandTag();
    return islandId;

}


class btSortConstraintOnIslandPredicate
{
    public:

        bool operator() ( const btTypedConstraint* lhs, const btTypedConstraint* rhs )
        {
            int rIslandId0,lIslandId0;
            rIslandId0 = btGetConstraintIslandId(rhs);
            lIslandId0 = btGetConstraintIslandId(lhs);
            return lIslandId0 < rIslandId0;
        }
};



void    btDiscreteDynamicsWorld::solveConstraints(btContactSolverInfo& solverInfo)
{
    BT_PROFILE("solveConstraints");
    
    struct InplaceSolverIslandCallback : public btSimulationIslandManager::IslandCallback
    {

        btContactSolverInfo&    m_solverInfo;
        btConstraintSolver*     m_solver;
        btTypedConstraint**     m_sortedConstraints;
        int                     m_numConstraints;
        btIDebugDraw*           m_debugDrawer;
        btStackAlloc*           m_stackAlloc;
        btDispatcher*           m_dispatcher;
        
        btAlignedObjectArray<btCollisionObject*> m_bodies;
        btAlignedObjectArray<btPersistentManifold*> m_manifolds;
        btAlignedObjectArray<btTypedConstraint*> m_constraints;


        InplaceSolverIslandCallback(
            btContactSolverInfo& solverInfo,
            btConstraintSolver* solver,
            btTypedConstraint** sortedConstraints,
            int numConstraints,
            btIDebugDraw*   debugDrawer,
            btStackAlloc*           stackAlloc,
            btDispatcher* dispatcher)
            :m_solverInfo(solverInfo),
            m_solver(solver),
            m_sortedConstraints(sortedConstraints),
            m_numConstraints(numConstraints),
            m_debugDrawer(debugDrawer),
            m_stackAlloc(stackAlloc),
            m_dispatcher(dispatcher)
        {

        }


        InplaceSolverIslandCallback& operator=(InplaceSolverIslandCallback& other)
        {
            btAssert(0);
            (void)other;
            return *this;
        }
        virtual void    ProcessIsland(btCollisionObject** bodies,int numBodies,btPersistentManifold**   manifolds,int numManifolds, int islandId)
        {
            if (islandId<0)
            {
                if (numManifolds + m_numConstraints)
                {
                    m_solver->solveGroup( bodies,numBodies,manifolds, numManifolds,&m_sortedConstraints[0],m_numConstraints,m_solverInfo,m_debugDrawer,m_stackAlloc,m_dispatcher);
                }
            } else
            {
                    //also add all non-contact constraints/joints for this island
                btTypedConstraint** startConstraint = 0;
                int numCurConstraints = 0;
                int i;
                
                //find the first constraint for this island
                for (i=0;i<m_numConstraints;i++)
                {
                    if (btGetConstraintIslandId(m_sortedConstraints[i]) == islandId)
                    {
                        startConstraint = &m_sortedConstraints[i];
                        break;
                    }
                }
                //count the number of constraints in this island
                for (;i<m_numConstraints;i++)
                {
                    if (btGetConstraintIslandId(m_sortedConstraints[i]) == islandId)
                    {
                        numCurConstraints++;
                    }
                }

                if (m_solverInfo.m_minimumSolverBatchSize<=1)
                {
                    if (numManifolds + numCurConstraints)
                    {
                        m_solver->solveGroup( bodies,numBodies,manifolds, numManifolds,startConstraint,numCurConstraints,m_solverInfo,m_debugDrawer,m_stackAlloc,m_dispatcher);
                    }
                } else
                {
                    
                    for (i=0;i<numBodies;i++)
                        m_bodies.push_back(bodies[i]);
                    for (i=0;i<numManifolds;i++)
                        m_manifolds.push_back(manifolds[i]);
                    for (i=0;i<numCurConstraints;i++)
                        m_constraints.push_back(startConstraint[i]);
                    if ((m_constraints.size()+m_manifolds.size())>m_solverInfo.m_minimumSolverBatchSize)
                    {
                        processConstraints();
                    } else
                    {
                        //printf("deferred\n");
                    }
                }
            }
        }
        void    processConstraints()
        {
            if (m_manifolds.size() + m_constraints.size()>0)
            {
                m_solver->solveGroup( &m_bodies[0],m_bodies.size(), &m_manifolds[0], m_manifolds.size(), &m_constraints[0], m_constraints.size() ,m_solverInfo,m_debugDrawer,m_stackAlloc,m_dispatcher);
            }
            m_bodies.resize(0);
            m_manifolds.resize(0);
            m_constraints.resize(0);

        }

    };

    

    //sorted version of all btTypedConstraint, based on islandId
    btAlignedObjectArray<btTypedConstraint*>    sortedConstraints;
    sortedConstraints.resize( m_constraints.size());
    int i; 
    for (i=0;i<getNumConstraints();i++)
    {
        sortedConstraints[i] = m_constraints[i];
    }

//  btAssert(0);
        
    

    sortedConstraints.quickSort(btSortConstraintOnIslandPredicate());
    
    btTypedConstraint** constraintsPtr = getNumConstraints() ? &sortedConstraints[0] : 0;
    
    InplaceSolverIslandCallback solverCallback( solverInfo, m_constraintSolver, constraintsPtr,sortedConstraints.size(),    m_debugDrawer,m_stackAlloc,m_dispatcher1);
    
    m_constraintSolver->prepareSolve(getCollisionWorld()->getNumCollisionObjects(), getCollisionWorld()->getDispatcher()->getNumManifolds());
    
    m_islandManager->buildAndProcessIslands(getCollisionWorld()->getDispatcher(),getCollisionWorld(),&solverCallback);

    solverCallback.processConstraints();

    m_constraintSolver->allSolved(solverInfo, m_debugDrawer, m_stackAlloc);
}




void    btDiscreteDynamicsWorld::calculateSimulationIslands()
{
    BT_PROFILE("calculateSimulationIslands");

    getSimulationIslandManager()->updateActivationState(getCollisionWorld(),getCollisionWorld()->getDispatcher());

    {
        int i;
        int numConstraints = int(m_constraints.size());
        for (i=0;i< numConstraints ; i++ )
        {
            btTypedConstraint* constraint = m_constraints[i];

            const btRigidBody* colObj0 = &constraint->getRigidBodyA();
            const btRigidBody* colObj1 = &constraint->getRigidBodyB();

            if (((colObj0) && (!(colObj0)->isStaticOrKinematicObject())) &&
                ((colObj1) && (!(colObj1)->isStaticOrKinematicObject())))
            {
                if (colObj0->isActive() || colObj1->isActive())
                {

                    getSimulationIslandManager()->getUnionFind().unite((colObj0)->getIslandTag(),
                        (colObj1)->getIslandTag());
                }
            }
        }
    }

    //Store the island id in each body
    getSimulationIslandManager()->storeIslandActivationState(getCollisionWorld());

    
}




class btClosestNotMeConvexResultCallback : public btCollisionWorld::ClosestConvexResultCallback
{
    btCollisionObject* m_me;
    btScalar m_allowedPenetration;
    btOverlappingPairCache* m_pairCache;
    btDispatcher* m_dispatcher;


public:
    btClosestNotMeConvexResultCallback (btCollisionObject* me,const btVector3& fromA,const btVector3& toA,btOverlappingPairCache* pairCache,btDispatcher* dispatcher) : 
      btCollisionWorld::ClosestConvexResultCallback(fromA,toA),
        m_me(me),
        m_allowedPenetration(0.0f),
        m_pairCache(pairCache),
        m_dispatcher(dispatcher)
    {
    }

    virtual btScalar addSingleResult(btCollisionWorld::LocalConvexResult& convexResult,bool normalInWorldSpace)
    {
        if (convexResult.m_hitCollisionObject == m_me)
            return 1.0f;

        //ignore result if there is no contact response
        if(!convexResult.m_hitCollisionObject->hasContactResponse())
            return 1.0f;

        btVector3 linVelA,linVelB;
        linVelA = m_convexToWorld-m_convexFromWorld;
        linVelB = btVector3(0,0,0);//toB.getOrigin()-fromB.getOrigin();

        btVector3 relativeVelocity = (linVelA-linVelB);
        //don't report time of impact for motion away from the contact normal (or causes minor penetration)
        if (convexResult.m_hitNormalLocal.dot(relativeVelocity)>=-m_allowedPenetration)
            return 1.f;

        return ClosestConvexResultCallback::addSingleResult (convexResult, normalInWorldSpace);
    }

    virtual bool needsCollision(btBroadphaseProxy* proxy0) const
    {
        //don't collide with itself
        if (proxy0->m_clientObject == m_me)
            return false;

        if (!ClosestConvexResultCallback::needsCollision(proxy0))
            return false;

        btCollisionObject* otherObj = (btCollisionObject*) proxy0->m_clientObject;

        //call needsResponse, see http://code.google.com/p/bullet/issues/detail?id=179
        if (m_dispatcher->needsResponse(m_me,otherObj))
        {
            btAlignedObjectArray<btPersistentManifold*> manifoldArray;
            btBroadphasePair* collisionPair = m_pairCache->findPair(m_me->getBroadphaseHandle(),proxy0);
            if (collisionPair)
            {
                if (collisionPair->m_algorithm)
                {
                    manifoldArray.resize(0);
                    collisionPair->m_algorithm->getAllContactManifolds(manifoldArray);
                    for (int j=0;j<manifoldArray.size();j++)
                    {
                        btPersistentManifold* manifold = manifoldArray[j];
                        if (manifold->getNumContacts()>0)
                            return false;
                    }
                }
            }
        }
        return true;
    }


};

int gNumClampedCcdMotions=0;

//#include "stdio.h"
void    btDiscreteDynamicsWorld::integrateTransforms(btScalar timeStep)
{
    BT_PROFILE("integrateTransforms");
    btTransform predictedTrans;
    for ( int i=0;i<m_nonStaticRigidBodies.size();i++)
    {
        btRigidBody* body = m_nonStaticRigidBodies[i];
        body->setHitFraction(1.f);

        if (body->isActive() && (!body->isStaticOrKinematicObject()))
        {
            body->predictIntegratedTransform(timeStep, predictedTrans);
            btScalar squareMotion = (predictedTrans.getOrigin()-body->getWorldTransform().getOrigin()).length2();

            if (body->getCcdSquareMotionThreshold() && body->getCcdSquareMotionThreshold() < squareMotion)
            {
                BT_PROFILE("CCD motion clamping");
                if (body->getCollisionShape()->isConvex())
                {
                    gNumClampedCcdMotions++;
                    
                    btClosestNotMeConvexResultCallback sweepResults(body,body->getWorldTransform().getOrigin(),predictedTrans.getOrigin(),getBroadphase()->getOverlappingPairCache(),getDispatcher());
                    //btConvexShape* convexShape = static_cast<btConvexShape*>(body->getCollisionShape());
                    btSphereShape tmpSphere(body->getCcdSweptSphereRadius());//btConvexShape* convexShape = static_cast<btConvexShape*>(body->getCollisionShape());

                    sweepResults.m_collisionFilterGroup = body->getBroadphaseProxy()->m_collisionFilterGroup;
                    sweepResults.m_collisionFilterMask  = body->getBroadphaseProxy()->m_collisionFilterMask;

                    convexSweepTest(&tmpSphere,body->getWorldTransform(),predictedTrans,sweepResults);
                    if (sweepResults.hasHit() && (sweepResults.m_closestHitFraction < 1.f))
                    {
                        body->setHitFraction(sweepResults.m_closestHitFraction);
                        body->predictIntegratedTransform(timeStep*body->getHitFraction(), predictedTrans);
                        body->setHitFraction(0.f);
//                          printf("clamped integration to hit fraction = %f\n",fraction);
                    }
                }
            }
            
            body->proceedToTransform( predictedTrans);
        }
    }
}





void    btDiscreteDynamicsWorld::predictUnconstraintMotion(btScalar timeStep)
{
    BT_PROFILE("predictUnconstraintMotion");
    for ( int i=0;i<m_nonStaticRigidBodies.size();i++)
    {
        btRigidBody* body = m_nonStaticRigidBodies[i];
        if (!body->isStaticOrKinematicObject())
        {
            body->integrateVelocities( timeStep);
            //damping
            body->applyDamping(timeStep);

            body->predictIntegratedTransform(timeStep,body->getInterpolationWorldTransform());
        }
    }
}


void    btDiscreteDynamicsWorld::startProfiling(btScalar timeStep)
{
    (void)timeStep;

#ifndef BT_NO_PROFILE
    CProfileManager::Reset();
#endif //BT_NO_PROFILE

}




    

void btDiscreteDynamicsWorld::debugDrawConstraint(btTypedConstraint* constraint)
{
    bool drawFrames = (getDebugDrawer()->getDebugMode() & btIDebugDraw::DBG_DrawConstraints) != 0;
    bool drawLimits = (getDebugDrawer()->getDebugMode() & btIDebugDraw::DBG_DrawConstraintLimits) != 0;
    btScalar dbgDrawSize = constraint->getDbgDrawSize();
    if(dbgDrawSize <= btScalar(0.f))
    {
        return;
    }

    switch(constraint->getConstraintType())
    {
        case POINT2POINT_CONSTRAINT_TYPE:
            {
                btPoint2PointConstraint* p2pC = (btPoint2PointConstraint*)constraint;
                btTransform tr;
                tr.setIdentity();
                btVector3 pivot = p2pC->getPivotInA();
                pivot = p2pC->getRigidBodyA().getCenterOfMassTransform() * pivot; 
                tr.setOrigin(pivot);
                getDebugDrawer()->drawTransform(tr, dbgDrawSize);
                // that ideally should draw the same frame  
                pivot = p2pC->getPivotInB();
                pivot = p2pC->getRigidBodyB().getCenterOfMassTransform() * pivot; 
                tr.setOrigin(pivot);
                if(drawFrames) getDebugDrawer()->drawTransform(tr, dbgDrawSize);
            }
            break;
        case HINGE_CONSTRAINT_TYPE:
            {
                btHingeConstraint* pHinge = (btHingeConstraint*)constraint;
                btTransform tr = pHinge->getRigidBodyA().getCenterOfMassTransform() * pHinge->getAFrame();
                if(drawFrames) getDebugDrawer()->drawTransform(tr, dbgDrawSize);
                tr = pHinge->getRigidBodyB().getCenterOfMassTransform() * pHinge->getBFrame();
                if(drawFrames) getDebugDrawer()->drawTransform(tr, dbgDrawSize);
                btScalar minAng = pHinge->getLowerLimit();
                btScalar maxAng = pHinge->getUpperLimit();
                if(minAng == maxAng)
                {
                    break;
                }
                bool drawSect = true;
                if(minAng > maxAng)
                {
                    minAng = btScalar(0.f);
                    maxAng = SIMD_2_PI;
                    drawSect = false;
                }
                if(drawLimits) 
                {
                    btVector3& center = tr.getOrigin();
                    btVector3 normal = tr.getBasis().getColumn(2);
                    btVector3 axis = tr.getBasis().getColumn(0);
                    getDebugDrawer()->drawArc(center, normal, axis, dbgDrawSize, dbgDrawSize, minAng, maxAng, btVector3(0,0,0), drawSect);
                }
            }
            break;
        case CONETWIST_CONSTRAINT_TYPE:
            {
                btConeTwistConstraint* pCT = (btConeTwistConstraint*)constraint;
                btTransform tr = pCT->getRigidBodyA().getCenterOfMassTransform() * pCT->getAFrame();
                if(drawFrames) getDebugDrawer()->drawTransform(tr, dbgDrawSize);
                tr = pCT->getRigidBodyB().getCenterOfMassTransform() * pCT->getBFrame();
                if(drawFrames) getDebugDrawer()->drawTransform(tr, dbgDrawSize);
                if(drawLimits)
                {
                    //const btScalar length = btScalar(5);
                    const btScalar length = dbgDrawSize;
                    static int nSegments = 8*4;
                    btScalar fAngleInRadians = btScalar(2.*3.1415926) * (btScalar)(nSegments-1)/btScalar(nSegments);
                    btVector3 pPrev = pCT->GetPointForAngle(fAngleInRadians, length);
                    pPrev = tr * pPrev;
                    for (int i=0; i<nSegments; i++)
                    {
                        fAngleInRadians = btScalar(2.*3.1415926) * (btScalar)i/btScalar(nSegments);
                        btVector3 pCur = pCT->GetPointForAngle(fAngleInRadians, length);
                        pCur = tr * pCur;
                        getDebugDrawer()->drawLine(pPrev, pCur, btVector3(0,0,0));

                        if (i%(nSegments/8) == 0)
                            getDebugDrawer()->drawLine(tr.getOrigin(), pCur, btVector3(0,0,0));

                        pPrev = pCur;
                    }                       
                    btScalar tws = pCT->getTwistSpan();
                    btScalar twa = pCT->getTwistAngle();
                    bool useFrameB = (pCT->getRigidBodyB().getInvMass() > btScalar(0.f));
                    if(useFrameB)
                    {
                        tr = pCT->getRigidBodyB().getCenterOfMassTransform() * pCT->getBFrame();
                    }
                    else
                    {
                        tr = pCT->getRigidBodyA().getCenterOfMassTransform() * pCT->getAFrame();
                    }
                    btVector3 pivot = tr.getOrigin();
                    btVector3 normal = tr.getBasis().getColumn(0);
                    btVector3 axis1 = tr.getBasis().getColumn(1);
                    getDebugDrawer()->drawArc(pivot, normal, axis1, dbgDrawSize, dbgDrawSize, -twa-tws, -twa+tws, btVector3(0,0,0), true);

                }
            }
            break;
        case D6_SPRING_CONSTRAINT_TYPE:
        case D6_CONSTRAINT_TYPE:
            {
                btGeneric6DofConstraint* p6DOF = (btGeneric6DofConstraint*)constraint;
                btTransform tr = p6DOF->getCalculatedTransformA();
                if(drawFrames) getDebugDrawer()->drawTransform(tr, dbgDrawSize);
                tr = p6DOF->getCalculatedTransformB();
                if(drawFrames) getDebugDrawer()->drawTransform(tr, dbgDrawSize);
                if(drawLimits) 
                {
                    tr = p6DOF->getCalculatedTransformA();
                    const btVector3& center = p6DOF->getCalculatedTransformB().getOrigin();
                    btVector3 up = tr.getBasis().getColumn(2);
                    btVector3 axis = tr.getBasis().getColumn(0);
                    btScalar minTh = p6DOF->getRotationalLimitMotor(1)->m_loLimit;
                    btScalar maxTh = p6DOF->getRotationalLimitMotor(1)->m_hiLimit;
                    btScalar minPs = p6DOF->getRotationalLimitMotor(2)->m_loLimit;
                    btScalar maxPs = p6DOF->getRotationalLimitMotor(2)->m_hiLimit;
                    getDebugDrawer()->drawSpherePatch(center, up, axis, dbgDrawSize * btScalar(.9f), minTh, maxTh, minPs, maxPs, btVector3(0,0,0));
                    axis = tr.getBasis().getColumn(1);
                    btScalar ay = p6DOF->getAngle(1);
                    btScalar az = p6DOF->getAngle(2);
                    btScalar cy = btCos(ay);
                    btScalar sy = btSin(ay);
                    btScalar cz = btCos(az);
                    btScalar sz = btSin(az);
                    btVector3 ref;
                    ref[0] = cy*cz*axis[0] + cy*sz*axis[1] - sy*axis[2];
                    ref[1] = -sz*axis[0] + cz*axis[1];
                    ref[2] = cz*sy*axis[0] + sz*sy*axis[1] + cy*axis[2];
                    tr = p6DOF->getCalculatedTransformB();
                    btVector3 normal = -tr.getBasis().getColumn(0);
                    btScalar minFi = p6DOF->getRotationalLimitMotor(0)->m_loLimit;
                    btScalar maxFi = p6DOF->getRotationalLimitMotor(0)->m_hiLimit;
                    if(minFi > maxFi)
                    {
                        getDebugDrawer()->drawArc(center, normal, ref, dbgDrawSize, dbgDrawSize, -SIMD_PI, SIMD_PI, btVector3(0,0,0), false);
                    }
                    else if(minFi < maxFi)
                    {
                        getDebugDrawer()->drawArc(center, normal, ref, dbgDrawSize, dbgDrawSize, minFi, maxFi, btVector3(0,0,0), true);
                    }
                    tr = p6DOF->getCalculatedTransformA();
                    btVector3 bbMin = p6DOF->getTranslationalLimitMotor()->m_lowerLimit;
                    btVector3 bbMax = p6DOF->getTranslationalLimitMotor()->m_upperLimit;
                    getDebugDrawer()->drawBox(bbMin, bbMax, tr, btVector3(0,0,0));
                }
            }
            break;
        case SLIDER_CONSTRAINT_TYPE:
            {
                btSliderConstraint* pSlider = (btSliderConstraint*)constraint;
                btTransform tr = pSlider->getCalculatedTransformA();
                if(drawFrames) getDebugDrawer()->drawTransform(tr, dbgDrawSize);
                tr = pSlider->getCalculatedTransformB();
                if(drawFrames) getDebugDrawer()->drawTransform(tr, dbgDrawSize);
                if(drawLimits)
                {
                    btTransform tr = pSlider->getUseLinearReferenceFrameA() ? pSlider->getCalculatedTransformA() : pSlider->getCalculatedTransformB();
                    btVector3 li_min = tr * btVector3(pSlider->getLowerLinLimit(), 0.f, 0.f);
                    btVector3 li_max = tr * btVector3(pSlider->getUpperLinLimit(), 0.f, 0.f);
                    getDebugDrawer()->drawLine(li_min, li_max, btVector3(0, 0, 0));
                    btVector3 normal = tr.getBasis().getColumn(0);
                    btVector3 axis = tr.getBasis().getColumn(1);
                    btScalar a_min = pSlider->getLowerAngLimit();
                    btScalar a_max = pSlider->getUpperAngLimit();
                    const btVector3& center = pSlider->getCalculatedTransformB().getOrigin();
                    getDebugDrawer()->drawArc(center, normal, axis, dbgDrawSize, dbgDrawSize, a_min, a_max, btVector3(0,0,0), true);
                }
            }
            break;
        default : 
            break;
    }
    return;
}





void    btDiscreteDynamicsWorld::setConstraintSolver(btConstraintSolver* solver)
{
    if (m_ownsConstraintSolver)
    {
        btAlignedFree( m_constraintSolver);
    }
    m_ownsConstraintSolver = false;
    m_constraintSolver = solver;
}

btConstraintSolver* btDiscreteDynamicsWorld::getConstraintSolver()
{
    return m_constraintSolver;
}


int     btDiscreteDynamicsWorld::getNumConstraints() const
{
    return int(m_constraints.size());
}
btTypedConstraint* btDiscreteDynamicsWorld::getConstraint(int index)
{
    return m_constraints[index];
}
const btTypedConstraint* btDiscreteDynamicsWorld::getConstraint(int index) const
{
    return m_constraints[index];
}



void    btDiscreteDynamicsWorld::serializeRigidBodies(btSerializer* serializer)
{
    int i;
    //serialize all collision objects
    for (i=0;i<m_collisionObjects.size();i++)
    {
        btCollisionObject* colObj = m_collisionObjects[i];
        if (colObj->getInternalType() & btCollisionObject::CO_RIGID_BODY)
        {
            int len = colObj->calculateSerializeBufferSize();
            btChunk* chunk = serializer->allocate(len,1);
            const char* structType = colObj->serialize(chunk->m_oldPtr, serializer);
            serializer->finalizeChunk(chunk,structType,BT_RIGIDBODY_CODE,colObj);
        }
    }

    for (i=0;i<m_constraints.size();i++)
    {
        btTypedConstraint* constraint = m_constraints[i];
        int size = constraint->calculateSerializeBufferSize();
        btChunk* chunk = serializer->allocate(size,1);
        const char* structType = constraint->serialize(chunk->m_oldPtr,serializer);
        serializer->finalizeChunk(chunk,structType,BT_CONSTRAINT_CODE,constraint);
    }
}


void    btDiscreteDynamicsWorld::serialize(btSerializer* serializer)
{

    serializer->startSerialization();

    serializeRigidBodies(serializer);

    serializeCollisionObjects(serializer);

    serializer->finishSerialization();
}