btDiscreteDynamicsWorld.cpp

Go to the documentation of this file.

/*
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 "BulletDynamics/ConstraintSolver/btContactConstraint.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"

#if 0
btAlignedObjectArray<btVector3> debugContacts;
btAlignedObjectArray<btVector3> debugNormals;
int startHit=2;
int firstHit=startHit;
#endif

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

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(
                btConstraintSolver*     solver,
                btStackAlloc* stackAlloc,
                btDispatcher* dispatcher)
                :m_solverInfo(NULL),
                m_solver(solver),
                m_sortedConstraints(NULL),
                m_numConstraints(0),
                m_debugDrawer(NULL),
                m_stackAlloc(stackAlloc),
                m_dispatcher(dispatcher)
        {

        }

        InplaceSolverIslandCallback& operator=(InplaceSolverIslandCallback& other)
        {
                btAssert(0);
                (void)other;
                return *this;
        }

        SIMD_FORCE_INLINE void setup ( btContactSolverInfo* solverInfo, btTypedConstraint** sortedConstraints,  int     numConstraints, btIDebugDraw* debugDrawer)
        {
                btAssert(solverInfo);
                m_solverInfo = solverInfo;
                m_sortedConstraints = sortedConstraints;
                m_numConstraints = numConstraints;
                m_debugDrawer = debugDrawer;
                m_bodies.resize (0);
                m_manifolds.resize (0);
                m_constraints.resize (0);
        }

        
        virtual void    processIsland(btCollisionObject** bodies,int numBodies,btPersistentManifold**   manifolds,int numManifolds, int islandId)
        {
                if (islandId<0)
                {
                        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)
                        {
                                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()
        {

                btCollisionObject** bodies = m_bodies.size()? &m_bodies[0]:0;
                btPersistentManifold** manifold = m_manifolds.size()?&m_manifolds[0]:0;
                btTypedConstraint** constraints = m_constraints.size()?&m_constraints[0]:0;
                        
                m_solver->solveGroup( bodies,m_bodies.size(),manifold, m_manifolds.size(),constraints, m_constraints.size() ,*m_solverInfo,m_debugDrawer,m_stackAlloc,m_dispatcher);
                m_bodies.resize(0);
                m_manifolds.resize(0);
                m_constraints.resize(0);

        }

};



btDiscreteDynamicsWorld::btDiscreteDynamicsWorld(btDispatcher* dispatcher,btBroadphaseInterface* pairCache,btConstraintSolver* constraintSolver, btCollisionConfiguration* collisionConfiguration)
:btDynamicsWorld(dispatcher,pairCache,collisionConfiguration),
m_sortedConstraints     (),
m_solverIslandCallback ( NULL ),
m_constraintSolver(constraintSolver),
m_gravity(0,-10,0),
m_localTime(0),
m_synchronizeAllMotionStates(false),
m_applySpeculativeContactRestitution(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;

        {
                void* mem = btAlignedAlloc(sizeof(InplaceSolverIslandCallback),16);
                m_solverIslandCallback = new (mem) InplaceSolverIslandCallback (m_constraintSolver, m_stackAlloc, dispatcher);
        }
}


btDiscreteDynamicsWorld::~btDiscreteDynamicsWorld()
{
        //only delete it when we created it
        if (m_ownsIslandManager)
        {
                m_islandManager->~btSimulationIslandManager();
                btAlignedFree( m_islandManager);
        }
        if (m_solverIslandCallback)
        {
                m_solverIslandCallback->~InplaceSolverIslandCallback();
                btAlignedFree(m_solverIslandCallback);
        }
        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 | btIDebugDraw::DBG_DrawNormals)))
        {
                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();


    createPredictiveContacts(timeStep);
    
        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);
}




void    btDiscreteDynamicsWorld::solveConstraints(btContactSolverInfo& solverInfo)
{
        BT_PROFILE("solveConstraints");
        
        m_sortedConstraints.resize( m_constraints.size());
        int i; 
        for (i=0;i<getNumConstraints();i++)
        {
                m_sortedConstraints[i] = m_constraints[i];
        }

//      btAssert(0);
                
        

        m_sortedConstraints.quickSort(btSortConstraintOnIslandPredicate());
        
        btTypedConstraint** constraintsPtr = getNumConstraints() ? &m_sortedConstraints[0] : 0;
        
        m_solverIslandCallback->setup(&solverInfo,constraintsPtr,m_sortedConstraints.size(),getDebugDrawer());
        m_constraintSolver->prepareSolve(getCollisionWorld()->getNumCollisionObjects(), getCollisionWorld()->getDispatcher()->getNumManifolds());
        
        m_islandManager->buildAndProcessIslands(getCollisionWorld()->getDispatcher(),getCollisionWorld(),m_solverIslandCallback);

        m_solverIslandCallback->processConstraints();

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


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

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

    {
        //merge islands based on speculative contact manifolds too
        for (int i=0;i<this->m_predictiveManifolds.size();i++)
        {
            btPersistentManifold* manifold = m_predictiveManifolds[i];
            
            const btCollisionObject* colObj0 = manifold->getBody0();
            const btCollisionObject* colObj1 = manifold->getBody1();
            
            if (((colObj0) && (!(colObj0)->isStaticOrKinematicObject())) &&
                ((colObj1) && (!(colObj1)->isStaticOrKinematicObject())))
            {
                if (colObj0->isActive() || colObj1->isActive())
                {
                    
                    getSimulationIslandManager()->getUnionFind().unite((colObj0)->getIslandTag(),
                                                                       (colObj1)->getIslandTag());
                }
            }
        }
    }
    
        {
                int i;
                int numConstraints = int(m_constraints.size());
                for (i=0;i< numConstraints ; i++ )
                {
                        btTypedConstraint* constraint = m_constraints[i];
                        if (constraint->isEnabled())
                        {
                                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
{
public:

        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))
                {
#if 0
                        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;
                                        }
                                }
                        }
#endif
                        return true;
                }

                return false;
        }


};

int gNumClampedCcdMotions=0;


void    btDiscreteDynamicsWorld::createPredictiveContacts(btScalar timeStep)
{
        BT_PROFILE("createPredictiveContacts");
        
        {
                BT_PROFILE("release predictive contact manifolds");

                for (int i=0;i<m_predictiveManifolds.size();i++)
                {
                        btPersistentManifold* manifold = m_predictiveManifolds[i];
                        this->m_dispatcher1->releaseManifold(manifold);
                }
                m_predictiveManifolds.clear();
        }

        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 (getDispatchInfo().m_useContinuous && body->getCcdSquareMotionThreshold() && body->getCcdSquareMotionThreshold() < squareMotion)
                        {
                                BT_PROFILE("predictive convexSweepTest");
                                if (body->getCollisionShape()->isConvex())
                                {
                                        gNumClampedCcdMotions++;
#ifdef PREDICTIVE_CONTACT_USE_STATIC_ONLY
                                        class StaticOnlyCallback : public btClosestNotMeConvexResultCallback
                                        {
                                        public:

                                                StaticOnlyCallback (btCollisionObject* me,const btVector3& fromA,const btVector3& toA,btOverlappingPairCache* pairCache,btDispatcher* dispatcher) : 
                                                  btClosestNotMeConvexResultCallback(me,fromA,toA,pairCache,dispatcher)
                                                {
                                                }

                                                virtual bool needsCollision(btBroadphaseProxy* proxy0) const
                                                {
                                                        btCollisionObject* otherObj = (btCollisionObject*) proxy0->m_clientObject;
                                                        if (!otherObj->isStaticOrKinematicObject())
                                                                return false;
                                                        return btClosestNotMeConvexResultCallback::needsCollision(proxy0);
                                                }
                                        };

                                        StaticOnlyCallback sweepResults(body,body->getWorldTransform().getOrigin(),predictedTrans.getOrigin(),getBroadphase()->getOverlappingPairCache(),getDispatcher());
#else
                                        btClosestNotMeConvexResultCallback sweepResults(body,body->getWorldTransform().getOrigin(),predictedTrans.getOrigin(),getBroadphase()->getOverlappingPairCache(),getDispatcher());
#endif
                                        //btConvexShape* convexShape = static_cast<btConvexShape*>(body->getCollisionShape());
                                        btSphereShape tmpSphere(body->getCcdSweptSphereRadius());//btConvexShape* convexShape = static_cast<btConvexShape*>(body->getCollisionShape());
                                        sweepResults.m_allowedPenetration=getDispatchInfo().m_allowedCcdPenetration;

                                        sweepResults.m_collisionFilterGroup = body->getBroadphaseProxy()->m_collisionFilterGroup;
                                        sweepResults.m_collisionFilterMask  = body->getBroadphaseProxy()->m_collisionFilterMask;
                                        btTransform modifiedPredictedTrans = predictedTrans;
                                        modifiedPredictedTrans.setBasis(body->getWorldTransform().getBasis());

                                        convexSweepTest(&tmpSphere,body->getWorldTransform(),modifiedPredictedTrans,sweepResults);
                                        if (sweepResults.hasHit() && (sweepResults.m_closestHitFraction < 1.f))
                                        {
                                        
                                                btVector3 distVec = (predictedTrans.getOrigin()-body->getWorldTransform().getOrigin())*sweepResults.m_closestHitFraction;
                                                btScalar distance = distVec.dot(-sweepResults.m_hitNormalWorld);

                                                
                                                btPersistentManifold* manifold = m_dispatcher1->getNewManifold(body,sweepResults.m_hitCollisionObject);
                                                m_predictiveManifolds.push_back(manifold);
                                                
                                                btVector3 worldPointB = body->getWorldTransform().getOrigin()+distVec;
                                                btVector3 localPointB = sweepResults.m_hitCollisionObject->getWorldTransform().inverse()*worldPointB;

                                                btManifoldPoint newPoint(btVector3(0,0,0), localPointB,sweepResults.m_hitNormalWorld,distance);

                                                bool isPredictive = true;
                                                int index = manifold->addManifoldPoint(newPoint, isPredictive);
                                                btManifoldPoint& pt = manifold->getContactPoint(index);
                                                pt.m_combinedRestitution = 0;
                                                pt.m_combinedFriction = btManifoldResult::calculateCombinedFriction(body,sweepResults.m_hitCollisionObject);
                                                pt.m_positionWorldOnA = body->getWorldTransform().getOrigin();
                                                pt.m_positionWorldOnB = worldPointB;

                                        }
                                }
                        }
                }
        }
}
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 (getDispatchInfo().m_useContinuous && body->getCcdSquareMotionThreshold() && body->getCcdSquareMotionThreshold() < squareMotion)
                        {
                                BT_PROFILE("CCD motion clamping");
                                if (body->getCollisionShape()->isConvex())
                                {
                                        gNumClampedCcdMotions++;
#ifdef USE_STATIC_ONLY
                                        class StaticOnlyCallback : public btClosestNotMeConvexResultCallback
                                        {
                                        public:

                                                StaticOnlyCallback (btCollisionObject* me,const btVector3& fromA,const btVector3& toA,btOverlappingPairCache* pairCache,btDispatcher* dispatcher) : 
                                                  btClosestNotMeConvexResultCallback(me,fromA,toA,pairCache,dispatcher)
                                                {
                                                }

                                                virtual bool needsCollision(btBroadphaseProxy* proxy0) const
                                                {
                                                        btCollisionObject* otherObj = (btCollisionObject*) proxy0->m_clientObject;
                                                        if (!otherObj->isStaticOrKinematicObject())
                                                                return false;
                                                        return btClosestNotMeConvexResultCallback::needsCollision(proxy0);
                                                }
                                        };

                                        StaticOnlyCallback sweepResults(body,body->getWorldTransform().getOrigin(),predictedTrans.getOrigin(),getBroadphase()->getOverlappingPairCache(),getDispatcher());
#else
                                        btClosestNotMeConvexResultCallback sweepResults(body,body->getWorldTransform().getOrigin(),predictedTrans.getOrigin(),getBroadphase()->getOverlappingPairCache(),getDispatcher());
#endif
                                        //btConvexShape* convexShape = static_cast<btConvexShape*>(body->getCollisionShape());
                                        btSphereShape tmpSphere(body->getCcdSweptSphereRadius());//btConvexShape* convexShape = static_cast<btConvexShape*>(body->getCollisionShape());
                                        sweepResults.m_allowedPenetration=getDispatchInfo().m_allowedCcdPenetration;

                                        sweepResults.m_collisionFilterGroup = body->getBroadphaseProxy()->m_collisionFilterGroup;
                                        sweepResults.m_collisionFilterMask  = body->getBroadphaseProxy()->m_collisionFilterMask;
                                        btTransform modifiedPredictedTrans = predictedTrans;
                                        modifiedPredictedTrans.setBasis(body->getWorldTransform().getBasis());

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

#if 0
                                                btVector3 linVel = body->getLinearVelocity();

                                                btScalar maxSpeed = body->getCcdMotionThreshold()/getSolverInfo().m_timeStep;
                                                btScalar maxSpeedSqr = maxSpeed*maxSpeed;
                                                if (linVel.length2()>maxSpeedSqr)
                                                {
                                                        linVel.normalize();
                                                        linVel*= maxSpeed;
                                                        body->setLinearVelocity(linVel);
                                                        btScalar ms2 = body->getLinearVelocity().length2();
                                                        body->predictIntegratedTransform(timeStep, predictedTrans);

                                                        btScalar sm2 = (predictedTrans.getOrigin()-body->getWorldTransform().getOrigin()).length2();
                                                        btScalar smt = body->getCcdSquareMotionThreshold();
                                                        printf("sm2=%f\n",sm2);
                                                }
#else
                                                
                                                //don't apply the collision response right now, it will happen next frame
                                                //if you really need to, you can uncomment next 3 lines. Note that is uses zero restitution.
                                                //btScalar appliedImpulse = 0.f;
                                                //btScalar depth = 0.f;
                                                //appliedImpulse = resolveSingleCollision(body,(btCollisionObject*)sweepResults.m_hitCollisionObject,sweepResults.m_hitPointWorld,sweepResults.m_hitNormalWorld,getSolverInfo(), depth);
                                                

#endif

                                        continue;
                                        }
                                }
                        }
                        

                        body->proceedToTransform( predictedTrans);
                
                }

        }

        if (m_applySpeculativeContactRestitution)
        {
                BT_PROFILE("apply speculative contact restitution");
                for (int i=0;i<m_predictiveManifolds.size();i++)
                {
                        btPersistentManifold* manifold = m_predictiveManifolds[i];
                        btRigidBody* body0 = btRigidBody::upcast((btCollisionObject*)manifold->getBody0());
                        btRigidBody* body1 = btRigidBody::upcast((btCollisionObject*)manifold->getBody1());
                        
                        for (int p=0;p<manifold->getNumContacts();p++)
                        {
                                const btManifoldPoint& pt = manifold->getContactPoint(p);
                                btScalar combinedRestitution = btManifoldResult::calculateCombinedRestitution(body0, body1);

                                if (combinedRestitution>0 && pt.m_appliedImpulse != 0.f)
                                //if (pt.getDistance()>0 && combinedRestitution>0 && pt.m_appliedImpulse != 0.f)
                                {
                                        btVector3 imp = -pt.m_normalWorldOnB * pt.m_appliedImpulse* combinedRestitution;
                                
                                        const btVector3& pos1 = pt.getPositionWorldOnA();
                                        const btVector3& pos2 = pt.getPositionWorldOnB();

                                        btVector3 rel_pos0 = pos1 - body0->getWorldTransform().getOrigin(); 
                                        btVector3 rel_pos1 = pos2 - body1->getWorldTransform().getOrigin();

                                        if (body0)
                                                body0->applyImpulse(imp,rel_pos0);
                                        if (body1)
                                                body1->applyImpulse(-imp,rel_pos1);
                                }
                        }
                }
        }
        
}






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())
                {
                        //don't integrate/update velocities here, it happens in the constraint solver

                        //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;
        m_solverIslandCallback->m_solver = 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::serializeDynamicsWorldInfo(btSerializer* serializer)
{
#ifdef BT_USE_DOUBLE_PRECISION
                int len = sizeof(btDynamicsWorldDoubleData);
                btChunk* chunk = serializer->allocate(len,1);
                btDynamicsWorldDoubleData* worldInfo = (btDynamicsWorldDoubleData*)chunk->m_oldPtr;
#else//BT_USE_DOUBLE_PRECISION
                int len = sizeof(btDynamicsWorldFloatData);
                btChunk* chunk = serializer->allocate(len,1);
                btDynamicsWorldFloatData* worldInfo = (btDynamicsWorldFloatData*)chunk->m_oldPtr;
#endif//BT_USE_DOUBLE_PRECISION

                memset(worldInfo ,0x00,len);

                m_gravity.serialize(worldInfo->m_gravity);
                worldInfo->m_solverInfo.m_tau = getSolverInfo().m_tau;
                worldInfo->m_solverInfo.m_damping = getSolverInfo().m_damping;
                worldInfo->m_solverInfo.m_friction = getSolverInfo().m_friction;
                worldInfo->m_solverInfo.m_timeStep = getSolverInfo().m_timeStep;

                worldInfo->m_solverInfo.m_restitution = getSolverInfo().m_restitution;
                worldInfo->m_solverInfo.m_maxErrorReduction = getSolverInfo().m_maxErrorReduction;
                worldInfo->m_solverInfo.m_sor = getSolverInfo().m_sor;
                worldInfo->m_solverInfo.m_erp = getSolverInfo().m_erp;

                worldInfo->m_solverInfo.m_erp2 = getSolverInfo().m_erp2;
                worldInfo->m_solverInfo.m_globalCfm = getSolverInfo().m_globalCfm;
                worldInfo->m_solverInfo.m_splitImpulsePenetrationThreshold = getSolverInfo().m_splitImpulsePenetrationThreshold;
                worldInfo->m_solverInfo.m_splitImpulseTurnErp = getSolverInfo().m_splitImpulseTurnErp;
                
                worldInfo->m_solverInfo.m_linearSlop = getSolverInfo().m_linearSlop;
                worldInfo->m_solverInfo.m_warmstartingFactor = getSolverInfo().m_warmstartingFactor;
                worldInfo->m_solverInfo.m_maxGyroscopicForce = getSolverInfo().m_maxGyroscopicForce;
                worldInfo->m_solverInfo.m_singleAxisRollingFrictionThreshold = getSolverInfo().m_singleAxisRollingFrictionThreshold;
                
                worldInfo->m_solverInfo.m_numIterations = getSolverInfo().m_numIterations;
                worldInfo->m_solverInfo.m_solverMode = getSolverInfo().m_solverMode;
                worldInfo->m_solverInfo.m_restingContactRestitutionThreshold = getSolverInfo().m_restingContactRestitutionThreshold;
                worldInfo->m_solverInfo.m_minimumSolverBatchSize = getSolverInfo().m_minimumSolverBatchSize;
                
                worldInfo->m_solverInfo.m_splitImpulse = getSolverInfo().m_splitImpulse;
        
#ifdef BT_USE_DOUBLE_PRECISION
                const char* structType = "btDynamicsWorldDoubleData";
#else//BT_USE_DOUBLE_PRECISION
                const char* structType = "btDynamicsWorldFloatData";
#endif//BT_USE_DOUBLE_PRECISION
                serializer->finalizeChunk(chunk,structType,BT_DYNAMICSWORLD_CODE,worldInfo);
}

void    btDiscreteDynamicsWorld::serialize(btSerializer* serializer)
{

        serializer->startSerialization();

        serializeDynamicsWorldInfo(serializer);

        serializeRigidBodies(serializer);

        serializeCollisionObjects(serializer);

        serializer->finishSerialization();
}