/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/

This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose, 
including commercial applications, and to alter it and redistribute it freely, 
subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/


#include "btDiscreteDynamicsWorld.h"

//collision detection
#include "BulletCollision/CollisionDispatch/btCollisionDispatcher.h"
#include "BulletCollision/BroadphaseCollision/btSimpleBroadphase.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"

//for debug rendering
#include "BulletCollision/CollisionShapes/btBoxShape.h"
#include "BulletCollision/CollisionShapes/btCapsuleShape.h"
#include "BulletCollision/CollisionShapes/btCompoundShape.h"
#include "BulletCollision/CollisionShapes/btConeShape.h"
#include "BulletCollision/CollisionShapes/btConvexTriangleMeshShape.h"
#include "BulletCollision/CollisionShapes/btCylinderShape.h"
#include "BulletCollision/CollisionShapes/btMultiSphereShape.h"
#include "BulletCollision/CollisionShapes/btPolyhedralConvexShape.h"
#include "BulletCollision/CollisionShapes/btSphereShape.h"
#include "BulletCollision/CollisionShapes/btTriangleCallback.h"
#include "BulletCollision/CollisionShapes/btTriangleMeshShape.h"
#include "BulletCollision/CollisionShapes/btStaticPlaneShape.h"
#include "LinearMath/btIDebugDraw.h"



//vehicle
#include "BulletDynamics/Vehicle/btRaycastVehicle.h"
#include "BulletDynamics/Vehicle/btVehicleRaycaster.h"
#include "BulletDynamics/Vehicle/btWheelInfo.h"
//character
#include "BulletDynamics/Character/btCharacterControllerInterface.h"

#include "LinearMath/btIDebugDraw.h"
#include "LinearMath/btQuickprof.h"
#include "LinearMath/btMotionState.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(btScalar(1.)/btScalar(60.)),
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)
		{
				btTransform predictedTrans;
				if (body->getActivationState() != ISLAND_SLEEPING)
				{
					if (body->isKinematicObject())
					{
						//to calculate velocities next frame
						body->saveKinematicState(timeStep);
					}
				}
		}
	}
}

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

	if (getDebugDrawer() && getDebugDrawer()->getDebugMode() & btIDebugDraw::DBG_DrawContactPoints)
	{
		int numManifolds = getDispatcher()->getNumManifolds();
		btVector3 color(0,0,0);
		for (int i=0;i<numManifolds;i++)
		{
			btPersistentManifold* contactManifold = getDispatcher()->getManifoldByIndexInternal(i);
			//btCollisionObject* obA = static_cast<btCollisionObject*>(contactManifold->getBody0());
			//btCollisionObject* obB = static_cast<btCollisionObject*>(contactManifold->getBody1());

			int numContacts = contactManifold->getNumContacts();
			for (int j=0;j<numContacts;j++)
			{
				btManifoldPoint& cp = contactManifold->getContactPoint(j);
				getDebugDrawer()->drawContactPoint(cp.m_positionWorldOnB,cp.m_normalWorldOnB,cp.getDistance(),cp.getLifeTime(),color);
			}
		}
	}


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

		for (  i=0;i<m_collisionObjects.size();i++)
		{
			btCollisionObject* colObj = m_collisionObjects[i];
			if (getDebugDrawer() && getDebugDrawer()->getDebugMode() & btIDebugDraw::DBG_DrawWireframe)
			{
				btVector3 color(btScalar(255.),btScalar(255.),btScalar(255.));
				switch(colObj->getActivationState())
				{
				case  ACTIVE_TAG:
					color = btVector3(btScalar(255.),btScalar(255.),btScalar(255.)); break;
				case ISLAND_SLEEPING:
					color =  btVector3(btScalar(0.),btScalar(255.),btScalar(0.));break;
				case WANTS_DEACTIVATION:
					color = btVector3(btScalar(0.),btScalar(255.),btScalar(255.));break;
				case DISABLE_DEACTIVATION:
					color = btVector3(btScalar(255.),btScalar(0.),btScalar(0.));break;
				case DISABLE_SIMULATION:
					color = btVector3(btScalar(255.),btScalar(255.),btScalar(0.));break;
				default:
					{
						color = btVector3(btScalar(255.),btScalar(0.),btScalar(0.));
					}
				};

				debugDrawObject(colObj->getWorldTransform(),colObj->getCollisionShape(),color);
			}
			if (m_debugDrawer && (m_debugDrawer->getDebugMode() & btIDebugDraw::DBG_DrawAabb))
			{
				btVector3 minAabb,maxAabb;
				btVector3 colorvec(1,0,0);
				colObj->getCollisionShape()->getAabb(colObj->getWorldTransform(), minAabb,maxAabb);
				m_debugDrawer->drawAabb(minAabb,maxAabb,colorvec);
			}

		}
	
		for (  i=0;i<this->m_vehicles.size();i++)
		{
			for (int v=0;v<m_vehicles[i]->getNumWheels();v++)
			{
				btVector3 wheelColor(0,255,255);
				if (m_vehicles[i]->getWheelInfo(v).m_raycastInfo.m_isInContact)
				{
					wheelColor.setValue(0,0,255);
				} else
				{
					wheelColor.setValue(255,0,255);
				}
		
				btVector3 wheelPosWS = m_vehicles[i]->getWheelInfo(v).m_worldTransform.getOrigin();

				btVector3 axle = btVector3(	
					m_vehicles[i]->getWheelInfo(v).m_worldTransform.getBasis()[0][m_vehicles[i]->getRightAxis()],
					m_vehicles[i]->getWheelInfo(v).m_worldTransform.getBasis()[1][m_vehicles[i]->getRightAxis()],
					m_vehicles[i]->getWheelInfo(v).m_worldTransform.getBasis()[2][m_vehicles[i]->getRightAxis()]);


				//m_vehicles[i]->getWheelInfo(v).m_raycastInfo.m_wheelAxleWS
				//debug wheels (cylinders)
				m_debugDrawer->drawLine(wheelPosWS,wheelPosWS+axle,wheelColor);
				m_debugDrawer->drawLine(wheelPosWS,m_vehicles[i]->getWheelInfo(v).m_raycastInfo.m_contactPointWS,wheelColor);

			}
		}
	}
}

void	btDiscreteDynamicsWorld::clearForces()
{
	///@todo: iterate over awake simulation islands!
	for ( int i=0;i<m_collisionObjects.size();i++)
	{
		btCollisionObject* colObj = m_collisionObjects[i];
		
		btRigidBody* body = btRigidBody::upcast(colObj);
		if (body)
		{
			body->clearForces();
		}
	}
}	

///apply gravity, call this once per timestep
void	btDiscreteDynamicsWorld::applyGravity()
{
	///@todo: iterate over awake simulation islands!
	for ( int i=0;i<m_collisionObjects.size();i++)
	{
		btCollisionObject* colObj = m_collisionObjects[i];
		
		btRigidBody* body = btRigidBody::upcast(colObj);
		if (body && 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
		///@todo: add 'dirty' flag
		//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");
	{
		//todo: iterate over awake simulation islands!
		for ( int i=0;i<m_collisionObjects.size();i++)
		{
			btCollisionObject* colObj = m_collisionObjects[i];
			
			btRigidBody* body = btRigidBody::upcast(colObj);
			if (body)
				synchronizeSingleMotionState(body);
		}
	}

	if (getDebugDrawer() && getDebugDrawer()->getDebugMode() & btIDebugDraw::DBG_DrawWireframe)
	{
		for ( int i=0;i<this->m_vehicles.size();i++)
		{
			for (int v=0;v<m_vehicles[i]->getNumWheels();v++)
			{
				//synchronize the wheels with the (interpolated) chassis worldtransform
				m_vehicles[i]->updateWheelTransform(v,true);
			}
		}
	}

}


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())
	{
		gDisableDeactivation = (getDebugDrawer()->getDebugMode() & btIDebugDraw::DBG_NoDeactivation) != 0;
	}
	if (numSimulationSubSteps)
	{

		saveKinematicState(fixedTimeStep);

		applyGravity();

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

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

	} 

	synchronizeMotionStates();

	clearForces();

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

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

	///apply gravity, predict motion
	predictUnconstraintMotion(timeStep);

	btDispatcherInfo& dispatchInfo = getDispatchInfo();

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

	///perform collision detection
	performDiscreteCollisionDetection();

	calculateSimulationIslands();

	
	getSolverInfo().m_timeStep = timeStep;
	


	///solve contact and other joint constraints
	solveConstraints(getSolverInfo());
	
	///CallbackTriggers();

	///integrate transforms
	integrateTransforms(timeStep);

	///update vehicle simulation
	updateVehicles(timeStep);
	
	updateCharacters(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_collisionObjects.size();i++)
	{
		btCollisionObject* colObj = m_collisionObjects[i];
		btRigidBody* body = btRigidBody::upcast(colObj);
		if (body)
		{
			body->setGravity(gravity);
		}
	}
}

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


void	btDiscreteDynamicsWorld::removeRigidBody(btRigidBody* body)
{
	removeCollisionObject(body);
}

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

	if (body->getCollisionShape())
	{
		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->setGravity(m_gravity);
	}

	if (body->getCollisionShape())
	{
		addCollisionObject(body,group,mask);
	}
}


void	btDiscreteDynamicsWorld::updateVehicles(btScalar timeStep)
{
	BT_PROFILE("updateVehicles");
	
	for ( int i=0;i<m_vehicles.size();i++)
	{
		btRaycastVehicle* vehicle = m_vehicles[i];
		vehicle->updateVehicle( timeStep);
	}
}

void	btDiscreteDynamicsWorld::updateCharacters(btScalar timeStep)
{
	BT_PROFILE("updateCharacters");
	
	for ( int i=0;i<m_characters.size();i++)
	{
		btCharacterControllerInterface* character = m_characters[i];
		character->preStep (this);
		character->playerStep (this,timeStep);
	}
}

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

	for ( int i=0;i<m_collisionObjects.size();i++)
	{
		btCollisionObject* colObj = m_collisionObjects[i];
		btRigidBody* body = btRigidBody::upcast(colObj);
		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::addVehicle(btRaycastVehicle* vehicle)
{
	m_vehicles.push_back(vehicle);
}

void	btDiscreteDynamicsWorld::removeVehicle(btRaycastVehicle* vehicle)
{
	m_vehicles.remove(vehicle);
}

void	btDiscreteDynamicsWorld::addCharacter(btCharacterControllerInterface* character)
{
	m_characters.push_back(character);
}

void	btDiscreteDynamicsWorld::removeCharacter(btCharacterControllerInterface* character)
{
	m_characters.remove(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;

		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)
			{
				///we don't split islands, so all constraints/contact manifolds/bodies are passed into the solver regardless the island id
				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++;
					}
				}

				///only call solveGroup if there is some work: avoid virtual function call, its overhead can be excessive
				if (numManifolds + numCurConstraints)
				{
					m_solver->solveGroup( bodies,numBodies,manifolds, numManifolds,startConstraint,numCurConstraints,m_solverInfo,m_debugDrawer,m_stackAlloc,m_dispatcher);
				}
		
			}
		}

	};

	//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];
	}

//	assert(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());
	
	/// solve all the constraints for this island
	m_islandManager->buildAndProcessIslands(getCollisionWorld()->getDispatcher(),getCollisionWorld(),&solverCallback);

	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());

	
}


#include "BulletCollision/BroadphaseCollision/btCollisionAlgorithm.h"

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


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

	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;

		///don't do CCD when the collision filters are not matching
		if (!ClosestConvexResultCallback::needsCollision(proxy0))
			return false;

		///don't do CCD when there are already contact points (touching contact/penetration)
		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;
	}


};

///internal debugging variable. this value shouldn't be too high
int gNumClampedCcdMotions=0;

//#include "stdio.h"
void	btDiscreteDynamicsWorld::integrateTransforms(btScalar timeStep)
{
	BT_PROFILE("integrateTransforms");
	btTransform predictedTrans;
	for ( int i=0;i<m_collisionObjects.size();i++)
	{
		btCollisionObject* colObj = m_collisionObjects[i];
		btRigidBody* body = btRigidBody::upcast(colObj);
		if (body)
		{
			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());
						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_collisionObjects.size();i++)
	{
		btCollisionObject* colObj = m_collisionObjects[i];
		btRigidBody* body = btRigidBody::upcast(colObj);
		if (body)
		{
			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

}




	

class DebugDrawcallback : public btTriangleCallback, public btInternalTriangleIndexCallback
{
	btIDebugDraw*	m_debugDrawer;
	btVector3	m_color;
	btTransform	m_worldTrans;

public:

	DebugDrawcallback(btIDebugDraw*	debugDrawer,const btTransform& worldTrans,const btVector3& color) :
                m_debugDrawer(debugDrawer),
		m_color(color),
		m_worldTrans(worldTrans)
	{
	}

	virtual void internalProcessTriangleIndex(btVector3* triangle,int partId,int  triangleIndex)
	{
		processTriangle(triangle,partId,triangleIndex);
	}

	virtual void processTriangle(btVector3* triangle,int partId, int triangleIndex)
	{
		(void)partId;
		(void)triangleIndex;

		btVector3 wv0,wv1,wv2;
		wv0 = m_worldTrans*triangle[0];
		wv1 = m_worldTrans*triangle[1];
		wv2 = m_worldTrans*triangle[2];
		m_debugDrawer->drawLine(wv0,wv1,m_color);
		m_debugDrawer->drawLine(wv1,wv2,m_color);
		m_debugDrawer->drawLine(wv2,wv0,m_color);
	}
};

void btDiscreteDynamicsWorld::debugDrawSphere(btScalar radius, const btTransform& transform, const btVector3& color)
{
	btVector3 start = transform.getOrigin();

	const btVector3 xoffs = transform.getBasis() * btVector3(radius,0,0);
	const btVector3 yoffs = transform.getBasis() * btVector3(0,radius,0);
	const btVector3 zoffs = transform.getBasis() * btVector3(0,0,radius);

	// XY 
	getDebugDrawer()->drawLine(start-xoffs, start+yoffs, color);
	getDebugDrawer()->drawLine(start+yoffs, start+xoffs, color);
	getDebugDrawer()->drawLine(start+xoffs, start-yoffs, color);
	getDebugDrawer()->drawLine(start-yoffs, start-xoffs, color);

	// XZ
	getDebugDrawer()->drawLine(start-xoffs, start+zoffs, color);
	getDebugDrawer()->drawLine(start+zoffs, start+xoffs, color);
	getDebugDrawer()->drawLine(start+xoffs, start-zoffs, color);
	getDebugDrawer()->drawLine(start-zoffs, start-xoffs, color);

	// YZ
	getDebugDrawer()->drawLine(start-yoffs, start+zoffs, color);
	getDebugDrawer()->drawLine(start+zoffs, start+yoffs, color);
	getDebugDrawer()->drawLine(start+yoffs, start-zoffs, color);
	getDebugDrawer()->drawLine(start-zoffs, start-yoffs, color);
}

void btDiscreteDynamicsWorld::debugDrawObject(const btTransform& worldTransform, const btCollisionShape* shape, const btVector3& color)
{
	// Draw a small simplex at the center of the object
	{
		btVector3 start = worldTransform.getOrigin();
		getDebugDrawer()->drawLine(start, start+worldTransform.getBasis() * btVector3(1,0,0), btVector3(1,0,0));
		getDebugDrawer()->drawLine(start, start+worldTransform.getBasis() * btVector3(0,1,0), btVector3(0,1,0));
		getDebugDrawer()->drawLine(start, start+worldTransform.getBasis() * btVector3(0,0,1), btVector3(0,0,1));
	}

	if (shape->getShapeType() == COMPOUND_SHAPE_PROXYTYPE)
	{
		const btCompoundShape* compoundShape = static_cast<const btCompoundShape*>(shape);
		for (int i=compoundShape->getNumChildShapes()-1;i>=0;i--)
		{
			btTransform childTrans = compoundShape->getChildTransform(i);
			const btCollisionShape* colShape = compoundShape->getChildShape(i);
			debugDrawObject(worldTransform*childTrans,colShape,color);
		}

	} else
	{
		switch (shape->getShapeType())
		{

		case SPHERE_SHAPE_PROXYTYPE:
			{
				const btSphereShape* sphereShape = static_cast<const btSphereShape*>(shape);
				btScalar radius = sphereShape->getMargin();//radius doesn't include the margin, so draw with margin
				
				debugDrawSphere(radius, worldTransform, color);
				break;
			}
		case MULTI_SPHERE_SHAPE_PROXYTYPE:
			{
				const btMultiSphereShape* multiSphereShape = static_cast<const btMultiSphereShape*>(shape);

				for (int i = multiSphereShape->getSphereCount()-1; i>=0;i--)
				{
					btTransform childTransform = worldTransform;
					childTransform.getOrigin() += multiSphereShape->getSpherePosition(i);
					debugDrawSphere(multiSphereShape->getSphereRadius(i), childTransform, color);
				}

				break;
			}
		case CAPSULE_SHAPE_PROXYTYPE:
			{
				const btCapsuleShape* capsuleShape = static_cast<const btCapsuleShape*>(shape);

				btScalar radius = capsuleShape->getRadius();
				btScalar halfHeight = capsuleShape->getHalfHeight();
				
				int upAxis = capsuleShape->getUpAxis();

				
				btVector3 capStart(0.f,0.f,0.f);
				capStart[upAxis] = -halfHeight;

				btVector3 capEnd(0.f,0.f,0.f);
				capEnd[upAxis] = halfHeight;

				// Draw the ends
				{
					
					btTransform childTransform = worldTransform;
					childTransform.getOrigin() = worldTransform * capStart;
					debugDrawSphere(radius, childTransform, color);
				}

				{
					btTransform childTransform = worldTransform;
					childTransform.getOrigin() = worldTransform * capEnd;
					debugDrawSphere(radius, childTransform, color);
				}

				// Draw some additional lines
				btVector3 start = worldTransform.getOrigin();

				
				capStart[(upAxis+1)%3] = radius;
				capEnd[(upAxis+1)%3] = radius;
				getDebugDrawer()->drawLine(start+worldTransform.getBasis() * capStart,start+worldTransform.getBasis() * capEnd, color);
				capStart[(upAxis+1)%3] = -radius;
				capEnd[(upAxis+1)%3] = -radius;
				getDebugDrawer()->drawLine(start+worldTransform.getBasis() * capStart,start+worldTransform.getBasis() * capEnd, color);

				capStart[(upAxis+1)%3] = 0.f;
				capEnd[(upAxis+1)%3] = 0.f;

				capStart[(upAxis+2)%3] = radius;
				capEnd[(upAxis+2)%3] = radius;
				getDebugDrawer()->drawLine(start+worldTransform.getBasis() * capStart,start+worldTransform.getBasis() * capEnd, color);
				capStart[(upAxis+2)%3] = -radius;
				capEnd[(upAxis+2)%3] = -radius;
				getDebugDrawer()->drawLine(start+worldTransform.getBasis() * capStart,start+worldTransform.getBasis() * capEnd, color);

				
				break;
			}
		case CONE_SHAPE_PROXYTYPE:
			{
				const btConeShape* coneShape = static_cast<const btConeShape*>(shape);
				btScalar radius = coneShape->getRadius();//+coneShape->getMargin();
				btScalar height = coneShape->getHeight();//+coneShape->getMargin();
				btVector3 start = worldTransform.getOrigin();

				int upAxis= coneShape->getConeUpIndex();
				

				btVector3	offsetHeight(0,0,0);
				offsetHeight[upAxis] = height * btScalar(0.5);
				btVector3	offsetRadius(0,0,0);
				offsetRadius[(upAxis+1)%3] = radius;
				btVector3	offset2Radius(0,0,0);
				offset2Radius[(upAxis+2)%3] = radius;

				getDebugDrawer()->drawLine(start+worldTransform.getBasis() * (offsetHeight),start+worldTransform.getBasis() * (-offsetHeight+offsetRadius),color);
				getDebugDrawer()->drawLine(start+worldTransform.getBasis() * (offsetHeight),start+worldTransform.getBasis() * (-offsetHeight-offsetRadius),color);
				getDebugDrawer()->drawLine(start+worldTransform.getBasis() * (offsetHeight),start+worldTransform.getBasis() * (-offsetHeight+offset2Radius),color);
				getDebugDrawer()->drawLine(start+worldTransform.getBasis() * (offsetHeight),start+worldTransform.getBasis() * (-offsetHeight-offset2Radius),color);



				break;

			}
		case CYLINDER_SHAPE_PROXYTYPE:
			{
				const btCylinderShape* cylinder = static_cast<const btCylinderShape*>(shape);
				int upAxis = cylinder->getUpAxis();
				btScalar radius = cylinder->getRadius();
				btScalar halfHeight = cylinder->getHalfExtentsWithMargin()[upAxis];
				btVector3 start = worldTransform.getOrigin();
				btVector3	offsetHeight(0,0,0);
				offsetHeight[upAxis] = halfHeight;
				btVector3	offsetRadius(0,0,0);
				offsetRadius[(upAxis+1)%3] = radius;
				getDebugDrawer()->drawLine(start+worldTransform.getBasis() * (offsetHeight+offsetRadius),start+worldTransform.getBasis() * (-offsetHeight+offsetRadius),color);
				getDebugDrawer()->drawLine(start+worldTransform.getBasis() * (offsetHeight-offsetRadius),start+worldTransform.getBasis() * (-offsetHeight-offsetRadius),color);
				break;
			}

			case STATIC_PLANE_PROXYTYPE:
				{
					const btStaticPlaneShape* staticPlaneShape = static_cast<const btStaticPlaneShape*>(shape);
					btScalar planeConst = staticPlaneShape->getPlaneConstant();
					const btVector3& planeNormal = staticPlaneShape->getPlaneNormal();
					btVector3 planeOrigin = planeNormal * planeConst;
					btVector3 vec0,vec1;
					btPlaneSpace1(planeNormal,vec0,vec1);
					btScalar vecLen = 100.f;
					btVector3 pt0 = planeOrigin + vec0*vecLen;
					btVector3 pt1 = planeOrigin - vec0*vecLen;
					btVector3 pt2 = planeOrigin + vec1*vecLen;
					btVector3 pt3 = planeOrigin - vec1*vecLen;
					getDebugDrawer()->drawLine(worldTransform*pt0,worldTransform*pt1,color);
					getDebugDrawer()->drawLine(worldTransform*pt2,worldTransform*pt3,color);
					break;

				}
		default:
			{

				if (shape->isConcave())
				{
					btConcaveShape* concaveMesh = (btConcaveShape*) shape;
					
					///@todo pass camera, for some culling? no -> we are not a graphics lib
					btVector3 aabbMax(btScalar(1e30),btScalar(1e30),btScalar(1e30));
					btVector3 aabbMin(btScalar(-1e30),btScalar(-1e30),btScalar(-1e30));

					DebugDrawcallback drawCallback(getDebugDrawer(),worldTransform,color);
					concaveMesh->processAllTriangles(&drawCallback,aabbMin,aabbMax);

				}

				if (shape->getShapeType() == CONVEX_TRIANGLEMESH_SHAPE_PROXYTYPE)
				{
					btConvexTriangleMeshShape* convexMesh = (btConvexTriangleMeshShape*) shape;
					//todo: pass camera for some culling			
					btVector3 aabbMax(btScalar(1e30),btScalar(1e30),btScalar(1e30));
					btVector3 aabbMin(btScalar(-1e30),btScalar(-1e30),btScalar(-1e30));
					//DebugDrawcallback drawCallback;
					DebugDrawcallback drawCallback(getDebugDrawer(),worldTransform,color);
					convexMesh->getMeshInterface()->InternalProcessAllTriangles(&drawCallback,aabbMin,aabbMax);
				}


				/// for polyhedral shapes
				if (shape->isPolyhedral())
				{
					btPolyhedralConvexShape* polyshape = (btPolyhedralConvexShape*) shape;

					int i;
					for (i=0;i<polyshape->getNumEdges();i++)
					{
						btVector3 a,b;
						polyshape->getEdge(i,a,b);
						btVector3 wa = worldTransform * a;
						btVector3 wb = worldTransform * b;
						getDebugDrawer()->drawLine(wa,wb,color);

					}

					
				}
			}
		}
	}
}


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];
}