/*
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 "OdeConstraintSolver.h"

#include "BulletCollision/NarrowPhaseCollision/btPersistentManifold.h"
#include "BulletDynamics/Dynamics/btRigidBody.h"
#include "BulletDynamics/ConstraintSolver/btContactConstraint.h"
#include "BulletDynamics/ConstraintSolver/btSolve2LinearConstraint.h"
#include "BulletDynamics/ConstraintSolver/btContactSolverInfo.h"
#include "OdeJoint.h"
#include "OdeContactJoint.h"
#include "OdeSolverBody.h"
#include <new.h>
#include "LinearMath/btQuickprof.h"

#include "LinearMath/btIDebugDraw.h"

#define USE_SOR_SOLVER

#include "SorLcp.h"

#include <math.h>
#include <float.h>//FLT_MAX
#ifdef WIN32
#include <memory.h>
#endif
#include <string.h>
#include <stdio.h>

#if defined (WIN32)
#include <malloc.h>
#else
#if defined (__FreeBSD__)
#include <stdlib.h>
#else
#include <alloca.h>
#endif
#endif

class BU_Joint;

//see below

//to bridge with ODE quickstep, we make a temp copy of the rigidbodies in each simultion island
#define ODE_MAX_SOLVER_BODIES 16384
#define ODE_MAX_SOLVER_JOINTS 65535
static OdeSolverBody	gSolverBodyArray[ODE_MAX_SOLVER_BODIES];
static ContactJoint		gJointArray[ODE_MAX_SOLVER_JOINTS];


OdeConstraintSolver::OdeConstraintSolver():
m_cfm(0.f),//1e-5f),
m_erp(0.4f)
{
}



//iterative lcp and penalty method
btScalar OdeConstraintSolver::solveGroup(btCollisionObject** bodies,int numBulletBodies,btPersistentManifold** manifoldPtr, int numManifolds,btTypedConstraint** constraints,int numConstraints,const btContactSolverInfo& infoGlobal,btIDebugDraw* debugDrawer,btStackAlloc* stackAlloc)
{
	BEGIN_PROFILE("prepareConstraints");

	m_CurBody = 0;
	m_CurJoint = 0;

	int numBodies = 0;
	OdeSolverBody* odeBodies [ODE_MAX_SOLVER_BODIES];
	int numJoints = 0;
	BU_Joint* joints [ODE_MAX_SOLVER_JOINTS];
	
	for (int j=0;j<numManifolds;j++)
	{

		int body0=-1,body1=-1;

		btPersistentManifold* manifold = manifoldPtr[j];
		if (manifold->getNumContacts() > 0)
		{
			body0 = ConvertBody((btRigidBody*)manifold->getBody0(),odeBodies,numBodies);
			body1 = ConvertBody((btRigidBody*)manifold->getBody1(),odeBodies,numBodies);
			ConvertConstraint(manifold,joints,numJoints,odeBodies,body0,body1,debugDrawer);
		}
	}

	END_PROFILE("prepareConstraints");
	BEGIN_PROFILE("solveConstraints");
	SolveInternal1(m_cfm,m_erp,odeBodies,numBodies,joints,numJoints,infoGlobal);

	//write back resulting velocities
	for (int i=0;i<numBodies;i++)
	{
		if (odeBodies[i]->m_invMass)
		{
			odeBodies[i]->m_originalBody->setLinearVelocity(odeBodies[i]->m_linearVelocity);
			odeBodies[i]->m_originalBody->setAngularVelocity(odeBodies[i]->m_angularVelocity);
		}
	}
	END_PROFILE("solveConstraints");
	return 0.f;

}

/////////////////////////////////////////////////////////////////////////////////


typedef btScalar dQuaternion[4];
#define _R(i,j) R[(i)*4+(j)]

void dRfromQ1 (dMatrix3 R, const dQuaternion q)
{
  // q = (s,vx,vy,vz)
  btScalar qq1 = 2.f*q[1]*q[1];
  btScalar qq2 = 2.f*q[2]*q[2];
  btScalar qq3 = 2.f*q[3]*q[3];
  _R(0,0) = 1.f - qq2 - qq3;
  _R(0,1) = 2*(q[1]*q[2] - q[0]*q[3]);
  _R(0,2) = 2*(q[1]*q[3] + q[0]*q[2]);
  _R(0,3) = 0.f;
	
  _R(1,0) = 2*(q[1]*q[2] + q[0]*q[3]);
  _R(1,1) = 1.f - qq1 - qq3;
  _R(1,2) = 2*(q[2]*q[3] - q[0]*q[1]);
  _R(1,3) = 0.f;

  _R(2,0) = 2*(q[1]*q[3] - q[0]*q[2]);
  _R(2,1) = 2*(q[2]*q[3] + q[0]*q[1]);
  _R(2,2) = 1.f - qq1 - qq2;
  _R(2,3) = 0.f;

}



int OdeConstraintSolver::ConvertBody(btRigidBody* orgBody,OdeSolverBody** bodies,int& numBodies)
{
	assert(orgBody);
	if (!orgBody || (orgBody->getInvMass() == 0.f) )
	{
		return -1;
	}

	//first try to find
	int i,j;
	for (i=0;i<numBodies;i++)
	{
		if (bodies[i]->m_originalBody == orgBody)
			return i;
	}
	//if not found, create a new body
	OdeSolverBody* body = bodies[numBodies] = &gSolverBodyArray[numBodies];
	numBodies++;

	body->m_originalBody = orgBody;

	body->m_facc.setValue(0,0,0,0);
	body->m_tacc.setValue(0,0,0,0);

	body->m_linearVelocity = orgBody->getLinearVelocity();
	body->m_angularVelocity = orgBody->getAngularVelocity();
	body->m_invMass = orgBody->getInvMass();
	body->m_centerOfMassPosition = orgBody->getCenterOfMassPosition();
	body->m_friction = orgBody->getFriction();
	
	//are the indices the same ?
	for (i=0;i<4;i++)
	{
		for ( j=0;j<3;j++)
		{
			body->m_invI[i+4*j] = 0.f;
			body->m_I[i+4*j] = 0.f;
		}
	}
	body->m_invI[0+4*0] = 	orgBody->getInvInertiaDiagLocal()[0];
	body->m_invI[1+4*1] = 	orgBody->getInvInertiaDiagLocal()[1];
	body->m_invI[2+4*2] = 	orgBody->getInvInertiaDiagLocal()[2];

	body->m_I[0+0*4] = 1.f/orgBody->getInvInertiaDiagLocal()[0];
	body->m_I[1+1*4] = 1.f/orgBody->getInvInertiaDiagLocal()[1];
	body->m_I[2+2*4] = 1.f/orgBody->getInvInertiaDiagLocal()[2];
	

	
	
	dQuaternion q;

	q[1] = orgBody->getOrientation()[0];
	q[2] = orgBody->getOrientation()[1];
	q[3] = orgBody->getOrientation()[2];
	q[0] = orgBody->getOrientation()[3];
	
	dRfromQ1(body->m_R,q);
	
	return numBodies-1;
}




	




void OdeConstraintSolver::ConvertConstraint(btPersistentManifold* manifold,BU_Joint** joints,int& numJoints,
					   OdeSolverBody** bodies,int _bodyId0,int _bodyId1,btIDebugDraw* debugDrawer)
{


	manifold->refreshContactPoints(((btRigidBody*)manifold->getBody0())->getCenterOfMassTransform(),
		((btRigidBody*)manifold->getBody1())->getCenterOfMassTransform());

	int bodyId0 = _bodyId0,bodyId1 = _bodyId1;

	int i,numContacts = manifold->getNumContacts();
	
	bool swapBodies = (bodyId0 < 0);

	
	OdeSolverBody* body0,*body1;

	if (swapBodies)
	{
		bodyId0 = _bodyId1;
		bodyId1 = _bodyId0;

		body0 = bodyId0>=0 ? bodies[bodyId0] : 0;//(btRigidBody*)manifold->getBody1();
		body1 = bodyId1>=0 ? bodies[bodyId1] : 0;//(btRigidBody*)manifold->getBody0();

	} else
	{
		body0 = bodyId0>=0 ? bodies[bodyId0] : 0;//(btRigidBody*)manifold->getBody0();
		body1 = bodyId1>=0 ? bodies[bodyId1] : 0;//(btRigidBody*)manifold->getBody1();
	}

	assert(bodyId0 >= 0);

	btVector3 color(0,1,0);
	for (i=0;i<numContacts;i++)
	{

		if (debugDrawer)
		{
			const btManifoldPoint& cp = manifold->getContactPoint(i);

			debugDrawer->drawContactPoint(
				cp.m_positionWorldOnB,
				cp.m_normalWorldOnB,
				cp.getDistance(),
				cp.getLifeTime(),
				color);

		}
		assert (m_CurJoint < ODE_MAX_SOLVER_JOINTS);

//		if (manifold->getContactPoint(i).getDistance() < 0.0f)
		{
			ContactJoint* cont = new (&gJointArray[m_CurJoint++]) ContactJoint( manifold ,i, swapBodies,body0,body1);

			cont->node[0].joint = cont;
			cont->node[0].body = bodyId0 >= 0 ? bodies[bodyId0] : 0;
			
			cont->node[1].joint = cont;
			cont->node[1].body = bodyId1 >= 0 ? bodies[bodyId1] : 0;
			
			joints[numJoints++] = cont;
			for (int i=0;i<6;i++)
				cont->lambda[i] = 0.f;

			cont->flags = 0;
		}
	}

	//create a new contact constraint
};