path: root/tests/bullet/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.cpp

/*
Bullet Continuous Collision Detection and Physics Library
btConeTwistConstraint is Copyright (c) 2007 Starbreeze Studios

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.

Written by: Marcus Hennix
*/


#include "btConeTwistConstraint.h"
#include "BulletDynamics/Dynamics/btRigidBody.h"
#include "LinearMath/btTransformUtil.h"
#include "LinearMath/btMinMax.h"
#include <new>



//#define CONETWIST_USE_OBSOLETE_SOLVER true
#define CONETWIST_USE_OBSOLETE_SOLVER false
#define CONETWIST_DEF_FIX_THRESH btScalar(.05f)


SIMD_FORCE_INLINE btScalar computeAngularImpulseDenominator(const btVector3& axis, const btMatrix3x3& invInertiaWorld)
{
	btVector3 vec = axis * invInertiaWorld;
	return axis.dot(vec);
}




btConeTwistConstraint::btConeTwistConstraint(btRigidBody& rbA,btRigidBody& rbB, 
											 const btTransform& rbAFrame,const btTransform& rbBFrame)
											 :btTypedConstraint(CONETWIST_CONSTRAINT_TYPE, rbA,rbB),m_rbAFrame(rbAFrame),m_rbBFrame(rbBFrame),
											 m_angularOnly(false),
											 m_useSolveConstraintObsolete(CONETWIST_USE_OBSOLETE_SOLVER)
{
	init();
}

btConeTwistConstraint::btConeTwistConstraint(btRigidBody& rbA,const btTransform& rbAFrame)
											:btTypedConstraint(CONETWIST_CONSTRAINT_TYPE,rbA),m_rbAFrame(rbAFrame),
											 m_angularOnly(false),
											 m_useSolveConstraintObsolete(CONETWIST_USE_OBSOLETE_SOLVER)
{
	m_rbBFrame = m_rbAFrame;
	init();	
}


void btConeTwistConstraint::init()
{
	m_angularOnly = false;
	m_solveTwistLimit = false;
	m_solveSwingLimit = false;
	m_bMotorEnabled = false;
	m_maxMotorImpulse = btScalar(-1);

	setLimit(btScalar(BT_LARGE_FLOAT), btScalar(BT_LARGE_FLOAT), btScalar(BT_LARGE_FLOAT));
	m_damping = btScalar(0.01);
	m_fixThresh = CONETWIST_DEF_FIX_THRESH;
	m_flags = 0;
	m_linCFM = btScalar(0.f);
	m_linERP = btScalar(0.7f);
	m_angCFM = btScalar(0.f);
}


void btConeTwistConstraint::getInfo1 (btConstraintInfo1* info)
{
	if (m_useSolveConstraintObsolete)
	{
		info->m_numConstraintRows = 0;
		info->nub = 0;
	} 
	else
	{
		info->m_numConstraintRows = 3;
		info->nub = 3;
		calcAngleInfo2(m_rbA.getCenterOfMassTransform(),m_rbB.getCenterOfMassTransform(),m_rbA.getInvInertiaTensorWorld(),m_rbB.getInvInertiaTensorWorld());
		if(m_solveSwingLimit)
		{
			info->m_numConstraintRows++;
			info->nub--;
			if((m_swingSpan1 < m_fixThresh) && (m_swingSpan2 < m_fixThresh))
			{
				info->m_numConstraintRows++;
				info->nub--;
			}
		}
		if(m_solveTwistLimit)
		{
			info->m_numConstraintRows++;
			info->nub--;
		}
	}
}

void btConeTwistConstraint::getInfo1NonVirtual (btConstraintInfo1* info)
{
	//always reserve 6 rows: object transform is not available on SPU
	info->m_numConstraintRows = 6;
	info->nub = 0;
		
}
	

void btConeTwistConstraint::getInfo2 (btConstraintInfo2* info)
{
	getInfo2NonVirtual(info,m_rbA.getCenterOfMassTransform(),m_rbB.getCenterOfMassTransform(),m_rbA.getInvInertiaTensorWorld(),m_rbB.getInvInertiaTensorWorld());
}

void btConeTwistConstraint::getInfo2NonVirtual (btConstraintInfo2* info,const btTransform& transA,const btTransform& transB,const btMatrix3x3& invInertiaWorldA,const btMatrix3x3& invInertiaWorldB)
{
	calcAngleInfo2(transA,transB,invInertiaWorldA,invInertiaWorldB);
	
	btAssert(!m_useSolveConstraintObsolete);
    // set jacobian
    info->m_J1linearAxis[0] = 1;