btHingeConstraint.h

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/*
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.
*/

/* Hinge Constraint by Dirk Gregorius. Limits added by Marcus Hennix at Starbreeze Studios */

#ifndef HINGECONSTRAINT_H
#define HINGECONSTRAINT_H

#include "LinearMath/btVector3.h"
#include "btJacobianEntry.h"
#include "btTypedConstraint.h"

class btRigidBody;

#ifdef BT_USE_DOUBLE_PRECISION
#define btHingeConstraintData   btHingeConstraintDoubleData
#define btHingeConstraintDataName       "btHingeConstraintDoubleData"
#else
#define btHingeConstraintData   btHingeConstraintFloatData
#define btHingeConstraintDataName       "btHingeConstraintFloatData"
#endif //BT_USE_DOUBLE_PRECISION


enum btHingeFlags
{
        BT_HINGE_FLAGS_CFM_STOP = 1,
        BT_HINGE_FLAGS_ERP_STOP = 2,
        BT_HINGE_FLAGS_CFM_NORM = 4
};


class btHingeConstraint : public btTypedConstraint
{
#ifdef IN_PARALLELL_SOLVER
public:
#endif
        btJacobianEntry m_jac[3]; //3 orthogonal linear constraints
        btJacobianEntry m_jacAng[3]; //2 orthogonal angular constraints+ 1 for limit/motor

        btTransform m_rbAFrame; // constraint axii. Assumes z is hinge axis.
        btTransform m_rbBFrame;

        btScalar        m_motorTargetVelocity;
        btScalar        m_maxMotorImpulse;

        btScalar        m_limitSoftness; 
        btScalar        m_biasFactor; 
        btScalar    m_relaxationFactor; 

        btScalar    m_lowerLimit;       
        btScalar    m_upperLimit;       
        
        btScalar        m_kHinge;

        btScalar        m_limitSign;
        btScalar        m_correction;

        btScalar        m_accLimitImpulse;
        btScalar        m_hingeAngle;
        btScalar    m_referenceSign;

        bool            m_angularOnly;
        bool            m_enableAngularMotor;
        bool            m_solveLimit;
        bool            m_useSolveConstraintObsolete;
        bool            m_useOffsetForConstraintFrame;
        bool            m_useReferenceFrameA;

        btScalar        m_accMotorImpulse;

        int                     m_flags;
        btScalar        m_normalCFM;
        btScalar        m_stopCFM;
        btScalar        m_stopERP;

        
public:

        btHingeConstraint(btRigidBody& rbA,btRigidBody& rbB, const btVector3& pivotInA,const btVector3& pivotInB, btVector3& axisInA,btVector3& axisInB, bool useReferenceFrameA = false);

        btHingeConstraint(btRigidBody& rbA,const btVector3& pivotInA,btVector3& axisInA, bool useReferenceFrameA = false);
        
        btHingeConstraint(btRigidBody& rbA,btRigidBody& rbB, const btTransform& rbAFrame, const btTransform& rbBFrame, bool useReferenceFrameA = false);

        btHingeConstraint(btRigidBody& rbA,const btTransform& rbAFrame, bool useReferenceFrameA = false);


        virtual void    buildJacobian();

        virtual void getInfo1 (btConstraintInfo1* info);

        void getInfo1NonVirtual(btConstraintInfo1* info);

        virtual void getInfo2 (btConstraintInfo2* info);

        void    getInfo2NonVirtual(btConstraintInfo2* info,const btTransform& transA,const btTransform& transB,const btVector3& angVelA,const btVector3& angVelB);

        void    getInfo2Internal(btConstraintInfo2* info,const btTransform& transA,const btTransform& transB,const btVector3& angVelA,const btVector3& angVelB);
        void    getInfo2InternalUsingFrameOffset(btConstraintInfo2* info,const btTransform& transA,const btTransform& transB,const btVector3& angVelA,const btVector3& angVelB);
                

        void    updateRHS(btScalar      timeStep);

        const btRigidBody& getRigidBodyA() const
        {
                return m_rbA;
        }
        const btRigidBody& getRigidBodyB() const
        {
                return m_rbB;
        }

        btRigidBody& getRigidBodyA()    
        {               
                return m_rbA;   
        }       

        btRigidBody& getRigidBodyB()    
        {               
                return m_rbB;   
        }       
        
        void    setAngularOnly(bool angularOnly)
        {
                m_angularOnly = angularOnly;
        }

        void    enableAngularMotor(bool enableMotor,btScalar targetVelocity,btScalar maxMotorImpulse)
        {
                m_enableAngularMotor  = enableMotor;
                m_motorTargetVelocity = targetVelocity;
                m_maxMotorImpulse = maxMotorImpulse;
        }

        // extra motor API, including ability to set a target rotation (as opposed to angular velocity)
        // note: setMotorTarget sets angular velocity under the hood, so you must call it every tick to
        //       maintain a given angular target.
        void enableMotor(bool enableMotor)      { m_enableAngularMotor = enableMotor; }
        void setMaxMotorImpulse(btScalar maxMotorImpulse) { m_maxMotorImpulse = maxMotorImpulse; }
        void setMotorTarget(const btQuaternion& qAinB, btScalar dt); // qAinB is rotation of body A wrt body B.
        void setMotorTarget(btScalar targetAngle, btScalar dt);


        void    setLimit(btScalar low,btScalar high,btScalar _softness = 0.9f, btScalar _biasFactor = 0.3f, btScalar _relaxationFactor = 1.0f)
        {
                m_lowerLimit = btNormalizeAngle(low);
                m_upperLimit = btNormalizeAngle(high);

                m_limitSoftness =  _softness;
                m_biasFactor = _biasFactor;
                m_relaxationFactor = _relaxationFactor;

        }

        void    setAxis(btVector3& axisInA)
        {
                btVector3 rbAxisA1, rbAxisA2;
                btPlaneSpace1(axisInA, rbAxisA1, rbAxisA2);
                btVector3 pivotInA = m_rbAFrame.getOrigin();
//              m_rbAFrame.getOrigin() = pivotInA;
                m_rbAFrame.getBasis().setValue( rbAxisA1.getX(),rbAxisA2.getX(),axisInA.getX(),
                                                                                rbAxisA1.getY(),rbAxisA2.getY(),axisInA.getY(),
                                                                                rbAxisA1.getZ(),rbAxisA2.getZ(),axisInA.getZ() );

                btVector3 axisInB = m_rbA.getCenterOfMassTransform().getBasis() * axisInA;

                btQuaternion rotationArc = shortestArcQuat(axisInA,axisInB);
                btVector3 rbAxisB1 =  quatRotate(rotationArc,rbAxisA1);
                btVector3 rbAxisB2 = axisInB.cross(rbAxisB1);


                m_rbBFrame.getOrigin() = m_rbA.getCenterOfMassTransform()(pivotInA);
                m_rbBFrame.getBasis().setValue( rbAxisB1.getX(),rbAxisB2.getX(),axisInB.getX(),
                                                                                rbAxisB1.getY(),rbAxisB2.getY(),axisInB.getY(),
                                                                                rbAxisB1.getZ(),rbAxisB2.getZ(),axisInB.getZ() );
        }

        btScalar        getLowerLimit() const
        {
                return m_lowerLimit;
        }

        btScalar        getUpperLimit() const
        {
                return m_upperLimit;
        }


        btScalar getHingeAngle();

        btScalar getHingeAngle(const btTransform& transA,const btTransform& transB);

        void testLimit(const btTransform& transA,const btTransform& transB);


        const btTransform& getAFrame() const { return m_rbAFrame; };    
        const btTransform& getBFrame() const { return m_rbBFrame; };

        btTransform& getAFrame() { return m_rbAFrame; };        
        btTransform& getBFrame() { return m_rbBFrame; };

        inline int getSolveLimit()
        {
                return m_solveLimit;
        }

        inline btScalar getLimitSign()
        {
                return m_limitSign;
        }

        inline bool getAngularOnly() 
        { 
                return m_angularOnly; 
        }
        inline bool getEnableAngularMotor() 
        { 
                return m_enableAngularMotor; 
        }
        inline btScalar getMotorTargetVelosity() 
        { 
                return m_motorTargetVelocity; 
        }
        inline btScalar getMaxMotorImpulse() 
        { 
                return m_maxMotorImpulse; 
        }
        // access for UseFrameOffset
        bool getUseFrameOffset() { return m_useOffsetForConstraintFrame; }
        void setUseFrameOffset(bool frameOffsetOnOff) { m_useOffsetForConstraintFrame = frameOffsetOnOff; }


        virtual void    setParam(int num, btScalar value, int axis = -1);
        virtual btScalar getParam(int num, int axis = -1) const;

        virtual int     calculateSerializeBufferSize() const;

        virtual const char*     serialize(void* dataBuffer, btSerializer* serializer) const;


};

struct  btHingeConstraintDoubleData
{
        btTypedConstraintData   m_typeConstraintData;
        btTransformDoubleData m_rbAFrame; // constraint axii. Assumes z is hinge axis.
        btTransformDoubleData m_rbBFrame;
        int                     m_useReferenceFrameA;
        int                     m_angularOnly;
        int                     m_enableAngularMotor;
        float   m_motorTargetVelocity;
        float   m_maxMotorImpulse;

        float   m_lowerLimit;
        float   m_upperLimit;
        float   m_limitSoftness;
        float   m_biasFactor;
        float   m_relaxationFactor;

};
struct  btHingeConstraintFloatData
{
        btTypedConstraintData   m_typeConstraintData;
        btTransformFloatData m_rbAFrame; // constraint axii. Assumes z is hinge axis.
        btTransformFloatData m_rbBFrame;
        int                     m_useReferenceFrameA;
        int                     m_angularOnly;
        
        int                     m_enableAngularMotor;
        float   m_motorTargetVelocity;
        float   m_maxMotorImpulse;

        float   m_lowerLimit;
        float   m_upperLimit;
        float   m_limitSoftness;
        float   m_biasFactor;
        float   m_relaxationFactor;

};



SIMD_FORCE_INLINE       int     btHingeConstraint::calculateSerializeBufferSize() const
{
        return sizeof(btHingeConstraintData);
}

SIMD_FORCE_INLINE       const char*     btHingeConstraint::serialize(void* dataBuffer, btSerializer* serializer) const
{
        btHingeConstraintData* hingeData = (btHingeConstraintData*)dataBuffer;
        btTypedConstraint::serialize(&hingeData->m_typeConstraintData,serializer);

        m_rbAFrame.serialize(hingeData->m_rbAFrame);
        m_rbBFrame.serialize(hingeData->m_rbBFrame);

        hingeData->m_angularOnly = m_angularOnly;
        hingeData->m_enableAngularMotor = m_enableAngularMotor;
        hingeData->m_maxMotorImpulse = float(m_maxMotorImpulse);
        hingeData->m_motorTargetVelocity = float(m_motorTargetVelocity);
        hingeData->m_useReferenceFrameA = m_useReferenceFrameA;
        
        hingeData->m_lowerLimit = float(m_lowerLimit);
        hingeData->m_upperLimit = float(m_upperLimit);
        hingeData->m_limitSoftness = float(m_limitSoftness);
        hingeData->m_biasFactor = float(m_biasFactor);
        hingeData->m_relaxationFactor = float(m_relaxationFactor);

        return btHingeConstraintDataName;
}

#endif //HINGECONSTRAINT_H