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
#define _BT_USE_CENTER_LIMIT_ 1


#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
};


ATTRIBUTE_ALIGNED16(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;


#ifdef  _BT_USE_CENTER_LIMIT_
    btAngularLimit  m_limit;
#else
    btScalar    m_lowerLimit;   
    btScalar    m_upperLimit;   
    btScalar    m_limitSign;
    btScalar    m_correction;

    btScalar    m_limitSoftness; 
    btScalar    m_biasFactor; 
    btScalar    m_relaxationFactor; 

    bool        m_solveLimit;
#endif

    btScalar    m_kHinge;


    btScalar    m_accLimitImpulse;
    btScalar    m_hingeAngle;
    btScalar    m_referenceSign;

    bool        m_angularOnly;
    bool        m_enableAngularMotor;
    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, const btVector3& axisInA,const btVector3& axisInB, bool useReferenceFrameA = false);

    btHingeConstraint(btRigidBody& rbA,const btVector3& pivotInA,const 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;   
    }

    btTransform& getFrameOffsetA()
    {
    return m_rbAFrame;
    }

    btTransform& getFrameOffsetB()
    {
        return m_rbBFrame;
    }

    void setFrames(const btTransform& frameA, const btTransform& frameB);
    
    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)
    {
#ifdef  _BT_USE_CENTER_LIMIT_
        m_limit.set(low, high, _softness, _biasFactor, _relaxationFactor);
#else
        m_lowerLimit = btNormalizeAngle(low);
        m_upperLimit = btNormalizeAngle(high);
        m_limitSoftness =  _softness;
        m_biasFactor = _biasFactor;
        m_relaxationFactor = _relaxationFactor;
#endif
    }

    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_rbB.getCenterOfMassTransform().inverse()(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() );
        m_rbBFrame.getBasis() = m_rbB.getCenterOfMassTransform().getBasis().inverse() * m_rbBFrame.getBasis();

    }

    btScalar    getLowerLimit() const
    {
#ifdef  _BT_USE_CENTER_LIMIT_
    return m_limit.getLow();
#else
    return m_lowerLimit;
#endif
    }

    btScalar    getUpperLimit() const
    {
#ifdef  _BT_USE_CENTER_LIMIT_
    return m_limit.getHigh();
#else       
    return m_upperLimit;
#endif
    }


    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()
    {
#ifdef  _BT_USE_CENTER_LIMIT_
    return m_limit.isLimit();
#else
    return m_solveLimit;
#endif
    }

    inline btScalar getLimitSign()
    {
#ifdef  _BT_USE_CENTER_LIMIT_
    return m_limit.getSign();
#else
        return m_limitSign;
#endif
    }

    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;
#ifdef  _BT_USE_CENTER_LIMIT_
    hingeData->m_lowerLimit = float(m_limit.getLow());
    hingeData->m_upperLimit = float(m_limit.getHigh());
    hingeData->m_limitSoftness = float(m_limit.getSoftness());
    hingeData->m_biasFactor = float(m_limit.getBiasFactor());
    hingeData->m_relaxationFactor = float(m_limit.getRelaxationFactor());
#else
    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);
#endif

    return btHingeConstraintDataName;
}

#endif //HINGECONSTRAINT_H