btGeneric6DofConstraint.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.
*/


/*
2007-09-09
btGeneric6DofConstraint Refactored by Francisco Le?n
email: projectileman@yahoo.com
http://gimpact.sf.net
*/


#ifndef GENERIC_6DOF_CONSTRAINT_H
#define GENERIC_6DOF_CONSTRAINT_H

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

class btRigidBody;




class btRotationalLimitMotor
{
public:
    btScalar m_loLimit;
    btScalar m_hiLimit;
    btScalar m_targetVelocity;
    btScalar m_maxMotorForce;
    btScalar m_maxLimitForce;
    btScalar m_damping;
    btScalar m_limitSoftness;
    btScalar m_normalCFM;
    btScalar m_stopERP;
    btScalar m_stopCFM;
    btScalar m_bounce;
    bool m_enableMotor;


    btScalar m_currentLimitError;
    btScalar m_currentPosition;     
    int m_currentLimit;
    btScalar m_accumulatedImpulse;

    btRotationalLimitMotor()
    {
        m_accumulatedImpulse = 0.f;
        m_targetVelocity = 0;
        m_maxMotorForce = 0.1f;
        m_maxLimitForce = 300.0f;
        m_loLimit = 1.0f;
        m_hiLimit = -1.0f;
        m_normalCFM = 0.f;
        m_stopERP = 0.2f;
        m_stopCFM = 0.f;
        m_bounce = 0.0f;
        m_damping = 1.0f;
        m_limitSoftness = 0.5f;
        m_currentLimit = 0;
        m_currentLimitError = 0;
        m_enableMotor = false;
    }

    btRotationalLimitMotor(const btRotationalLimitMotor & limot)
    {
        m_targetVelocity = limot.m_targetVelocity;
        m_maxMotorForce = limot.m_maxMotorForce;
        m_limitSoftness = limot.m_limitSoftness;
        m_loLimit = limot.m_loLimit;
        m_hiLimit = limot.m_hiLimit;
        m_normalCFM = limot.m_normalCFM;
        m_stopERP = limot.m_stopERP;
        m_stopCFM = limot.m_stopCFM;
        m_bounce = limot.m_bounce;
        m_currentLimit = limot.m_currentLimit;
        m_currentLimitError = limot.m_currentLimitError;
        m_enableMotor = limot.m_enableMotor;
    }



    bool isLimited()
    {
        if(m_loLimit > m_hiLimit) return false;
        return true;
    }

    bool needApplyTorques()
    {
        if(m_currentLimit == 0 && m_enableMotor == false) return false;
        return true;
    }


    int testLimitValue(btScalar test_value);

    btScalar solveAngularLimits(btScalar timeStep,btVector3& axis, btScalar jacDiagABInv,btRigidBody * body0, btRigidBody * body1);

};



class btTranslationalLimitMotor
{
public:
    btVector3 m_lowerLimit;
    btVector3 m_upperLimit;
    btVector3 m_accumulatedImpulse;
    btScalar    m_limitSoftness;
    btScalar    m_damping;
    btScalar    m_restitution;
    btVector3   m_normalCFM;
    btVector3   m_stopERP;
    btVector3   m_stopCFM;

    bool        m_enableMotor[3];
    btVector3   m_targetVelocity;
    btVector3   m_maxMotorForce;
    btVector3   m_currentLimitError;
    btVector3   m_currentLinearDiff;
    int         m_currentLimit[3];

    btTranslationalLimitMotor()
    {
        m_lowerLimit.setValue(0.f,0.f,0.f);
        m_upperLimit.setValue(0.f,0.f,0.f);
        m_accumulatedImpulse.setValue(0.f,0.f,0.f);
        m_normalCFM.setValue(0.f, 0.f, 0.f);
        m_stopERP.setValue(0.2f, 0.2f, 0.2f);
        m_stopCFM.setValue(0.f, 0.f, 0.f);

        m_limitSoftness = 0.7f;
        m_damping = btScalar(1.0f);
        m_restitution = btScalar(0.5f);
        for(int i=0; i < 3; i++) 
        {
            m_enableMotor[i] = false;
            m_targetVelocity[i] = btScalar(0.f);
            m_maxMotorForce[i] = btScalar(0.f);
        }
    }

    btTranslationalLimitMotor(const btTranslationalLimitMotor & other )
    {
        m_lowerLimit = other.m_lowerLimit;
        m_upperLimit = other.m_upperLimit;
        m_accumulatedImpulse = other.m_accumulatedImpulse;

        m_limitSoftness = other.m_limitSoftness ;
        m_damping = other.m_damping;
        m_restitution = other.m_restitution;
        m_normalCFM = other.m_normalCFM;
        m_stopERP = other.m_stopERP;
        m_stopCFM = other.m_stopCFM;

        for(int i=0; i < 3; i++) 
        {
            m_enableMotor[i] = other.m_enableMotor[i];
            m_targetVelocity[i] = other.m_targetVelocity[i];
            m_maxMotorForce[i] = other.m_maxMotorForce[i];
        }
    }


    inline bool isLimited(int limitIndex)
    {
       return (m_upperLimit[limitIndex] >= m_lowerLimit[limitIndex]);
    }
    inline bool needApplyForce(int limitIndex)
    {
        if(m_currentLimit[limitIndex] == 0 && m_enableMotor[limitIndex] == false) return false;
        return true;
    }
    int testLimitValue(int limitIndex, btScalar test_value);


    btScalar solveLinearAxis(
        btScalar timeStep,
        btScalar jacDiagABInv,
        btRigidBody& body1,const btVector3 &pointInA,
        btRigidBody& body2,const btVector3 &pointInB,
        int limit_index,
        const btVector3 & axis_normal_on_a,
        const btVector3 & anchorPos);


};

enum bt6DofFlags
{
    BT_6DOF_FLAGS_CFM_NORM = 1,
    BT_6DOF_FLAGS_CFM_STOP = 2,
    BT_6DOF_FLAGS_ERP_STOP = 4
};
#define BT_6DOF_FLAGS_AXIS_SHIFT 3 // bits per axis



class btGeneric6DofConstraint : public btTypedConstraint
{
protected:

    btTransform m_frameInA;
    btTransform m_frameInB;


    btJacobianEntry m_jacLinear[3];
    btJacobianEntry m_jacAng[3];


    btTranslationalLimitMotor m_linearLimits;


    btRotationalLimitMotor m_angularLimits[3];


protected:
    btScalar m_timeStep;
    btTransform m_calculatedTransformA;
    btTransform m_calculatedTransformB;
    btVector3 m_calculatedAxisAngleDiff;
    btVector3 m_calculatedAxis[3];
    btVector3 m_calculatedLinearDiff;
    btScalar    m_factA;
    btScalar    m_factB;
    bool        m_hasStaticBody;
    
    btVector3 m_AnchorPos; // point betwen pivots of bodies A and B to solve linear axes

    bool    m_useLinearReferenceFrameA;
    bool    m_useOffsetForConstraintFrame;
    
    int     m_flags;


    btGeneric6DofConstraint&    operator=(btGeneric6DofConstraint&  other)
    {
        btAssert(0);
        (void) other;
        return *this;
    }


    int setAngularLimits(btConstraintInfo2 *info, int row_offset,const btTransform& transA,const btTransform& transB,const btVector3& linVelA,const btVector3& linVelB,const btVector3& angVelA,const btVector3& angVelB);

    int setLinearLimits(btConstraintInfo2 *info, int row, const btTransform& transA,const btTransform& transB,const btVector3& linVelA,const btVector3& linVelB,const btVector3& angVelA,const btVector3& angVelB);

    void buildLinearJacobian(
        btJacobianEntry & jacLinear,const btVector3 & normalWorld,
        const btVector3 & pivotAInW,const btVector3 & pivotBInW);

    void buildAngularJacobian(btJacobianEntry & jacAngular,const btVector3 & jointAxisW);

    // tests linear limits
    void calculateLinearInfo();

    void calculateAngleInfo();



public:

    bool        m_useSolveConstraintObsolete;

    btGeneric6DofConstraint(btRigidBody& rbA, btRigidBody& rbB, const btTransform& frameInA, const btTransform& frameInB ,bool useLinearReferenceFrameA);
    btGeneric6DofConstraint(btRigidBody& rbB, const btTransform& frameInB, bool useLinearReferenceFrameB);
    

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

    void calculateTransforms();


    const btTransform & getCalculatedTransformA() const
    {
        return m_calculatedTransformA;
    }


    const btTransform & getCalculatedTransformB() const
    {
        return m_calculatedTransformB;
    }

    const btTransform & getFrameOffsetA() const
    {
        return m_frameInA;
    }

    const btTransform & getFrameOffsetB() const
    {
        return m_frameInB;
    }


    btTransform & getFrameOffsetA()
    {
        return m_frameInA;
    }

    btTransform & getFrameOffsetB()
    {
        return m_frameInB;
    }


    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& linVelA,const btVector3& linVelB,const btVector3& angVelA,const btVector3& angVelB);


    void    updateRHS(btScalar  timeStep);


    btVector3 getAxis(int axis_index) const;


    btScalar getAngle(int axis_index) const;


    btScalar getRelativePivotPosition(int axis_index) const;

    void setFrames(const btTransform & frameA, const btTransform & frameB);


    bool testAngularLimitMotor(int axis_index);

    void    setLinearLowerLimit(const btVector3& linearLower)
    {
        m_linearLimits.m_lowerLimit = linearLower;
    }

    void    getLinearLowerLimit(btVector3& linearLower)
    {
        linearLower = m_linearLimits.m_lowerLimit;
    }

    void    setLinearUpperLimit(const btVector3& linearUpper)
    {
        m_linearLimits.m_upperLimit = linearUpper;
    }

    void    getLinearUpperLimit(btVector3& linearUpper)
    {
        linearUpper = m_linearLimits.m_upperLimit;
    }

    void    setAngularLowerLimit(const btVector3& angularLower)
    {
        for(int i = 0; i < 3; i++) 
            m_angularLimits[i].m_loLimit = btNormalizeAngle(angularLower[i]);
    }

    void    getAngularLowerLimit(btVector3& angularLower)
    {
        for(int i = 0; i < 3; i++) 
            angularLower[i] = m_angularLimits[i].m_loLimit;
    }

    void    setAngularUpperLimit(const btVector3& angularUpper)
    {
        for(int i = 0; i < 3; i++)
            m_angularLimits[i].m_hiLimit = btNormalizeAngle(angularUpper[i]);
    }

    void    getAngularUpperLimit(btVector3& angularUpper)
    {
        for(int i = 0; i < 3; i++)
            angularUpper[i] = m_angularLimits[i].m_hiLimit;
    }

    btRotationalLimitMotor * getRotationalLimitMotor(int index)
    {
        return &m_angularLimits[index];
    }

    btTranslationalLimitMotor * getTranslationalLimitMotor()
    {
        return &m_linearLimits;
    }

    //first 3 are linear, next 3 are angular
    void setLimit(int axis, btScalar lo, btScalar hi)
    {
        if(axis<3)
        {
            m_linearLimits.m_lowerLimit[axis] = lo;
            m_linearLimits.m_upperLimit[axis] = hi;
        }
        else
        {
            lo = btNormalizeAngle(lo);
            hi = btNormalizeAngle(hi);
            m_angularLimits[axis-3].m_loLimit = lo;
            m_angularLimits[axis-3].m_hiLimit = hi;
        }
    }


    bool    isLimited(int limitIndex)
    {
        if(limitIndex<3)
        {
            return m_linearLimits.isLimited(limitIndex);

        }
        return m_angularLimits[limitIndex-3].isLimited();
    }

    virtual void calcAnchorPos(void); // overridable

    int get_limit_motor_info2(  btRotationalLimitMotor * limot,
                                const btTransform& transA,const btTransform& transB,const btVector3& linVelA,const btVector3& linVelB,const btVector3& angVelA,const btVector3& angVelB,
                                btConstraintInfo2 *info, int row, btVector3& ax1, int rotational, int rotAllowed = false);

    // 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;

    void setAxis( const btVector3& axis1, const btVector3& axis2);


    virtual int calculateSerializeBufferSize() const;

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

    
};

struct btGeneric6DofConstraintData
{
    btTypedConstraintData   m_typeConstraintData;
    btTransformFloatData m_rbAFrame; // constraint axii. Assumes z is hinge axis.
    btTransformFloatData m_rbBFrame;
    
    btVector3FloatData  m_linearUpperLimit;
    btVector3FloatData  m_linearLowerLimit;

    btVector3FloatData  m_angularUpperLimit;
    btVector3FloatData  m_angularLowerLimit;
    
    int m_useLinearReferenceFrameA;
    int m_useOffsetForConstraintFrame;
};

SIMD_FORCE_INLINE   int btGeneric6DofConstraint::calculateSerializeBufferSize() const
{
    return sizeof(btGeneric6DofConstraintData);
}

SIMD_FORCE_INLINE   const char* btGeneric6DofConstraint::serialize(void* dataBuffer, btSerializer* serializer) const
{

    btGeneric6DofConstraintData* dof = (btGeneric6DofConstraintData*)dataBuffer;
    btTypedConstraint::serialize(&dof->m_typeConstraintData,serializer);

    m_frameInA.serializeFloat(dof->m_rbAFrame);
    m_frameInB.serializeFloat(dof->m_rbBFrame);

        
    int i;
    for (i=0;i<3;i++)
    {
        dof->m_angularLowerLimit.m_floats[i] =  float(m_angularLimits[i].m_loLimit);
        dof->m_angularUpperLimit.m_floats[i] =  float(m_angularLimits[i].m_hiLimit);
        dof->m_linearLowerLimit.m_floats[i] = float(m_linearLimits.m_lowerLimit[i]);
        dof->m_linearUpperLimit.m_floats[i] = float(m_linearLimits.m_upperLimit[i]);
    }
    
    dof->m_useLinearReferenceFrameA = m_useLinearReferenceFrameA? 1 : 0;
    dof->m_useOffsetForConstraintFrame = m_useOffsetForConstraintFrame ? 1 : 0;

    return "btGeneric6DofConstraintData";
}





#endif //GENERIC_6DOF_CONSTRAINT_H