btGeneric6DofSpringConstraint.h

Go to the documentation of this file.

/*
Bullet Continuous Collision Detection and Physics Library, http://bulletphysics.org
Copyright (C) 2006, 2007 Sony Computer Entertainment Inc. 

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.
*/

#ifndef GENERIC_6DOF_SPRING_CONSTRAINT_H
#define GENERIC_6DOF_SPRING_CONSTRAINT_H


#include "LinearMath/btVector3.h"
#include "btTypedConstraint.h"
#include "btGeneric6DofConstraint.h"




class btGeneric6DofSpringConstraint : public btGeneric6DofConstraint
{
protected:
    bool        m_springEnabled[6];
    btScalar    m_equilibriumPoint[6];
    btScalar    m_springStiffness[6];
    btScalar    m_springDamping[6]; // between 0 and 1 (1 == no damping)
    void internalUpdateSprings(btConstraintInfo2* info);
public: 
    btGeneric6DofSpringConstraint(btRigidBody& rbA, btRigidBody& rbB, const btTransform& frameInA, const btTransform& frameInB ,bool useLinearReferenceFrameA);
    void enableSpring(int index, bool onOff);
    void setStiffness(int index, btScalar stiffness);
    void setDamping(int index, btScalar damping);
    void setEquilibriumPoint(); // set the current constraint position/orientation as an equilibrium point for all DOF
    void setEquilibriumPoint(int index);  // set the current constraint position/orientation as an equilibrium point for given DOF
    void setEquilibriumPoint(int index, btScalar val);

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

    virtual void getInfo2 (btConstraintInfo2* info);

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

};


struct btGeneric6DofSpringConstraintData
{
    btGeneric6DofConstraintData m_6dofData;
    
    int         m_springEnabled[6];
    float       m_equilibriumPoint[6];
    float       m_springStiffness[6];
    float       m_springDamping[6];
};

SIMD_FORCE_INLINE   int btGeneric6DofSpringConstraint::calculateSerializeBufferSize() const
{
    return sizeof(btGeneric6DofSpringConstraintData);
}

SIMD_FORCE_INLINE   const char* btGeneric6DofSpringConstraint::serialize(void* dataBuffer, btSerializer* serializer) const
{
    btGeneric6DofSpringConstraintData* dof = (btGeneric6DofSpringConstraintData*)dataBuffer;
    btGeneric6DofConstraint::serialize(&dof->m_6dofData,serializer);

    int i;
    for (i=0;i<6;i++)
    {
        dof->m_equilibriumPoint[i] = m_equilibriumPoint[i];
        dof->m_springDamping[i] = m_springDamping[i];
        dof->m_springEnabled[i] = m_springEnabled[i]? 1 : 0;
        dof->m_springStiffness[i] = m_springStiffness[i];
    }
    return "btGeneric6DofConstraintData";
}

#endif // GENERIC_6DOF_SPRING_CONSTRAINT_H