SpringEdgeDataForceField.h

Go to the documentation of this file.

/******************************************************************************
*       SOFA, Simulation Open-Framework Architecture, version 1.0 beta 3      *
*                (c) 2006-2008 MGH, INRIA, USTL, UJF, CNRS                    *
*                                                                             *
* This library is free software; you can redistribute it and/or modify it     *
* under the terms of the GNU Lesser General Public License as published by    *
* the Free Software Foundation; either version 2.1 of the License, or (at     *
* your option) any later version.                                             *
*                                                                             *
* This library is distributed in the hope that it will be useful, but WITHOUT *
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or       *
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License *
* for more details.                                                           *
*                                                                             *
* You should have received a copy of the GNU Lesser General Public License    *
* along with this library; if not, write to the Free Software Foundation,     *
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA.          *
*******************************************************************************
*                               SOFA :: Modules                               *
*                                                                             *
* Authors: The SOFA Team and external contributors (see Authors.txt)          *
*                                                                             *
* Contact information: contact@sofa-framework.org                             *
******************************************************************************/
#ifndef SOFA_COMPONENT_FORCEFIELD_SPRINGEDGEDATAFORCEFIELD_H
#define SOFA_COMPONENT_FORCEFIELD_SPRINGEDGEDATAFORCEFIELD_H

#include <sofa/core/componentmodel/behavior/ForceField.h>
#include <sofa/core/componentmodel/behavior/MechanicalState.h>
#include <sofa/component/topology/EdgeData.h>
#include <sofa/component/topology/EdgeData.inl>
#include <sofa/defaulttype/Vec.h>
#include <vector>


namespace sofa
{

namespace component
{

namespace forcefield
{

using namespace sofa::defaulttype;

//using namespace sofa::core::objectmodel;

template<class DataTypes>
class SpringEdgeDataForceField : public core::componentmodel::behavior::ForceField<DataTypes>, public  virtual core::objectmodel::BaseObject
{
public:
    typedef typename DataTypes::VecCoord VecCoord;
    typedef typename DataTypes::VecDeriv VecDeriv;
    typedef typename DataTypes::Coord Coord;
    typedef typename DataTypes::Deriv Deriv;
    typedef typename Coord::value_type Real;
    class Mat3 : public fixed_array<Deriv,3>
    {
    public:
        Deriv operator*(const Deriv& v) const
        {
            return Deriv((*this)[0]*v,(*this)[1]*v,(*this)[2]*v);
        }
    };

    struct Spring {
        Real  ks;           // spring stiffness
        Real  kd;           // damping factor 
        Real  restLength;   // rest length of the spring 
        Mat3  dfdx; // the edge stiffness matrix
        
        Spring(Real _ks, Real _kd, Real _rl) : ks(_ks), kd(_kd), restLength(_rl) {
        }
        Spring() : ks(1.0),kd(1.0),restLength(0.0) {
        }
    };
protected:
    double m_potentialEnergy;
    bool updateMatrix;
    component::topology::EdgeData<Spring> springArray;
    core::componentmodel::behavior::MechanicalState<DataTypes>* object;
    component::topology::EdgeSetTopology<DataTypes> *topology;
    DataField<std::string> m_filename;
    DataField<double> m_stiffness;
    DataField<double> m_viscosity;

    //void addSpringForce(double& potentialEnergy, VecDeriv& f1, const VecCoord& p1, const VecDeriv& v1, VecDeriv& f2, const VecCoord& p2, const VecDeriv& v2, int i, const Spring& spring);
    z   void addSpring(int m1, int m2, SReal ks, SReal kd, SReal initlen);

    void resizeArray(unsigned int n);

public:
    
    SpringEdgeDataForceField(core::componentmodel::behavior::MechanicalState<DataTypes>* _object);
    
    bool load(const char *filename);
    
    core::componentmodel::behavior::MechanicalState<DataTypes>* getObject() { return object; }

    virtual void init();

    void createDefaultSprings();
    
    virtual void handleEvent( Event* e );
    
    virtual void addForce (VecDeriv& f, const VecCoord& x, const VecDeriv& v);

    virtual void addDForce (VecDeriv& df, const VecDeriv& dx);

    virtual double getPotentialEnergy(const VecCoord& ) { return m_potentialEnergy; }

    Real getStiffness() const {
        return (Real)(m_stiffness.getValue());
    }
    const Real getViscosity() const {
        return (Real)(m_viscosity.getValue());
    }
    const component::topology::EdgeData<Spring> &getSpringArray() const{
        return springArray;
    }
    void draw();
    
    // -- Modifiers
    
    void clear(int reserve=0)
    {
        springArray.clear();
        if (reserve) springArray.reserve(reserve);
    }
    class Loader;
    friend class Loader;
    
};


} // namespace forcefield

} // namespace component

} // namespace sofa

#endif