/****************************************************************************
* Copyright (C) 2009      Daniel Chappuis                                  *
****************************************************************************
* This file is part of ReactPhysics3D.                                     *
*                                                                          *
* ReactPhysics3D 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 3 of the License, or     *
* (at your option) any later version.                                      *
*                                                                          *
* ReactPhysics3D 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 ReactPhysics3D. If not, see <http://www.gnu.org/licenses/>.   *
***************************************************************************/

#ifndef RUNGEKUTTA4_H
#define RUNGEKUTTA4_H

// Libraries
#include "IntegrationAlgorithm.h"
#include "../body/BodyState.h"
#include "../body/DerivativeBodyState.h"

// Namespace ReactPhysics3D
namespace reactphysics3d {

/*  -------------------------------------------------------------------
    Class RungeKutta4 :
        This class will be used to solve the differential equation of
        movement by integrating a body state. This class implements
        the Runge-Kutta 4 (RK4) integrator.
    -------------------------------------------------------------------
*/
class RungeKutta4 : public IntegrationAlgorithm {
    private :
        DerivativeBodyState evaluate(const BodyState& bodyState, const Time& time);                                 // Compute a derivative body state
        DerivativeBodyState evaluate(BodyState bodyState, const Time& time,
                                     const Time& timeStep, const DerivativeBodyState& lastDerivativeBodyState);     // Compute a derivative body state

    public :
        RungeKutta4();                                          // Constructor
        RungeKutta4(const RungeKutta4& rk4);                    // Copy-constructor
        virtual ~RungeKutta4();                                 // Destructor

        void integrate(BodyState& bodyState, const Time& t, const Time& dt);    // Integrate a body state over time
};

}

#endif