/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM 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 General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

\*---------------------------------------------------------------------------*/

#include "shiftedForce.H"
#include "addToRunTimeSelectionTable.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{
namespace energyScalingFunctions
{

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

defineTypeNameAndDebug(shiftedForce, 0);

addToRunTimeSelectionTable
(
    energyScalingFunction,
    shiftedForce,
    dictionary
);


// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

shiftedForce::shiftedForce
(
    const word& name,
    const dictionary& energyScalingFunctionProperties,
    const pairPotential& pairPot
)
:
    energyScalingFunction(name, energyScalingFunctionProperties, pairPot),
    rCut_(pairPot.rCut()),
    e_at_rCut_(pairPot.unscaledEnergy(rCut_)),
    de_dr_at_rCut_(pairPot.energyDerivative(rCut_, false))
{}


// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //

void shiftedForce::scaleEnergy(scalar& e, const scalar r) const
{
    e -= ( e_at_rCut_ + de_dr_at_rCut_ * (r - rCut_) );
}


bool shiftedForce::read(const dictionary& energyScalingFunctionProperties)
{
    energyScalingFunction::read(energyScalingFunctionProperties);

    return true;
}


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace energyScalingFunctions
} // End namespace Foam

// ************************************************************************* //
