DrudeForce.h

#ifndef OPENMM_DRUDEFORCE_H_
#define OPENMM_DRUDEFORCE_H_

/* -------------------------------------------------------------------------- *
 *                                   OpenMM                                   *
 * -------------------------------------------------------------------------- *
 * This is part of the OpenMM molecular simulation toolkit originating from   *
 * Simbios, the NIH National Center for Physics-Based Simulation of           *
 * Biological Structures at Stanford, funded under the NIH Roadmap for        *
 * Medical Research, grant U54 GM072970. See https://simtk.org.               *
 *                                                                            *
 * Portions copyright (c) 2013 Stanford University and the Authors.           *
 * Authors: Peter Eastman                                                     *
 * Contributors:                                                              *
 *                                                                            *
 * Permission is hereby granted, free of charge, to any person obtaining a    *
 * copy of this software and associated documentation files (the "Software"), *
 * to deal in the Software without restriction, including without limitation  *
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,   *
 * and/or sell copies of the Software, and to permit persons to whom the      *
 * Software is furnished to do so, subject to the following conditions:       *
 *                                                                            *
 * The above copyright notice and this permission notice shall be included in *
 * all copies or substantial portions of the Software.                        *
 *                                                                            *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,   *
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL    *
 * THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,    *
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR      *
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE  *
 * USE OR OTHER DEALINGS IN THE SOFTWARE.                                     *
 * -------------------------------------------------------------------------- */

#include "openmm/Context.h"
#include "openmm/Force.h"
#include <vector>
#include "internal/windowsExportDrude.h"

namespace OpenMM {

class OPENMM_EXPORT_DRUDE DrudeForce : public Force {
public:
    DrudeForce();
    int getNumParticles() const {
        return particles.size();
    }
    int getNumScreenedPairs() const {
        return screenedPairs.size();
    }
    int addParticle(int particle, int particle1, int particle2, int particle3, int particle4, double charge, double polarizability, double aniso12, double aniso34);
    void getParticleParameters(int index, int& particle, int& particle1, int& particle2, int& particle3, int& particle4, double& charge, double& polarizability, double& aniso12, double& aniso34) const;
    void setParticleParameters(int index, int particle, int particle1, int particle2, int particle3, int particle4, double charge, double polarizability, double aniso12, double aniso34);
    int addScreenedPair(int particle1, int particle2, double thole);
    void getScreenedPairParameters(int index, int& particle1, int& particle2, double& thole) const;
    void setScreenedPairParameters(int index, int particle1, int particle2, double thole);
    void updateParametersInContext(Context& context);
    bool usesPeriodicBoundaryConditions() const {
        return false;
    }
protected:
    ForceImpl* createImpl() const;
private:
    class ParticleInfo;
    class ScreenedPairInfo;
    std::vector<ParticleInfo> particles;
    std::vector<ScreenedPairInfo> screenedPairs;
};

class DrudeForce::ParticleInfo {
public:
    int particle, particle1, particle2, particle3, particle4;
    double charge, polarizability, aniso12, aniso34;
    ParticleInfo() {
        particle = particle1 = particle2 = particle3 = particle4 = -1;
        charge = polarizability = aniso12 = aniso34 = 0.0;
    }
    ParticleInfo(int particle, int particle1, int particle2, int particle3, int particle4, double charge, double polarizability, double aniso12, double aniso34) :
        particle(particle), particle1(particle1), particle2(particle2), particle3(particle3), particle4(particle4), charge(charge), polarizability(polarizability), aniso12(aniso12), aniso34(aniso34) {
    }
};

class DrudeForce::ScreenedPairInfo {
public:
    int particle1, particle2;
    double thole;
    ScreenedPairInfo() {
        particle1 = particle2 = -1;
        thole = 0.0;
    }
    ScreenedPairInfo(int particle1, int particle2, double thole) :
        particle1(particle1), particle2(particle2), thole(thole) {
    }
};

} // namespace OpenMM

#endif /*OPENMM_DRUDEFORCE_H_*/