/* Portions copyright (c) 2006 Stanford University and Simbios.
 * Contributors: Pande Group
 *
 * 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.
 */

#ifndef __ReferencePairIxn_H__
#define __ReferencePairIxn_H__

#include "openmm/Vec3.h"
#include "openmm/internal/windowsExport.h"
#include <vector>

namespace OpenMM {

class OPENMM_EXPORT ReferencePairIxn {

   private:

   public:

      /**---------------------------------------------------------------------------------------
      
         Constructor
      
         --------------------------------------------------------------------------------------- */

       ReferencePairIxn();

      /**---------------------------------------------------------------------------------------
      
         Destructor
      
         --------------------------------------------------------------------------------------- */

       ~ReferencePairIxn();

      /**---------------------------------------------------------------------------------------
      
         Calculate pair ixn
      
         @param numberOfAtoms    number of atoms
         @param atomCoordinates  atom coordinates
         @param atomParameters   atom parameters (charges, c6, c12, ...)     atomParameters[atomIndex][paramterIndex]
         @param exclusions       atom exclusion indices                      exclusions[atomIndex][atomToExcludeIndex]
         @param fixedParameters  non-atom parameters
         @param forces           force array (forces added)
         @param energyByAtom     atom energy
         @param totalEnergy      total energy
            
         --------------------------------------------------------------------------------------- */
          
      virtual void calculatePairIxn(int numberOfAtoms, std::vector<OpenMM::Vec3>& atomCoordinates,
                            double** atomParameters, int** exclusions,
                            double* fixedParameters, std::vector<OpenMM::Vec3>& forces,
                            double* energyByAtom, double* totalEnergy) const = 0;
      
};

} // namespace OpenMM

#endif // __ReferencePairIxn_H__