AdditivePair.hpp

#ifndef OPENMPCD_PAIRPOTENTIALS_ADDITIVEPAIR_HPP
#define OPENMPCD_PAIRPOTENTIALS_ADDITIVEPAIR_HPP
 
#include <OpenMPCD/PairPotentials/Base.hpp>
 
#include <OpenMPCD/CUDA/DeviceCode/Utilities.hpp>
#include <OpenMPCD/OPENMPCD_DEBUG_ASSERT.hpp>
 
namespace OpenMPCD
{
namespace PairPotentials
{
 
/**
 * Represents a potential that consists of the sum of two other potentials.
 */
template<typename T = FP>
class AdditivePair : public Base<T>
{
public:
    /**
     * The constructor.
     *
     * @throw OpenMPCD::NULLPointerException
     *        If `OPENMPCD_DEBUG` is defined, throws if `potential1 == nullptr`
     *        or `potential2 == nullptr`.
     *
     * @param[in] potential1 A pointer to the first potential.
     *                       This pointer must remain valid as long as this
     *                       instance exists.
     * @param[in] potential2 A pointer to the second potential.
     *                       This pointer must remain valid as long as this
     *                       instance exists.
     */
    OPENMPCD_CUDA_HOST_AND_DEVICE
    AdditivePair(
        const Base<T>* const potential1, const Base<T>* const potential2)
        : potential1(potential1), potential2(potential2)
    {
        #ifdef OPENMPCD_DEBUG
            if(potential1 == NULL || potential2 == NULL)
            {
                OPENMPCD_THROW(
                    NULLPointerException, "`potential1`, `potential2`");
            }
        #endif
    }
 
    /**
     * Returns the force vector of the interaction for a given position vector.
     *
     * @param[in] R The relative position vector.
     */
    OPENMPCD_CUDA_HOST_AND_DEVICE
    Vector3D<T> force(const Vector3D<T>& R) const
    {
        return potential1->force(R) + potential2->force(R);
    }
 
    /**
     * Returns the potential of the interaction for a given position vector.
     *
     * @param[in] R The relative position vector.
     */
    OPENMPCD_CUDA_HOST_AND_DEVICE
    T potential(const Vector3D<T>& R) const
    {
        return potential1->potential(R) + potential2->potential(R);
    }
 
private:
    const Base<T>* const potential1; ///< The first potential.
    const Base<T>* const potential2; ///< The second potential.
}; //class AdditivePair
 
} //namespace PairPotentials
} //namespace OpenMPCD
#endif //OPENMPCD_PAIRPOTENTIALS_ADDITIVEPAIR_HPP