src/gromacs/mdtypes/iforceprovider.h

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  35 /*! \libinternal \file
  36  * \brief
  37  * Declares gmx::IForceProvider and ForceProviders.
  38  *
  39  * See \ref page_mdmodules for an overview of this and associated interfaces.
  40  *
  41  * \author Teemu Murtola <teemu.murtola@gmail.com>
  42  * \author Carsten Kutzner <ckutzne@gwdg.de>
  43  * \inlibraryapi
  44  * \ingroup module_mdtypes
  45  */
  46 #ifndef GMX_MDTYPES_IFORCEPROVIDER_H
  47 #define GMX_MDTYPES_IFORCEPROVIDER_H
  48
  49 #include "gromacs/math/vec.h"
  50 #include "gromacs/utility/arrayref.h"
  51 #include "gromacs/utility/classhelpers.h"
  52 #include "gromacs/utility/gmxassert.h"
  53
  54 struct gmx_enerdata_t;
  55 struct t_commrec;
  56 struct t_forcerec;
  57 struct t_mdatoms;
  58
  59 namespace gmx
  60 {
  61
  62 template<typename T>
  63 class ArrayRef;
  64 class ForceWithVirial;
  65
  66
  67 /*! \libinternal \brief
  68  * Helper struct that bundles data for passing it over to the force providers
  69  *
  70  * This is a short-lived container that bundles up all necessary input data for the
  71  * force providers. Its only purpose is to allow calling forceProviders->calculateForces()
  72  * with just two arguments, one being the container for the input data,
  73  * the other the container for the output data.
  74  *
  75  * Both ForceProviderInput as well as ForceProviderOutput only package existing
  76  * data structs together for handing it over to calculateForces(). Apart from the
  77  * POD entries they own nothing.
  78  */
  79 class ForceProviderInput
  80 {
  81 public:
  82     /*! \brief Constructor assembles all necessary force provider input data
  83      *
  84      * \param[in]  x        Atomic positions
  85      * \param[in]  cr       Communication record structure
  86      * \param[in]  box      The simulation box
  87      * \param[in]  time     The current time in the simulation
  88      * \param[in]  mdatoms  The atomic data
  89      */
  90     ForceProviderInput(ArrayRef<const RVec> x,
  91                        const t_mdatoms&     mdatoms,
  92                        double               time,
  93                        const matrix         box,
  94                        const t_commrec&     cr) :
  95         x_(x),
  96         mdatoms_(mdatoms),
  97         t_(time),
  98         cr_(cr)
  99     {
 100         copy_mat(box, box_);
 101     }
 102
 103     ArrayRef<const RVec> x_;       //!< The atomic positions
 104     const t_mdatoms&     mdatoms_; //!< Atomic data
 105     double               t_;       //!< The current time in the simulation
 106     matrix               box_ = { { 0, 0, 0 }, { 0, 0, 0 }, { 0, 0, 0 } }; //!< The simulation box
 107     const t_commrec&     cr_; //!< Communication record structure
 108 };
 109
 110 /*! \brief Take pointer, check if valid, return reference
 111  */
 112 template<class T>
 113 T& makeRefFromPointer(T* ptr)
 114 {
 115     GMX_ASSERT(ptr != nullptr, "got null pointer");
 116     return *ptr;
 117 }
 118
 119 /*! \libinternal \brief
 120  * Helper struct bundling the output data of a force provider
 121  *
 122  * Same as for the ForceProviderInput class, but these variables can be written as well.
 123  */
 124 class ForceProviderOutput
 125 {
 126 public:
 127     /*! \brief Constructor assembles all necessary force provider output data
 128      *
 129      * \param[in,out]  forceWithVirial  Container for force and virial
 130      * \param[in,out]  enerd            Structure containing energy data
 131      */
 132     ForceProviderOutput(ForceWithVirial* forceWithVirial, gmx_enerdata_t* enerd) :
 133         forceWithVirial_(makeRefFromPointer(forceWithVirial)),
 134         enerd_(makeRefFromPointer(enerd))
 135     {
 136     }
 137
 138     ForceWithVirial& forceWithVirial_; //!< Container for force and virial
 139     gmx_enerdata_t&  enerd_;           //!< Structure containing energy data
 140 };
 141
 142
 143 /*! \libinternal \brief
 144  * Interface for a component that provides forces during MD.
 145  *
 146  * Modules implementing IMDModule generally implement this internally, and use
 147  * IMDModule::initForceProviders() to register their implementation in
 148  * ForceProviders.
 149  *
 150  * The interface most likely requires additional generalization for use in
 151  * other modules than the current electric field implementation.
 152  *
 153  * The forces that are produced by force providers are not taken into account
 154  * in the calculation of the virial. When applicable, the provider should
 155  * compute its own virial contribution.
 156  *
 157  * \inlibraryapi
 158  * \ingroup module_mdtypes
 159  */
 160 class IForceProvider
 161 {
 162 public:
 163     /*! \brief
 164      * Computes forces.
 165      *
 166      * \param[in]    forceProviderInput    struct that collects input data for the force providers
 167      * \param[in,out] forceProviderOutput   struct that collects output data of the force providers
 168      */
 169     virtual void calculateForces(const ForceProviderInput& forceProviderInput,
 170                                  ForceProviderOutput*      forceProviderOutput) = 0;
 171
 172 protected:
 173     ~IForceProvider() {}
 174 };
 175
 176 /*! \libinternal \brief
 177  * Evaluates forces from a collection of gmx::IForceProvider.
 178  *
 179  * \inlibraryapi
 180  * \ingroup module_mdtypes
 181  */
 182 class ForceProviders
 183 {
 184 public:
 185     ForceProviders();
 186     ~ForceProviders();
 187
 188     /*! \brief
 189      * Adds a provider.
 190      */
 191     void addForceProvider(gmx::IForceProvider* provider);
 192
 193     //! Whether there are modules added.
 194     bool hasForceProvider() const;
 195
 196     //! Computes forces.
 197     void calculateForces(const gmx::ForceProviderInput& forceProviderInput,
 198                          gmx::ForceProviderOutput*      forceProviderOutput) const;
 199
 200 private:
 201     class Impl;
 202
 203     gmx::PrivateImplPointer<Impl> impl_;
 204 };
 205
 206 } // namespace gmx
 207
 208 #endif