lammps/src/fix_external.cpp

123 lines
3.1 KiB
C++

/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
Copyright (2003) Sandia Corporation. Under the terms of Contract
DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
certain rights in this software. This software is distributed under
the GNU General Public License.
See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */
#include "stdio.h"
#include "string.h"
#include "fix_external.h"
#include "atom.h"
#include "update.h"
#include "memory.h"
#include "error.h"
using namespace LAMMPS_NS;
using namespace FixConst;
/* ---------------------------------------------------------------------- */
FixExternal::FixExternal(LAMMPS *lmp, int narg, char **arg) :
Fix(lmp, narg, arg)
{
if (narg != 3) error->all(FLERR,"Illegal fix external command");
callback = NULL;
nmax = 0;
fexternal = NULL;
}
/* ---------------------------------------------------------------------- */
FixExternal::~FixExternal()
{
memory->destroy(fexternal);
}
/* ---------------------------------------------------------------------- */
int FixExternal::setmask()
{
int mask = 0;
mask |= POST_FORCE;
mask |= MIN_POST_FORCE;
return mask;
}
/* ---------------------------------------------------------------------- */
void FixExternal::init()
{
if (callback == NULL)
error->all(FLERR,"Fix external callback function not set");
}
/* ---------------------------------------------------------------------- */
void FixExternal::setup(int vflag)
{
post_force(vflag);
}
/* ---------------------------------------------------------------------- */
void FixExternal::min_setup(int vflag)
{
post_force(vflag);
}
/* ---------------------------------------------------------------------- */
void FixExternal::post_force(int vflag)
{
if (atom->nlocal > nmax) {
memory->destroy(fexternal);
nmax = atom->nmax;
memory->create(fexternal,nmax,3,"external:fexternal");
}
// invoke the callback in driver program
// it will fill fexternal with forces
(this->callback)(ptr_caller,update->ntimestep,
atom->nlocal,atom->tag,atom->x,fexternal);
// add forces from fexternal to atoms in group
double **f = atom->f;
int *mask = atom->mask;
int nlocal = atom->nlocal;
for (int i = 0; i < nlocal; i++)
if (mask[i] & groupbit) {
f[i][0] += fexternal[i][0];
f[i][1] += fexternal[i][1];
f[i][2] += fexternal[i][2];
}
}
/* ---------------------------------------------------------------------- */
void FixExternal::min_post_force(int vflag)
{
post_force(vflag);
}
/* ----------------------------------------------------------------------
external caller sets a callback function to invoke in post_force()
------------------------------------------------------------------------- */
void FixExternal::set_callback(FnPtr caller_callback, void *caller_ptr)
{
callback = caller_callback;
ptr_caller = caller_ptr;
}