MD-Bench/src/pbc.c
Jan Eitzinger 35273c491b Introduce generic variant targets
Change Makefiles to allow multiple binary targets specified by VARIANT
environment variabel. For specified variants a matching main-<VARIANT>.c
source file must be present.
2021-04-12 08:24:27 +02:00

169 lines
6.1 KiB
C

/*
* =======================================================================================
*
* Author: Jan Eitzinger (je), jan.eitzinger@fau.de
* Copyright (c) 2020 RRZE, University Erlangen-Nuremberg
*
* This file is part of MD-Bench.
*
* MD-Bench is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* MD-Bench is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public License along
* with MD-Bench. If not, see <https://www.gnu.org/licenses/>.
* =======================================================================================
*/
#include <stdlib.h>
#include <stdio.h>
#include <pbc.h>
#include <atom.h>
#include <allocate.h>
#define DELTA 20000
static int NmaxGhost;
static int *BorderMap;
static int *PBCx, *PBCy, *PBCz;
static void growPbc();
/* exported subroutines */
void initPbc()
{
NmaxGhost = 0;
BorderMap = NULL;
PBCx = NULL; PBCy = NULL; PBCz = NULL;
}
/* update coordinates of ghost atoms */
/* uses mapping created in setupPbc */
void updatePbc(Atom *atom, Parameter *param)
{
int nlocal = atom->Nlocal;
MD_FLOAT xprd = param->xprd;
MD_FLOAT yprd = param->yprd;
MD_FLOAT zprd = param->zprd;
for(int i = 0; i < atom->Nghost; i++) {
atom_x(nlocal + i) = atom_x(BorderMap[i]) + PBCx[i] * xprd;
atom_y(nlocal + i) = atom_y(BorderMap[i]) + PBCy[i] * yprd;
atom_z(nlocal + i) = atom_z(BorderMap[i]) + PBCz[i] * zprd;
}
}
/* relocate atoms that have left domain according
* to periodic boundary conditions */
void updateAtomsPbc(Atom *atom, Parameter *param)
{
MD_FLOAT xprd = param->xprd;
MD_FLOAT yprd = param->yprd;
MD_FLOAT zprd = param->zprd;
for(int i = 0; i < atom->Nlocal; i++) {
if(atom_x(i) < 0.0) {
atom_x(i) += xprd;
} else if(atom_x(i) >= xprd) {
atom_x(i) -= xprd;
}
if(atom_y(i) < 0.0) {
atom_y(i) += yprd;
} else if(atom_y(i) >= yprd) {
atom_y(i) -= yprd;
}
if(atom_z(i) < 0.0) {
atom_z(i) += zprd;
} else if(atom_z(i) >= zprd) {
atom_z(i) -= zprd;
}
}
}
/* setup periodic boundary conditions by
* defining ghost atoms around domain
* only creates mapping and coordinate corrections
* that are then enforced in updatePbc */
#define ADDGHOST(dx,dy,dz) \
Nghost++; \
BorderMap[Nghost] = i; \
PBCx[Nghost] = dx; \
PBCy[Nghost] = dy; \
PBCz[Nghost] = dz;
void setupPbc(Atom *atom, Parameter *param)
{
MD_FLOAT xprd = param->xprd;
MD_FLOAT yprd = param->yprd;
MD_FLOAT zprd = param->zprd;
MD_FLOAT Cutneigh = param->cutneigh;
int Nghost = -1;
for(int i = 0; i < atom->Nlocal; i++) {
if (atom->Nlocal + Nghost + 7 >= atom->Nmax) {
growAtom(atom);
}
if (Nghost + 7 >= NmaxGhost) {
growPbc();
}
MD_FLOAT x = atom_x(i);
MD_FLOAT y = atom_y(i);
MD_FLOAT z = atom_z(i);
/* Setup ghost atoms */
/* 6 planes */
if (x < Cutneigh) { ADDGHOST(+1,0,0); }
if (x >= (xprd-Cutneigh)) { ADDGHOST(-1,0,0); }
if (y < Cutneigh) { ADDGHOST(0,+1,0); }
if (y >= (yprd-Cutneigh)) { ADDGHOST(0,-1,0); }
if (z < Cutneigh) { ADDGHOST(0,0,+1); }
if (z >= (zprd-Cutneigh)) { ADDGHOST(0,0,-1); }
/* 8 corners */
if (x < Cutneigh && y < Cutneigh && z < Cutneigh) { ADDGHOST(+1,+1,+1); }
if (x < Cutneigh && y >= (yprd-Cutneigh) && z < Cutneigh) { ADDGHOST(+1,-1,+1); }
if (x < Cutneigh && y >= Cutneigh && z >= (zprd-Cutneigh)) { ADDGHOST(+1,+1,-1); }
if (x < Cutneigh && y >= (yprd-Cutneigh) && z >= (zprd-Cutneigh)) { ADDGHOST(+1,-1,-1); }
if (x >= (xprd-Cutneigh) && y < Cutneigh && z < Cutneigh) { ADDGHOST(-1,+1,+1); }
if (x >= (xprd-Cutneigh) && y >= (yprd-Cutneigh) && z < Cutneigh) { ADDGHOST(-1,-1,+1); }
if (x >= (xprd-Cutneigh) && y < Cutneigh && z >= (zprd-Cutneigh)) { ADDGHOST(-1,+1,-1); }
if (x >= (xprd-Cutneigh) && y >= (yprd-Cutneigh) && z >= (zprd-Cutneigh)) { ADDGHOST(-1,-1,-1); }
/* 12 edges */
if (x < Cutneigh && z < Cutneigh) { ADDGHOST(+1,0,+1); }
if (x < Cutneigh && z >= (zprd-Cutneigh)) { ADDGHOST(+1,0,-1); }
if (x >= (xprd-Cutneigh) && z < Cutneigh) { ADDGHOST(-1,0,+1); }
if (x >= (xprd-Cutneigh) && z >= (zprd-Cutneigh)) { ADDGHOST(-1,0,-1); }
if (y < Cutneigh && z < Cutneigh) { ADDGHOST(0,+1,+1); }
if (y < Cutneigh && z >= (zprd-Cutneigh)) { ADDGHOST(0,+1,-1); }
if (y >= (yprd-Cutneigh) && z < Cutneigh) { ADDGHOST(0,-1,+1); }
if (y >= (yprd-Cutneigh) && z >= (zprd-Cutneigh)) { ADDGHOST(0,-1,-1); }
if (y < Cutneigh && x < Cutneigh) { ADDGHOST(+1,+1,0); }
if (y < Cutneigh && x >= (xprd-Cutneigh)) { ADDGHOST(-1,+1,0); }
if (y >= (yprd-Cutneigh) && x < Cutneigh) { ADDGHOST(+1,-1,0); }
if (y >= (yprd-Cutneigh) && x >= (xprd-Cutneigh)) { ADDGHOST(-1,-1,0); }
}
// increase by one to make it the ghost atom count
atom->Nghost = Nghost + 1;
}
/* internal subroutines */
void growPbc()
{
int nold = NmaxGhost;
NmaxGhost += DELTA;
BorderMap = (int*) reallocate(BorderMap, ALIGNMENT, NmaxGhost * sizeof(int), nold * sizeof(int));
PBCx = (int*) reallocate(PBCx, ALIGNMENT, NmaxGhost * sizeof(int), nold * sizeof(int));
PBCy = (int*) reallocate(PBCy, ALIGNMENT, NmaxGhost * sizeof(int), nold * sizeof(int));
PBCz = (int*) reallocate(PBCz, ALIGNMENT, NmaxGhost * sizeof(int), nold * sizeof(int));
}