/*! The buffer for the neighbour list has a finite length MAX_NGB. For a large
* search region, this buffer can get full, in which case this routine can be
* called to eliminate some of the superfluous particles in the "corners" of
* the search box - only the ones in the inscribed sphere need to be kept.
*/
int ngb_clear_buf(FLOAT searchcenter[3], FLOAT hsml, int numngb)
{
int i, p;
FLOAT dx, dy, dz, r2;
#ifdef PERIODIC
double xtmp;
#endif
for(i = 0; i < numngb; i++)
{
p = Ngblist[i];
#ifdef PERIODIC
dx = NGB_PERIODIC_X(P[p].Pos[0] - searchcenter[0]);
dy = NGB_PERIODIC_Y(P[p].Pos[1] - searchcenter[1]);
dz = NGB_PERIODIC_Z(P[p].Pos[2] - searchcenter[2]);
#else
dx = P[p].Pos[0] - searchcenter[0];
dy = P[p].Pos[1] - searchcenter[1];
dz = P[p].Pos[2] - searchcenter[2];
#endif
r2 = dx * dx + dy * dy + dz * dz;
if(r2 > hsml * hsml)
{
Ngblist[i] = Ngblist[numngb - 1];
i--;
numngb--;
}
}
return numngb;
}
/*! This routine finds all neighbours `j' that can interact with the
* particle `i' in the communication buffer.
*
* Note that an interaction can take place if
* \f$ r_{ij} < h_i \f$ OR if \f$ r_{ij} < h_j \f$.
*
* In the range-search this is taken into account, i.e. it is guaranteed that
* all particles are found that fulfil this condition, including the (more
* difficult) second part of it. For this purpose, each node knows the
* maximum h occuring among the particles it represents.
*/
int ngb_treefind_pairs(FLOAT searchcenter[3], FLOAT hsml, int *startnode)
{
int k, no, p, numngb;
FLOAT hdiff;
FLOAT searchmin[3], searchmax[3];
struct NODE *this;
#ifdef PERIODIC
double xtmp;
#endif
for(k = 0; k < 3; k++) /* cube-box window */
{
searchmin[k] = searchcenter[k] - hsml;
searchmax[k] = searchcenter[k] + hsml;
}
numngb = 0;
no = *startnode;
while(no >= 0)
{
if(no < All.MaxPart) /* single particle */
{
p = no;
no = Nextnode[no];
if(P[p].Type > 0)
continue;
hdiff = SphP[p].Hsml - hsml;
if(hdiff < 0)
hdiff = 0;
#ifdef PERIODIC
if(NGB_PERIODIC_X(P[p].Pos[0] - searchcenter[0]) < (-hsml - hdiff))
continue;
if(NGB_PERIODIC_X(P[p].Pos[0] - searchcenter[0]) > (hsml + hdiff))
continue;
if(NGB_PERIODIC_Y(P[p].Pos[1] - searchcenter[1]) < (-hsml - hdiff))
continue;
if(NGB_PERIODIC_Y(P[p].Pos[1] - searchcenter[1]) > (hsml + hdiff))
continue;
if(NGB_PERIODIC_Z(P[p].Pos[2] - searchcenter[2]) < (-hsml - hdiff))
continue;
if(NGB_PERIODIC_Z(P[p].Pos[2] - searchcenter[2]) > (hsml + hdiff))
continue;
#else
if(P[p].Pos[0] < (searchmin[0] - hdiff))
continue;
if(P[p].Pos[0] > (searchmax[0] + hdiff))
continue;
if(P[p].Pos[1] < (searchmin[1] - hdiff))
continue;
if(P[p].Pos[1] > (searchmax[1] + hdiff))
continue;
if(P[p].Pos[2] < (searchmin[2] - hdiff))
continue;
if(P[p].Pos[2] > (searchmax[2] + hdiff))
continue;
#endif
Ngblist[numngb++] = p;
if(numngb == MAX_NGB)
{
printf
("ThisTask=%d: Need to do a second neighbour loop in hydro-force for (%g|%g|%g) hsml=%g no=%d\n",
ThisTask, searchcenter[0], searchcenter[1], searchcenter[2], hsml, no);
*startnode = no;
return numngb;
}
}
else
{
if(no >= All.MaxPart + MaxNodes) /* pseudo particle */
{
Exportflag[DomainTask[no - (All.MaxPart + MaxNodes)]] = 1;
no = Nextnode[no - MaxNodes];
continue;
}
this = &Nodes[no];
hdiff = Extnodes[no].hmax - hsml;
if(hdiff < 0)
hdiff = 0;
no = this->u.d.sibling; /* in case the node can be discarded */
#ifdef PERIODIC
if((NGB_PERIODIC_X(this->center[0] - searchcenter[0]) + 0.5 * this->len) < (-hsml - hdiff))
continue;
if((NGB_PERIODIC_X(this->center[0] - searchcenter[0]) - 0.5 * this->len) > (hsml + hdiff))
continue;
if((NGB_PERIODIC_Y(this->center[1] - searchcenter[1]) + 0.5 * this->len) < (-hsml - hdiff))
continue;
if((NGB_PERIODIC_Y(this->center[1] - searchcenter[1]) - 0.5 * this->len) > (hsml + hdiff))
continue;
if((NGB_PERIODIC_Z(this->center[2] - searchcenter[2]) + 0.5 * this->len) < (-hsml - hdiff))
continue;
if((NGB_PERIODIC_Z(this->center[2] - searchcenter[2]) - 0.5 * this->len) > (hsml + hdiff))
continue;
#else
if((this->center[0] + 0.5 * this->len) < (searchmin[0] - hdiff))
continue;
if((this->center[0] - 0.5 * this->len) > (searchmax[0] + hdiff))
continue;
if((this->center[1] + 0.5 * this->len) < (searchmin[1] - hdiff))
continue;
if((this->center[1] - 0.5 * this->len) > (searchmax[1] + hdiff))
continue;
if((this->center[2] + 0.5 * this->len) < (searchmin[2] - hdiff))
continue;
if((this->center[2] - 0.5 * this->len) > (searchmax[2] + hdiff))
continue;
#endif
no = this->u.d.nextnode; /* ok, we need to open the node */
}
}
*startnode = -1;
return numngb;
}
/*! This function returns neighbours with distance <= hsml and returns them in
* Ngblist. Actually, particles in a box of half side length hsml are
* returned, i.e. the reduction to a sphere still needs to be done in the
* calling routine.
*/
int ngb_treefind_variable(FLOAT searchcenter[3], FLOAT hsml, int *startnode, int target)
{
int k, numngb;
int no, p;
struct NODE *this;
FLOAT searchmin[3], searchmax[3];
#ifdef PERIODIC
double xtmp;
#endif
int tid = 0;
#ifdef _OPENMP
tid = omp_get_thread_num();
#endif
for(k = 0; k < 3; k++) /* cube-box window */
{
searchmin[k] = searchcenter[k] - hsml;
searchmax[k] = searchcenter[k] + hsml;
}
numngb = 0;
no = *startnode;
while(no >= 0)
{
if(no < All.MaxPart) /* single particle */
{
p = no;
no = Nextnode[no];
if(P[p].Type > 0)
continue;
#ifdef PERIODIC
if(NGB_PERIODIC_X(P[p].Pos[0] - searchcenter[0]) < -hsml)
continue;
if(NGB_PERIODIC_X(P[p].Pos[0] - searchcenter[0]) > hsml)
continue;
if(NGB_PERIODIC_Y(P[p].Pos[1] - searchcenter[1]) < -hsml)
continue;
if(NGB_PERIODIC_Y(P[p].Pos[1] - searchcenter[1]) > hsml)
continue;
if(NGB_PERIODIC_Z(P[p].Pos[2] - searchcenter[2]) < -hsml)
continue;
if(NGB_PERIODIC_Z(P[p].Pos[2] - searchcenter[2]) > hsml)
continue;
#else
if(P[p].Pos[0] < searchmin[0])
continue;
if(P[p].Pos[0] > searchmax[0])
continue;
if(P[p].Pos[1] < searchmin[1])
continue;
if(P[p].Pos[1] > searchmax[1])
continue;
if(P[p].Pos[2] < searchmin[2])
continue;
if(P[p].Pos[2] > searchmax[2])
continue;
#endif
#ifdef _OPENMP
Ngblist[MAX_NGB*tid+numngb++] = p;
#else
Ngblist[numngb++] = p;
#endif
if(numngb == MAX_NGB)
{
numngb = ngb_clear_buf(searchcenter, hsml, numngb);
if(numngb == MAX_NGB)
{
printf("ThisTask=%d: Need to do a second neighbour loop for (%g|%g|%g) hsml=%g no=%d\n",
ThisTask, searchcenter[0], searchcenter[1], searchcenter[2], hsml, no);
*startnode = no;
return numngb;
}
}
}
else
{
if(no >= All.MaxPart + MaxNodes) /* pseudo particle */
{
Exportflag2[target*NTask+DomainTask[no - (All.MaxPart + MaxNodes)]] = 1;
no = Nextnode[no - MaxNodes];
continue;
}
this = &Nodes[no];
no = this->u.d.sibling; /* in case the node can be discarded */
#ifdef PERIODIC
if((NGB_PERIODIC_X(this->center[0] - searchcenter[0]) + 0.5 * this->len) < -hsml)
continue;
if((NGB_PERIODIC_X(this->center[0] - searchcenter[0]) - 0.5 * this->len) > hsml)
continue;
if((NGB_PERIODIC_Y(this->center[1] - searchcenter[1]) + 0.5 * this->len) < -hsml)
continue;
if((NGB_PERIODIC_Y(this->center[1] - searchcenter[1]) - 0.5 * this->len) > hsml)
continue;
if((NGB_PERIODIC_Z(this->center[2] - searchcenter[2]) + 0.5 * this->len) < -hsml)
continue;
if((NGB_PERIODIC_Z(this->center[2] - searchcenter[2]) - 0.5 * this->len) > hsml)
continue;
#else
if((this->center[0] + 0.5 * this->len) < (searchmin[0]))
continue;
if((this->center[0] - 0.5 * this->len) > (searchmax[0]))
continue;
if((this->center[1] + 0.5 * this->len) < (searchmin[1]))
continue;
if((this->center[1] - 0.5 * this->len) > (searchmax[1]))
continue;
if((this->center[2] + 0.5 * this->len) < (searchmin[2]))
continue;
if((this->center[2] - 0.5 * this->len) > (searchmax[2]))
continue;
#endif
no = this->u.d.nextnode; /* ok, we need to open the node */
}
}
*startnode = -1;
return numngb;
}
