void JelloMesh::GetCell(int idx, int& i, int &j, int& k) const
{
float rows = m_rows+1;
float cols = m_cols+1;
float stacks = m_stacks+1;
// derived from idx = cols*(rows*k + i) + j
float tmp = FLOOR(idx/cols);
j = (int) ROUND(cols*(FRACT(idx/cols)));
i = (int) ROUND(rows*(FRACT(tmp/rows)));
k = (int) FLOOR(tmp/rows);
}
void Init_Decomposition()
{
long factors[MAX_NUMPROC];
double processors,newfactor;
long i,sq,cu,maxcu,count;
/* figure out what to divide dimensions of image and volume by to */
/* partition data and computation to processors */
if (num_nodes == 1) {
image_section[X] = 1;
image_section[Y] = 1;
voxel_section[X] = 1;
voxel_section[Y] = 1;
voxel_section[Z] = 1;
}
else {
count = 1;
processors = (double)num_nodes;
sq = (long)sqrt(processors);
cu = (long)pow(processors,1.0/3.0);
factors[0] = 1;
for (i=2; i<sq; i++) {
if (FRACT(processors/(double)i) == 0.0) {
factors[count++] = i;
if (i <= cu) {
maxcu = i;
newfactor = (double)(num_nodes/i);
}
}
}
count--;
image_section[X] = factors[count];
image_section[Y] = num_nodes/factors[count];
sq = (long)sqrt(newfactor);
count = 1;
for (i=2; i<sq; i++) {
if (FRACT(newfactor/(double)i) == 0.0)
factors[count++] = i;
}
count--;
voxel_section[X] = MIN(factors[count],maxcu);
voxel_section[Y] = MAX(factors[count],maxcu);
voxel_section[Z] = (long)newfactor/factors[count];
}
}
