472     vector curpos, tmax, tdelta, pdeltaX, pdeltaY, pdeltaZ, nXp, nYp, nZp;  in grid_intersect()  local
493         tdelta.x = 0.0;  in grid_intersect()
499         tdelta.x = g->voxsize.x / -ry->d.x;  in grid_intersect()
504         tdelta.x = g->voxsize.x / ry->d.x;  in grid_intersect()
512         tdelta.y = 0.0;  in grid_intersect()
518         tdelta.y = g->voxsize.y / -ry->d.y;  in grid_intersect()
523         tdelta.y = g->voxsize.y / ry->d.y;  in grid_intersect()
531         tdelta.z = 0.0;  in grid_intersect()
537         tdelta.z = g->voxsize.z / -ry->d.z;  in grid_intersect()
542         tdelta.z = g->voxsize.z / ry->d.z;  in grid_intersect()
548     VScale(&pdeltaX, tdelta.x);  in grid_intersect()
550     VScale(&pdeltaY, tdelta.y);  in grid_intersect()
552     VScale(&pdeltaZ, tdelta.z);  in grid_intersect()
573             tmax.x += tdelta.x;  in grid_intersect()
592             tmax.z += tdelta.z;  in grid_intersect()
611             tmax.y += tdelta.y;  in grid_intersect()