DECLARE_CCTK_PARAMETERS;

  const array<bool, dim> per{
      periodic || periodic_x,
      periodic || periodic_y,
      periodic || periodic_z,
  };

      bbox[2 * d + f] = vbx[orient(d, f)] == domain[orient(d, f)];

      bbox[2 * d + f] = vbx[orient(d, f)] == domain[orient(d, f)] && !per[d];