Interval stencil_extent = st->is_empty (Y_AXIS) ? Interval (0, 0)
: st->extent (Y_AXIS);
shape_ = Line_shape (stencil_extent, stencil_extent); // pretend it goes all the way across
Interval stencil_extent = st->is_empty (Y_AXIS) ? Interval (0, 0)
: st->extent (Y_AXIS);
shape_ = Line_shape (stencil_extent, stencil_extent); // pretend it goes all the way across