fn build_wall_grid(walls: &mut Vec<WallRegion>, lvlsize: &Dimension<usize>) -> Grid<Vec<Rc<WallEdge>>> {
let size = dimen!(lvlsize.width / 20, lvlsize.height / 20); // TODO: make sure all walls fit within the grid bounds
let cs = point!(lvlsize.width / size.width, lvlsize.height / size.height);
fn build_wall_grid(walls: &mut Vec<WallRegion>, lvlsize: &Dimension<usize>) -> Grid<Vec<Rc<WallEdge>>> {
let size = dimen!(lvlsize.width / 20, lvlsize.height / 20); // TODO: make sure all walls fit within the grid bounds
let cs = point!(lvlsize.width / size.width, lvlsize.height / size.height);