+
+ fn find_regions(&self) -> Vec<Region> {
+ time_scope!("finding all regions");
+ let mut regions = vec!();
+ let mut marked = vec!(vec!(false; self.height); self.width);
+ for x in 0..self.width {
+ for y in 0..self.height {
+ if !marked[x][y] {
+ regions.push(self.get_region_at_point(x, y, &mut marked));
+ }
+ }
+ }
+ regions
+ }
+
+ fn get_region_at_point(&self, x: usize, y: usize, marked: &mut Vec<Vec<bool>>) -> Region {
+ let value = self.cells[x][y];
+ let mut cells = vec!();
+ let mut queue = vec!((x, y));
+ marked[x][y] = true;
+
+ while let Some(p) = queue.pop() {
+ cells.push(p);
+ for i in &[(-1, 0), (1, 0), (0, -1), (0, 1)] {
+ let ip = (p.0 as isize + i.0, p.1 as isize + i.1);
+ if ip.0 >= 0 && ip.0 < self.width as isize && ip.1 >= 0 && ip.1 < self.height as isize {
+ let up = (ip.0 as usize, ip.1 as usize);
+ if self.cells[up.0][up.1] == value && !marked[up.0][up.1] {
+ marked[up.0][up.1] = true;
+ queue.push(up);
+ }
+ }
+ }
+ }
+
+ Region { value, cells }
+ }
+
+ fn delete_region(&mut self, region: &Region) {
+ for c in ®ion.cells {
+ self.cells[c.0][c.1] = !region.value;
+ }
+ }
+
+ pub fn filter_regions(&mut self) {
+ let min_wall_size = 0.0015;
+ println!("grid size: ({}, {}) = {} cells", self.width, self.height, self.width * self.height);
+ println!("min wall size: {}", (self.width * self.height) as f64 * min_wall_size);
+
+ // delete all smaller wall regions
+ for r in self.find_regions().iter().filter(|r| r.value) {
+ let percent = r.cells.len() as f64 / (self.width * self.height) as f64;
+ if percent < min_wall_size {
+ println!("delete wall region of size {}", r.cells.len());
+ self.delete_region(r);
+ }
+ }
+
+ // delete all rooms but the largest
+ let regions = self.find_regions(); // check again, because if a removed room contains a removed wall, the removed wall will become a room
+ let mut rooms: Vec<&Region> = regions.iter().filter(|r| !r.value).collect();
+ rooms.sort_by_key(|r| r.cells.len());
+ rooms.reverse();
+ while rooms.len() > 1 {
+ self.delete_region(rooms.pop().unwrap());
+ }
+ }
+}
+
+////////// REGION //////////////////////////////////////////////////////////////
+
+struct Region {
+ value: bool,
+ cells: Vec<(usize, usize)>,