Delete smaller wall regions and leave only one room

diff --git a/src/core/game.rs b/src/core/game.rs
index 1bdaa8d..3e017b1 100644 (file)
--- a/src/core/game.rs
+++ b/src/core/game.rs
@@ -57,6 +57,9 @@ impl AppState for GameState {
            Event::KeyDown { keycode: Some(Keycode::KpMinus), .. } => {
                self.world.level.decrease_iteration();
            }
+           Event::KeyDown { keycode: Some(Keycode::KpEnter), .. } => {
+               self.world.level.filter_regions();
+           }
            _ => {}
        }
     }

diff --git a/src/core/level.rs b/src/core/level.rs
index bab89e0..65e74ff 100644 (file)
--- a/src/core/level.rs
+++ b/src/core/level.rs
@@ -34,6 +34,10 @@ impl Level {
        println!("iterate {} time(s)", self.iterations);
     }
 
+    pub fn filter_regions(&mut self) {
+       self.grid.filter_regions();
+    }
+
     pub fn render(&mut self, renderer: &mut Renderer, _sprites: &SpriteManager) {
        let w = renderer.viewport().0 as i32;
 
@@ -189,4 +193,77 @@ impl Grid {
            cells
        }
     }
+
+    fn find_regions(&self) -> Vec<Region> {
+       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 &region.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)>,
 }