atomises rooms and corridors

- room sorter
- rounding room corners
- dogleg and bsp corridors
- room exploder

src/map_builders/room_exploder.rs

@@ -0,0 +1,82 @@
+use super::{paint, BuilderMap, MetaMapBuilder, Rect, Symmetry, TileType};
+use rltk::RandomNumberGenerator;
+
+pub struct RoomExploder {}
+
+impl MetaMapBuilder for RoomExploder {
+    fn build_map(&mut self, rng: &mut rltk::RandomNumberGenerator, build_data: &mut BuilderMap) {
+        self.build(rng, build_data);
+    }
+}
+
+impl RoomExploder {
+    #[allow(dead_code)]
+    pub fn new() -> Box<RoomExploder> {
+        return Box::new(RoomExploder {});
+    }
+
+    fn build(&mut self, rng: &mut RandomNumberGenerator, build_data: &mut BuilderMap) {
+        let rooms: Vec<Rect>;
+        if let Some(rooms_builder) = &build_data.rooms {
+            rooms = rooms_builder.clone();
+        } else {
+            panic!("RoomExploder requires a builder with rooms.");
+        }
+        for room in rooms.iter() {
+            let start = room.centre();
+            let n_diggers = rng.roll_dice(1, 20) - 5;
+            if n_diggers > 0 {
+                for _i in 0..n_diggers {
+                    let mut drunk_x = start.0;
+                    let mut drunk_y = start.1;
+                    let mut drunk_life = 20;
+                    let mut did_something = false;
+
+                    while drunk_life > 0 {
+                        let drunk_idx = build_data.map.xy_idx(drunk_x, drunk_y);
+                        if build_data.map.tiles[drunk_idx] == TileType::Wall {
+                            did_something = true;
+                        }
+                        paint(&mut build_data.map, Symmetry::None, 1, drunk_x, drunk_y);
+                        build_data.map.tiles[drunk_idx] = TileType::DownStair;
+
+                        let stagger_direction = rng.roll_dice(1, 4);
+                        match stagger_direction {
+                            1 => {
+                                if drunk_x > 2 {
+                                    drunk_x -= 1;
+                                }
+                            }
+                            2 => {
+                                if drunk_x < build_data.map.width - 2 {
+                                    drunk_x += 1;
+                                }
+                            }
+                            3 => {
+                                if drunk_y > 2 {
+                                    drunk_y -= 1;
+                                }
+                            }
+                            _ => {
+                                if drunk_y < build_data.map.height - 2 {
+                                    drunk_y += 1;
+                                }
+                            }
+                        }
+
+                        drunk_life -= 1;
+                    }
+                    if did_something {
+                        build_data.take_snapshot();
+                    }
+
+                    for t in build_data.map.tiles.iter_mut() {
+                        if *t == TileType::DownStair {
+                            *t = TileType::Floor;
+                        }
+                    }
+                }
+            }
+        }
+    }
+}