FillEdges map builder, to fill walkable edges with overmap transition

src/map_builders/fill_edges.rs

@@ -1,8 +1,10 @@
 use super::{ BuilderMap, MetaMapBuilder, TileType };
+use crate::tile_walkable;
 use rltk::RandomNumberGenerator;
 
 pub struct FillEdges {
     fill_with: TileType,
+    only_walkable: bool,
 }
 
 impl MetaMapBuilder for FillEdges {
@@ -15,21 +17,32 @@ impl MetaMapBuilder for FillEdges {
 impl FillEdges {
     #[allow(dead_code)]
     pub fn wall() -> Box<FillEdges> {
-        return Box::new(FillEdges { fill_with: TileType::Wall });
+        return Box::new(FillEdges { fill_with: TileType::Wall, only_walkable: false });
+    }
+    pub fn overmap_transition(id: i32) -> Box<FillEdges> {
+        return Box::new(FillEdges { fill_with: TileType::ToOvermap(id), only_walkable: true });
     }
 
     fn fill_edges(&mut self, _rng: &mut RandomNumberGenerator, build_data: &mut BuilderMap) {
+        // Get map edges as possible points to fill
+        let mut possible_idxs: Vec<usize> = Vec::new();
         for x in 0..build_data.map.width {
             let mut idx = build_data.map.xy_idx(x, 0);
-            build_data.map.tiles[idx] = self.fill_with;
+            possible_idxs.push(idx);
             idx = build_data.map.xy_idx(x, build_data.map.height - 1);
-            build_data.map.tiles[idx] = self.fill_with;
+            possible_idxs.push(idx);
         }
         for y in 0..build_data.map.height {
             let mut idx = build_data.map.xy_idx(0, y);
-            build_data.map.tiles[idx] = self.fill_with;
+            possible_idxs.push(idx);
             idx = build_data.map.xy_idx(build_data.map.width - 1, y);
-            build_data.map.tiles[idx] = self.fill_with;
+            possible_idxs.push(idx);
+        }
+        // For every possible point, first check if we only want to fill walkable tiles (and if its walkable if so)
+        for idx in possible_idxs {
+            if !self.only_walkable || tile_walkable(build_data.map.tiles[idx]) {
+                build_data.map.tiles[idx] = self.fill_with;
+            }
         }
     }
 }

src/map_builders/town.rs

@@ -1,4 +1,4 @@
-use super::{ BuilderChain, BuilderMap, InitialMapBuilder, Position, TileType };
+use super::{ BuilderChain, BuilderMap, InitialMapBuilder, Position, TileType, FillEdges };
 use std::collections::HashSet;
 use crate::data::names::*;
 
@@ -21,6 +21,7 @@ pub fn town_builder(
         initial_player_level
     );
     chain.start_with(TownBuilder::new());
+    chain.with(FillEdges::overmap_transition(new_id));
 
     return chain;
 }
@@ -74,8 +75,6 @@ impl TownBuilder {
             x: build_data.width - 2,
             y: wall_gap_y,
         });
-        let overmap_entrance = build_data.map.xy_idx(build_data.width - 2, wall_gap_y);
-        build_data.map.tiles[overmap_entrance] = TileType::ToOvermap(build_data.map.id);
 
         build_data.take_snapshot();
     }