Refactor map generation to return original player position

src/main.rs

@@ -386,11 +386,15 @@ impl State {
         // Build a new map and place the player
         let worldmap;
         let current_depth;
+        let player_start;
         {
             let mut worldmap_resource = self.ecs.write_resource::<Map>();
             current_depth = worldmap_resource.depth;
 
-            *worldmap_resource = map_builders::build_random_map(current_depth + 1);
+            let (newmap, start) = map_builders::build_random_map(current_depth + 1);
+
+            *worldmap_resource = newmap;
+            player_start = start;
             worldmap = worldmap_resource.clone();
         }
 
@@ -400,7 +404,7 @@ impl State {
         }
 
         // Place the player and update resources
-        let (player_x, player_y) = worldmap.rooms[0].center();
+        let (player_x, player_y) = (player_start.x, player_start.y);
         let mut player_position = self.ecs.write_resource::<Point>();
         *player_position = Point::new(player_x, player_y);
         let mut position_components = self.ecs.write_storage::<Position>();
@@ -442,9 +446,13 @@ impl State {
 
         // Build a new map and place the player
         let worldmap;
+        let player_start;
         {
             let mut worldmap_resource = self.ecs.write_resource::<Map>();
-            *worldmap_resource = map_builders::build_random_map(1);
+            let (newmap, start) = map_builders::build_random_map(1);
+
+            *worldmap_resource = newmap;
+            player_start = start;
             worldmap = worldmap_resource.clone();
         }
 
@@ -454,7 +462,7 @@ impl State {
         }
 
         // Place the player and update resources
-        let (player_x, player_y) = worldmap.rooms[0].center();
+        let (player_x, player_y) = (player_start.x, player_start.y);
         let player_entity = spawner::player(&mut self.ecs, player_x, player_y);
         let mut player_position = self.ecs.write_resource::<Point>();
         *player_position = Point::new(player_x, player_y);
@@ -526,8 +534,8 @@ fn main() -> rltk::BError {
 
     gs.ecs.insert(SimpleMarkerAllocator::<SerializeMe>::new());
 
-    let map = map_builders::build_random_map(1);
-    let (player_x, player_y) = map.rooms[0].center();
+    let (map, player_start) = map_builders::build_random_map(1);
+    let (player_x, player_y) = (player_start.x, player_start.y);
 
     let player_entity = spawner::player(&mut gs.ecs, player_x, player_y);
 

src/map_builders/mod.rs

@@ -1,14 +1,14 @@
 mod common;
 mod simple_map;
 
-use crate::Map;
+use crate::{Map, Position};
 use common::*;
 use simple_map::SimpleMapBuilder;
 
 trait MapBuilder {
-    fn build(new_depth: i32) -> Map;
+    fn build(new_depth: i32) -> (Map, Position);
 }
 
-pub fn build_random_map(new_depth: i32) -> Map {
+pub fn build_random_map(new_depth: i32) -> (Map, Position) {
     SimpleMapBuilder::build(new_depth)
 }

src/map_builders/simple_map.rs

@@ -1,21 +1,20 @@
 use super::{apply_horizontal_tunnel, apply_room_to_map, apply_vertical_tunnel, MapBuilder};
-use crate::{Map, Rect, TileType};
+use crate::{Map, Position, Rect, TileType};
 use rltk::RandomNumberGenerator;
 
 pub struct SimpleMapBuilder {}
 
 impl MapBuilder for SimpleMapBuilder {
-    fn build(new_depth: i32) -> Map {
+    fn build(new_depth: i32) -> (Map, Position) {
         let mut map = Map::new(new_depth);
+        let playerpos = SimpleMapBuilder::rooms_and_corridors(&mut map);
 
-        SimpleMapBuilder::rooms_and_corridors(&mut map);
-
-        map
+        (map, playerpos)
     }
 }
 
 impl SimpleMapBuilder {
-    fn rooms_and_corridors(map: &mut Map) {
+    fn rooms_and_corridors(map: &mut Map) -> Position {
         const MAX_ROOMS: i32 = 30;
         const MIN_SIZE: i32 = 6;
         const MAX_SIZE: i32 = 10;
@@ -60,5 +59,12 @@ impl SimpleMapBuilder {
         let stairs_position = map.rooms[map.rooms.len() - 1].center();
         let stairs_idx = map.xy_idx(stairs_position.0, stairs_position.1);
         map.tiles[stairs_idx] = TileType::DownStairs;
+
+        let start_pos = map.rooms[0].center();
+
+        Position {
+            x: start_pos.0,
+            y: start_pos.1,
+        }
     }
 }