Refactor entity spawning into its own module

src/gui.rs

@@ -88,7 +88,13 @@ fn draw_tooltips(ecs: &World, ctx: &mut Rltk) {
             let mut y = mouse_pos.1;
 
             for s in tooltip.iter() {
-                ctx.print_color(left_x, y, RGB::named(rltk::WHITE), RGB::named(rltk::GREY), s);
+                ctx.print_color(
+                    left_x,
+                    y,
+                    RGB::named(rltk::WHITE),
+                    RGB::named(rltk::GREY),
+                    s,
+                );
                 let padding = (width - s.len() as i32) - 1;
                 for i in 0..padding {
                     ctx.print_color(

src/main.rs

@@ -1,4 +1,4 @@
-use rltk::{GameState, Point, Rltk, RGB};
+use rltk::{GameState, Point, Rltk};
 use specs::prelude::*;
 
 mod components;
@@ -22,6 +22,7 @@ use damage_system::DamageSystem;
 mod gamelog;
 mod gui;
 pub use gamelog::GameLog;
+mod spawner;
 
 pub const MAP_SIZE: usize = 80 * 50;
 
@@ -133,78 +134,11 @@ fn main() -> rltk::BError {
     let map: Map = Map::new_map_rooms_and_corridors();
     let (player_x, player_y) = map.rooms[0].center();
 
-    let player_entity = gs
+    let player_entity = spawner::player(&mut gs.ecs, player_x, player_y);
-        .ecs
-        .create_entity()
-        .with(Position {
-            x: player_x,
-            y: player_y,
-        })
-        .with(Renderable {
-            glyph: rltk::to_cp437('@'),
-            fg: RGB::named(rltk::YELLOW),
-            bg: RGB::named(rltk::BLACK),
-        })
-        .with(Player {})
-        .with(Viewshed {
-            visible_tiles: Vec::new(),
-            range: 8,
-            dirty: true,
-        })
-        .with(Name {
-            name: "Player".to_string(),
-        })
-        .with(CombatStats {
-            max_hp: 30,
-            hp: 30,
-            defense: 2,
-            power: 5,
-        })
-        .build();
 
-    let mut rng = rltk::RandomNumberGenerator::new();
+    gs.ecs.insert(rltk::RandomNumberGenerator::new());
-    for (i, room) in map.rooms.iter().skip(1).enumerate() {
+    for room in map.rooms.iter().skip(1) {
-        let (x, y) = room.center();
+        spawner::spawn_room(&mut gs.ecs, room);
-
-        let glyph: rltk::FontCharType;
-        let name: String;
-        let roll = rng.roll_dice(1, 2);
-        match roll {
-            1 => {
-                glyph = rltk::to_cp437('g');
-                name = "Goblin".to_string();
-            }
-            _ => {
-                glyph = rltk::to_cp437('o');
-                name = "Orc".to_string();
-            }
-        }
-
-        gs.ecs
-            .create_entity()
-            .with(Position { x, y })
-            .with(Renderable {
-                glyph,
-                fg: RGB::named(rltk::RED),
-                bg: RGB::named(rltk::BLACK),
-            })
-            .with(Viewshed {
-                visible_tiles: Vec::new(),
-                range: 8,
-                dirty: true,
-            })
-            .with(Monster {})
-            .with(Name {
-                name: format!("{} #{}", &name, i),
-            })
-            .with(BlocksTile {})
-            .with(CombatStats {
-                max_hp: 16,
-                hp: 16,
-                defense: 1,
-                power: 4,
-            })
-            .build();
     }
 
     gs.ecs.insert(map);

src/map.rs

@@ -3,9 +3,9 @@ use rltk::{Algorithm2D, BaseMap, Point, RandomNumberGenerator, Rltk, SmallVec, R
 use specs::prelude::*;
 use std::cmp::{max, min};
 
-const MAP_WIDTH: usize = 80;
+pub const MAP_WIDTH: usize = 80;
-const MAP_HEIGHT: usize = 43;
+pub const MAP_HEIGHT: usize = 43;
-const MAP_COUNT: usize = MAP_HEIGHT * MAP_WIDTH;
+pub const MAP_COUNT: usize = MAP_HEIGHT * MAP_WIDTH;
 
 #[derive(PartialEq, Copy, Clone)]
 pub enum TileType {

src/spawner.rs

@@ -0,0 +1,121 @@
+use crate::{
+    BlocksTile, CombatStats, Monster, Name, Player, Position, Rect, Renderable, Viewshed, MAP_WIDTH,
+};
+use rltk::{RandomNumberGenerator, RGB};
+use specs::prelude::*;
+
+const MAX_MONSTERS: i32 = 4;
+const MAX_ITEMS: i32 = 2;
+
+/// Spawns the player and returns their entity object
+pub fn player(ecs: &mut World, player_x: i32, player_y: i32) -> Entity {
+    ecs.create_entity()
+        .with(Position {
+            x: player_x,
+            y: player_y,
+        })
+        .with(Renderable {
+            glyph: rltk::to_cp437('@'),
+            fg: RGB::named(rltk::YELLOW),
+            bg: RGB::named(rltk::BLACK),
+        })
+        .with(Player {})
+        .with(Viewshed {
+            visible_tiles: Vec::new(),
+            range: 8,
+            dirty: true,
+        })
+        .with(Name {
+            name: "Player".to_string(),
+        })
+        .with(CombatStats {
+            max_hp: 30,
+            hp: 30,
+            defense: 2,
+            power: 5,
+        })
+        .build()
+}
+
+/// Spawns a random monster at a given location
+pub fn random_monster(ecs: &mut World, x: i32, y: i32) {
+    let roll: i32;
+
+    {
+        let mut rng = ecs.write_resource::<RandomNumberGenerator>();
+        roll = rng.roll_dice(1, 2);
+    }
+
+    match roll {
+        1 => orc(ecs, x, y),
+        _ => goblin(ecs, x, y),
+    }
+}
+
+fn orc(ecs: &mut World, x: i32, y: i32) {
+    monster(ecs, x, y, rltk::to_cp437('o'), "Orc");
+}
+
+fn goblin(ecs: &mut World, x: i32, y: i32) {
+    monster(ecs, x, y, rltk::to_cp437('g'), "Goblin");
+}
+
+fn monster<S: ToString>(ecs: &mut World, x: i32, y: i32, glyph: rltk::FontCharType, name: S) {
+    ecs.create_entity()
+        .with(Position { x, y })
+        .with(Renderable {
+            glyph,
+            fg: RGB::named(rltk::RED),
+            bg: RGB::named(rltk::BLACK),
+        })
+        .with(Viewshed {
+            visible_tiles: Vec::new(),
+            range: 8,
+            dirty: true,
+        })
+        .with(Monster {})
+        .with(Name {
+            name: name.to_string(),
+        })
+        .with(BlocksTile {})
+        .with(CombatStats {
+            max_hp: 16,
+            hp: 16,
+            defense: 1,
+            power: 4,
+        })
+        .build();
+}
+
+/// fills a room with stuff!
+pub fn spawn_room(ecs: &mut World, room: &Rect) {
+    let mut monster_spawn_points: Vec<usize> = Vec::new();
+
+    // Scope to keep the borrow checker happy
+    {
+        let mut rng = ecs.write_resource::<RandomNumberGenerator>();
+        let num_monsters = rng.roll_dice(1, MAX_MONSTERS + 2) - 3;
+
+        for _i in 0..num_monsters {
+            let mut added = false;
+            while !added {
+                let x = (room.x1 + rng.roll_dice(1, i32::abs(room.x2 - room.x1))) as usize;
+                let y = (room.y1 + rng.roll_dice(1, i32::abs(room.y2 - room.y1))) as usize;
+                let idx = (y * MAP_WIDTH) + x;
+
+                if !monster_spawn_points.contains(&idx) {
+                    monster_spawn_points.push(idx);
+                    added = true;
+                }
+            }
+        }
+    }
+
+    // Actually spawn the monsters
+    for idx in monster_spawn_points.iter() {
+        let x = *idx % MAP_WIDTH;
+        let y = *idx / MAP_WIDTH;
+
+        random_monster(ecs, x as i32, y as i32);
+    }
+}