Complete chapter 2.8

src/components.rs

@@ -13,6 +13,7 @@ pub struct Renderable {
     pub glyph: rltk::FontCharType,
     pub fg: RGB,
     pub bg: RGB,
+    pub render_order: i32,
 }
 
 #[derive(Component, Debug)]

src/main.rs

@@ -157,7 +157,9 @@ impl GameState for State {
         let renderables = self.ecs.read_storage::<Renderable>();
         let map = self.ecs.fetch::<Map>();
 
-        for (pos, render) in (&positions, &renderables).join() {
+        let mut data = (&positions, &renderables).join().collect::<Vec<_>>();
+        data.sort_by(|&a, &b| b.1.render_order.cmp(&a.1.render_order));
+        for (pos, render) in data.iter() {
             let idx = map.xy_idx(pos.x, pos.y);
 
             if map.visible_tiles[idx] {

src/spawner.rs

@@ -19,6 +19,7 @@ pub fn player(ecs: &mut World, player_x: i32, player_y: i32) -> Entity {
             glyph: rltk::to_cp437('@'),
             fg: RGB::named(rltk::YELLOW),
             bg: RGB::named(rltk::BLACK),
+            render_order: 0,
         })
         .with(Player {})
         .with(Viewshed {
@@ -68,6 +69,7 @@ fn monster<S: ToString>(ecs: &mut World, x: i32, y: i32, glyph: rltk::FontCharTy
             glyph,
             fg: RGB::named(rltk::RED),
             bg: RGB::named(rltk::BLACK),
+            render_order: 1,
         })
         .with(Viewshed {
             visible_tiles: Vec::new(),
@@ -152,6 +154,7 @@ fn health_potion(ecs: &mut World, x: i32, y: i32) {
             glyph: rltk::to_cp437('¡'),
             fg: RGB::named(rltk::MAGENTA),
             bg: RGB::named(rltk::BLACK),
+            render_order: 2,
         })
         .with(Name {
             name: "Health Potion".to_string(),