Adds debug drawing system for the tile grid

src/level.rs

@@ -14,6 +14,30 @@ pub struct LevelPlugin;
 impl Plugin for LevelPlugin {
     fn build(&self, app: &mut App) {
         app.add_systems(OnEnter(AppState::InGame), generate_level);
+
+        #[cfg(debug_assertions)]
+        {
+            app.add_systems(Update, debug_draw_tiles.after(generate_level));
+        }
+    }
+}
+
+#[cfg(debug_assertions)]
+fn debug_draw_tiles(
+    query: Query<(&Transform, Option<&BorderTile>), With<Tile>>,
+    mut gizmos: Gizmos,
+) {
+    for (transform, border_tile) in &query {
+        gizmos.rect_2d(
+            transform.translation.truncate(),
+            0.,
+            TILE_SIZE,
+            if border_tile.is_some() {
+                Color::BLACK
+            } else {
+                Color::FUCHSIA
+            },
+        );
     }
 }