relaod mechanic

src/heads/mod.rs

@@ -25,6 +25,8 @@ pub struct HeadState {
     pub health_max: u32,
     pub ammo: u32,
     pub ammo_max: u32,
+    pub reload_duration: f32,
+    pub last_use: f32,
 }
 
 impl HeadState {
@@ -36,6 +38,8 @@ impl HeadState {
             ammo,
             ammo_max: ammo,
             ability: HeadAbility::None,
+            reload_duration: 5.,
+            last_use: 0.,
         }
     }
 
@@ -61,12 +65,13 @@ impl ActiveHeads {
         self.heads[self.current_slot]
     }
 
-    pub fn use_ammo(&mut self) {
+    pub fn use_ammo(&mut self, time: f32) {
         let Some(head) = &mut self.heads[self.current_slot] else {
             error!("cannot use ammo of empty head");
             return;
         };
 
+        head.last_use = time;
         head.ammo = head.ammo.saturating_sub(1);
     }
 
@@ -77,6 +82,16 @@ impl ActiveHeads {
     pub fn head(&self, slot: usize) -> Option<HeadState> {
         self.heads[slot]
     }
+
+    pub fn reloading(&self) -> bool {
+        for head in self.heads {
+            if head.map(|head| head.ammo == 0).unwrap_or(false) {
+                return true;
+            }
+        }
+
+        false
+    }
 }
 
 #[derive(Event, Reflect)]
@@ -103,6 +118,7 @@ pub fn plugin(app: &mut App) {
     });
 
     app.add_systems(OnEnter(GameState::Playing), setup);
+    app.add_systems(Update, reload.run_if(in_state(GameState::Playing)));
 
     app.add_observer(on_select_active_head);
     app.add_observer(on_swap_backpack);
@@ -117,6 +133,22 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
     commands.insert_resource(HeadsImages { heads });
 }
 
+fn reload(mut active: ResMut<ActiveHeads>, time: Res<Time>) {
+    if !active.reloading() {
+        return;
+    }
+
+    for head in active.heads.iter_mut() {
+        let Some(head) = head else {
+            continue;
+        };
+
+        if !head.has_ammo() && (head.last_use + head.reload_duration <= time.elapsed_secs()) {
+            head.ammo = head.ammo_max;
+        }
+    }
+}
+
 fn on_select_active_head(
     trigger: Trigger<SelectActiveHead>,
     mut commands: Commands,