Make flap and rewind buttons shimmer

src/bin/flappy/main.rs

@@ -39,9 +39,11 @@ fn main() {
             ),
         )
         .add_systems(OnEnter(PlayerState::Alive), alive_bird)
+        .add_systems(OnEnter(PlayerState::Alive), reset_button::<FlapButton>)
         .add_systems(OnEnter(PlayerState::Rewind), (start_rewinding, alive_bird))
         .add_systems(OnEnter(PlayerState::Pause), pause_bird)
         .add_systems(OnEnter(PlayerState::Stasis), pause_bird)
+        .add_systems(OnExit(PlayerState::Stasis), reset_button::<RewindButton>)
         .add_systems(
             Update,
             (
@@ -93,6 +95,8 @@ fn main() {
                 update_batch_position.run_if(any_component_changed::<Batch>),
                 move_batches.run_if(on_event::<CollisionStarted>),
                 manage_score.run_if(on_event::<CollisionStarted>.or(on_event::<CollisionEnded>)),
+                shimmer_button::<RewindButton>.run_if(in_state(PlayerState::Stasis)),
+                shimmer_button::<FlapButton>.run_if(in_state(PlayerState::Pause)),
             ),
         )
         .add_observer(flap)
@@ -407,12 +411,18 @@ fn init_assets(
 #[derive(Component)]
 struct FlapSfx;
 
+#[derive(Component)]
+struct FlapButton;
+
 #[derive(Component)]
 struct BonkSfx;
 
 #[derive(Component)]
 struct RewindSfx;
 
+#[derive(Component)]
+struct RewindButton;
+
 fn init_ui(mut commands: Commands) {
     commands
         .spawn((
@@ -532,11 +542,9 @@ fn init_ui(mut commands: Commands) {
                 flex_direction: FlexDirection::Column,
                 ..default()
             },
-            Button,
             PlayerState::Pause,
-            children![Text::new("Go!"),],
-        ))
-        .observe(start_game);
+            children![Text::new("Go!")],
+        ));
 
     commands
         .spawn(Node {
@@ -550,13 +558,15 @@ fn init_ui(mut commands: Commands) {
                 .spawn((
                     Node { ..default() },
                     Button,
+                    BackgroundColor::default(),
+                    RewindButton,
                     children![Text::new("Rewind!"),],
                 ))
                 .observe(start_rewind)
                 .observe(end_rewind);
 
             parent
-                .spawn((Node { ..default() }, Button, children![Text::new("Flap!"),]))
+                .spawn((Node { ..default() }, Button, FlapButton, children![Text::new("Flap!"),]))
                 .observe(flap_button);
         });
 
@@ -585,7 +595,12 @@ fn flap_button(
     _trigger: Trigger<Pointer<Pressed>>,
     mut commands: Commands,
     bird: Single<Entity, With<Bird>>,
+    curr: Res<State<PlayerState>>,
+    mut next: ResMut<NextState<PlayerState>>,
 ) {
+    if !matches!(curr.get(), PlayerState::Alive) {
+        next.set(PlayerState::Alive);
+    }
     let e = *bird;
     debug!("Flapping {:?}", e);
     commands.trigger_targets(Flap, e);
@@ -994,3 +1009,21 @@ fn start_rewinding(
         RewindSfx,
     ));
 }
+
+fn shimmer_button<T: Component>(
+    mut bg: Single<&mut BackgroundColor, With<T>>,
+    time: Res<Time>,
+) {
+    let t = time.elapsed_secs();
+    let period = 3.0;
+    let r = (((t / period) % 1.0) * std::f32::consts::PI).cos();
+    let g = ((((t / period) + 0.3) % 1.0) * std::f32::consts::PI).cos();
+    let b = ((((t / period) + 0.6) % 1.0) * std::f32::consts::PI).cos();
+    bg.0 = Srgba::rgb(r, g, b).into();
+}
+
+fn reset_button<T: Component>(
+    mut bg: Single<&mut BackgroundColor, With<T>>,
+) {
+    bg.0 = WHITE.into();
+}