support cutscene camera

src/cutscene.rs

@@ -0,0 +1,60 @@
+use crate::{DebugVisuals, tb_entities::CutsceneCamera};
+use bevy::prelude::*;
+
+#[derive(Event, Debug)]
+pub struct StartCutscene(pub String);
+
+#[derive(Resource, Debug, Default)]
+enum CutsceneState {
+    #[default]
+    None,
+    Playing {
+        timer: Timer,
+    },
+}
+
+pub fn plugin(app: &mut App) {
+    app.init_resource::<CutsceneState>();
+    app.add_systems(Update, update);
+    app.add_observer(on_start_cutscene);
+}
+
+fn on_start_cutscene(
+    trigger: Trigger<StartCutscene>,
+    cutscenes: Query<(&Transform, &CutsceneCamera), Without<Camera>>,
+    mut res: ResMut<DebugVisuals>,
+    mut cutscene_state: ResMut<CutsceneState>,
+    mut cam: Query<&mut Transform, With<Camera>>,
+) {
+    let cutscene = trigger.event().0.clone();
+
+    let Some((t, _)) = cutscenes
+        .iter()
+        .find(|(_, cutscene_camera)| cutscene == cutscene_camera.name)
+    else {
+        return;
+    };
+
+    res.cam_follow = false;
+
+    *cam.single_mut() = *t;
+
+    *cutscene_state = CutsceneState::Playing {
+        timer: Timer::from_seconds(2.0, TimerMode::Once),
+    };
+}
+
+fn update(
+    mut res: ResMut<DebugVisuals>,
+    mut cutscene_state: ResMut<CutsceneState>,
+    time: Res<Time>,
+) {
+    if let CutsceneState::Playing { timer, .. } = &mut *cutscene_state {
+        timer.tick(time.delta());
+
+        if timer.finished() {
+            res.cam_follow = true;
+            *cutscene_state = CutsceneState::None;
+        }
+    }
+}