Stephan/hez 2 npc should loose head if 0 health (#34)

src/head_drop.rs

@@ -0,0 +1,71 @@
+use crate::{
+    GameState, billboards::Billboard, global_observer, loading_assets::GameAssets, player::Player,
+    squish_animation::SquishAnimation,
+};
+use avian3d::prelude::*;
+use bevy::prelude::*;
+use std::f32::consts::PI;
+
+#[derive(Event, Reflect)]
+pub struct HeadDrops(pub Vec3, pub usize);
+
+#[derive(Component, Reflect)]
+#[reflect(Component)]
+struct HeadDrop(pub usize);
+
+#[derive(Event, Reflect)]
+pub struct HeadCollected(pub usize);
+
+pub fn plugin(app: &mut App) {
+    app.add_systems(Update, collect_head.run_if(in_state(GameState::Playing)));
+
+    global_observer!(app, on_head_drop);
+}
+
+fn on_head_drop(trigger: Trigger<HeadDrops>, mut commands: Commands, assets: Res<GameAssets>) {
+    let HeadDrops(position, id) = trigger.event();
+
+    let angle = rand::random::<f32>() * PI * 2.;
+    let spawn_dir = Quat::from_rotation_y(angle) * Vec3::new(0.5, 0.6, 0.).normalize();
+
+    commands
+        .spawn((
+            Name::new("headdrop"),
+            HeadDrop(*id),
+            Transform::from_translation(*position),
+            Visibility::default(),
+            Collider::sphere(1.5),
+            ExternalImpulse::new(spawn_dir * 180.).with_persistence(false),
+            LockedAxes::ROTATION_LOCKED,
+            RigidBody::Dynamic,
+            Restitution::new(0.6),
+        ))
+        .with_child((
+            Billboard,
+            SquishAnimation(2.6),
+            SceneRoot(assets.mesh_head_drop.clone()),
+        ));
+}
+
+fn collect_head(
+    mut commands: Commands,
+    mut collision_event_reader: EventReader<CollisionStarted>,
+    query_player: Query<&Player>,
+    query_collectable: Query<&HeadDrop>,
+) {
+    for CollisionStarted(e1, e2) in collision_event_reader.read() {
+        let collectable = if query_player.contains(*e1) && query_collectable.contains(*e2) {
+            *e2
+        } else if query_player.contains(*e2) && query_collectable.contains(*e1) {
+            *e1
+        } else {
+            continue;
+        };
+
+        let key = query_collectable.get(collectable).unwrap();
+
+        // commands.trigger(PlaySound::KeyCollect);
+        commands.trigger(HeadCollected(key.0));
+        commands.entity(collectable).despawn_recursive();
+    }
+}