fix: batch spawned projectiles

src/physics/projectiles.rs

@@ -59,7 +59,7 @@ fn on_bullet_fired_event(
     mut events: EventReader<BulletFiredEvent>,
     resources: Res<BulletResources>,
 ) {
-    for event in events.read()
+    let to_bullet_entity = |event: &BulletFiredEvent|
     {
         let rotation = Quat::from_scaled_axis(Vec3::new(
             rand::random::<f32>() * f32::to_radians(360.0),
@@ -68,21 +68,24 @@ fn on_bullet_fired_event(
             ));
         let transform = Transform::IDENTITY
             .with_translation(event.position)
-            .with_scale(Vec3::splat(event.radius))
             .with_rotation(rotation)
+            .with_scale(Vec3::splat(event.radius))
             .looking_to(event.direction, Vec3::Y);
 
-        commands.spawn((
+        (
             Bullet,
             resources.mesh.clone(),
             resources.material.clone(),
             resources.collider.clone(),
             transform,
-            ColliderDensity(event.density),
-            AngularVelocity(event.gyro * event.direction),
             RigidBody::Dynamic,
-            FrameRaycastAntiGhost,
+            ColliderDensity(event.density),
             LinearVelocity(event.velocity * event.direction),
-        ));
-    }
+            AngularVelocity(event.gyro * event.direction),
+            FrameRaycastAntiGhost,
+        )
+    };
+
+    let bullet_entities = events.read().map(to_bullet_entity).collect::<Vec<_>>();
+    commands.spawn_batch(bullet_entities);
 }