feat(ecs): entity spawning

src/ecs/mod.rs

@@ -27,6 +27,7 @@ where
             return *id;
         }
     }
+
     let new_id = ComponentId(
         NonZeroU64::new(COMPONENT_ID_CREATOR.fetch_add(1, core::sync::atomic::Ordering::Relaxed))
             .unwrap(),
@@ -48,11 +49,10 @@ pub trait Component: core::fmt::Debug + Send + Sized + 'static {
 
     fn id() -> ComponentId {
         static COMPONENT_ID: AtomicU64 = AtomicU64::new(0);
-        // TODO: reevaluate ordering later
-        let mut current_id = COMPONENT_ID.load(core::sync::atomic::Ordering::SeqCst);
+        let mut current_id = COMPONENT_ID.load(core::sync::atomic::Ordering::Relaxed);
         if current_id == 0 {
             current_id = create_component_id::<Self>().0.into_integer();
-            COMPONENT_ID.store(current_id, core::sync::atomic::Ordering::SeqCst);
+            COMPONENT_ID.store(current_id, core::sync::atomic::Ordering::Relaxed);
         }
         ComponentId(NonZeroU64::new(current_id).unwrap())
     }
@@ -79,6 +79,16 @@ pub struct ComponentSet<A = allocator_api2::alloc::Global> {
 
 pub struct EntityComponentSystem {
     components: ComponentSet,
+    next_id: AtomicU64,
+}
+
+impl EntityComponentSystem {
+    fn spawn(&mut self) -> Entity {
+        let entity_id = self
+            .next_id
+            .fetch_add(1, core::sync::atomic::Ordering::Relaxed);
+        Entity(entity_id)
+    }
 }
 
 impl ComponentSet {