feat(ecs): add creating static entities

1 files changed, 30 insertions, 0 deletions

diff --git a/ecs/src/entity.rs b/ecs/src/entity.rs
index abc5991..18f229a 100644
--- a/ecs/src/entity.rs
+++ b/ecs/src/entity.rs
@@ -1,5 +1,9 @@
 use std::sync::atomic::{AtomicU64, Ordering};
 
+use linkme::distributed_slice;
+
+use crate::World;
+
 static NEXT_UID: AtomicU64 = AtomicU64::new(0);
 
 /// Unique entity ID.
@@ -28,3 +32,29 @@ impl Uid
         }
     }
 }
+
+#[macro_export]
+macro_rules! static_entity {
+    ($visibility: vis $ident: ident, $components: expr) => {
+        $visibility static $ident: ::std::sync::LazyLock<$crate::entity::Uid> =
+            ::std::sync::LazyLock::new(|| $crate::entity::Uid::new_unique());
+
+        $crate::private::paste::paste! {
+            mod [<__ecs_ $ident:lower _static_entity_priv>] {
+                use super::*;
+
+                #[$crate::private::linkme::distributed_slice(
+                    $crate::entity::CREATE_STATIC_ENTITIES
+                )]
+                #[linkme(crate=$crate::private::linkme)]
+                static CREATE_STATIC_ENTITY: fn(&$crate::World) = |world| {
+                    world.create_entity_with_uid($components, *$ident);
+                };
+            }
+        }
+    }
+}
+
+#[distributed_slice]
+#[doc(hidden)]
+pub static CREATE_STATIC_ENTITIES: [fn(&World)];