single returns nil when empty

src/ecs.odin

@@ -39,9 +39,9 @@ run :: proc(app: ^App) {
 
 	rl.SetTargetFPS(60)
 	for !rl.WindowShouldClose() {
-		rl.ClearBackground(window.background)
 		for i in app.systems[UPDATE] {i()}
 		rl.BeginDrawing()
+		rl.ClearBackground(window.background)
 		for i in app.systems[DRAW] {i()}
 		rl.EndDrawing()
 	}

src/entities.odin

@@ -44,7 +44,7 @@ single :: proc(storage: ^Storage($T)) -> (Entity, ^T) {
 	for i, &v in slice(storage) {
 		return i, &v
 	}
-	return Entity{}, new(T)
+	return 0, nil
 }
 
 // get component of type from entity
@@ -54,8 +54,3 @@ get_component :: proc(entity: Entity, storage: ^Storage($T)) -> ^T {
 	}
 	return new(T)
 }
-
-// alias for direct mutation access
-get_component_with_ref :: proc(entity: Entity, storage: ^Storage($T)) -> ^T {
-	return get_component(entity, storage)
-}

src/systems.odin

@@ -9,7 +9,7 @@ DefaultPlugin :: proc(app: ^App) {
 	add_component(
 		display,
 		&Window,
-		WindowComponent{width = 800, height = 600, title = "shoal window"},
+		WindowComponent{width = 800, height = 600, title = "shoal window", background = rl.BLACK},
 	)
 }