Improving entity manager and entity support for a simpler version, made some cleanup on the road to support serialization of world

Game/Entity/EntityManager.h

@@ -1,24 +1,32 @@
-#pragma once
+#pragma once
 
 #include <Core/Common/CoreTypes.h>
 #include <Core/Container/Vector.h>
-#include <game.h>
-
-using EntityID = uint64_t;
+#include <Entity/Entity.h>
 
 struct Entity;
+struct World;
+
+struct typed_entity_array
+{
+    Arena*           arena;
+    entity_template* array;
+    size_t           count;
+};
+
 struct EntityManager
 {
     static EntityID ID;
 
-    Arena* Arena;
-
     // TODO: Should be a pool
-    VectorArena<Entity, 1024> Entities;
+    VectorArena<Entity, 100'000> Entities;
+
+    typed_entity_array by_type[ENTITY(Count)];
 };
 
-void           InitEntityManager(NonNullPtr<World> world);
-void           ShutdownEntityManager();
-EntityManager& GetEntityManager();
-void           RegisterEntity(EntityManager& manager, Entity* entity);
-void           UpdateEntityManager(EntityManager& manager);
+void             InitEntityManager(NonNullPtr<World> world);
+void             ShutdownEntityManager();
+EntityManager&   GetEntityManager();
+void             Serialize(NonNullPtr<EntityManager> entityManager);
+entity_template* RegisterEntity(EntityManager& manager, Entity* base, DerivedType entity);
+void             UpdateEntityManager(EntityManager& manager);