Added support for "Impure" systems, which only update once per frame and contain their own logic for manipulating the world, instead of relying on a single list of components.

include/Engine/Core/System.h

@@ -7,19 +7,39 @@
 
 class System
 {
-    friend class SystemPipeline;
-
-public:
-    System(EventBroker* eventBroker, std::string componentType)
+protected:
+    System(EventBroker* eventBroker)
         : m_EventBroker(eventBroker)
-        , m_ComponentType(componentType)
     { }
 
-    virtual void Update(World* world, ComponentWrapper& component, double dt) = 0;
-
-protected:
-    std::string m_ComponentType;
     EventBroker* m_EventBroker;
 };
 
+class PureSystem : public System
+{
+    friend class SystemPipeline;
+
+protected:
+    PureSystem(EventBroker* eventBroker, std::string componentType)
+        : System(eventBroker)
+        , m_ComponentType(componentType)
+    { }
+
+    const std::string m_ComponentType;
+
+    virtual void UpdateComponent(World* world, ComponentWrapper& component, double dt) = 0;
+};
+
+class ImpureSystem : public System
+{
+    friend class SystemPipeline;
+
+protected:
+    ImpureSystem(EventBroker* eventBroker)
+        : System(eventBroker)
+    { }
+
+    virtual void Update(World* world, double dt) = 0;
+};
+
 #endif