Fix issues with UI renderer

openVulkanoCpp/Scene/UI/UI.hpp

@@ -17,25 +17,34 @@ namespace openVulkanoCpp::Scene::UI
 	public:
 		std::vector<std::shared_ptr<UiElement>> children;
 
-		virtual ~UiElement() override = default;
+		~UiElement() override = default;
 
-		virtual void Tick() override {};
+		void Tick() override {};
 
-		virtual void Draw() const;
-
-		void Render() const
+		void Render()
 		{
+			BeginDraw();
 			Draw();
 			for(const auto& child : children)
 			{
 				child->Render();
 			}
+			EndDraw();
 		}
+
+	protected:
+		virtual void BeginDraw() {};
+
+		virtual void Draw() = 0;
+
+		virtual void EndDraw() {};
 	};
 
 	class Ui : public UiElement
 	{
 	public:
-		void Draw() const override {}
+		virtual void Init() = 0;
+
+		void Draw() override {}
 	};
 }