Fixed some rendering bugs and some code refactoring

include/Engine/Rendering/Renderer.h

@@ -20,6 +20,7 @@
 #include "ImGuiRenderPass.h"
 #include "Camera.h"
 #include "../Core/Transform.h"
+#include "imgui/imgui.h"
 
 class Renderer : public IRenderer
 {
@@ -45,6 +46,8 @@ private:
     Model* m_UnitQuad;
     Model* m_UnitSphere;
 
+    int m_DebugTextureToDraw = 0;
+
     PickingPass* m_PickingPass;
     LightCullingPass* m_LightCullingPass;
     ImGuiRenderPass* m_ImGuiRenderPass;