--- a/qmlfrontend/game_view.h	Fri Mar 22 21:06:12 2019 +0100
+++ b/qmlfrontend/game_view.h	Fri Mar 22 21:29:10 2019 +0100
@@ -58,6 +58,7 @@
   bool m_windowChanged;
   QPointer<EngineInstance> m_engineInstance;
   QSize m_viewportSize;
+  QPoint m_centerPoint;
 };
 
 #endif  // GAMEVIEW_H