Simple solution to this redrawing issue is global flag signifying whether refresh is needed that is cleared in the frame loop after all gui calls. Also complete

Simple solution to this redrawing issue is global flag signifying whether refresh is needed that is cleared in the frame loop after all gui calls. Also complete redraw on every frame is how most game UIs work anyway and it's not significant performance issue today (it was an issue 15 years ago when I wrote several immediate UI libraries for DOS, although performance issue there had more to do with overhead of synchronizing redraws with mouse driver than graphics performance itself). The main problem with this approach is that you essentially end up doing one large busyloop across many irrelevant parts of code. This implementation seems to solve this by blocking at the end of each iteration waiting for any event to occur, but probably still wastes CPU time significantly.