[Fry]

There's obviously a bunch of problems with Gonstruct, but the main issue would be the terrible GTK+OpenGL widget it is using right now:

Basically there are two "working" GTK OpenGL widgets, gtkglarea and gtkglext. The latter is the one we tried first, since it is actively maintained and has C++ bindings available. Unfortunately quite a few people had problems with it on Windows, where it did not properly refresh the screen so the level display became unusable.

It took me ages to reproduce it on my system, but unfortunately I did not figure out the reason for it, so we gave gtkglarea a try. This ended up working relatively reliably on Windows and other systems, but that OpenGL widget sadly hasn't been maintained for a while and does not work with the most recent GTK version anymore (at least on Windows, Linux/Mac are fine as far as I remember).

The way to deal with that would probably be to give gtkglext another try, since it is the de-facto OpenGL widget for GTK and actively maintained. Maybe things are working now, or if not maybe it is possible to figure out the reason for the problems.

In retrospect we should probably have used Qt though. While GTK is much nicer to work with in setting up widgets and windows, even after all these years it still has very fragile cross-platform support.