OpenGL wall z-fighting issues

These windows and many others in THZ2 are being drawn on top of the walls and causing z-fighting. Interestingly it seems that only the sloped parts of the windows are affected.

Many banners in CEZ2 are clashing with the walls. I'm not sure if the underlying issue is the same or not.

With the THZ2 windows, this could (probably) be fixed from the map's point of view, by sloping the glass FOF's edges to match the metal wall instead of (presumably) using a fixed-height FOF even in the sloped areas of the wall.

With the CEZ2 banners, moving the banners slightly out in front of the wall would likely mitigate it well, and using a texture where the banners are "baked" "into" the wall texture would completely prevent it.

This Z-Fighting is also an issue in one of my custom maps, and because of how it's done I can't easily redesign that part of the map just because OpenGL error

added Bug OpenGL renderer labels

mentioned in merge request !1361 (merged)

mentioned in merge request !1376 (merged)

closed