Feature request: Underlays
Currently it is possible to add overlays that are drawn on top of everything else. However, sometimes I want to add something in the background, such as an image, or some text that is visible most of the time, but that I don't want to cover the actual content (my atoms) if they happen to cover the same area as the text.
I think it should be fairly easy to add underlays, which would be the same as overlays, except that they are the very first thing that are painted, instead of last thing.