Thanks! I did find that, but also ran across a very compact version on the BBS that does precisely what I need. It's the "circle map" function here: https://www.lexaloffle.com/bbs/?tid=38881 in case anyone else is looking for something similar.
I integrated this into the game and it works great. So that's off the list, as well as the start screen. At this point I feel like the stuff that's left is very doable in the remaining time :)