As implied in adffa1c, a single segment-switching translation unit for
both rendering functions and game logic is the most straightforward
solution for those two games. Especially once you look at TH04, and
realize that the wildly chaotic order of the *_fg_render() functions in
the first code segment exactly matches the order of the *_update()
functions in the third.
Part of P0225, funded by Enderwolf, Blue Bolt, 32th System, and Yanga.
nmlgc