[Ohrrpgce] SVN: teeemcee/13412 gfx_fb: don't ever switch from 32-bit color back to 8-bit

[subversion at HamsterRepublic.com]

teeemcee
2023-12-15 02:04:39 -0800 (Fri, 15 Dec 2023)
297
gfx_fb: don't ever switch from 32-bit color back to 8-bit

Doing so recreates the window, which is nasty. 8<->32 bit changes are especially
frequent after the previous commit (every multichoice!), but they already
happened a lot (e.g. entering/leaving the map editor toplevel menu), so avoid
them.
---
U   wip/gfx_fb.bas