Determining the color depth of X?

[d13f00l]

Hey.  I've been trying to iron out a couple bugs running some programs in
wine.

Running ZSNES reports that ZSNES cannot run in 24 bit depth mode.
I'm also running an old game that uses dibs, I took a profiler to wine.  We
repeatedly call convert_888_to_0888_asis on a surface per blit.  The game
determines the color depth by what depth you're running windows at.

Basicaly, where/how does wine determine your bit depth?  Isn't 24 actually 3
significacant bytes + a worthless one in X?   XRGB.  I didn't see any code
determining the bit depth trying to follow what happens when you
CreateCompatibleDC(0).  Anyone have any ideas?  This could be potential for
a nice speedup.  Thanks.

-Dylan