Probably dumb question: glyph rendering on unicode-2 branch

[Adrian Robert <arobert@cogsci.ucsd.edu>]

Hi,

I apologize if this is a dumb question, but I've been looking through  
the code and can't figure this one out: on the unicode-2 branch, if a  
font specifies "iso-10646-1" for XLFD registry/encoding (and then  
fontset.c sets 'charset' accordingly), what exactly is getting passed  
in struct glyph_string.char2b to x_draw_glyph_string()?  Not UTF-8,  
since it's just 2 bytes.  UCS-2?  UTF-16?  Don't these exclude a lot  
of unicode characters?  Is that what the "composition" machinery is  
for?  (But I thought that had to do with the script itself involving  
composition, like Arabic or Korean Hangul..)

Does emacs provide any internal facility to get UTF-8?

Also, what (encoding) is in glyph.u.ch?  Is that UCS-4?  UTF-32?

thanks,
Adrian