From: Marcus Sundberg <e94_msu@elixir.e.kth.se>
  To  : ggi-develop@eskimo.com
  Date: Wed, 12 Aug 1998 21:22:18 +0200

Re: Graph types...

> > >  we define a couple of graphtypes, but for exampl GT_16BIT, what IS 16 bit?
> > >  is it a 5-5-5-1 (XGA) mode, a 5-6-5 (TARGA) mode, or even a 6-6-5 RGB
> > >  mode?
> > 
> > It depends on the hardware.  The mode could be RGB 5:6:5 or 6:6:4 or
> > 5:7:4, with or without byte swapping (e.g. little endian card in a big
> > endian machine).  Once you set the mode, you can query the format with
> > the ggiGetPixelFormat() function or via the DirectBuffer interface.
> > 
> Ok, and what should be set as default in a RAMDAC driver then? Since the
> ramdac has to set different multiplexing values for each? Since we don't
> support Overlay, that's not a problem, I'll discount those modes, but, a
> 565 mode would then be more exact I assume...

Please note that the KGI API still uses the old, limited and VGA
centric graphtype scheme which only defines GT_1/4/8/15/16/24/32BIT
and GT_TEXT16/32.

Whereas libggi uses a new system where a graphtype is made up of
depth (number of significant bits), size (physical pixelsize), a
"scheme" (palette/truecolor/grayscale/text) and a "subscheme"
(endianness and such), where the GT_??BIT modes are just some
common predefines.

Look at degas/include/ggi/types.h in the devel CVS to see the new
graphtype API.

Btw, I hope that the graphtype system in Steffens new KGI API is
more flexible than in the current KGI(s).

//Marcus
-- 
-------------------------------+------------------------------------
        Marcus Sundberg        | http://www.stacken.kth.se/~mackan
 Royal Institute of Technology |       Phone: +46 707 295404
       Stockholm, Sweden       |      E-Mail: e94_msu@e.kth.se