From: Johan Karlberg <wlfshmn@failure.ml.org>
  To  : ggi-develop@eskimo.com
  Date: Wed, 12 Aug 1998 19:10:58 +0200 (CEST)

Re: Graph types...

On Wed, 12 Aug 1998, Andrew Apted wrote:

> Johan Karlberg writes:
> 
> >  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...

also, I'm not sure about the differance in the XGA specifications of
Direct-Color and True-Color, both support the same color depth, but
Direct-Color seems to support overlay data while True-color does not, on
the other hand True color seem to support pre-color gamma correction, I
know we don't have overlay supoprt in the KGI API, anything about Gamma?
or should I just go for what performs the best?

Johan