gamma correction

[Martijn Sipkema]

> > I've been thinking some more about gamma correction...
> > 
> > - (almost) no hardware can do per window gamma correction, i.e.  gamma
> >   corrected and uncorrected visuals.
> > - most systems don't do full gamma correction in the framebuffer LUT.
> >   SGI has a default system gamma of 1.5, Mac uses 1.8. I suppose
> >   Windows uses 2.2.
> 
>   Well, Mac's API uses 1.8 and I think it gets converted, at least that
> was my understanding.  Like, that's just for their software drawing API.
> I don't think they actually set up the LUTs for a 1.8 gamma.

AFAIK Macs do use a 1/1.4 LUT..

--ms