Proprosed break in libGL / DRI driver ABI

[Roland Mainz]

Brian Paul wrote:
[snip]
> > I thought we treated channels as bytes everywhere, unless GLchan was defined
> > to something bigger, and even then only for OSMesa.  Even if it's not an ABI
> > change, I suspect that growing GLchan beyond 8 bits while still preserving
> > performance is non-trivial.
> 
> This is separate from Ian's ABI discussion.  It's true that core Mesa
> has to be recompiled to support 8, 16 or 32-bit color channels.
> That's something I'd like to change in the future.  It will be a lot
> of work but it can be done.
> 
> Currently, there aren't any hardware drivers that support > 8-bit
> color channels.

Doesn't Nvidia support >24bit RGB ? In general there is some hardware
out there (my favorite example are Sun's XVR-1000/-4000 framebuffer
series) which would require support for 30bit (or deeper) RGB in Mesa
first...

> If we did want to support deeper channels in a
> hardware driver we'd have a lot of work to do in any case.  One
> approach would be to compile core Mesa for 16-bit channels, then
> shift/drop bits in the driver whenever we write to a color buffer.  Of
> course, there's more to it than that, but it would be feasible.

What about the software rasterizer ? Would it be possible to run it in
30bit TrueColor right now ?

----

Bye,
Roland

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