Re: Gnome Games will make 3D mandatory for 2.28

["Jason D. Clinton" <me jasonclinton com>]

On Tue, Mar 17, 2009 at 3:00 PM, Chris Burkhardt <chris mretc net> wrote:
>> Unless a clutter engine can work OK with software rendering? With lots
>> of stuff disabled maybe? Is that plausible?
>>
>
> From the 2.25.1 announcement (http://lwn.net/Articles/305999/):
>
> "We have tested software-based rendering with Mesa 7.2 and clutter and
> found it a little lacking, even on a modern CPU.
> [...]
> We hope that in the future, low-hanging fruit in the Mesa software
> rendering pipeline can be fixed enabling even software-fallback to work
> optimally for
> the subset of OpenGL functions needed for rendering a clutter stage."
>
> That was in November... I wonder if any progress has been made.

No, no one has. I did look much, much further in to it. Basically, the
software rendering stack has a huge problem: it block execution of the
calling program while it renders at least one frame. So basically, as
it is currently designed, software rendering will never work. It needs
to be asynchronous. And that's no small feat. As far as I know, no one
working on Mesa has even the slightest interest in working on it.

It's more likely that someone working on the librt (ray tracing) stuff
would come along with a new Mesa "driver" that would replace the
existing driver with a proper highly parallel ray tracer. That appears
to be the only place energy is being expended on software rendering.
(Partially funded by Intel; gotta find a use for all those cores in
the CPU's they're selling.)