Re: [Nautilus-list] Hardware Accelerated Alpha blending

[Owen Taylor <otaylor redhat com>]

Ty Norton <ty norton to> writes:

> Has anyone given any thought into supporting some form of hardware
> accelerated alpha blending in nautilus?
> (Also, Does nautilus use X's alpha blending extension or it's own?)
> 
> I know nvidia's detonator 4 driver revisions (Windows) gave XP a needed
> boost in it's alpha blending performance. Does anyone know if their new
> det4 Linux release added some form of acceleration for the alpha
> blending extension that exists in X?

Even the older releases of the nvidia drivers for linux support
hardware acceleration of the XRENDER extension which does alpha
blending - you can try comparing the results of something like
'x11perf -aa10text' on different machines - hardware acceleration can
give you a nice 20 time speedup, though the performance isn't that bad
even unaccelerated.

> It would certainly be nice to take some pressure off the slow blending
> that nautilus now faces on many slower machines.

Integrating XRENDER support into Nautilus's rendering is certainly
possible but not particularly easy; the anti-aliased rendering in
Nautilus is all done in the client, not in the X server, the simplest
way of getting things to work would be to have three code paths:

 a) Core X
 b) Client side rendering
 c) XRENDER

Where there is currently only a) and b).

Honestly, I've seen little evidence that rendering is the major
problem with Nautilus performance ... once windows come up, they
render quite well on even modest machines. The performance slow spots
are still things like new speed.

Regards,
                                        Owen