[Mesa-dev] Mesa + glxPixmaps problems
ian.molton at collabora.co.uk
Fri Aug 27 02:24:52 PDT 2010
On 27/08/10 08:53, Michel Dänzer wrote:
> Note that it's XGet*Window*Attributes. This call seems totally
> inappropriate for pixmaps and it might be pure luck if it ever does
> anything other than fail in that case.
Indeed - but there it is...
It does in fact work on any X drawable - but not on glxPixmaps which
appear not to count as X drawables
>> > Sadly, however, it appears that there are many more similar looking bugs
>> > in Mesa. Has anyone actually used Mesa to render to glxPixmaps? are
>> > there patches available to make this stuff work?
> The Mesa demos rendering to GLXPixmaps and gnubg have been working for
> me at least basically.
I have a simple testcase which highlights the above problem. I can send
it to anyone who wants it.
The problem, I expect, is much worse though. glxPixmap support was added
later to Mesa and I think has had little 'hard' use. as a result, only a
few code paths have got tested.
My program is redirecting calls from multiple applications that would
normally have rendered to a window onto glxpixmaps. As a result, there
is a LOT of GL context switching going on. I am starting to see a lot of
BadDrawable errors cropping up and I suspect its no co-incidence.
If the code is modified to use offscreen *windows* instead of
glxPixmaps, it works much better.
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