Re: X hardware acceleration still flaky?

[Jon TURNEY <jon dot turney at dronecode dot org dot uk>]

On 08/08/2010 15:57, L.Wood@surrey.ac.uk wrote:
> Hi Jon,
>
> I just downloaded the current X server and its libraries in the Cygwin distro; the xwin-gl allusion came from the previous thread I mentioned.

So, the current problem is with OpenGL on X.

"OpenGL" and "hardware acceleration" are not synonyms.

Testing with the experimental AIGLX code is moot if it doesn't work with the 
current X server.

> Compiling geomview 1.9.4 --with-opengl is straightforward (that's one improvement on pre-7.4 X; configure doesn't get confused about X library locations and building is easier). I then tried running savi with geomview:
> - using OpenGL. 30 seconds of slow flickering (slow enough to be the software rendering that you alluded to?), then the X server consistently crashes, even before I've had a chance to turn on texturemapping...

I've built savi and geomview, and I'm afraid I can't reproduce this crash.

There's no flickering unless I use the mouse to rotate the planet, which 
almost looks like it's not using double-buffering for some reason, as the 
whole frame looks like it's being drawn into the front buffer...


I've rebuilt X server 1.8.2-1 with debugging symbols and uploaded it at [1], 
can you run that under gdb and reproduce your crash and post a backtrace, please.

[1] ftp://cygwin.com/pub/cygwinx/XWin.20100808-git-66f3680cb47fbd09.exe.bz2

> - forcing internal geomview software rendering using geomview -noopengl -run ../savi1.4.3/savi $* . Works, but is rather stately. No texturemapping support, obviously. Less slow than the brief opengl attempt, though, which figures given that doing OpenGL in software imposes more layers of overhead?
>
> That's the status from testing with what cygwin ships at the moment. I haven't tried your older binaries. Please let me know when you get to another test release, and I'll try it out.
>
> thanks,
>
> L.
>
> SaVi satellite constellation visualization http://savi.sf.net/
>
> On 8 Aug 2010, at 13:57, Jon TURNEY wrote:
>
> > On 08/08/2010 10:18, L.Wood@surrey.ac.uk wrote:
> > > Well, it's been eighteen months since I last asked:
> > > http://www.cygwin.com/ml/cygwin-xfree/2009-02/msg00259.html
> >
> > > so I attempted to use opengl hardware acceleration with Cygwin and XFree 7.4, using Geomview (www.geomview.org) as the test application on an uptodate Cygwin 1.7 install.
> > >
> > > Lots of flickering for about thirty seconds (of correct output), but then the X server crashes. So, no visible change over previous. It's still a regression on pre-7.4.
> >
> > I'm not sure what you were testing here, but I can't see how it could be
> > hardware AIGLX.
> >
> > xwin-gl is obsolete, an empty package since R7.4 [1], so if you are running
> > that somehow, it must be an old version, which I am surprised works at all.
> >
> > Alternatively, you are using xwin with software rendering, and your
> > application exposes some bug in the Xserver which makes it crash.
> >
> >
> > I am happy to work with you to resolve these issues.
> >
> > > Has any work been attempted on improving hardware acceleration in xwin-gl?
> >
> > Yes, this is something I have been working on in my copious free time(TM):
> >
> > http://cygwin.com/ml/cygwin-xfree/2009-06/msg00088.html
> > http://sourceware.org/ml/cygwin-xfree/2009-08/msg00021.html
> > http://x.cygwin.com/devel/todo.html
> >
> > I hope you'll note that savi is one of the applications I've been testing with.
> >
> > However, given the lack of response so far, it seems that you and me are the
> > only 2 people interested in working AIGLX for XWin :-)
> >
> > I wouldn't suggest testing with those binaries at this stage, as I've moved on
> > a bit.  I hope to shortly make another test release containing AIGLX based on
> > the upcoming Xserver 1.9, and I would very much appreciate some testing of the
> > AIGLX functionality in that, when it is available.
> >
> > [1] http://cygwin.com/cgi-bin2/package-grep.cgi?grep=xwin-gl

--
Jon TURNEY
Volunteer Cygwin/X X Server maintainer

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