Re: [UFO-devel] Bug#385945: boson: crashes on singleplayer game start

[Andreas B. <b_...@gm...>]

(Removing the CC's cause this is imho relevant to libufo-devel only)

On Saturday 16 September 2006 10:58, Johannes Schmidt wrote:
> Le Samedi 16 Septembre 2006 02:06, Andreas Beckermann a écrit :
> [...]
>
> > I have done some additional research and have been able to reproduce the
> > bug on one of my own machines. It happens with mesa based drivers only.
> > It appears to me that this is a bug in mesa, in particular I believe it
> > is
> > http://www.mail-archive.com/mesa3d-dev%40lists.sourceforge.net/msg00772.h
> >tm l The fact that this problem goes away with libgl1-mesa-dri
> > 6.5.0.cvs.20060524-1 seems to confirm that, as current mesa versions
> > don't include the fix yet, cvs does.
>
> Hmm, I'm using here libgl1-mesa-dri 6.4.1-0ubuntu8 and can't reproduce the
> problem.
> If you can create a minimal example, please send it to the libufo mailing
> list.

Sure:
current libufo cvs, ufo-0.5/test/buttons.cpp

Attached is a log, including a backtrace and my glxinfo output.
If this crash does not happen on your system - maybe ubunto has patched it's 
mesa to include the fix?

> > However I have no idea how to write around this problem so that it works
> > for broken mesa versions, too. The only way I can see atm is not to use
> > vertex arrays, but this solution _really_ sucks and would require quite
> > some changes to libufo.
>
> IIRC, the only place where we are using vertex arrays in libufo is in
> GL_Graphics::drawVertexArray.
> You could replace the vertex array with plain glBegin, glVertex, glEnd
> calls. But using immediate mode is a performance penalty ...

I doubt that the difference is measurable considering the size of the arrays 
(usually < 10 vertices) used by libufo

> It's strange that this occurs only with triangles ...

It's a strange bug

> Best,
> Johannes

CU
Andi