Re: [Plib-devel] Patches for FreeBSD

[Bert D. <dri...@pl...>]

On Thu, 30 Dec 2004, Steve Baker wrote:

>> By the way, I'm perfectly willing to take ownership of FreeBSD portability 
>> issues if people think it'll help. My sourceforge id is "driehuis".
>
> That would be very useful.   Do you need developer access to PLIB?

Yes, please!

> > glIsValidContext() fails when there is a mismatch in the pthread
> > implementation between different libraries used by Plib.
> 
> !!!!
> 
> I think it's *far* more likely that there is a bug in the application
> you are using to test with.
> 
> It's quite possible for a threaded application to open a GL context in
> one thread and do OpenGL calls in another thread.  It's easy to imagine
> a situation where there would be a race hazard that would result in some
> thread implementations allowing the application to work as intended and
> other thread implementations to show up the problem that was there in 
> the application all along.

This is definitely a possibility. It is also possible that NVidia is 
somehow involved (I'm using the NVidia binary-only libraries).

I'll really have to experiment changing one variable at a time, but 
being able to build Flightgear from CVS would be a very good start :-)

For what it's worth, I think that _if_ there are legitimate uses of not 
calling glIsValidContext, we should do something like this:

   if (getenv("PLIB_SKIP_GLCHECK") != NULL) {
     cout << "Skipping glIsValidContext: use at your own risk!\n";
   } else {
     if (!glIsValidContext()) {
 	cout << "ssgInit called without valid OpenGL context\n";
 	cout << "Set PLIB_SKIP_GLCHECK=yes in your environment to skip ";
 	cout << "this test AT YOUR OWN RISK\n";
     }
   }

Cheers,

 				-- Bert

-- 
Bert Driehuis -- dri...@pl... -- +31-20-3116119
If the only tool you've got is an axe, every problem looks like fun!