R: [Plib-users] Threads and textures

[Paolo L. <p.l...@ci...>]

> -----Messaggio originale-----
> Da: pli...@li...=20
> [mailto:pli...@li...] Per conto di=20
> Curtis L. Olson
> Inviato: mercoled=EC 11 gennaio 2006 21.28
> A: pli...@li...
> Oggetto: Re: [Plib-users] Threads and textures
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> Tinoshi Kitazawa wrote:
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> > I think I have got a problem related with OpenGL context and
> > threads... I'm loading my database in a secondary thread,=20
> and textures=20
> > are not loaded!!! if i print(stdout," ",3) the Leaf i load,=20
> textures=20
> > handles are always set to 0, while geometry (vertex) are correctly=20
> > drawn. If I load the database in the main thread, textures=20
> are loaded!
> > I tryed to pass to the thread the ssgGetCurrentContext() and to=20
> > makeCurrent() just inside the thread function, but I=20
> doesn't work...=20
> > What can I do???
> > =20
> > Thanks!!!
> > =20
> > P.S. OS is WindowsXP, I use Visual Studio 6.0
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> I'm not an opengl guru, but we have the same issue with FlightGear. =20
> Basically opengl is not multithreaded.  In other words, if=20
> you generate=20
> opengl calls from multiple threads, you can expect that the=20
> calls will=20
> be interleaved in unpredictable ways and cause all kinds of strange=20
> behavior and problems.  The fact that your program actually survived=20
> this without crashing is actually a bit surprising! :-)

Loading/filling a SSG scene graph shouldn't involve OpenGL as far as =
don't
create display lists for leaf nodes - excepting textures, which, infact,
seems to arise the problem.

Greetings -

Paolo Leoncini