[SDL] OpenGL fubar

[Michael Vance]

Hmm, if you modify testgl.c to run its OpenGL subsystem twice, I get a
lock in XSync(). This is the strack trace:

Program received signal SIGINT, Interrupt.
0x405bac98 in _XFlushInt ()
(gdb) where
#0  0x405bac98 in _XFlushInt ()
#1  0x405bac4b in _XFlush ()
#2  0x405b7d5a in XSync ()
#3  0x401a89aa in XMesaGarbageCollect () at xmesa1.c:2442
#4  0x4026b699 in X11_CreateWindow (this=0x804a6f0, screen=0x804ce90,
w=640, 
    h=480, flags=2) at SDL_x11video.c:536
#5  0x4026bb03 in X11_SetVideoMode (this=0x804a6f0, current=0x804ce90,
    width=640, height=480, bpp=16, flags=2) at SDL_x11video.c:689
#6  0x40267793 in SDL_SetVideoMode (width=640, height=480, bpp=16,
flags=2)
    at SDL_video.c:492
#7  0x8048df7 in RunOpenGL (argc=1, argv=0xbffffa74) at testgl2.c:85
#8  0x8049209 in main (argc=1, argv=0xbffffa74) at testgl2.c:209
#9  0x402efcb3 in __libc_start_main (main=0x80491dc <main>, argc=1, 
    argv=0xbffffa74, init=0x804896c <_init>, fini=0x804923c <_fini>, 
    rtld_fini=0x4000a350 <_dl_fini>, stack_end=0xbffffa6c)
    at ../sysdeps/generic/libc-start.c:78
(gdb) 

It's actually locking in the call to glXCreateContext().

The important thing to note is that between #3 and #4 there is no
X11_GL_CreateWindow() and no glXCreateContext( ), as there should
be. Furthermore, there should also be a Fake_glXCreateContext() call,
because that's where XMesaGarbageCollect() is called from. Hmm...

I've added a call to glXMakeCurrent( GFX_Display, NULL, NULL ) in
X11_VideoQuit(), but that was wishful thinking on my part.

Any thoughts from gurus out there? It looks like we clean up state
pretty well... although I notice we never do anything with the
XVisualInfo* returned from glXChooseVisual(). Are we responsible for
releasing that somehow?

m.

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