Sementation fault in OpenGL application

Tron Thomas tron.thomas@verizon.net
Mon Mar 24 19:25:00 GMT 2003


Actually I'm thinking that the problem is not with the video driver.  I 
renamed the driver dll so that the system would use the software 
renderer instead of the video card driver.  The same problem occurred in 
a call to wglChoosePixelFormat provided by the software render.

I checked the documentation for DrvSetPixelFormat on the Microsoft 
website.  It mentioned that this call should only be made once and 
calling it multiple times can cause problems with the window manager and 
the multithreaded applications.  I would think that this function has 
already been called earlier in the program when I actually specify my 
pixel format while initializing OpenGL with calls to the 
ChoosePixelFormat and SetPixelFormat API's.

After this initialization, I then try to create a texture, and that is 
where the problem is occuring.   I'm not sure why this DrvSetPixelFormat 
is being called while making the texture.  It seems that this method 
might be called when it shouldn't be, and that could be related to the 
problem.

lhall@pop.ma.ultranet.com wrote:

>Unless someone here has the same video card, driver (+version), and
>can reproduce your problem, I'm not sure you'll get much response 
>here beyond the advice already given.  Certainly it is possible that
>there is a video driver issue and that would certainly be specific to
>the card in question.  But it's also possible that your program is 
>causing a problem for the video driver.  It's also possible that there's
>a bug elsewhere (i.e. gcc) which is contributing to this failure.  But
>the answer to where the problem actually lies will come from some analysis.
>Then again, there might be someone here on the list that has seen exactly
>this problem and will pipe up with a solution.  It's my impression that if
>that was the case, you would've heard from that person already.  So I'm
>recommending you don't hold your breath waiting for that nice, simple 
>solution to come your way. ;-)
>
>Larry
>
>Original Message:
>-----------------
>From: Tron Thomas tron.thomas@verizon.net
>Date: Sun, 23 Mar 2003 16:31:07 -0800
>To: cygwin@cygwin.com
>Subject: Sementation fault in OpenGL application
>
>
>Earlier I had posted a message concerning I segmentation fault I get 
>when I build an OpenGL application using the GCC compiler on Cygwin.  I 
>have since discovered that the debugger spits out some information when 
>the segmentation fault occurs.  The is what it says:
>
>Program received signal SIGSEGV, Segmentation fault.
>0x6966190c in nvoglnt!DrvSetPixelFormat ()
>
>I have a 64 Megabyte nVidia GeForce 3 video card on my system.  The 
>debug message implies the error is occuring in the video driver.  I do 
>not know what would be causing this, especially when the program runs 
>fine when built with other compilers.
>
>Can anyone offer any help on this matter?
>
>
>
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