Re: access violation when calling glGenFramebuffers

Cyrille Rossant <[email protected]> Wed, 3 Apr 2013 18:24:40 +0100
Newsgroups gmane.comp.python.opengl.user
Message-ID <CA+-1RQQ0biEkT57rvP_+=SKDs8hThiYyLd4P20PPXOY5h8+0xA@mail.gmail.com>
Do you have the possibility to test your program on another configuration?
I had a program working perfectly well on multiple configurations (Windows,
Mac, Linux, etc.), except a particular one (Windows 8 64 bits, Python 64
bits, Intel HD 3000). So this bug might be due to some interaction between
the Intel Windows drivers and PyOpenGL/Python 64 bits. I fear that this bug
may be very hard to fix (especially if the drivers contain a bug somewhere).

How much RAM do you have? If you have an Intel HD card I suppose that you
don't have so much memory that you absolutely need Python 64 bits (with 32
bits you're probably limited to ~4GB objects). Those who will really need a
64 bits distribution will probably have a better graphics card anyway and
may be able to use your program.

Cyrille

2013/4/3 Patrick Dietrich <[email protected]>

>
> As I'm trying to get my program fit for the future, I would like to
> avoid "downgrading" to 32 bit python.
>
> I tracked the problem a bit further:
>
> I replaced
>
>          self.framebuffer_id = glGenFramebuffers(1);
>
> with
>
>          fbo = ctypes.c_uint(1)
> OpenGL.raw.GL.EXT.framebuffer_object.glGenFramebuffersEXT(1,
> ctypes.byref(fbo))
>          self.framebuffer_id = int(fbo.value)
>
> I'm not sure if the code is ctype-wise correct but I think that doesn't
> make a real difference for the error:
>
> Traceback (most recent call last):
> ...
>    File "C:\Users\Patrick\Dev\PCT\open_gl_widgets.py", line 203, in
> __init__
>      OpenGL.raw.GL.EXT.framebuffer_object.glGenFramebuffersEXT(1,
> ctypes.byref(fbo))
>    File "C:\Python27\lib\site-packages\OpenGL\platform\baseplatform.py",
> line 379, in __call__
>      return self( *args, **named )
> WindowsError: exception: access violation writing 0xFFFFFFFFE812A790
>
> Could anyone from the developers please help me track down the problem
> further? I'm very happy to assist in fixing this problem!
>
> Cheers,
> Patrick
>
>
> Am 03.04.2013 17:50, schrieb Cyrille Rossant:
> > I had a similar problem with a similar configuration and a similar
> > graphics card. I couldn't solve the problem, so I ended up removing my
> > whole 64 bits Python distribution and reinstalling everything with
> > Python 32 bits... and it worked.
> >
> > Cyrille
> >
>

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