Re: [PyOpenGL-Users] PyOpenGL GLX extension problem

[Mike C. F. <mcf...@vr...>]

On 13-03-29 07:30 AM, Jean-Baptiste Molle wrote:
> |Hi,
>
> I'm trying to create a program with PyOpenGL but I'm stuck with a GLX problem.
> |
|Attached find a script that does what your code is doing AFAICS, though 
without a pixmap to actually use, it doesn't do anything useful.  It is 
written to be run from the PyOpenGL source-code checkout tests 
directory|, but that's just so that I don't have to go about creating 
contexts and the like.

Quick summary:

  * you need the [0]'th element of the returned Display pointer to get
    the Display reference that all other calls are expecting (you have
    to dereference the pointer, basically)
  * the array-of-enums pattern is shown, in this case I'm using ctypes
    arrays to create the data:
      o note that you need an ordered sequence (list or tuple) not a set
        (the C syntax for arrays happens to look like a literal set in
        Python)
      o GLint * len(attributes) -> creates an array type
      o (*attributes) --> then creates an instance of that array type
        which is initialized to the values in the list
  * you could also have used:
      o GLintArray.asArray( attributes )
      o but I'd suggest being explicit about this kind of thing where
        possible

Note that the GLX API is not "wrapped" in the same way as the GL API, 
it's an auto-generated/raw wrapper with little or no attempt to make the 
API clean or friendly.

Hope that helps,
Mike