[Pyobjc-dev] Confused on opaque pointers

[Andy M. <nzm...@gm...>]

I'm using the OpenGl library (successfully) with an __init__ that looks
like:
import objc as _objc
import sys
__bundle__ = _objc.initFrameworkWrapper("CGL",
      frameworkIdentifier="com.apple.opengl",
      frameworkPath=_objc.pathForFramework(
       "/System/Library/Frameworks/OpenGL.framework"),
     globals=globals())

However there is a function that takes an opaque pointer that I'm struggling
to wrap.

The opaque pointer is CGLPixelFormatObj and it's defined as
  typedef struct _CGLPixelFormatObject  *CGLPicelFormatObj;

The function I need to use is CGLChoosePixelFormat defined as
  CGLError CGLChoosePixelFormat ( const CGLPixelFormatAttribute *attribs,
CGLPixelFormatObj *pix, GLint *npix )

The ChoosePixelFormat function uses the Attributes (which I can create OK)
to modify the PixelFormatObj pointer to point to a newly created Object as
well as modifying npix to represent the number of screens..

First problem is that I am unable to create a CGLPixelFormatObj - get a
TypeError: Cannot create CGLPixelFormatObj objects.  I've tried using
createOpaquePointerType without any success..  How do I get this pointer
creates - -and then once I do that I presume I'll need to tweak the calling
signature of ChoosePixelFormat  to return the modified 'pix' and 'npix' ?

Thanks
Andy