[PyOpenGL-Users] Question about glSeparableFilter2DEXT

[Gary H. <gh...@is...>]

I'm writing an application that has need for a 2D convolution, and so
hoped to use the function glSeparableFilter2DEXT from the module
OpenGL.GL.EXT.convolution.  However, when I call
glSeparableFilter2DEXT, I get the following error message which I'd
like to understand:

    OpenGL.GL.GLerror: [Errno (1282,)] Dynamic function loading not
    implemented/supported on this platform

I believe I get this because the OpenGL library does not implement the
convolution extension (neither GL_EXT_convolution nor GL_ARB_imaging
string appear in the GL_EXTENSIONS list), but I keep tripping over my
hazy understanding of OpenGL version, PyOpenGL version, and various
extension.

Two questions I hope someone can answer:

1. What does the above error mean?

2. How do these facts fit together: The various filter/convolution
   operations seem to be defined in the GL_EXT_convolution extension
   (True?), but later these and other extensions appear to be under an
   umbrella-like extension GL_ARB_imaging (True?), and in a later
   version of the OpenGL spec, these operations migrated into the
   OpenGL core (True?), but as an optional feature (True?).  Can I
   tell if a particular implementation (of OpenGL version 1.4 in my
   case) provides this function in the core or not by looking at the
   GL_EXTENSIONS string?  If it does provide SeparableFilter2D, can
   PyOpenGL call it or will I trip over a version mismatch since
   PyOpenGL supports only up to OpenGL version 1.1?

3. Is it really possible that a several-month-old top-of-the-line
   graphics card does not support simple convolutions?

Sorry for the long question 2, but I would dearly like to clear up my
hazy understanding here.

System facts:
    Windows XP
    Python 2.3, 
    PyOpenGL 2.0.1.07
OpenGL facts:
    GL_RENDERER:  RADEON 9800 Pro x86/SSE2
    GL_VERSION:   1.4.4103 WinXP Release

Thanks,
Gary Herron