Re: [PyOpenGL-Users] problem with soya's usage of OpenGL

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

We don't do anything particularly fancy in the wrapper for glGetString, 
here's what it looks like for the generated OpenGL 1.1 wrapper from 
PyOpenGL 2.0.1.08:

static PyObject *_wrap_glGetString(PyObject *self, PyObject *args) {
    PyObject *resultobj;
    GLenum arg1 ;
    GLubyte *result;
    PyObject * obj0  = 0 ;
   
    if(!PyArg_ParseTuple(args,(char *)"O:glGetString",&obj0)) return NULL;
    arg1 = (GLenum) PyInt_AsLong(obj0);
    if (PyErr_Occurred()) return NULL;
    {
        result = (GLubyte *)glGetString(arg1);
        if (GLErrOccurred()) return NULL;
    }
    {
        if (result)
        {
            resultobj= PyString_FromString(result);
        }
        else
        {
            Py_INCREF(resultobj = Py_None);
        }
    }
    return resultobj;
}

I can't see anything there which is markedly different from your 
approach.  PyOpenGL is fairly minimal wrt what it sets up for contexts.  
AFAIK we aren't doing anything funky with initialising our reference to 
OpenGL, leaving the context-creation work to the GUI libraries as much 
as possible, (though I should note that that stuff would all have been 
written by someone else, so it could be we spend thousands of lines of 
code on it somewhere and I've just missed it during maintenance).  We do 
some minimal stuff such as defining functions for retrieving the current 
context under OpenGL 1.0, but I doubt that's relevant.

 From the docs: 
(http://pyopengl.sourceforge.net/documentation/manual/glGetString.3G.xml)
            GL_INVALID_OPERATION is generated if glGetString is executed 
between the
            execution of glBegin and the corresponding execution of glEnd.

I'd confirm that you are not calling this within those functions.  That 
and an invalid enum (feature-name) are the only two listed errors, and a 
0 (NULL) return value apparently only occurs on error.  Could your 
GLenum somehow be suffering from an off-by-one or similar error such 
that it's giving you lots of "invalid enum" errors across many parts of 
the API?

Seems your check_gl_error() isn't picking up the failure for some 
reason, but that doesn't solve the base problem.

Good luck,
Mike

________________________________________________
  Mike C. Fletcher
  Designer, VR Plumber, Coder
  http://members.rogers.com/mcfletch/
  blog: http://zope.vex.net/~mcfletch/plumbing/