Re: glGenVertexArrays producing 'invalid enumerant' error.

On Tue, Oct 18, 2011 at 4:56 AM, Mike C. Fletcher <[email protected]>wrote:

> On 11-10-12 03:34 AM, tolomea wrote:
> > Version stuff:
> > Python 2.7.1+ (r271:86832, Apr 11 2011, 18:05:24)
> > [GCC 4.5.2] on linux2
> > Type "help", "copyright", "credits" or "license" for more information.
> > import OpenGL
> > OpenGL.__version__
> > '3.0.2a1'
> > I'm using FORWARD_COMPATIBLE_ONLY, context version 3.3 and
> GLUT_CORE_PROFILE.
> >
> >
> > I'm porting a working (same machine and environment etc) C program to
> Python,
> > and the glGenVertexArrays function is giving me grief.
> >
> > The pythonic form:
> >     vao = glGenVertexArrays(1)
> > produces "TypeError: this function takes at least 2 arguments" which I
> presume
> > means it hasn't been wrapped yet.
> Yes.
> > I've no idea what could be causing that and googling hasn't turned up
> anything
> > useful.
> >
> > Does anyone have any suggestions as to where to look?
> > Are there any known working examples of using vertex array objects and
> pyopengl
> > that I could cross check against?
> My go-to guess with almost any Python-differs-from-C problems during
> init is to look at the error-checking code.  PyOpenGL's biggest
> difference from C code is that it runs error checking after every call.
> I'm guessing either your context isn't quite ready-to-go and you're
> getting an error from the error checking, or that the line before had an
> error and the error checking picked it up a line late.
>
> import OpenGL
> OpenGL.USE_ACCELERATE = False
> OpenGL.ERROR_CHECKING = False
>
> at the top of your script should let you quickly determine a) where the
> problem is b) whether the problem is with error checking.
>
>
If I turn error checking off it dies much earlier on a glCreateShader call
with:

WARNING:OpenGL.errors:Failure on glCreateShader: Traceback (most recent call
last):
  File "/usr/local/lib/python2.7/dist-packages/OpenGL/logs.py", line 74, in
__call__
    return function( *args, **named )
ArgumentError: argument 3: <type 'exceptions.TypeError'>: Don't know how to
convert parameter 3

Traceback (most recent call last):
  File "main.py", line 237, in <module>
    main(sys.argv)
  File "main.py", line 227, in main
    init()
  File "main.py", line 147, in init
    init_program()
  File "main.py", line 122, in init_program
    vert = gl.VertexShader("data/shaders/basic.vert")
  File "/mnt/drive1/home/gordon/code/spacecraft2/gl.py", line 50, in
__init__
    _Shader.__init__(self, fname, VERTEX_SHADER)
  File "/mnt/drive1/home/gordon/code/spacecraft2/gl.py", line 37, in
__init__
    self.shader = createShader(shader_type)
  File
"/usr/local/lib/python2.7/dist-packages/OpenGL/platform/baseplatform.py",
line 372, in __call__
    return self( *args, **named )
  File "/usr/local/lib/python2.7/dist-packages/OpenGL/logs.py", line 74, in
__call__
    return function( *args, **named )
ctypes.ArgumentError: argument 3: <type 'exceptions.TypeError'>: Don't know
how to convert parameter 3


That doesn't seem like progress.

With error checking on calling glGetError right before the glGenVertexArrays
call returns 0.

Toggling use accelerate hasn't made any noticeable difference.

I don't know if it helps any but I turned on full logging and attached a
dump of the output.

G

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