Re: [PyOpenGL-Users] glGenVertexArrays producing 'invalid enumerant' error.

[Gordon W. <go...@to...>]

The plot thickens, if I bypass pyopengl and do the glGenVertexArrays call
direct through ctypes the "invalid enumerant" error moves to the
subsequent glBindVertexArray call, if I use cytpes for that as well then
everything starts working.

G

On Fri, Nov 4, 2011 at 11:30 PM, Gordon Wrigley <go...@to...> wrote:

> I just got a chance to get back to this and I've made a little head way,
> far enough that I have something on screen.
> Specifying GLUT_COMPATIBILITY_PROFILE instead of GLUT_CORE_PROFILE got
> round the glGenVertexArrays error.
> I also had to do ctypes stuff to work around the lack of wrapper for that
> function.
> And the function glVertexAttribPointer was getting cast errors on the last
> argument so I had to ctypes around that as well.
> I believe that's the only dirty stuff I have so far.
>
> G
>
>
> On Tue, Oct 25, 2011 at 1:56 AM, Mike C. Fletcher <mcf...@vr...>wrote:
>
>> **
>> On 11-10-20 06:41 AM, Gordon Wrigley wrote:
>>
>> And I attached the wrong log, here's the correct one.
>>
>>
>> Hrm, not much to go on there.  The call to createShader() does not appear
>> in the stack, which is a bit weird.  Is this code I could trace through to
>> try to find the error (i.e. not something proprietary?)
>>
>> Good luck,
>> Mike
>>
>>
>>
>> On Thu, Oct 20, 2011 at 9:39 PM, Gordon Wrigley <go...@to...>wrote:
>>
>>>   On Tue, Oct 18, 2011 at 4:56 AM, Mike C. Fletcher <
>>> mcf...@vr...> 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
>>>
>>>
>>>
>>
>>
>> --
>> ________________________________________________
>>   Mike C. Fletcher
>>   Designer, VR Plumber, Coder
>>   http://www.vrplumber.com
>>   http://blog.vrplumber.com
>>
>>
>