Re: [PyOpenGL-Users] glDeleteBuffers() and arrays.vbo

[Dan H. <Dan...@no...>]

Mike C. Fletcher wrote:
> Dan Helfman wrote:
>> Exception OpenGL.error.NullFunctionError: NullFunctionError('Attempt to 
>> call an undefined function glDeleteBuffers, check for 
>> bool(glDeleteBuffers) before calling',) in <function doBufferDeletion at 
>> 0x0A8892B0> ignored
>>   
> This sounds like the VBO is getting deleted after module cleanup?  You
> should always have a glDeleteBuffers implementation if you have a
> glGenBuffers implementation.  Basically this code is getting called
> after the system has done so much cleanup that the functions aren't
> available any more (at least, that's my interpretation).

This is happening when a VBO instance is finalized after its containing 
object goes away. And as far as I can tell, the deleter is only being 
called once for each VBO. So I'm not sure what else could be doing the 
cleanup unless it's in the underlying C code. I put some prints in the 
explicit VBO.delete() call, so I've confirmed that that's not getting 
called.

I should mention that this is all with the 3.0.0 release.

> That's now fixed in bzr head, will show up in the 3.0.1a2 release.  i.e.
> we catch the NullFunctionError, so you shouldn't see the ignored error
> messages any more.

Great, thanks!

> That said, you *shouldn't* ever need to explicitly call delete on the
> VBO instance unless for some reason you want to "reuse" the VBO object
> but not the GL-side buffer (I can't think of a real use-case for that).

Gotcha.

Dan