Re: [PyOpenGL-Users] Question on glBufferData / glBufferSubData

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

On 03/25/2014 12:54 PM, Walter White wrote:
> Hello Mike,
>
> still no success on the issue.
> I tried two different machines, identical set-up, Win7,64-bit,Python 3.3,
> same problem.
>
> This is the complete error message, maybe you can take a look:
>
> http://bpaste.net/show/2KUuv5TCRPrYbI1OkCa5/
>
> I guess the following calls are identical, right?
>
> glBufferSubData(...,...,..., ADT.voidDataPointer(tmpArray))
> glBufferSubData(...,...,..., tmpArray)

Yes, voidDataPointer is automatically called, no reason to do the call 
yourself.

I see that vispy has encountered the *same* error you are seeing on some 
particular machine:

     https://github.com/vispy/vispy/issues/64

The commit linked there suggests that this is a bug in specific ATI 
drivers. Almar worked around it by redoing the call with glBufferData 
IFF the values happen to cover the whole buffer.

I am *not* seeing the bug on AMD Linux, as noted, but possibly some AMD 
Windows driver has it?  I have to say I'm pretty surprised to see 
something as basic as glBufferSubData have an error like this... this is 
pretty basic/core functionality to have it not work.

Precise hardware/driver information is likely relevant here, the fact 
that the two machines failing are identical lends credence to the 
driver/hardware issue, I suppose.

Thanks,
Mike

-- 
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   Mike C. Fletcher
   Designer, VR Plumber, Coder
   http://www.vrplumber.com
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