On Jun 30, 2009, at 7:08 PM, Ondrej Certik wrote:

> On Tue, Jun 30, 2009 at 7:30 PM, Lisandro Dalcin<[email protected]>  
> wrote:
>> On Tue, Jun 30, 2009 at 10:14 PM, Ondrej Certik<[email protected]>  
>> wrote:
>>>
>>> Ah, I think I am wrong. Numpy's strides is exactly what I need,  
>>> right?
>>>
>>> http://docs.scipy.org/doc/numpy/reference/generated/ 
>>> numpy.ndarray.strides.html
>>>
>>> so I just take *any*  numpy array, as long as it has the right  
>>> dtype,
>>> and then just pass the pointer to .data and strides to the opengl
>>> function.
>>>
>>
>> Perhaps it works... Just in case, test it with a numpy array using
>> Fortran ordering, perhaps OpenGL does not like it?
>
> So far all functions in opengl use 1D arrays only.
>
>>
>> BTW, do arrays with more than two dimensions make sense in OpenGL? Do
>> you know exactly what numpy strides mean (any nd-array have
>> nd-strides, even the contiguous ones) ?
>
> Yes, a stride is the number of bytes you need to move your pointer to
> get to the next element in the array. opengl only accepts 1D arrays,
> but it *does* accept a stride.
>
> Can it happen, that a 1D numpy array has stride which is bigger than
> sizeof(dtype)? so far I didn't manage to create one.

Yes.

sage: a = numpy.zeros(10)[::5]
sage: a.strides
(40,)

- Robert
_______________________________________________
Cython-dev mailing list
[email protected]
http://codespeak.net/mailman/listinfo/cython-dev

Reply via email to