Re: [PyOpenGL-Users] Perl vs. Python OpenGL bindings benchmarks

[Aleksandar B. S. <asa...@gm...>]

On 6/5/07, Mike C. Fletcher <mcf...@vr...> wrote:
> Here's what a cProfile run of their "benchmark" method shows (they had a
> .tar.gz on the site, I'd thought it was just the one file, it includes
> the whole suite):
>
>    [ snip ]
>

Mike,

Thanks for running cProfile on this benchmark, and for providing
results.  Everything is as expected, I'd say - overhead regarding
using Python arrays is not that big after all, error checking is
indeed taking lots of running time, and most of running time is spent
in actually awaiting OpenGL to complete drawing (which is very
interesting in itself, because it shows that wrappers are probably not
a bottleneck at all).  So overall, I think we're good, I'll try to
work with POGL guys to have PyOpenGL based benchmark properly run on
their machines, so that they could eventually confirm what I'm seeing
on my machine (that both wrappers are approximately of same
performance), and update results on their site.

As for passing arrays to glVertexPointer: so what would be your
suggestion on best approach to accomplish this (if we're talking about
large arrays, and if we put aside that we should be doing all of this
in C instead of Python)?  I tried to replace using ctypes arrays with
using numpy arrays in trislam_pyopengl_ctp.py, and then to use
glVertexPointer() (with 4 arguments) instead of glVertexPointerf()
(with 1 argument); diff is attached (against trislam_pyopengl_ctp.py
from POGL site) and benchmark results are practically unchanged...

Regards,
Alex

------------
[alex@r51 trislam]$ diff trislam_pyopengl_ctp.py trislam_pyopengl_num.py
24c24
< import ctypes
---
> import numpy
88c88
<     data = (ctypes.c_float * 2 * (count * count * 4))()
---
>     data = numpy.empty((count * count * 4, 2), numpy.float32)
104c104
<     data = (ctypes.c_float * 2 * (count * (count + 1) * 2))()
---
>     data = numpy.empty((count * (count + 1) * 2, 2), numpy.float32)
116c116
<     data = (ctypes.c_float * 2 * (count * count * 6))()
---
>     data = numpy.empty((count * count * 6, 2), numpy.float32)
137c137
<     data = (ctypes.c_float * 2 * (count * (count + 1) * 2))()
---
>     data = numpy.empty((count * (count + 1) * 2, 2), numpy.float32)
171c171
<     glVertexPointerf(va)
---
>     glVertexPointer(2, GL_FLOAT, 0, va)
198c198
<     glVertexPointerf(va)
---
>     glVertexPointer(2, GL_FLOAT, 0, va)
213c213
<     glVertexPointerf(va)
---
>     glVertexPointer(2, GL_FLOAT, 0, va)
245c245
<     glVertexPointerf(va)
---
>     glVertexPointer(2, GL_FLOAT, 0, va)
273c273
<     glVertexPointerf(va)
---
>     glVertexPointer(2, GL_FLOAT, 0, va)
288c288
<     glVertexPointerf(va)
---
>     glVertexPointer(2, GL_FLOAT, 0, va)