Re: [matplotlib-devel] Experiments and questions / OpenGL backend

[Nicolas R. <Nic...@in...>]

I've created a fork at: https://github.com/rougier/matplotlib/tree/gl-backend

The name of the backend is glut (it requires OpenGL) and does not display anything, it only measures fps.

It seems to be stuck at 100fps with the following test script:

import matplotlib
matplotlib.use('glut')
from pylab import *
plot([1,2,3])
show()

while the same do-nothing window directly in pyOpenGL is around 2000fps on the same machine.

I would like to understand why this is so slow and if it can be fixed.



Nicolas






On Jul 27, 2011, at 3:28 PM, Benjamin Root wrote:

> 
> 
> On Wednesday, July 27, 2011, Nicolas Rougier <Nic...@in...> wrote:
> >
> >
> > Hi all,
> >
> > I've been testing various idea around the idea of a GL backend, and I would have a few questions.
> > First, I tried to use the backend template to quickly test an empty pyglet backend and I've been quite surprised by the bad performances. Without drawing anything, I can hardly reach 100FPS and I wonder if I did something wrong ? (The backend is available backend_pyglet.py <http://www.loria.fr/~rougier/tmp/backend_pyglet.py> and the test file is at test_backend_pyglet.py <http://www.loria.fr/~rougier/tmp/test_backend_pyglet.py>)
> >
> > Second, I've been experimenting with proper anti-alias technics (using shaders) and the results are not so bad so far (IMHO) :
> > Antialiased line with thickness varying by 0.1 pixels:
> > http://www.loria.fr/~rougier/tmp/aa-line.png
> > (don't paid attention to the cap, it's not done yet)
> >
> > Antialiased circles (small circles position is increased by 0.1 pixels)
> > http://www.loria.fr/~rougier/tmp/aa-circle.png
> > (I can post source code if anyone is interested)
> > I don't know yet if all matplotlib artists can be drawing using these technics.
> >
> > My question relates to the cairo backend that now seems to support gl and shaders. Does anyone know the status of the gl-backend and how it would improve performances of matplotlib ? (I had a hard time finding any information). 
> >
> > Nicolas
> 
> Nicolas,
> 
> I want to immediately encourage you to continue on your efforts.  PLEASE make a fork on github so that we may be able to experiment better.
> 
> Cheers!
> Ben Root