[pygame] Accessing opengl surface as a numpy array

[nbl <nblouveton@xxxxxxxxx>]

Hi everybody !

Usually, I use the pygame.surfarray pixels2d function to reference the
pygame-display's surface as a numpy array.

As long as I used a standard pygame surface with
pygame.display.set_mode, this method worked fine but now, I try to do
the same thing with 3d displays setting the OPENGL flag...

Unfortunately, it seems pixels2d method doesn't work in this case.
Pixels2d return a reference to an array with correct shape but with
all cells set to zero whatever it is displayed on the screen.

So, I would want to know if there is an incompatibility between
surfarray's methods and opengl surfaces (I didn't find this
information in the pygame documentation) and in this case how could I
do the same job with an OPENGL surfaces ?

Cheers,
Nicolas