Re: [PyOpenGL-Users] mixing C++ and python w/ opengl

[Philip W. <pwi...@gm...>]

>
> You may want to try using Cython, rather than raw C.


We've been meaning to investigate Cython.  We use C/C++ libraries and ctypes
today.  One advantage of C is that other C/C++ programs can use the
libraries.  But I'm interested in trying Cython just to learn about it.

> Rather than pull it into Python and then push it
> > back with pyopengl, it seems like we could just draw it from C, if that
> > is allowed.
>
> well, I don't know that I'd do it for this reason -- if you pull/push
> the data as numpy arrays, you can do all that without data copying, so
> keeping it in Python may be fine.
>

You might be right.

How do you completely avoid the copy?  I do something really simple/dumb
when right now when I need to return an array from C to Python.  I do use
numpy, but I do the allocation in Python and then hand the empty array to C
to copy the values into.

I saw some stuff about defining an allocator but it looked complicated.

I wonder if my simplistic approach if the copy would hurt me.  I wonder if I
should be using a better no-copy approach instead.

Anyway probably I should start by keeping drawing in Python and if/when I
measure a real performance problem consider pushing it to C.  This is how we
operate with other stuff, resorting to C only to solve a specific
performance issue.

-Philip