Re: [PyOpenGL-Users] Controlling vertical sync on Mac OS X / crashes when trying to access platform-specific stuff via ctypes

[Ian M. <ia...@ge...>]

On Fri, Jun 14, 2013 at 8:03 PM, Nathaniel Virgo
<nat...@gm...>wrote:

> Hi Ian
>
> As far as I can tell, the glX* functions referred to in that link are the
> platform-specific stuff for X Windows, whereas the CGL* functions used in
> the code I posted are the equivalent for a Mac. However, the problem is
> that I can't seem to call any of these platform specific functions from
> within Python without causing a segmentation fault.
>
> Of course, if you or anyone else has any code for calling glX* functions
> on linux from PyOpenGL it would really help a lot, because maybe I can
> modify it to use the CGL* functions that I need to use on OS X.
>
> Kind regards,
> Nathaniel
>
I meant, that link has some of the information to get you started. Getting
started with double-buffering instead of tweaking VSync is probably the
solution to most problems. Because of the way displays work, a completely
rendered graphics frame is much more important than synchronizing display
blit to the actual rendering.

Many windowing systems automatically enable VSync initially. SDL (PyGame in
Python) is one example. GLUT is not one, as I remember. Ultimately any
solution is platform specific--though it may be masked in a platform
independent layer. GLUT apparently doesn't provide such a platform
independent layer for you, so any solution is going to be platform specific.

But that's already been established. GLUT has other problems. Its callback
methods are crude and inflexible. Its support for context creation is
lacking. It's built on ancient technology and is semi-proprietary. It
supports only one window and has a restricted set of controller inputs and,
as you see, poor platform abstraction for some tasks.

I don't know what's wrong with your ctypes code, but I *can* tell you that
there are much better options than GLUT. PyGame, which I mentioned earlier
is an excellent choice. It is better than or equal to GLUT in literally
every way, including VSync support--which you can toggle when creating a
window. I know it's not really what you asked for, but it's my
recommendation.

Ian