Re: [Visualpython-users] OS X Native

[Jonathan B. <jbr...@ea...>]

On Fri, 2005-06-24 at 19:25 -0400, Ilan Volow wrote:
> I've never understood why VPython wasn't written purely in python  
> using PyOpenGL as opposed to using C/C++ to do the OpenGL stuff as it  
> currently does. The few times I've looked at the VPython code, it  
> looked like a messy interweaving of python calling C calling python  
> calling C calling python etc.

Actually, its entirely Python->C++.  Right now, C++ never calls Python
code.

>  If all the OpenGL stuff were done with  
> PyOpenGL (and possibly PyGame), I would think that the code would be  
> cleaner and far more portable.

Bruce hit on the first reason - raw speed.  The fewer CPU cycles spent
rendering, the more can be spent doing physics.  The second is that the
rendering is performed asynchronously in a separate thread.  Python is
not really designed for multithreading; only one thread at a time can be
executing, even on Hyperthreading-equipped Pentium 4s, multiprocessor,
and multicore systems.

I have done some experimentation with PyOpenGL to prototype a different
OpenGL-using application.  I found that the performance was unacceptable
for any kind of dynamic scene, such as what most VPython client programs
create.

-Jonathan