Fwd: Re: [Pysdl-devel] Announce: pyAliens 1.0

[David C. <D. C. <si...@te...>]

> Does the speed limitation of the Python
> interpreter mean that it runs at somewhat similar
> speed on different-speed cpus?

My guess about the source of the speed limitation is apparently
incorrect. Running on the same system using HWSURFACE vs. SWSURFACE
results in a huge speed difference, as you comment. Thus, the
limitation in speed is due to SDL and/or pySDL. I suspect it's due to
SDL, since running the C version of aliens without the frame rate
limiter results in a similar jump when going from software to video
memory.

Nonetheless, you're right - different systems will play my pyAliens at
vastly different speeds. The reason is simple. Sam's aliens is speed
limited - it can never get above 50 fps, no matter how fast your
computer is. This is The Right Thing. I chose not to port that section
of code ( wait_frame() for anyone who wants to write a patch ),
partially because I wanted to see how performance varied over
different systems and different video flags, but mostly because I
didn't want to bother learning Python timing techniques last
night. You see, SDL has a timing-specific subsystem, but Mark has
decided (rightly, IMO) not to incorporate that subsystem into pySDL,
instead leaving timing issues up to the python library. I may write
the appropriate code tonight; we'll see how motivated I am.

David Clark
si...@te...
Preliminary pySDL documentation:
http://www3.telus.net/futility/futility/docs/pysdl/index.html