Cooperative multitasking for games

[John Peterson <jjbpaq@...>]

Hello everybody! I'm new to Lua and it's my pleasure
to greet everybody on this list that is interested in
the wonderful language Lua!

I'm yet another game developer that's intent on using
Lua! The Lua language really rocks! But I and I guess
many like me have a GREAT problem... please read on.

For the past days I have been reading the archived Lua
mailing list, and was pleasantly surprised to find
fine professionals such as Bret Mogilefsky talking
just about what I'm interested in: implementing some
form of non-preemtive multitasking in my would-be
adventure game engine using Lua. After some research I
was immediately convinced that Lua is the most
suitable language for this in terms of its
unencumbered syntax and fast execution, not to mention
special features. Then I was surprised that Lua was
used in a successful commercial game project: Grim
Fandango from LucasArts. I think that's a great
success for Lua and its developers should be very
proud of it! Indeed!

Now, before I read the mailing list, I was convinced I
could implement cooperative multitasking using a queue
of Lua states and switching between them in response
to a delay or sleep command from the script.
Needless to say, Bret Mogilefsky's comments to how he
did these at LucasAts did clear up some details and
confirmed I am on the right track.

However, not being aware of the problems with
continuation that arise from Lua stack usage, I felt
quite discouraged from the difficulties of modifying
Lua for this purpose.

Observing that has been inactivity for about 5 months
after the initial discussion of these matters, I felt
obliged to ask all interested:

Has anyone already succeeded in modifying Lua to
support cooperative multitasking necessary for an
adventure game engine?
Bret Mogilefsky was talking about a patch to the final
Lua 4.0 but of course he's busy (Who is not?).

I feel discouraged because I see that there's some
confusion about the
way this multitasking can be implemented, and ask if
there's any progress before I start -- oh, no --- to
delve into the Lua code and try to save myself
somehow.

Any report of the progress of the situation would be
REALLY APPRECIATED.

My apologies if I've annoyed or bored anyone.

Thanks in advance.

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