Re: Game Integration

[Ignacio Castaño <castanyo@...>]

Sorry Chris, that's what you would do on the C side:

First, create your main lua state with lua_open.

Create a new thread for each scripts that you want to run in parallel, that
is a state with its own stack.

Instead of lua_dofile, use lua_load or any of the functions that provides
the aux library (ie. luaL_loadbuffer). That parses your script and leaves
the main function on the top of the stack.

Instead of using lua_pcall to run that function, use lua_resume, that way,
it will yield when it finds a yield function. You can resume the thread as
many times as you want, but you will have to use some kind of return codes
to determine the end of the execution (or use lua_getstack).

while(1) {
    lua_resume( thread, 0 );

    // check return code
    if( !lua_isnil( thread ) ) break;

    // render your world
    ...
}


> Ignacio, are you suggesting that my game script need to call in to my C
> code to 'resume'. If that is so doesn't it mean that the misson script
will
> need to know how to drive the game, rather than just be concerned about
the
> mission at hand?

I was suggesting the use of a message queue to have better control over the
execution of the script. Instead of resuming the script every frame you
could do it just when the script wants, that is, after a few seconds, when
an animation ends, when some event happens, etc.


Hope that helps,


Ignacio Castaño
castanyo@yahoo.es


Chris Brodie wrote:
I still cannot see how I can get the C code working. How do I stop my
lua_dofile from blocking my applications main loop from executing?

For example I run a script that runs my mission. How can the game render
while the mission is running? The script never returns. If someone can
suggest a way that doesn't block my games code from executing I'll also need
some kind of C function to resume that script periodically.

I thank everyone for their help but nobody seems to suggest what I should be
doing ni C to make this all work.

Ignacio, are you suggesting that my game script need to call in to my C code
to 'resume'. If that is so doesn't it mean that the misson script will need
to know how to drive the game, rather than just be concerned about the
mission at hand?