Re: Scripting

[Steve Baker <sjbaker1@airmail.net>]

Mark Collins wrote:
> 
> On Wednesday 17 April 2002 10:52 am, you wrote:
> > Again, without instructions that can span frames, this cannot be a simple
> > script that's part of the game world.
> 
> Python does support embedded scripts running in a seperate thread, so the
> arguments about scripts being run accross multiple frames are kinda
> opintless, as this can be remedied with a sungle call (I don't have the
> Python docs on this machine, so I can't tell you what the call is)

Is that a real OS-level thread or simply the (single-threaded) interpreter
jumping from interpreting one script to interpreting a different one?

If it's the latter then that's a useful thing and I should go back to using
it instead of my own byte-code interpreter for a home-made C subset.

If it's the former then it's not much use because the OS won't efficiently
support enough full-blown threads for the number of AI scripts and other
behaviours that I'd like to have.

I'd like things like:

  behaviour_for_light_switch ()
  {
    while ( 1 )
    {
      sleep ( 10 frames ) ;

      if ( someone_hit_the_light_switch )
      {
        toggle ( switch_graphic ) ;
        toggle ( lightbulb_graphic ) ;
        if ( lightbulb_graphic == ON )
        {
          sleep ( 10 seconds ) ;
          signal ( security_system, INTRUSION_DETECTED ) ;
        }
      }
    }
  }

...and run one copy of this (or a slight variation of it) for every
light switch in a 100 room building, another for every creature, another
for every collectable...you name it, it has a short script for it.

Having a couple of thousand Linux threads (even if they are mostly
sleeping) isn't a good idea, but a bytecode interpreter (or perhaps
Python if it works the way I'd hope) handles this with ease.

----------------------------- Steve Baker -------------------------------
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