Re: Simple AI Scripting, Help Me!

["Tim" <tryness@...>]

Thanks for you help, I really appreciate it, my only question now is I need
to call a function everyframe to update a dudes position or state (every
frame or every 5 or whatever).  Not sure how I would do this with this
example below.  How would it tie in with my player class etc.  I don't want
to really expose a whole players class (from lua), nothing if I can help it.
I want the scripts
to be really high level, so anyone could write scripts for it.  I don't want
to write the scripts myself, I want to set them up, and hand them off to
some else who doesn't have
much knowledge of programming (if need be).  So I don't really want it to
look like c++, or c (lua does resemble it), just they way one would think
enemyclose(), runforcover(), seekhealth(), findescort(), etc etc, and I
expose those functions to lua.  If I load this main.lua it will parse the
whole thing, and stall my app, I call it from my initfunction of my game,
where is before, I called a function to update a guy from c++, everyframe,
and returned true when it finished the function .. his goals.


Thanks,

Tim Ryness

----- Original Message ----- 
From: "Kevin Baca" <lualist@aidiastudios.com>
To: "'Lua list'" <lua@bazar2.conectiva.com.br>
Sent: Saturday, December 06, 2003 3:59 PM
Subject: RE: Simple AI Scripting, Help Me!


> There are many ways to do this, and the "file == class" technique (where
> a file containing methods represents a class) is not necessarily the
> easiest or most straightforward.
>
> The most straightforward, IMO, is described here:
>
> http://lua-users.org/wiki/ObjectOrientationTutorial
>
> If you want to use the "file == class" technique, look at loadfile():
>
> http://www.lua.org/manual/5.0/manual.html#5.1
>
> A simple example:
>
> BadGuy.lua
> ----------
> local BadGuy = {}
>
> function BadGuy:doSomething()
>     print( "Bad Guy doing something" )
> end
>
> return BadGuy
>
> GoodGuy.lua
> ----------
> local GoodGuy = {}
>
> function GoodGuy:doSomething()
>     print( "Good Guy doing something" )
> end
>
> return GoodGuy
>
> main.lua
> --------
> local BadGuy = assert( loadfile( "BadGuy.lua" ) )()
> local GoodGuy = assert( loadfile( "GoodGuy.lua" ) )()
>
> function createBadGuy()
>    return setmetatable( {}, { __index = BadGuy } )
> end
>
> function createGoodGuy()
>    return setmetatable( {}, { __index = GoodGuy } )
> end
>
> Interpreter
> -----------
> > dofile "main.lua"
> > badguy = createBadGuy()
> > goodguy = createGoodGuy()
> > badguy:doSomething()
> Bad Guy doing something
> > goodguy:doSomething()
> Good Guy doing something
> >
>
> See the following for examples on associating lua objects with C
> objects:
>
> http://lua-users.org/wiki/SimpleCppBinding
>
> You should try to minimize the number of interfaces between lua and C.
> This implies that you should minimize the number of C data structures
> that have direct counterparts in lua, and vice versa.
>
> Based on my own experience I've found that if you plan to have most of
> your game logic in C, you should create your heavyweight entity
> structures in C and use lua only for configuration, variable
> definitions, etc.
>
> OTOH, if you plan to have your game logic in lua then your heavyweight
> entity structures should be in lua.
>
> -Kevin
>
> -----Original Message-----
> From: lua-bounces@bazar2.conectiva.com.br
> [mailto:lua-bounces@bazar2.conectiva.com.br] On Behalf Of Tim
> Sent: Saturday, December 06, 2003 2:35 PM
> To: lua@bazar2.conectiva.com.br
> Subject: Simple AI Scripting, Help Me!
>
>
> I have been playing with lua for the last little while trying to get lua
> working within the game.  I can run a single script via/ lua_dofile, and
> register some functions.  So I now I have a script such as the
> following.
>
> function playerinit()
> local rvalue = 0
>     if ( keyhit("DIK_SPACE") > 0 ) then
>         drawstring(-1,30,"hit spacebar")
>         rvalue = 1
>     end
>   return rvalue
> end
>
> ok yeah really simple, I get this just fine, what I want to do is have
> every player in the game, have it's own script like badguy  uses =
> badguy.lua, hero uses = hero.lua  what I want to do now is have three
> states for every player like init, process, exit, so I have a
> playerinit(), playerproc(), playerexit() in each ai script, so when I
> process my guy from my c++ code, I can say (from my main process loop
> c++) registerplayer(this), it registers my luaclass with a pointer to
> the active player.  Then I  then later call lua .. via
> lua_getglobal(luaVM, "playerinit") etc, but I want each of my .lua files
> to have the same function names init proccess exit.  when a
> state(funcion in lua) is complete it returns true, and then I change
> from say init to process, and inside process would have commands like..
>
> if(enemyisnear()) runforcover();
> else patrolpath();
>
> That would be my process function, the problem I guess I'm having, is
> the whole problem with multiple lua_states, and stuff, and how to
> arrange it, how to set it up, etc.  My app is not multithreaded, but can
> I use lua_newthread?  I'm basically lost, combing through threads of
> threads looking for answers so I have come to this.   What it seems as
> though is happening, is that when I add a new guy into the world, and
> call lua_dofile(), it basically becomes the script in which all players
> use, I tried something with calling lua_open and storing a state in the
> player class, but that didn't seem to work to well..  Ideally I would
> like to use one lua_state, and then when the lua functions are called
> from c, it just works itself out, I have no idea, how to set this up.
> I'm beyond frustrated, I'm a beginner user, I don't have lots of time to
> spend researching this stuff, but I want to use it, it's a great
> language, there must be a good and easy way to do this.  I think I could
> probably do it if each guy had unique function names, and somehow, store
> them in the class and call them as needed, but I would rather have the
> same set of functions for every actor in the world.
>
>
> Any Ideas?
>
>
> Thanks,
>
> Tim Ryness
>