[airstrike] two player mode now working

[Ulf Ekström]

> A POV model from the plane wreck (whether it's red or blue) is missing,
> I wonder whether anybody could work on that?

Also some new planes would be good, now it's very easy to add them.
 
> >From the usability point of view a couple of things are still missing:
> - Player dying:
>   - IMHO engine shouldn't work (and addition to machine gun) when
>     the plane has been wrecked.  Control could otherwise work though.

I agree.

>   - How / where player is supposed to be "reborn"?
>    - Should the sprite field have a field for "regen" position or should we
>      have generator objects?

maybe we can do

spawn{
	x = 34
	y = 344
	max_children = 8
	delay = 10 # wait 10 seconds between spawnings 
	sprite{
		type = zeppelin 
		..
	}
}

>    - How to define them so that in settings file one can still give all the
>     current options for the objects to generate?

This is a bit of a problem.. 

> - Score counting
> - Computer (AI) for single player mode.
>   - I would assume adding the one from earlier version of Airstrike as
>     biplane controller should  be fairly easy now that infrastructure is in
>     place, right?

Yes, in principle. 

>   - Should this be controlled from the level file (i.e. we would have single
>     player levels and two player levels), or from the command line?

I think  the level file should have possibilities for both types of
ai, and then it should be possible to change it in game or on the commandline.

We can do something like:

ai1 = player1_ai
ai2 = cpu_ai

sprite{ type = biplane
	ai = ai1
	..
}


>     If from command line, it would probably affect all the levels, with e.g.
>     options:
>     -ais player1,player2,ai1,ai2
>     -names "Player 1","Player 2","Blue Duke","Red Baron"
>     And it would of course complain if number of ais and names wouldn't
>     correspond.  Ai names would be pre-defined so that ones starting with
>     "player" would be controlled from keyboard, ones with "ai" would be
>     computer AI (In Airstrike 2 we might have "net" AIs too :-)))

I think we should unify the settings file with the command line
arguments, such that the commandlines overrides the settings but
with the same syntax. Then this will follow almost automatically. Another
thing we have to do is to implement a menu systems inside the game.

Ulf