Re: [stella] Gunfight 2600: Descissions had to be made

Subject: Re: [stella] Gunfight 2600: Descissions had to be made
From: Erik Mooney <emooney@xxxxxxxxxxxxxxxx>
Date: Tue, 06 Mar 2001 03:04:08 -0500
On Mon, 05 Mar 2001 16:36:48 +0100, you wrote:

>The next step I'll work on is the weapons system. Continuing with the
>playfield right now doesn't make sense, since I just don't now how many
>RAM is left after I'm done with the weapons. (I need at least need 2
>bytes of X/Y coordinates, plus one byte direction + one byte lifetime
>per bullet, so handling 12 bullets for example would eat up a minimum of
>48 bytes RAM...) 

You don't need 8 bits each for direction and lifetime.  The direction is
only 8-way right?  That's only 3 bits for direction.  I'm not sure how
long the bullets last, but 6 bits gives you over one second at 60 fps.

Can't quite compress it to one byte per bullet which would be convenient,
unless you have half-second bullet lifetimes, or run the bullet processing
only every 2 or 3 frames -- although some of the best 2600 games are built
on compromises like that.  At any rate, you can certainly stuff 2 bullet
directions per byte.

I'm not quite sure of the behavior of the bullets - do they bounce or
anything?  If not, you're storing redundant information somewhere in the
X/Y/lifetime bytes.

>Please comment on the new demo. I hope it works fine for both players, I
>just had no second player to test if the players can interfere with each
>other during some weird Joystick movements :-)

Not sure what comments you want to see, but it does look good.  Hope
there's time to load some playfield data instead of storing what looks
like the scanline counter.

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