RE: [stella] he got game

Subject: RE: [stella] he got game
From: KirkIsrael@xxxxxxxxxxxxx
Date: 2 Sep 2003 03:07:41 -0000
> Hi Kirk,
> > Right now I'm using a 2 line kernal, so I don't have quite as
> > much fine tuning in the vert speed dept.
> I was wondering about this. Why are you doing a 2LK? It seems there is
> no need with the 2 players and a ball. Is it just a preference for you?
> You could easily position your objects horizontally during VBLANK. Then
> in scan-out you should have plenty of time to position them vertically.

Oh yeah, all the horizontal stuff is during VBLANK
(one of my first mistakes back in the "thin red line" demo was trying 
to HMOVE every scanline...)

It's the vertical position that's getting me, then.  I was finding
stuff disappearing on the left side of the screen, because I wasn't 
loading it in time. I came up with my "PlayerBufferStuffer" logic
(using a byte of RAM as a buffer, so that you can take your time 
computing what each player looks like for the next scanline, then
in the HBLANK copy that buffer into GRP0 and GRP1) but I don't 
remember what all I went through to get the kernal in its current

> I have to agree with Andrew. I think a 1/x frame movement routine would
> work better for your game. Also, having the ball velocity and position
> determined by where the paddle hit the ball would be good too. 

Getting back to the concept of moving across the field...
player player collisions are a trickier than you'd think to
do really well...I remember back in the InterGalactic SpaceMan
BlastFest days...the trouble is if both players are moving 
slowly, and one tries to land on top of the other...very trick
to make it look convincing.

    "My stomach says no but my sick carny sense of humor says yes..."
             --Mr. Wick (The Drew Carey Show)

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