Re: [stella] Sprites - AAAAARGH!

Subject: Re: [stella] Sprites - AAAAARGH!
From: KirkIsrael@xxxxxxxxxxxxx
Date: 30 Jan 2004 19:03:46 -0000
> Hi there!
> > About the "battlezone" code, before it starts, what 
> > value needs to be set to the horizontal position of 
> > the object?
> Uhm... what?
> Greetings,
> 	Manuel

Ok, I'm probably being an idiot, but here's the code, right?

> PosElement
>        SEC
>        STA WSYNC
> .wait
>        SBC #$0F
>        BCS .wait
>        EOR #$07
>        ASL
>        ASL
>        ASL
>        ASL
>        STA HMP0,X
>        STA RESP0,X
>        RTS

This code, I assume, WSYNCs, and then waits just long enough
so that when the RESP0 is called the object is repositioned
at just the right point?

Does this code assume that when it's called as a subroutine
Accumulator is set to the position, and X is 0 or 1 based on
which player you're trying to move, or what? In short, what 
are the preconditions for this routine, and/or does it involve
something w/ the stack? (Actually, I tend to be more concerned
about time than ROM space (or reusability) so I tend not to use
subrotuines much at all...)

     "Stupid people see beauty only in beautiful things."
              --Oliviero Toscani quoting Dadaist Saying

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