Re: A83: tracking and moving many objects
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Re: A83: tracking and moving many objects
Thanks to both Jimmy and Harper. Your explanations did indeed help. The spot
I slipped up on was keeping the order. The object code idea solves my
problem.
From: Chris
e-mail: apparatus@mediaone.net
----- Original Message -----
From: Richard Harper Maddox <gte172i@prism.gatech.edu>
To: Assembly-83 List <assembly-83@lists.ticalc.org>
Sent: Friday, June 30, 2000 6:58 PM
Subject: Re: A83: tracking and moving many objects
>
> i wrote a really good one for zelda, but i lost the source when i
> reformatted. I'm sure that Sam Heald has it, but i'll go ahead and
> explain it since the algorithm is simple.
>
> the best method is using a queue, where we have a static size of each item
> in the queue, but a variable size. Here is some code to explain:
>
> projectileQueue = savesscreen
> ; entry format
> ; .db <projectile ID>,<xpos>,<ypos>
>
> ...
>
> addEntryToQueue:
> ld hl,projectileQueue
>
> findEmptyQueueItem:
> ld a,(hl)
> or a
> jr z,emptyItemFound ; we are 3 bytes past the last item
> ; or at the first
>
> inc hl
> inc hl
> inc hl
> jr findEmptyQueueItem
>
> emptyItemFound:
> ld (hl),b ; projectile ID
> inc hl
> ld (hl),c ; xpos
> inc hl
> ld (hl),d ; ypos
> ret
>
> hope that helps.
>
> -harper
>
> On Fri, 30 Jun 2000, Man on the Moon wrote:
>
> >
> > What is a good method or algorithm to keep track of many objects, such
as
> > the coordinates of bullets in a game, and move these objects as well? I
did
> > come up with a method of storing each in a user defined varible but that
was
> > a pain in the neck, or code.
> >
> > From: Chris (Man on the Moon)
> > e-mail: apparatus@mediaone.net
> >
> >
> >
>
>
References: