Re: A85: Sliding Pixels

To: assembly-85@lists.ticalc.org
Subject: Re: A85: Sliding Pixels
From: PXGray@aol.com
Date: Tue, 6 Oct 1998 17:37:59 EDT
Delivered-To: assembly-85-outgoing@towerguard.unix.edu.sollentuna.se
Reply-To: assembly-85@lists.ticalc.org


In a message dated 10/6/98 1:22:24 PM US Eastern Standard Time,
humberto@engr.csufresno.edu writes:

> It depends on the size of your sprites (when you slide from left to right
>  or vice versa)  If your sprites are 8 pixels wide then you draw over the
>  sprite (only up 1 pixel) then if you have a background, draw the
>  background where the bottom of the sprite used to be.  This way you don't
>  use the graph mem and you have smooth scrolling.
>  Here's a picture if I made no sense..
>  
>  $FC00 ................ -> ..10001001....
>  $FC10 ..10001001...... -> ..10000001....
>  $FC20 ..10000001...... -> ..,,,,,,,,.... <-Uncovered BG
>  $FC30 ................ -> ..............
>  
>  If you're using a sprite routine that supports masking it makes using
>  backgrounds a lot easier.  In that case you would just draw you sprite
>  shifted up 1 then redraw the background that was uncovered.
>  
>  -Humberto Yeverino Jr.

This makes absolutely no sense.  Can anyone explain it in a simpler form of
the english language?

Follow-Ups:

Re: A85: Sliding Pixels

From: Humberto Yeverino <humberto@engr.csufresno.edu>