Re: A83: 16X16 Sprite routine

To: assembly-83@lists.ticalc.org
Subject: Re: A83: 16X16 Sprite routine
From: Jkhum98@aol.com
Date: Thu, 22 Jul 1999 17:22:56 EDT
Delivered-To: assembly-83-outgoing@towerguard.unix.edu.sollentuna.se
Delivered-To: assembly-83@lists.ticalc.org
Reply-To: assembly-83@lists.ticalc.org

In a message dated 7/22/99 3:51:16 PM Central Daylight Time, Edub311@aol.com 
writes:

> just wondering, whats the difference between aligned and non-aligned 
sprites? 
>  I saw that alot in movax's sprite routine.  
>  
>                                                      thanx,
>                                                      Bud

Aligned and Non-Aligned have to do with the coordinates at which you place 
the sprites. They are considered Aligned if their X Coordinate is a Multiple 
of 8 (i.e. 0,8,16,56,80) and those are easier and faster to place the sprite 
data onto the screen, because they are writing to fixed bytes in plotsscreen. 
If the X Coordinate of the sprite is not a Multiple of 8, then they are 
Non-Aligned, and it means you first have to find the byte it starts in on 
plotsscreen, then shift all the bits in the sprite data over a certain 
amount, to get it to start on the correct pixel of the screen. This procedure 
takes longer to do in sprite routines. Tilemap routines generally use 8x8 
aligned sprites which can make them pretty fast, and a tilemap that uses 
16x16 is prolly just as easy and fast... Did that original poster get the 
LargeSprite routine from ZGFXL to work, or is he needing a 16x16 sprite 
Tilemap Routine...? Speak Up. :)

Jason_K
TCPA Member
tcpa.calc.org

Follow-Ups:

A83: ASM programmer needed

From: Jesse McInturff <jmcintur@bevcomm.net>