Short:        Best scrolling algor. for games (doc+src)
Author:       georg.steger@rolmail.net (Georg Steger)
Uploader:     georg steger rolmail net (Georg Steger)
Type:         dev/src
Version:      1.0
Requires:     OS 3.0, OCS/ECS/AGA, 15khz Monitor (or scandoubler), Joystick
Architecture: m68k-amigaos

In this archive you find the fastest possible scrolling algorithms for
block-based (tile-based) games like Turrican, Giana Sisters, Lionheart,
Battle Squadron, Z-Out, R-Type, ...

You will find documentation (HTML) and demo programs with source code in C
for horizontal-only, vertical-only and 8-way scrollers. The scrolling algo-
rithms are extremely fast. They never scroll anything with the CPU or the
Blitter, only blocks that "come in" are blitted. The routines never blit
whole block-columns (horizontal scrolling) or whole block-rows (vertical
scrolling). Instead the job is divided into BLOCKWIDTH/BLOCKHEIGHT steps. 

All demo programs have an option to show what happens to the bitmap intern-
ally when one scrolls around. This makes it much easier to understand how
the algorithms work.

The algorithms are designed for the Amiga chipset and the demo programs hit
the hardware directly. Anyway it should be possible to use very very simi-
liar techniques on GFX cards. The docs gives some info on what to take into
account when trying to port certain algorithms to GFX cards (chunky pixel
mode). Maybe future versions of this archive will include RTG versions of
the demo programs which should also work on GFX cards = only OS functions
are used. Unfortunately I don't have a GFX card, so this is still very
uncertain.


  Georg Steger
  Hochlercher 30

  I-39030 St. Johann/Ahrntal
  
  EMail: georg.steger@rolmail.net