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Short:A Platform Game Engine in Amos
Author:amithlondestek at (Alper Sönmez)
Uploader:amithlondestek gmail com (Alper Sönmez)
Requires:AmosPro 2.00 or Amos Professional Unity
Download: - View contents

Amos has very convenient commands and underlying engines which provide easy
access to the capabilities of the Amiga hardware without the need to know the
dirty low level details. Unfortunately because the way some of them are designed
it is not possible to achieve the effects we see in games mostly written in
Assembly. Especially the display engine is an example to this. However, the
developers also provided a way to disable the built in display engine and go low
level to some extent, although we don't see many examples of it being used.
The "Copper Off" command.

By calling Copper Off and then writing your own copper list with the provided
"Cop" commands you can have access to tricks to create impressive graphics used
by Assembly coders like sprite multiplexing, screen mirroring, parallaxing,
changing color values, sprite and playfield priorities according to beam
position (aka. beam racing) etc.

But of course it comes with a price...

By installing your custom copper list, you lose the convenience of the commands
All the screen commands (except Screen Open/Close and Screen Copy of course)
All the colour commands like Colour, Palette, Fade, Rainbow etc.
All the Sprite commands...

You have to handle them yourself.

This project aims to provide a template for a side-scrolling platform game
with all the subroutines and procedures required to substitute the lost
commands mentioned above. It is not limited only to a platform game by the way.
Remove platforming stuff and maybe turn it into a side scrolling shooter. It is
all up to you.
It's open source and code is commented in detail. It also comes with some tools
as open Amos code to create the tile and sprite sets to use in the game.

  The template is designed as a single buffered DualPlayfield screen in NTSC
  compatible sizes which scrolls at 50 FPS and animate at 25 FPS. These can
  be easily modified according to needs.

- Scroll Engine
  Highly optimized limitless horizontal scrolling algorithm is implemented.
  Supports tilemaps of any size and can scroll any speed up to 16 pixels in one
  frame. The algorithm used for scrolling is "Scroller_XUnlimited" which is
  broadly explained in:

- Custom Sprite Engine
  A non-blitting* sprite engine that automatically handles attaching and/or
  connecting hardware sprites. Data is loaded as an Amos bank, but it has a
  completely different data structure.

  (*)built-in sprite engine in Amos uses blitter to set image data to sprites,
  this one doesn't and saves some time for your Bobs.

- Color Fade Engine
  A totally new algorithm which can fade colors in and out in any steps, keeping
  color hues constant during fade and making brighter colors appear/disappear
  simultaneously with darker ones. It can fade all color changes (ie. Rainbows)
  in the copper list as well.
  And it only uses addition/subtraction, so highly optimized.

- Collision and animation routines
  Some essential loops and variables are set up to provide a basic animation
  and platforming logic.

- Demo graphics
  A test tileset and background scenery converted to the required data formats
  are included.
  Tileset and background art by: Amatnieks (
  Player sprite image art by: Legnops (

- Tools
      Grabs sprite images from iff sprite sheets and creates a bank.
      Merges two sprite banks into one.
      A code to grab tiles from tile sheets into an Amos Icon bank.

  This is public domain. Use it whatever way you want. However I'd be truly very
  very grateful if you'd mention my name in your credits. Thanks in advance. :)

Version 0.34 (06.04.2021):
- Initial release version.

Contents of dev/amos/PlatformGameEngine.lha
---------- ----------- ------- ------- ------ ---------- ------------ ----------
[generic]                 2928    5166  56.7% -lh5- ed66 Apr  5  1980 PlatformGameEngine/background.iff
[generic]                 2032    4170  48.7% -lh5- eaf5 Apr  7  1980 PlatformGameEngine/Documents/PlatformGameEngine.readme
[generic]                 3350    8450  39.6% -lh5- 17d6 Apr  7  1980 PlatformGameEngine/Documents/TechnicalDetails
[generic]                13712   44034  31.1% -lh5- 6d03 Apr  6  1980 PlatformGameEngine/PlatformGameEngine.AMOS
[generic]                21708   62252  34.9% -lh5- 3615 Apr  6  1980 PlatformGameEngine/sprites.spr
[generic]                  362    2750  13.2% -lh5- 90d1 Apr  5  1980 PlatformGameEngine/testmap.txt
[generic]                 2781    5370  51.8% -lh5- 493b Apr  5  1980 PlatformGameEngine/tileset.abk
[generic]                 1058    2678  39.5% -lh5- 87ec Apr  5  1980 PlatformGameEngine/Tools/CustomSpriteMerger.AMOS
[generic]                 3599   11162  32.2% -lh5- 73bd Apr  6  1980 PlatformGameEngine/Tools/Sheet2CustomSprite.AMOS
[generic]                  926    1884  49.2% -lh5- df69 Apr  6  1980 PlatformGameEngine/Tools/Sheet2TileSet.AMOS
[generic]                16793   48354  34.7% -lh5- fe24 Apr  6  1980 PlatformGameEngine/Tools/sprite_sheet_all_L.iff
[generic]                16821   48226  34.9% -lh5- e051 Apr  6  1980 PlatformGameEngine/Tools/sprite_sheet_all_R.iff
[generic]                 4300    6340  67.8% -lh5- 9194 Apr  6  1980 PlatformGameEngine/Tools/tileset.iff
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 Total        13 files   90370  250836  36.0%            Apr  8 03:39

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