ASTEROID v2.1




by




Todd B. Crowe


Copyright (c) 1991
















ASTEROID is copyright (c) 1990, 1991 by Todd B. Crowe. There is
no warranty implied or otherwise. You may copy the program
freely but it must be accompanied by this text file. You may not
modify any of the code or this file without my permission. The
program may not be sold or distributed commercially or otherwise
for profit. I reserve all rights and privileges to this program.













I. Introduction


ASTEROID is a Presentation Manager implementation of the original
Asteroids(TM) game. Currently the only major shortcoming of
ASTEROID is the lack of sound (a feature which is not likely to
change). ASTEROID requires OS/2 1.2 or later.

ASTEROID 1.0 was first released in June 1990. It was followed in
September 1990 by a much improved version 2.0. The current
release of ASTEROID is 2.1.


A brief history of ASTEROID:

ASTEROID 1.0 Features/Problems
------------------------------
* Basic Asteroids game implementation
* Limited customization (number of ships, display of score)
* Allowed user to select play speed via command line options
* Simple display of score and number of ships
* Integer math for speed
* Scaled play screen to size of window

ASTEROID 2.0 Changes
--------------------
* New custom fonts
* Score display virtually identical to the arcade game
* Automatic play speed selection
* 1/2 Player games
* High score table
* Use of saved profile info to save screen characteristics
* Complete rewrite of code, including better integer math for
scaling

ASTEROID 2.1 Changes
--------------------
* Minor bug fixes from 2.0 (better screen updating)
* Menu bar, key definition, help screen
* User selection of number of ships and photons
* Shield Option (see below for more information)

























II. Game features


ASTEROID resembles very closely the arcade game Asteroids. It
supports the player attraction modes, the high score entry
screen, a high score table, a custom font, and 2 player mode.
Enemy space ships appear on the screen and fire directly at the
player's ship. The player may hyperspace, but, as in the arcade
game, the player's ship randomly blows up on reentry.

A new game play feature has been added to ASTEROID 2.1. The
player's ships now have a shield. The shield protects a ship
from asteroids, the enemy ships, and photons. It does, however,
have a drawback. The shield operates off of the hyperspace
drive, which has a limited energy reserve. When the shield is on
it draws energy from the hyperspace drive energy reserve.
Eventually, the reserve supply will become exhausted and the
shield will power down. When the hyperspace energy reserve is
low hyperspacing is more dangerous. If the shield is left off,
the hyperspace drive will slowly recharge the energy reserve.

Beginning in ASTEROID 2.0 high scores, window size and position
information, and frame control status were saved in a profile.
ASTEROID 2.1 adds a system menu, a help screen, and the ability
to customize the number of ships per game, the number photons
that may be fired at simultaneously, the use of the shield, and
the keys for controlling the ship.






































III. Running ASTEROID


If you want to run ASTEROID from a full screen prompt simply
type:

ASTEROID

If you want to install ASTEROID in a Presentation Manager program
group: create a "New..." program entry and supply a drive and
path in the "Path and file name" entry field:

C:\GAMES\ASTEROID.EXE

No parameters are required.

The file ASTEROID.DLL must be in a directory in your LIBPATH
(e.g. C:\OS2\DLL); if it is not ASTEROID.EXE will display an
error message box and then terminate. ASTEROID.DLL contains the
two custom fonts used by ASTEROID.EXE.

On slower machines asteroid movement may look very jumpy. In
fact, everything moves at the same rate on a slow computer as a
fast computer. On a slow computer the asteroids are just redrawn
less often.









































IV. Game controls


ASTEROID 2.1 now allows the user to select which keys control the
ship. To change the default keys select the "Keys..." menu item
in the "Options" menu.

The game play functions have the following default key
definitions:

Rotate Left =
Rotate Right =
Thrust =
Hyperspace =
Fire =
Shield = s

The following keys may not be redefined:

Help = F1
Select 1 Player Game = 1
Select 2 Player Game = 2
Hide Frame Controls = -f
Redefine Keys = -k
Pause Game = -p
Exit Game = F3 or -x



The mouse has the following functions:

Double Click Left Button = Hide/Show Frame Controls
Double Click Right Button = Pop up About dialog box
Left Button + Drag = Move screen without title bar
































V. Scoring


Scoring is the same as in the original arcade game:

Large Asteroid = 20 points
Medium Asteroid = 40 points
Small Asteroid = 100 points
Large Enemy Spaceship = 200 points
Small Enemy Spaceship = 1000 points

Free ship at 10,000 and every 10,000 thereafter.






















































VI. Afterword


ASTEROID is not shareware, but neither is it public domain. I do
not ask that you send me any money. If you enjoy ASTEROID (and I
know there are several of you who do), then I would appreciate
hearing from you. In the past, people have sent me examples of
their own programs. I also appreciate receiving comments and
suggestions for improvements. If you are an employer and are
interested in hiring a young OS/2 (or UNIX) programmer, I will be
graduating this June '91....

Todd Crowe
1310 Indian St.
Bellingham, Washington 98225
Internet Address: [email protected]