Begin
File:          	phreshold.tgz
Description:   	Alien-like arcade game (shoot'em up!)
Keywords:     	Photon - Game
Version:      	1.0.A
Entered-date:	August-06-1998
Author:			Oliver Singla (omsingla@qnx.com)
Ported-by:		/
Original-site:	/
Copying-policy: Freeware.
Supplemental:   Description of the game.


1) Presentation

   This free software implements an alien-like game, ie. a shot'em arcade game.
   This version implements 9 differents boards, each board with its own set
   of ships. It's easy to add new boards. Animation is implemented using
   a frame (480x360) which is drawn to screen 50 times per second. Prior
   to draw, all graphics elements are drawn into the memory frame. 
   
   Each board define:
   - some ships (bitmaps, from 1 to n states)
   - the way they move (randomly, grouped, etc.)
   - their agressivity (shells, attacks, etc.)
   - scrolling (left-right, bottom-top, etc.)
   - etc.

2) Rules of the game

   Well, 3 keys are used:
   - left key and right key to move
   - left-ctrl to shoot.

3) This is mainly a prototype. The game has only been tested on one machine
   (a P150), with a given graphics card. The graphics driver is really important:
   I use Pg.flat which let access to the video memory w/o any bank switching, so
   you should experiment with your own hardware. At startup, the software draws
   some frames for a second and give a report.
   
   I have coded a small assembler function to draw a bitmap into memory. The black is
   considered as the transparent color. Scrolling (in both directions) can be 
   actived. 3 logical operations are implemented: copy, or and xor. Currently,
   I only use blaster_or, experiment... Because, this function only works in
   256 colors, the game is only playable in a 256 colors mode.
   
   It seems also, that a ticksize which is under 1ms does not give very good
   results. Try with a ticksize of 1msec first.


4) Todo list (work in progress)

   - Some other boards (perhaps...)
   - Put a background (now this is a black background)
   - More parameters for a board
   - I will experiment using writing directly into the video memory instead of
     using PgDrawImagemx (getting address from /etc/config/trap/trap.node).
   - Any comments will be welcome.

5) Installation
  
   To install the archive:
      gzip -cd phreshold.tgz | pax -vr

   I suggest to install into:
      /usr/photon/apps/phreshold
   but this is not mandatory.

6) OS/Photon/Compiler versions
   
   The game has been successfully been tested under QNX 4.23, Photon 1.12
   and compiled with Watcom C Compiler v10.6.
   
   The game has been tested on a P150, with 32Mb ram. The graphics card was
   a 'Video Blaster' (chip cirrus), driver Pg.flat. It has been tested 
   successfuly on another machines with other video cards.

   The executable into the archive is compiled with photon 1.13 (slib).
   It does *not* run under photon 1.10 or 1.11. The main reason is that
   the PxConfig functions are used and were introduced with Photon 1.12
   Another good reason is that a DbContainer widget is used (only for 
   starting a ship).

   The software has been tested with the next screen resolutions, but
   always in 256 colors:
      - 640x480
	  - 800x600
	  - 1024x768
	  - 1280x1024

Have Fun !

Oliver Singla
omsingla@qnx.com
http://www.qnx.com/~omsingla