R A Y C A S T I N G

        			      by

				 Outlaw Triad

 ----------------------------------------------------------------------------

    Project     : Raycasting engine
    Version     : 1.7
    Last update : November 30 1998
    Language    : Pascal/asm
    Code by     : Vulture/OT
    Graphics by : Sappy/OT
    Textfile by : Vulture/OT
    E-mail      : vulturejc@hetnet.nl (Vulture)
                  mlimburg@worldonline.nl (Sappy)
    Homepages   : http://www.tem.nhl.nl/~comma400/otraycst.html
                  http://www.tem.nhl.nl/~comma400/vulture.html

 ----------------------------------------------------------------------------

  - BASIC INFORMATION -

  Raycasting is a technique to simulate 3d environments in which the viewer
  can 'walk' around. A famous implementation of this technique is the game
  Wolfenstein. Really advanced examples of raycasters are the Ultima Underworld
  1 and 2 games.

  A raycaster doesn't produce a real 3d world, but instead displays a 2d map
  in 3d. The viewer is unable to look up or down (x-axis usually), which
  makes this a fake 3d world. It does, however, create an acceptable visual
  view of a 3d environment and is as such suitable for games, although you
  can't compare such games to the standards in 3d games today.

  As I've been interested in creating virtual 3d worlds for quite some time
  now, I decided to get into coding a Wolfenstein clone. Reason for this is
  the fact that basic raycasting is a relatively simple technique and easy
  to implement.

  Start the engine by running the executable and move around using the mouse.
  Keyboard movement has to be implemented, but that's not a priority for me.
  Pressing the spacebar will open doors in front of the player. Open doors
  are closed after a period of time.

  - FEATURES -

  Currently this engine supports:

       - Texture mapped walls (various textures)
       - Seperate 2d maps for the walls and floor/ceiling
       - Mouse movement (forward and backwards)
       - Shading (simple depth shading; 16 colour shades)
       - Floor/ceiling texturing (need a faster method)
       - Game physics (when you stop walking, you 'slide' a bit further)
       - Transparent walls and doors (allowing windows)
       - Animated doors (vertical motion + there is a secret room in here!)
       - Different textures on X,Y sides of walls (adds more realism)
       - Collision detection (lame code, must be improved)
       - Viewport clipping (allowing a frame around the screen)

  This project is still at it's early stages and if a real game is build
  with this engine, the following needs to be implemented also (at least):

       - Level files / sector files (for easy level loading/handling)
       - Variable height walls (I need stairs and such)
       - Sprite handling (characters, objects; I'm busy with this)
       - Water (animated floors resembling water)
       - Lava (animated floors resembling lava streams)
       - Maybe 3d characters (using bone techniques?)
       - XMS memory for texture storage (already done in unreleased version)
       - 128x128 textures (already done in unreleased version)
       - Sound (thrilling background music and scary soundsamples)
       - More fixed point math and assembler code (raycasting procedures)
       - Remove the undocumented features (called 'bugs')

  Some of these things are pretty easy to implement (water/lava) and others
  are very complicated (3d characters). As you can see, there's a lot to do
  yet.

  - BUGS -

  I suspect there to be a few bugs in this engine, although at this point
  lame coding is more of a problem. Things can be made more efficient for
  sure. Drawing operations can be optimized by using more assembler code,
  which is a real 'must'.

  - HARDWARE -

  This program was made on a Pentium 75, with a 1 MB videocard. As you can
  see, no videohardware is used in this program, but this can be realised in
  future versions to enhance speed and visual appearance. It's ill advised
  to view this program on a machine less than a P75, because it will run
  terribly slow.

  - SOURCECODE-

  The entire engine is coded using Turbo Pascal 7.0 with inline assembler
  for drawing operations. Also, a little utility is used to convert the
  textures from PCX format to a simple data format. Textures are 64x64 and
  all bytes/pixels are written linear to external data files which are
  64x64=4096 bytes each. Eventually all textures will be written to 1 big
  external data file, together with level data, sprite data etc etc.

  I decided to release the sourcecode of what I've accomplished in order
  to motivate others to start coding virtual 3d worlds too. If you can use
  these sources, please do so. Give Outlaw Triad a greet if you use it in
  a demo or something like that. These sources are given AS IS, which means
  you are using these sources at your own risk.

  - GOALS -

  My final goal at this point is to create an engine which resembles the
  Doom engine in order to create an adventure game with it which will
  be much like the Ultima Underworld games. This probably means I'll have
  to write a sector polygonal engine (linedef engine), but for now I'll
  try to get as much as possible out of basic raycasting.

  - THANKS -

  I could not have made this program without the help of others, who were
  so kind to share their knowledge by making their programs/info available
  on the internet. I would like to thank the following people:

       - Jim (for our discussions on graphics programming)
       - Telemachos/PXD (for your tutorials and personal help)
       - F. Permadi (for your excellent html tutorial)

  Thanks very much.

  - CONTACT -

  I would like to get in contact with other people who are trying to create
  virtual reality programs, wether those programs are raycasters or not.
  Please feel free to contact me or Sappy/OT using the e-mail adresses stated
  above!

 ----------------------------------------------------------------------------