---------------------
What is this program?
---------------------

This program creates GIFs of random world maps, using a fractal algorithm. 
I (Martijn) don't know how this works, so if you're curious, ask the original 
author (John Olsson). I mention his email later in this file. Or check the 
source (worldgen.c) for more info.

I ported this program to DOS, which (thanks to DJGPP) was very easy. Only a
few very minor changes needed to be made to the original program. In fact,
I only needed to get it to save the GIFs to a binary file, instead of 
having them outputted to stdout.

It should work on any 386+ DOS machine, but if it doesn't, I'm afraid I
won't be of much help. Actually this adapted source ought to compile on a 
Unix machine also (just like the original source).

All credit for this program goes to John Olsson, who created it.
You can contact him at: 

d91johol@isy.liu.se 

His WWW page, where I found the source for this program 
(as well as a nice web interface for it), is at:

http://www.edu.isy.liu.se/~d91johol/

Check it out!

I compiled this program using DJGPP, which is a (free) Gnu C (GCC) compiler 
for DOS (386+ machines). The GO32.EXE to make it all work is included in this
zip file. 

-----------
MINI MANUAL
-----------

To use this program, just type 'worldgen' at the DOS prompt.

It will prompt you for the X size and Y size, which are simply the 
dimensions of the map that will be created. For example, the X size can be
set to 320, and the Y size to 200, which are the dimensions of a common 
VGA 256 color mode. But any size you want (as long as there's enough memory)
can be used.

Then enter a random seed. If you keep all other values the same, the same
random seed will produce the same map. Any number will do.

Next it will ask you for the 'number of faults'. This has to do with how
long the fractal algorithm will be continued. Low values create interesting
results, but no maps. Values up from 500 will produce good results. Very
large numbers (like 30,000) however don't seem to improve the results, and
make the program much slower. Experiment with it yourself!

Then, enter the percentage of the world that will be filled with water. 
Obviously this should be something between 0 and 100.

After that it will ask you for the size of ice caps on this world. Again a 
percentage.

Finally enter the filename the map should be saved to. '.GIF' will be
automatically appended. The file will be saved in the same directory.

Note that this program isn't fool proof. Entering nonsense values 
(150% water, or something) will be likely to produce nonsense results, or
no results at all.

After everything has been entered, the map will then be generated, 
and be saved as a GIF. This may take a while, especially for large maps 
with a high number of faults. Note that nothing will displayed on screen, 
view the GIF file with your favourite GIF viewer.

Enjoy!

Martijn Faassen (faassen@phil.ruu.nl)
