In 1993 (The date on my earliest existant source file is Feb 12, 1993), I
first saw a 'Random Dot' picture in an issue of 'Radio Electronics.' (a.k.a.
stereograms, 'Magic Eye') I though it was cool, and beside the picture was
the information to order software to make these.  I got out my credit card
and phoned.  As it turned out, the company refused to ship to Canada, so I
couldn't order the software.  For the next few days I sat in front of my
computer printing off strange sheets of paper and staring at them sort of
cross-eyed until I had it figured out.  I have revisited this code a few
times since then, so it has changed and evolved a bit.

These random dot programs are really a work no-longer-in progress.  I was
hoping to eventually rewrite it as a cgi script, and maybe as a full gui GTK
app, but I don't have the time right now.  So... the code is now released
under the terms of the GPL.

I have included 5 versions of the program in this archive:

R_D_0217.PAS 
This is the earliest version, written for msdos in Microsoft QuickPascal. 
It accepts a 320x240 16grey (4bit) .pcx file as input, and outputs directly
to an HP Laserjet 2 printer.  Not terribly useful.

RDOT_174.C
This is simply a rewrite in Microsoft QuickC which does the same.

RDOT_SCN.C
This one, also in Microsoft QuickC, displays the output on the screen rather
than printing it.  (Slightly more useful.)

rdot-gd-004.c
Finally, a Linux version.  (I haven't tried it on any other *nix.)  This
version accepts a gif as input and writes the output as a gif.  It uses
Thomas Boutell's gd library (available seperately at 
http://www.boutell.com/gd/ ) to handle the gifs.

rdot-gd-005.c
A variation on the above.  This one accepts a gif as the pattern to be
repeated.  This makes output very similar to those 'Magic Eye' books.

I've also included Linux/i386/libc6/ELF binaries of the last two.

The command line I used to build the binaries is:

gcc rdot-gd-005.c -I/usr/src/gd1.3 -L/usr/src/gd1.3 -lgd -o rdot005

Have fun, and let me know what you do with it.

Scott Walde
scott@saskatoon.com
Jan 30, 1999