DragonFly On-Line Manual Pages

munch(6)                      XScreenSaver manual                     munch(6)

NAME
       munch - munching squares

SYNOPSIS
       munch [-display host:display.screen] [-foreground color] [-background
       color] [-window] [-root] [-mono] [-install] [-visual visual] [-delay
       usecs] [-xor] [-noxor] [-clear number] [-simul number] [-classic |
       -mismunch | -random] [-fps]

DESCRIPTION
       The munch program performs the munching squares hack.  It picks square
       size, position, and gravity randomly.  It also displays a creatively
       broken misimplementation of the classic algorithm.

       The munching squares hack consists of drawing Y = X XOR T for a range
       of X and T over and over until all the possible combinations of X and T
       have come up.  It was reportedly discovered by Jackson Wright in 1962
       and took 5 instructions of PDP-6 code.

OPTIONS
       munch accepts the following options:

       -window Draw on a newly-created window.  This is the default.

       -root   Draw on the root window.

       -mono   If on a color display, pretend we're on a monochrome display.

       -install
               Install a private colormap for the window.

       -visual visual
               Specify which visual to use.  Legal values are the name of a
               visual class, or the id number (decimal or hex) of a specific
               visual.

       -delay usecs
               The delay between steps of the animation, in microseconds.
               Default: 2500.

       -xor    Use the XOR drawing function.  This is the default.

       -no-xor Don't use the XOR drawing function.

       -clear number
               Number of squares to misdraw before clearing the display.
               Default: 65.

       -simul number
               Number of squares to misdraw simultaneously.  Default: 5.

       -classic
               Draw classic munching squares only.

       -mismunch
               Draw "mismunch" only.

       -random Do one or the other.

       -fps    Display the current frame rate and CPU load.

ENVIRONMENT
       DISPLAY to get the default host and display number.

       XENVIRONMENT
               to get the name of a resource file that overrides the global
               resources stored in the RESOURCE_MANAGER property.

SEE ALSO
       X(1), xscreensaver(1),
       http://www.inwap.com/pdp10/hbaker/hakmem/hakmem.html

HISTORY
       HAKMEM: MIT AI Memo 239, Feb. 29, 1972.
               Beeler, M., Gosper, R.W., and Schroeppel, R.

               "Unless otherwise stated, all computer programs are in PDP-6/10
               assembly language."

               ITEM 146: MUNCHING SQUARES

                   Another simple display program. It is thought that this was
                   discovered by Jackson Wright on the RLE PDP-1 circa 1962.

                       DATAI 2
                       ADDB 1,2
                       ROTC 2,-22
                       XOR 1,2
                       JRST .-4
                   2=X, 3=Y. Try things like 1001002 in data switches. This
                   also does interesting things with operations other than
                   XOR, and rotations other than -22. (Try IOR; AND; TSC;
                   FADR; FDV(!); ROT -14, -9, -20, ...)

               ITEM 147 (Schroeppel):

                   Munching squares is just views of the graph Y = X XOR T for
                   consecutive values of T = time.

               ITEM 148 (Cohen, Beeler):

                   A modification to munching squares which reveals them in
                   frozen states through opening and closing curtains: insert
                   FADR 2,1 before the XOR. Try data switches =

                       4000,,4    1000,,2002    2000,,4    0,,1002
                   (Notation: <left half>,,<right half>)
                   Also try the FADR after the XOR, switches = 1001,,1.

COPYRIGHT
       Copyright 1997 Tim Showalter.
       Copyright 2004 Steven Hazel.
       Copyright 1992-2008 Jamie Zawinski.

       Permission to use, copy, modify, distribute, and sell this software and
       its documentation for any purpose is hereby granted without fee,
       provided that the above copyright notice appear in all copies and that
       both that copyright notice and this permission notice appear in
       supporting documentation.  No representations are made about the
       suitability of this software for any purpose.  It is provided "as is"
       without express or implied warranty.

X Version 11                  5.34 (24-Oct-2015)                      munch(6)