Newsgroups: comp.theory.cell-automata, comp.windows.news, comp.sys.sun.apps 
From: hopk...@turing.ac.uk (Don Hopkins) - Find messages by this author  
Date: 26 Jul 92 06:56:12 GMT 
Local: Sat, Jul 25 1992 11:56 pm  
Subject: HyperLook Cellular Automata Machine for OpenWindows V3 available for ftp 
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I've written a recreational CAM-6 simulator (Tofoli & Margolis's 
Cellular Automata Machine) and ported it to HyperLook (the user 
interface development system I'm working on at Turing).  It displays 
animated cellular automata that you can edit in real time with the 
mouse!  And it comes with a free Lava Lamp! 


The Cellular Automata Machine simulator (a SPARC binary with a bunch 
of PostScript and data files) and the HyperLook runtime system are now 
available for anonymous ftp!  HyperLook and the CAM simulator run 
under OpenWindows Version 3 on color SPARC workstations.  They're 
available for anonymous ftp from turing.com, in the file 
"pub/CAM.tar.Z", or ftp.uu.net, in the file "packages/NeWS/CAM.tar.Z". 
You will also need to retrieve the HyperLook runtime environment, from 
the same directory, with the name "HyperLook1.5-runtime.tar.Z".  There 
are several text and PostScript files explaining HyperLook, and other 
HyperLook demos and applications (including SimCity, which I've also 
ported to HyperLook).  Install and run HyperLook (set your $HLHOME 
enviornment variable), uncompress and un-tar CAM.tar.Z into a 
directory, go there, and type "cam". Press the "Help" key at the 
buttons and graphics to learn how to work the user interface. 


Here are some highlights of my Cellular Automata Machine simulator: 


The user interface is a HyperLook stack (kind of like PostScript 
HyperCard for Unix).  The simulator is written in C, and uses a 
look-up table in the same format as the CAM-6. The simulator 
implements several different neighborhoods, and several favorite hard 
wired rules.  The rules (that aren't hard wired in C) are specified in 
Forth (I use wmb's SPARC Forth, and have written some code that lets 
me define rules in the same language as used in T&M's "Cellular 
Automata Machines").  Forth compiles the rules and writes out lookup 
tables that are read by the simulator.  The simulator animates on the 
screen very quickly by using shared memory.  There's a button to tile 
the screen root background with the current pattern, which is worth 
its weight in LSD!  You can draw on the cells with the mouse as they 
animate!  It comes with a whole bunch of interesting rules.  Each rule 
has a brief (if not cryptic) description, and a list of pre-defined 
initial configurations that work will with the rule.  You can copy the 
cells onto the clipboard and paste them into the drawing editor 
(included with HyperLook) to edit or print them.  You can also paste 
structured PostScript drawings from the drawing editor into the cells! 
(My favorite trick is pasting usenix facesaver images into hglass.) 


One of the neatest built-in rules is Rudy Rucker's "Eco" rule (maybe 
he called it something different, but I think he came up with the 
idea). It runs "Anneal" in one plane, and either "AntiLife" or 
"Brian's Brain" in the other, depending on the "Anneal" bit.  It uses 
AntiLife (the bitwise complement of Life) instead of regular Life, 
because then the interaction with Brain's Brain along the annealing 
edges is, shall I understate, somewhat more intense!  (not to mention 
the 5 bits of echo!)  This rule looks really cool when started with a 
symetric configuration!  Then you can switch back and forth between 
symetry-preserving rules, and generate all kinds of interesting screen 
backgrounds!  Eco is a great rule to display in the Lava Lamp view! (A 
wee simulated lava lamp desk accessory that displayes the automata in 
an appropriately shaped window.)  Another rule that looks good in the 
Lava Lamp is "Heat", which is eight neighbor heat diffusion: sum the 
eight neighbors (plus a global heat change constant) and divide by 
eight (by shifting). The global heat change constant causes the heat 
of the entire system to rise or fall, and when a cell goes below 0 or 
above 255, it wraps around to the opposite heat, causing chaotic 
psychodellic churning and boiling! A modification I made to this rule, 
"DHeat", takes the remainder after dividing by 8, and adds it into the 
next sum (i.e. just keeps the low 3 bits that would be thrown away 
around for the next sum), resulting in a *much* more accurate heat 
diffusion simulation, with a wonderful dithered appearance.  The 
dithered heat diffusion (which doesn't preserve symetry) makes 
*really* keen screen backgrounds!   


        -Don