topical media & game development
#javascript-processing-example-topic-automata-wolfram.htm / htm
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</head><body><h1><a href="http://ejohn.org/blog/processingjs/">Processing.js</a></h1>
<h2>Wolfram</h2>
<p>by Daniel Shiffman.
Simple demonstration of a Wolfram 1-dimensional cellular automata
When the system reaches bottom of the window, it restarts with a new ruleset
Mouse click restarts as well.</p>
<p><a href="http://processing.org/learning/topics/wolfram.html"><b>Original Processing.org Example:</b> Wolfram</a><br>
<script type="application/processing">
CA ca; // An instance object to describe the Wolfram basic Cellular Automata
void setup() {
size(200,200);
frameRate(30);
background(0);
int[] ruleset = {0,1,0,1,1,0,1,0}; // An initial rule system
ca = new CA(ruleset); // Initialize CA
}
void draw() {
ca.render(); // Draw the CA
ca.generate(); // Generate the next level
if (ca.finished()) { // If we're done, clear the screen, pick a new ruleset and restart
background(0);
ca.randomize();
ca.restart();
}
}
void mousePressed() {
background(0);
ca.randomize();
ca.restart();
}
class CA {
int[] cells; // An array of 0s and 1s
int generation; // How many generations?
int scl; // How many pixels wide/high is each cell?
int[] rules; // An array to store the ruleset, for example {0,1,1,0,1,1,0,1}
CA(int[] r) {
rules = r;
scl = 1;
cells = new int[width/scl];
restart();
}
CA() {
scl = 1;
cells = new int[width/scl];
randomize();
restart();
}
// Set the rules of the CA
void setRules(int[] r) {
rules = r;
}
// Make a random ruleset
void randomize() {
for (int i = 0; i < 8; i++) {
rules[i] = int(random(2));
}
}
// Reset to generation 0
void restart() {
for (int i = 0; i < cells.length; i++) {
cells[i] = 0;
}
cells[cells.length/2] = 1; // We arbitrarily start with just the middle cell having a state of "1"
generation = 0;
}
// The process of creating the new generation
void generate() {
// First we create an empty array for the new values
int[] nextgen = new int[cells.length];
// For every spot, determine new state by examing current state, and neighbor states
// Ignore edges that only have one neighor
for (int i = 1; i < cells.length-1; i++) {
int left = cells[i-1]; // Left neighbor state
int me = cells[i]; // Current state
int right = cells[i+1]; // Right neighbor state
nextgen[i] = genRules(left,me,right); // Compute next generation state based on ruleset
}
// Copy the array into current value
cells = (int[]) nextgen.clone();
generation++;
}
// This is the easy part, just draw the cells, fill 255 for '1', fill 0 for '0'
void render() {
for (int i = 0; i < cells.length; i++) {
if (cells[i] == 1) fill(255);
else fill(0);
noStroke();
rect(i*scl,generation*scl, scl,scl);
}
}
// Implementing the Wolfram rules
// Could be improved and made more concise, but here we can explicitly see what is going on for each case
int genRules (int a, int b, int c) {
if (a == 1 && b == 1 && c == 1) return rules[0];
if (a == 1 && b == 1 && c == 0) return rules[1];
if (a == 1 && b == 0 && c == 1) return rules[2];
if (a == 1 && b == 0 && c == 0) return rules[3];
if (a == 0 && b == 1 && c == 1) return rules[4];
if (a == 0 && b == 1 && c == 0) return rules[5];
if (a == 0 && b == 0 && c == 1) return rules[6];
if (a == 0 && b == 0 && c == 0) return rules[7];
return 0;
}
// The CA is done if it reaches the bottom of the screen
boolean finished() {
if (generation > height/scl) {
return true;
} else {
return false;
}
}
}
</script><canvas width="200" height="200"></canvas></p>
<div style="overflow: hidden; height: 0px; width: 0px;"></div>
<pre><b>// All Examples Written by <a href="http://reas.com/">Casey Reas</a> and <a href="http://benfry.com/">Ben Fry</a>
// unless otherwise stated.</b>
CA ca; // An instance object to describe the Wolfram basic Cellular Automata
void setup() {
size(200,200);
frameRate(30);
background(0);
int[] ruleset = {0,1,0,1,1,0,1,0}; // An initial rule system
ca = new CA(ruleset); // Initialize CA
}
void draw() {
ca.render(); // Draw the CA
ca.generate(); // Generate the next level
if (ca.finished()) { // If we're done, clear the screen, pick a new ruleset and restart
background(0);
ca.randomize();
ca.restart();
}
}
void mousePressed() {
background(0);
ca.randomize();
ca.restart();
}
class CA {
int[] cells; // An array of 0s and 1s
int generation; // How many generations?
int scl; // How many pixels wide/high is each cell?
int[] rules; // An array to store the ruleset, for example {0,1,1,0,1,1,0,1}
CA(int[] r) {
rules = r;
scl = 1;
cells = new int[width/scl];
restart();
}
CA() {
scl = 1;
cells = new int[width/scl];
randomize();
restart();
}
// Set the rules of the CA
void setRules(int[] r) {
rules = r;
}
// Make a random ruleset
void randomize() {
for (int i = 0; i < 8; i++) {
rules[i] = int(random(2));
}
}
// Reset to generation 0
void restart() {
for (int i = 0; i < cells.length; i++) {
cells[i] = 0;
}
cells[cells.length/2] = 1; // We arbitrarily start with just the middle cell having a state of "1"
generation = 0;
}
// The process of creating the new generation
void generate() {
// First we create an empty array for the new values
int[] nextgen = new int[cells.length];
// For every spot, determine new state by examing current state, and neighbor states
// Ignore edges that only have one neighor
for (int i = 1; i < cells.length-1; i++) {
int left = cells[i-1]; // Left neighbor state
int me = cells[i]; // Current state
int right = cells[i+1]; // Right neighbor state
nextgen[i] = rules(left,me,right); // Compute next generation state based on ruleset
}
// Copy the array into current value
cells = (int[]) nextgen.clone();
generation++;
}
// This is the easy part, just draw the cells, fill 255 for '1', fill 0 for '0'
void render() {
for (int i = 0; i < cells.length; i++) {
if (cells[i] == 1) fill(255);
else fill(0);
noStroke();
rect(i*scl,generation*scl, scl,scl);
}
}
// Implementing the Wolfram rules
// Could be improved and made more concise, but here we can explicitly see what is going on for each case
int rules (int a, int b, int c) {
if (a == 1 && b == 1 && c == 1) return rules[0];
if (a == 1 && b == 1 && c == 0) return rules[1];
if (a == 1 && b == 0 && c == 1) return rules[2];
if (a == 1 && b == 0 && c == 0) return rules[3];
if (a == 0 && b == 1 && c == 1) return rules[4];
if (a == 0 && b == 1 && c == 0) return rules[5];
if (a == 0 && b == 0 && c == 1) return rules[6];
if (a == 0 && b == 0 && c == 0) return rules[7];
return 0;
}
// The CA is done if it reaches the bottom of the screen
boolean finished() {
if (generation > height/scl) {
return true;
} else {
return false;
}
}
}</pre>
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(C) Æliens
20/2/2008
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