Re: Cellular Automata :: Langton's Ant

[Velaki]

Thank for a cool program! Over lunch I whipped up a very quick and dirty Tk version.

Enjoy!

#!/usr/bin/perl -w

use strict;
use Tk;

########################################################
# Constants

  my $width  = 30;  # number of boxes wide
  my $height = 30;  # number of boxes high
  my $scale  = 15;  # size of boxes in pixels
  my $freq   = 50;  # update every 50 milliseconds

########################################################
# Variables

  my @board;
  my $dir;
  my $x;
  my $y;
  my $stop;

########################################################
# Set up board

my $m = MainWindow->new;
$m->repeat($freq => \&run);

my $c = $m->Canvas(-width => $width*$scale, -height => $height*$scale)
+;

&initBoard;

$m->MainLoop;  # <-- never exits

########################################################
# board utilities

sub loc {
  my ($x, $y) = @_;
  return ($x*$scale+1, $y*$scale+1, $x*$scale+$scale-1, $y*$scale+$sca
+le-1);
}

sub on {
  my ($x, $y) = @_;
  box($x,$y,"black");
  $board[$x][$y] = 1;
}

sub off {
  my ($x, $y) = @_;
  box($x,$y,"white");
  $board[$x][$y] = 0;
}

sub box {
  my ($x, $y, $color) = @_;
  $c->create('rectangle', loc($x,$y), -fill => $color);
}

sub initBoard {
  print "Initializing board...";
for my $i (0 .. $width) {
    for my $j (0 .. $height) {
      off($i, $j);
      print ".";
    }
    print "x";
  }
  $c->pack;
  print "...done\n";
}

########################################################
# main callback code

my $initFlag;

sub initVars {
  $dir = 0;
  $stop = 0;
  $initFlag++;
  $x = int($width/2);
  $y = int($height/2);
  $board[$x][$y]=1;
  on($x,$y);
  print "Initialized\n";
}

sub move {
  for ("$dir") {
    /0/ && do {
      if(($y-1)>=0) {
        $y--;
        &turn;
      }
      else {
        $stop = 1;
      }
      last;
    };
    /1/ && do {
      if(($x+1)<=$width) {
        $x++;
        &turn;
      }
      else {
        $stop = 1;
      }
      last;
    };
    /2/ && do {
      if(($y+1)<=$height) {
        $y++;
        &turn;
      }
      else {
        $stop = 1;
      }
      last;
    };
    /3/ && do {
      if(($x-1)>=0) {
        $x--;
        &turn;
      }
      else {
        $stop = 1;
      };
      last;
    }
  }
}

sub turn {
  if($board[$x][$y]==0) {
    $dir+=3;
    $dir%=4;
    on($x,$y);
  }
  else {
    $dir+=1;
    $dir%=4;
    off($x,$y);
  }
}

sub run {
  return if $stop;
  &initVars unless $initFlag;
  &move;
}

-v

[BrowserUk]

Fun.

It struck me (having just just read LW's "State of the Onion 2004"), that if you sat and watched that in a room full of Freudian psychoanalysts, calling out all the things you saw as the Ant crawls around, you could very quickly raise them to near orgasm as you satisfied their every, "If I had a patient that displayed X form of neurosis, I'd write a paper and present it to...", wet dreams.