Tk Mandelbrot - click on image to center and zoom in... highly inefficient...

Takes a numeric parameter, which sets the width and height, in pixels, of the canvas. Defaults to 100 if no valid argument - personally, I wouldn't try going higher than, say, 500...

<update>Now you can zoom out by right-clicking, and I've changed the colour-scheme...</update>

use strict;
use Tk;

my $debug = 0;

my $c_size = ($ARGV[0] =~ /^\d+$/ && $ARGV[0]>0) ? $ARGV[0] : 100;
my $scale = my $oldscale = 1;
my ($lasti, $lastr)=(0,-0.5);
my $first = 1;

my $mw = MainWindow -> new;
my $canvas = $mw -> Canvas(-height=>$c_size, -width=>$c_size) -> pack;
$canvas -> Tk::bind('all', '<ButtonPress-1>' => \&MakeMan0);
$canvas -> Tk::bind('all', '<ButtonPress-3>' => \&MakeMan1);
MakeMan(0);

MainLoop;

sub MakeMan0(){
  print "here0\n" if $debug;
  MakeMan(0);
}
sub MakeMan1(){
  print "here1\n" if $debug;
  MakeMan(1);
}

sub MakeMan(){
  $canvas -> delete('all');
  my ($e, $canv_x, $canv_y)=(0,$c_size/2,$c_size/2);
  if(!$first){
    $e = $canvas -> XEvent;
    $canv_x = $e->x;
    $canv_y = $e->y;
  }

  print "$_[0] : $scale : $oldscale\n" if $debug;
  $oldscale = $scale;
  my $px_old = (4/$oldscale)/$c_size;
  $scale = $scale * ($_[0] ? 0.5 : 2);
  $scale = 1 if $first;
  my $px_new = (4/$scale)/$c_size;
  print "$_[0] : $scale : $oldscale\n" if $debug;

  $first = 0;

  my $i = $lasti = $lasti + ($canv_y - ($c_size/2))*$px_old; # centre
  $i = $i - (($c_size/2)*$px_new); # left edge
  my $rconst = $lastr = $lastr + ($canv_x - ($c_size/2))*$px_old; # ce
+ntre
  $rconst = $rconst - (($c_size/2)*$px_new); # top edge

  my $icount = 1;
  while($icount <= $c_size){
    my $r = $rconst;
    my $rcount = 1;
    while($rcount <= $c_size){
      my $iter = ($c_size/10)*($scale**0.5);
      my $tr = $r;
      my $ti = $i;
      my $rgb_out = '#000000';
      my $red = 20;
      my $green = 20;
      my $blue = 20;
      for my $n(1..$iter){
        ($tr, $ti) = (($tr ** 2) - ($ti ** 2) + ($r), (2 * $tr * $ti) 
++ ($i));
        $red += int(130/$iter);
        $green += int(130/$iter);
        $blue +=int(235/$iter);
        if((($tr * $tr) + ($ti * $ti)) > 4){
          $rgb_out = '#' . (sprintf("%2.2X",$red)) . sprintf("%2.2X",$
+green) . (sprintf("%2.2X",$blue));
          last;
        }
      }
      $canvas -> createLine($rcount, $icount, $rcount+1, $icount, -fil
+l => $rgb_out, -width => 1);
      $rcount ++;
      $r += ((4/$scale)/$c_size);
    }
    $icount ++;
    $i += ((4/$scale)/$c_size);
  }
}

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In reply to Tk Mandelbrot Fractal by Melly

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