#!/usr/bin/perl -w

use CGI qw(:standard);
use strict;
use GD;

use vars qw($magnitude $P $Q $scale);

my ($x_centre,$y_centre) = (320,175);

if ( scalar param() < 3 )
  {
    my @configs = map {chomp; [ split ]} <DATA>; 
    ($P,$Q,$scale) = @{ $configs[rand @configs] };
   }
else
  {
   $P = param('real');
   $Q = param('imaginary');
   $scale = param('scale');
  }

   my $image = new GD::Image($x_centre * 2,$y_centre * 2);

   my $back_colour = $image->colorAllocate(255,255,255);
   my $fore_colour = $image->colorAllocate(0,0,0);

   my ($x,$y) = (0.50001,0);

   $magnitude = ($P*$P) + ($Q*$Q);

   $P = 4*$P/$magnitude;
   $Q = -4*$Q/$magnitude;

   $scale = $x_centre * $scale;

   for ( 1 .. 12000 )
      {
        my $temp_x = ($x * $P ) - ($y * $Q );
        $y = ($x * $Q) + ($y * $P );
        my $temp_y = $y;
        $x = 1 - $temp_x;

        $magnitude = sqrt(($x * $x ) + ($y * $y));

        $y = sqrt((-$x + $magnitude)/2);
        $x = sqrt(($x + $magnitude)/2);

        ($x = -$x) if ($temp_y < 0 );

        if ( rand() < 0.5 )
          {
            $x = -$x;
            $y = -$y;
          }

        $x = (1- $x) / 2;

        $y = $y / 2;

        my $col = int(($scale * ($x - 0.5 )) + $x_centre);
        my $row = int($y_centre - ($scale * $y));

         if ( ($_ > 0 ) &&
              ($col >= 0 ) &&
              ($col < (2 * $x_centre)) &&
              ($row >= 0 ) &&
              ($row < ($y_centre * 2 )))
            {
              $image->setPixel($col,$row,$fore_colour);
            }
     }

   print header('image/png');
   binmode(STDOUT);
   print $image->png;
__END__
1.646009    0.967049 0.75
2.447261    -0.967049 0.75
1.325508    0.786533 0.75
1.415414    0.856803 0.75
1.255399    0.691977 0.75
2.792809    -0.657593 0.75
3.018153    -0.098854 0.75
2.998122    0.004298 0.75