#!/usr/bin/env perl

use strict;
use warnings;
use Imager;

my $width   = 1280;
my $height  = 1024;
my $image   = Imager->new( xsize => $width, ysize => $height );
my @palette = Imager::Color->new( 0, 0, 0 );

for ( 1 .. 20 ) {
    my ( $r, $g, $b ) = map { int rand 255 } 1 .. 3;
    push @palette, Imager::Color->new( $r, $g, $b );
}

for my $x ( 0 .. $width - 1 ) {
    for my $y ( 0 .. $height - 1 ) {
        $image->setpixel(
            x     => $x,
            y     => $y,
            color => $palette[ mandelbrot( $x, $y ) ]
        );
    }
}

my $file = qq(mandelbrot.bmp);

$image->write( file => $file );

sub mandelbrot {
    my ( $x, $y ) = @_;
    my $re_c = ( $x - 3 * $width / 4 ) / ( $width / 3 );
    my $im_c = ( $y - $height / 2 ) / ( $width / 3 );
    my ( $re_z, $im_z, $iteration ) = (0) x 3;
    while (1) {
        my $temp = $re_z;
        $re_z = $re_z * $re_z - $im_z * $im_z + $re_c;
        $im_z = 2 * $temp * $im_z + $im_c;
        ++$iteration;
        last if $re_z * $re_z + $im_z * $im_z > 4;
        $iteration = 0, last if $iteration == 20;
    }
    return $iteration;
}

__END__