#!/usr/bin/perl
use strict;
use warnings;

use lib 'lib';

use Math::Fractal::Curve;
use Imager;

unless(@ARGV) {
	die <<HERE;
prob_koch.pl - generate probalistic von Koch fractals as PNG images.
Usage: $0 RecursionDepth

HERE
}

my $depth = shift @ARGV;

# Filename for image.
my $filename = sprintf('ProbalisticKoch-Depth%02i.png', $depth);

# This generates a von Koch-curve.
my $generator = sub {
	my $sign = int(rand(2));
	$sign = -1 unless $sign;
	[
		[0,   0,               1/3, 0              ],
		[1/3, 0,               1/2, $sign*sqrt(5)/6],
		[1/2, $sign*sqrt(5)/6, 2/3, 0              ],
		[2/3, 0,               1,   0              ],
	]
};
	
# New curve generator
my $curve_gen = Math::Fractal::Curve->new(generator => $generator);

# New curve
my $curve = $curve_gen->line(
	start => [-2, 0],
	end   => [2, 0],
);


# Image dimensions
my $max_x = 1000;
my $max_y = 700;

my $img = Imager->new(xsize => $max_x, ysize => $max_y);

my $edges = $curve->fractal($depth);

my $color = Imager::Color->new( 0, 0, 255 );

# Scale dimensions by 200.
@$_ = map $_*170, @$_ foreach @$edges;

foreach (@$edges) {
	$img->line(
		color => $color,
		x1 => $max_x/2 + $_->[0],
		y1 => $max_y/2 - $_->[1],
		x2 => $max_x/2 + $_->[2],
		y2 => $max_y/2 - $_->[3],
	);
}

$img->write(file=>$filename) or
        die $img->errstr;