#!/usr/bin/perl
# mcc@grumpybumpers.com

package evo; 
use GD::Image; 

# The following variables determine the program's behavior.
our $size = 32;    # How big is an image?
our $herd = 4;     # How many images do we create per generation?
our $litter = 2;   # How many new images are generated in each spawn event?
our $select = 2;   # How many spawns are generated in each selection selection event?
our $mutate = 16;  # How often do mutations happen? 
our $shades = 255; # Set this to 255 for a black-and-white image. Set it to 1 for a grayscale image.

sub colors {
	my ($image) = @_; 
	my @colors;
	if ($shades == 255) {
		push(@colors, $image->colorAllocate(0,0,0));
		push(@colors, $image->colorAllocate(255,255,255));
	} else {
		for my $c (0..255) {
			push(@colors, $image->colorAllocate($c,$c,$c));
		}
	}
	return @colors;
}

# Generates a $size x $size random image.
sub abiogenesis {
	my ($name) = @_;
	# setup the image
	my $image = GD::Image->new($size,$size);
	my @colors = colors($image);

	for my $x (0..$size) {
	for my $y (0..$size) {
		my $color;
		$color = $colors[rand @colors];
		$image->rectangle($x, $y, $x, $y, $color);
	}
	}

	open(FH, ">$name");
	print FH $image->gif();
	close(FH);
}

# Takes in two filenames of input GIFs and a list of filenames for output GIFs.
# For each output GIF name, genetically recombines the two input GIFs and saves the results.
sub spawn {
	my ($in1, $in2, @outnames) = @_;
	my $male = GD::Image->newFromGif($in1);
	my $female = GD::Image->newFromGif($in2);

	for my $name (@outnames) {
		# setup the image
		my $image = GD::Image->new($size,$size);
		my @colors = colors($image);

		# and the log
		my $log = GD::Image->new($size,$size);
		my $red = $log->colorAllocate(255,0,0);
		my $white = $log->colorAllocate(255,255,255);
		my $black = $log->colorAllocate(0,0,0);

		for my $x (0..$size) {
		for my $y (0..$size) {
			my ($color, $logcolor);
			if (0 == int(rand($mutate))) {
				$color = $colors[rand @colors];
				$logcolor = $red;
			} else {
				(my $pixel, $logcolor) = (rand() > 0.5 ? ($male, $white) : ($female, $black)); 
				my ($g) = $pixel->rgb($pixel->getPixel($x,$y)); 
				$color = $colors[$g/$shades];
			}
			$image->setPixel($x, $y, $color);
			$log->setPixel($x, $y, $logcolor);
		}
		}

		open(FH, ">$name"); 
		print FH $image->gif();
		close(FH);
                open(FH, ">$name.log.gif");
                print FH $log->gif();
                close(FH);
	}
}