NAME

Algorithm::BinPack::2D - efficiently pack items into rectangles

SYNOPSIS

Algorithm::BinPack::2D efficiently packs items into bins. The bins are given a maximum width and height, and items are packed in with as little empty space as possible. An example use would be backing up small images to concatenated images, while minimizing the number of images required.

my $bp = Algorithm::BinPack::2D->new(binwidth => 512, binheight => 512);

$bp->add_item(label => "one.png",   width =>  30, height =>  10);
$bp->add_item(label => "two.png",   width => 200, height =>  40);
$bp->add_item(label => "three.png", width =>  30, height => 300);
$bp->add_item(label => "four.png",  width => 400, height => 100);

for ($bp->pack_bins) {
    print "Bin width: ", $_->{width}, " x ", $_->{height}, "\n";
    print "     Item: ", $_->{label}, "\n" for @{ $_->{items} };
}

METHODS

new

Creates a new Algorithm::BinPack::2D object. The maximum bin width and height is specified as a named argument 'binwidth' and 'binheight', and is required.

my $bp = Algorithm::BinPack::2D->new(binwidth => 512, binheight => 512);

add_item

Adds an item to be packed into a bin. Required named arguments are 'label', 'width' and 'height', but any others can be specified, and will be saved.

$bp->add_item(label => 'one',  width => 1, height => 1);

pack_bins

Packs the items into bins. This method tries to leave as little empty space in each bin as possible. It returns a list of hashrefs with the key 'width' containing the total bin width, 'height' containing the total bin height, and 'items' containing an arrayref holding the items in the bin. Each item is in turn a hashref containing the keys 'label', 'x', 'y', 'width' and 'height'.

for my $bin ($bp->pack_bins) {
    print "Bin width: ", $bin->{width}, " x ", $bin->{height}, "\n";

    for my $item (@{ $bin->{items} }) {
        printf "  %-6s %-20s\n", $_, $item->{$_} for keys %{ $item };
        print  "  ---\n";
    }
}

SEE ALSO

Algorithm::BinPack

AUTHOR

Tasuku SUENAGA a.k.a. gunyarakun <tasuku-s-cpan@titech.ac<gt>

LICENSE