Tetromino

Introduction

First fit heuristic algorithm for 4D bin packing problem solver (4dbpp). An implementation of the "4D" bin packing problem i.e. given a list of items, how many boxes do you need to fit them all in taking into account physical dimensions and weights.

This project is a complete rewrite of box_packer

It also provide 2 additional "real life" features:

• Coerce items that can't be stacked.
• Coerce items that are not invertible.

...Especially if you need to pack (big) fragile items.

Installation

Add this line to your application's Gemfile:

gem 'tetromino'

And then execute:

$ bundle

Or install it yourself as:

$ gem install tetromino

Usage

tetromino = Tetromino.packer(dimensions: [40, 30, 20]) # Define the size of your box
tetromino.add_item!(dimensions: [40, 30, 10]) # Fill it up with item
tetromino.add_item!(dimensions: [10, 40, 30]) # ...Moarrr item!
tetromino.pack! # Pack your stuff
tetromino.packed_successfully? # => true

Dimensions

Dimensions should always be declared in the following order: [depth, width, height]

Detailed results

You can also get the results of the algorithm.

results = tetromino.results
=> [#<struct Tetromino::Packing
    placements=
    [
      #<struct Tetromino::Placement
        dimensions=[40, 30, 10],
        position=[0, 0, 0],
        weight=0>,
      #<struct Tetromino::Placement
        dimensions=[40, 30, 10],
        position=[0, 0, 10],
        weight=0>
    ],
    weight=0.0,
    spaces=
    [
      #<struct Tetromino::Space
        dimensions=[0, 30, 20],
        position=[40, 0, 0]>,
      #<struct Tetromino::Space
        dimensions=[40, 0, 20],
        position=[0, 30, 0]>,
      #<struct Tetromino::Space
        dimensions=[0, 30, 10],
        position=[40, 0, 10]>,
      #<struct Tetromino::Space
        dimensions=[40, 0, 10],
        position=[0, 30, 10]>,
      #<struct Tetromino::Space
        dimensions=[40, 30, 0],
        position=[0, 0, 20]>
    ]>
  ]

Placements

Placements represent how your items have been organized into your box(es) (dimensions & positions).

results.placements

Spaces

These are the empty spaces remaining in your box(es).

results.spaces

Weight

This is the total weight of the packed items.

results.weight

Advanced usages

Weight coercion

You can define a weight limit constraint on your box(es).

begin
tetromino = Tetromino.packer(dimensions: [40, 30, 20], max_weight: 4)
tetromino.add_item!(dimensions: [40, 15, 20], weight: 2)
tetromino.add_item!(dimensions: [40, 15, 20], weight: 3)
tetromino.pack!
tetromino.packed_successfully? # => false
rescue Tetromino::Exceptions::Error => error
  puts error.message # => Maximum boxes quantity exceeded
end

Multiple boxes

You can try to pack your items in multiple boxes.

tetromino = Tetromino.packer(dimensions: [40, 30, 20], boxes_limit: 2)
tetromino.add_item!(dimensions: [40, 30, 20])
tetromino.add_item!(dimensions: [30, 20, 40])
tetromino.pack!
tetromino.packed_successfully? # => true

Not stackable items

You can define if your items can't be stacked.

begin
  tetromino = Tetromino.packer(dimensions: [40, 30, 20])
  tetromino.add_item!(dimensions: [40, 30, 10], stackable: false)
  tetromino.add_item!(dimensions: [40, 30, 10], stackable: false)
  tetromino.pack!
  tetromino.packed_successfully? # => false
rescue Tetromino::Exceptions::Error => error
  puts error.message # => Maximum boxes quantity exceeded
end

Not invertible items

You can define if your items can't be leaned. (impossible to permute height with depth or width)

begin
  tetromino = Tetromino.packer(dimensions: [40, 30, 20])
  tetromino.add_item!(dimensions: [40, 30, 10], invertible: false)
  tetromino.add_item!(dimensions: [40, 10, 30], invertible: false)
  tetromino.pack!
  tetromino.packed_successfully? # => false
rescue Tetromino::Exceptions::Error => error
  puts error.message # => Maximum boxes quantity exceeded
end

Parameters combinations

You can combine all the parameters at once:

tetromino = Tetromino.packer(dimensions: [40, 30, 20], boxes_limit: 2, max_weight: 5)
tetromino.add_item!(dimensions: [40, 30, 10], invertible: false, stackable: false, weight: 2)
tetromino.add_item!(dimensions: [30, 40, 10], invertible: false, stackable: false, weight: 3)
tetromino.pack!
tetromino.packed_successfully? # => true

Errors handling

Tetromino will always raise an error if it is unable to pack your items with the given constraints.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/deliver-ee/tetromino.

License

The gem is available as open source under the terms of the MIT License.