Autotile

This library accepts a 2D array of truthy/falsey values representing the floor of a game level. This library returns a 2D array of numbers corresponding to the tileset offset which should then be used.

• Example tileset by Buch
• Algorithm by Sonny Bone

This implementation uses the 8-bit (cornered) approach. This implementation only works with 2 types of terrain (hence the true and false).

Tileset

You'll need to create a tileset with your tiles laid in the same order as shown here:

The number of columns you use isn't as important, that will probably be handled by whatever rendering engine you're using.

Usage

Imagine we have the following 2D representation of our levels floor, with white being floor and black being walls or holes:

This shape could look like the following (true/false or 1/0 both work). In this array, falsey values represent an absense of floor (e.g. a wall) and truthy values represent the floor.

const autotile = require('autotile');
const myLevel = [
  [0, 1, 0, 0, 0, 0, 0],
  [0, 1, 0, 1, 1, 1, 0],
  [0, 1, 1, 1, 0, 1, 0],
  [0, 0, 0, 0, 0, 1, 0],
  [0, 1, 1, 1, 1, 1, 0],
  [0, 1, 0, 1, 0, 0, 0],
  [0, 1, 1, 1, 1, 1, 0],
  [0, 0, 0, 0, 1, 1, 1],
  [0, 0, 0, 0, 1, 0, 0],
  [0, 0, 0, 1, 1, 0, 0],
  [0, 0, 0, 1, 0, 0, 0],
  [1, 0, 1, 1, 1, 0, 1],
  [0, 0, 1, 1, 1, 0, 0],
  [1, 0, 1, 1, 1, 0, 1],
  [1, 0, 0, 0, 0, 0, 1],
  [0, 0, 1, 0, 0, 0, 0],
  [0, 0, 1, 1, 1, 0, 0],
  [0, 1, 1, 1, 0, 0, 0],
  [0, 0, 0, 1, 0, 1, 1],
  [0, 0, 0, 0, 0, 0, 0],
];

const tiles = autotile(myLevel);

console.log(tiles);

Once we've run the map through autotile we will get the following result:

This is represented as an array of tileset offsets:

[
  [ 0, 13, 0, 0, 0, 0, 0 ],
  [ 0, 14, 0, 18, 8, 15, 0 ],
  [ 0, 6, 8, 3, 0, 14, 0 ],
  [ 0, 0, 0, 0, 0, 14, 0 ],
  [ 0, 18, 8, 21, 8, 3, 0 ],
  [ 0, 14, 0, 14, 0, 0, 0 ],
  [ 0, 6, 8, 9, 37, 26, 0 ],
  [ 0, 0, 0, 0, 20, 10, 2 ],
  [ 0, 0, 0, 0, 14, 0, 0 ],
  [ 0, 0, 0, 18, 3, 0, 0 ],
  [ 0, 0, 0, 14, 0, 0, 0 ],
  [ 47, 0, 34, 43, 26, 0, 47 ],
  [ 0, 0, 36, 46, 28, 0, 0 ],
  [ 13, 0, 7, 12 4, 0, 13 ],
  [ 1, 0, 0, 0, 0, 0, 1 ],
  [ 0, 0, 13 0, 0, 0, 0 ],
  [ 0, 0, 35 29 2, 0, 0 ],
  [ 0, 5, 11 17 0, 0, 0 ],
  [ 0, 0, 0, 1, 0, 5, 2 ],
  [ 0, 0, 0, 0, 0, 0, 0 ]
]

TODO

• Also implement a 4-bit (no corners) approach
• Allow for infinire number of terrain