Spritesmith

Utility that takes image files and generates spritesheets and coordinate maps.

Once you have satisfied the requirements, spritesmith can be installed via npm install spritesmith.

Spritesmith is also available as a grunt plugin.

Requirements

Spritesmith supports multiple sprite engines however all of the current engines require external software to be installed.

As a result, you must either have Cairo or Graphics Magick installed for Spritesmith to run properly.

Cairo (node-canvas)

Due to dependance on node-canvas, you must install Cairo.

Instructions on how to do this are provided in the node-canvas wiki.

Additionally, you will need to install node-gyp

sudo npm install -g node-gyp

Graphics Magick (gm)

The alternative engine is gm which runs on top of Graphics Magick.

I have found it is best to install from the site rather than through a package manager (e.g. apt-get) to get the latest as well as without transparency issues.

Documentation

Spritesmith is a standalone function

/**
 * Spritesmith generation function
 * @param {Object} params Parameters for spritesmith
 * @param {String[]} [params.src] Images to generate into sprite sheet
 * @param {String} [params.engine="auto"] Engine to use (canvas, gm, or user-defined via Spritesmith.addEngine)
 * @param {String} [params.algorithm="top-down"] Algorithm to pack images with (top-down or user-defined via Spritesmith.addAlgorithm)
 * @param {Mixed} [params.exportOpts] Options to pass through to engine for export
 * @param {Function} callback Function that receives compiled spritesheet and map
 * @returns {Mixed} callback[0] err If an error was encountered, this will be returned to callback
 * @returns {Object} callback[1] result Result object of spritesmith
 * @returns {String} callback[1].image Binary string representation of image
 * @returns {Object} callback[1].coordinates Map from file name to an object containing x, y, height, and width information about the source image
 */

Canvas export options

For the canvas engine, the current output options are:

{
  'format': 'png' // Format to export the canvas to (png or jpeg)
}

gm export options

For the gm engine, the current output options are:

{
  'format': 'png', // Format to export the canvas to (png or jpeg)
  'quality': 75 // Quality of the output image
}

Available packing algorithms

The available packing algorithms are: top-down, left-right, diagonal (\ format), alt-diagonal (/ format).

Adding new engines

Example engines can be found in src/engines.

New engines can be added via Spritesmith.addEngine(name, engine);.

If you decide to build a new engine, there are some utilities in src/utils which may be helpful.

Adding new packing algorithms

Algorithms are maintained inside of twolfson/layout. Example algorithms can be found in twolfson/layout/lib/algorithms.

New algorithms can be added via Spritesmith.Layout.addAlgorithm(name, algorithm);.

Examples

var sprites = ['sprite1.png', 'sprite2.jpg', 'sprite3.png'];
spritesmith({'src': sprites}, function (err, result) {
  result.image; // Binary string representation of image
  result.coordinates; // Object mapping filename to {x, y, width, height} of image
});

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint via grunt and test via npm test.

License

Copyright (c) 2012 Ensighten Licensed under the MIT license.