grunt-spritefiles

Grunt library for using spritesmith, a spritesheet and CSS pre-processor utility.

Synopsis

Spritesmith accepts a list of images, stiches them together, and returns that image along with a coordinate map of where each image is located and its dimensions.

Grunt is a node.js based CLI build tool.

json2css converts the output from Spritesmith and generates variables and helper functions for hooking into inside of your CSS pre-processor.

When you combine all three of these, you get a grunt plugin that makes maintaining sprites a breeze.

Getting Started

Install this grunt plugin next to your project's grunt.js gruntfile with: npm install grunt-spritefiles

Then add this line to your project's grunt.js gruntfile:

grunt.loadNpmTasks('grunt-spritefiles');

Requirements

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

Why Use This Task

You need to generate multiple sprite images and run custom processing over the results. If this isn't true, you probably want a simpler, more maintained plugin like grunt-spritesmith, the basis for this plugin. That being said, this plugin works and I'm happy to receive patches if it doesn't.

This module was written for a large, complex, existing product that needed to programatically generate sprite-creation tasks and run custom processing for sprites without changing old workflow. It uses the typical grunt src/dest/files attributes to generate multiple sprites per task. The spritesmith results are passed to a function to allow any customised processing.

Usage

// Load package if using extra functions from it
var sprite = require('./src/grunt-spritefiles.js');

// Provide a custom processing function
var customSprites = function(grunt, that, sprite, result) {
  // grunt: Grunt object, as available to task
  // that: this object from task
  // sprite: grunt files object for sprite
  // result: spritesmith result object
  grunt.verbose.writeflags(sprite, 'Files');
  grunt.verbose.writeflags(result.coordinates, 'Sprite coordinates');
};

grunt.initConfig({
  'sprite': {
    'all': {
      // Uses standard grunt src/dest/files attributes for building sprite image
      'files': [
        { dest: 'images/sprite.png', src: ['images/sprites/*.png'] },
        { dest: 'images/sprite.png', src: ['images/sprites/*.png'],
          // Processor function to run for each sprite
          processor: sprite.cssFile( // write CSS file (matches grunt-spritesmith)
            'css/sprite.json',  // css file location
            {
              // OPTIONAL: Specify CSS format (inferred from file's extension by default)
                  // (stylus, scss, sass, less, json)
              'cssFormat': 'json',

              // OPTIONAL: Manual override for imgPath specified in CSS
              'imgPath': '../sprite.png'
            })
        },
        'options': {
          // OPTIONAL: Specify algorithm (top-down, left-right, diagonal [\ format],
              // alt-diagonal [/ format], binary-tree [best packing])
          'algorithm': 'alt-diagonal',

          // OPTIONAL: Specify engine (auto, canvas, gm)
          'engine': 'canvas',

          // OPTIONAL: Specify img options
          'imgOpts': {
             // Format of the image (inferred from destImg' extension by default) (jpg, png)
             'format': 'png',

             // Quality of image (gm only)
             'quality': 90
          }
        }
      ]
    },
    'all': {
      dest: 'images/custom.png',
      src: ['images/*.gif'],
      processor: customSprites
    }
  }
});

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.

Algorithms

Algorithms are maintained via twolfson/layout. If you would like to add one, please submit it via a pull request.

Engines and image options

Engines and image options are maintained via Ensighten/spritesmith. If you would like to add one, please submit it via a pull request.

CSS formats

CSS formats are maintained via twolfson/json2css. If you would like to add one, please submit it via a pull request.

License

Copyright (c) 2012 Ensighten Copyright (c) 2013 Recognia Inc Licensed under the MIT license.