Lia

Lia finds image resources according to sprite_conf.js, then builds sprite images and output stylesheet files to specify directory.

If you are tend to build sprite images according to stylesheet, maybe you like Emilia.

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Features

• Supports rem as well as numerical conversion.
• Output multiple sprite pictures and stylesheet files in once time.
• Monitor file changes and incremental recompilation.
• Create sprites picture in current folder easily. May be useful for css or canvas keyframes animation.
• Supports custom template for coordinates infomation. It means scss, js and any format you want can be built.
• Supports reading .psd directly, and then output sprite images by layers or group with information context from Photoshop.

Getting started

Step 0

npm i -g lia

$ lia -h

  Usage: lia [command]

  Commands:

    init                   Create sprite_conf.js
    here                   Build sprite images in current directory
    -w, watch              Monitor file changes and incremental recompilation
    -h, help               Output usage information

Step 1

$ lia init
[info]: Created sprite_conf.js

Step 2

$ lia
[info]: Created build/sprite.png
[info]: Created build/sprite.css

That's all.

What we should be care about is sprite_conf.js. When lia init, it create the config file in current directory:

// sprite_conf.js
module.exports = [{
    src: ['*.png'],
    image: 'build/sprite.png',
    style: 'build/sprite.css',
    prefix: '',
    cssPath: './',
    unit: 'px',
    convert: 1,
    decimalPlaces: 6,
    blank: 0,
    padding: 10,
    algorithm: 'binary-tree',
    tmpl: '',
    psd: '',
    quiet: false
}];

And in the example above, it finally outputs sprite.css and sprite.png

/* build/sprite.css */
.icon0 {
    width: 256px;
    height: 256px;
    background: url('./sprite.png') no-repeat;
    background-size: 522px 366px;
    background-position: 0px 0px;
}
.icon1 {
    width: 256px;
    height: 256px;
    background: url('./sprite.png') no-repeat;
    background-size: 522px 366px;
    background-position: -266px 0px;
}
.icon2 {
    width: 100px;
    height: 100px;
    background: url('./sprite.png') no-repeat;
    background-size: 522px 366px;
    background-position: 0px -266px;
}

Having get those stylesheet files and sprite images, you can use it through @extend or directly use the selector. Whatever you like.

Parameter

src

• type: Array
• desc: origin image path, use glob-patterns
• default: ['*.png']

image

• type: String
• desc: output path of sprite image
• default: 'build/sprite.png'

style

• type: String
• desc: output path of stylesheet, can be css, scss, or with tmpl to be js, json, and any format.
• default: 'build/sprite.css'

prefix

• type: String
• desc: selector prefix
• default: ''

cssPath

• type: String
• desc: relative path or publish path of sprite image
• default: '../images/'

unit

• type: String
• desc: css unit
• default: 'px'

convert

• type: Number
• desc: numerical scale. Useful with rem and Retina pictures.
• default: 1

decimalPlaces

• type: Number
• desc: keep the number of decimal places with convert
• default: 6

blank

• type: Number
• desc: Create space in the edge of background container to avoid rem decimal calculation problem, which is common to cause background incomplete.
• default: 0

padding

• type: Number
• desc: padding between pictures
• default: 10

algorithm

• type: String
• desc: layout algorithm of pictures. Uses layout
• value: ['top-down' | 'left-right' | 'diagonal' | 'alt-diagonal' | 'binary-tree']
• default: 'binary-tree'

tmpl

• type: String
• desc: the path of template file, which is used to output not only stylesheet file. Uses Ejs.
• default: ''

psd

• type: String
• desc: the path of Photoshop file. If exist, src should match layers' name or groups' name in .psd.
• default: ''

Examples

Easily build sprite pictures in current directory

$ lia here
[info]: Created sprite-keyframe.png

All the pictures in current directory will be output as a sprite image in left-right layout order by filename, with padding 0. It does not output stylesheet file.

From:

To:

2. Monitor file change

The sprite_conf.js as follow.

// sprite_conf
module.exports = [{
    src: ['animal/*.png'],
    image: './sprites/sp-animal.png',
    style: './sprites/sp-animal.scss',
    cssPath: './',
    unit: 'px',
}, {
    src: ['icon/*.png'],
    image: './sprites/sp-icon.png',
    style: './sprites/sp-icon.scss',
    cssPath: './',
    unit: 'px',
}];

And when run lia watch, it works.

$ lia -w
[info]: Created ./sprites/sp-animal.png
[info]: Created ./sprites/sp-animal.scss
[info]: Created ./sprites/sp-icon.png
[info]: Created ./sprites/sp-icon.scss
[info]: Finish in 76ms. Waiting...
[info]: Created ./sprites/sp-animal.png
[info]: Created ./sprites/sp-animal.scss
[info]: Finish in 32ms. Waiting...

3. Custom template with Ejs

Lia supports output file in any format with sprite coordinates by custom Ejs template. It may be helpful in canvas animation.

Context

The Ejs template has the follow context

{
    basename: '', // sprite image's basename
    path: '', // sprites image's relative path
    realpath: '', // sprites image's realpath
    unit: '',
    size: {
        with: 0,
        height: 0
    },
    items: [{
        name: '', // origin image's basename
        size: {
            width: 0,
            height: 0
        },
        x: 0, // offset x
        y: 0, // offset y
        layer: { // Photoshop layer information if `psd` exist
            name: '', // layer name
            top: 0, // coordinate in Photoshop
            left: 0,
            right: 0,
            bottom: 0,
            width: 0,
            height: 0
        }
    }, ...],
    psd: { // Photoshop file information if `psd` exist
        width: 0,
        height: 0
    },
    _options: {} // the options you provide, can also inject some other data
}

The default template can be found in template.ejs

Example

sprite_conf.js as follow.

// sprite_conf.js
module.exports = [{
    src: ['test/fixtures/*.png'],
    image: 'test/tmp/sprite.png',
    style: 'test/tmp/sprite.js',
    tmpl: 'test/fixtures/template.ejs'
}];

Custom template file as follow.

// template.ejs
var opt = {
    width: <%= size.width %>,
    height: <%= size.height %>,
    src: '<%= realpath %>',
    count: <%= items.length %>,
    items: [
<% items.forEach(function(item, idx) { -%>
    {
        index: <%= idx %>,
        name: '<%= item.name %>',
        width: <%= item.size.width %>,
        height: <%= item.size.height %>,
        x: <%= item.x %>
        y: <%= item.y %>
    },
<% }) -%>
    ]
}

Run in CLI.

$ lia
[info]: Created test/tmp/sprite.png
[info]: Created test/tmp/sprite.js

Then you get sprite.js and sprite.png

// sprite.js
var opt = {
    width: 522,
    height: 256,
    src: '/Users/Lance/home/lia/test/tmp/sprite.png',
    count: 2,
    items: [
    {
        index: 0,
        name: 'icon0',
        width: 256,
        height: 256,
        x: 0
        y: 0
    },
    {
        index: 1,
        name: 'icon1',
        width: 256,
        height: 256,
        x: 266
        y: 0
    },
    ]
}

4. Work with .psd

It's possible to read layers or group from Photoshop directly. When .psd filepath is given, src will be the glob pattern match layers' or group's name instead of filepath.

And Lia is abled to output normally sprite image or keyframe sprite image.

// normal
module.exports = [{
    src: 'icon*',
    image: 'build/sprite.png',
    style: 'build/sprite.css',
    padding: 0,
    algorithm: 'left-right',
    psd: 'demo.psd'
}]

// keyframes
module.exports = [{
    src: 'group/',
    image: 'build/sprite.png',
    style: 'build/sprite.css',
    padding: 0,
    algorithm: 'left-right',
    psd: 'demo.psd'
}]

To be simple, only when src is a single group name that ends up with / will be considered to be a keyframe sprite image, and each visible layers under the group is one frame with the same size. Otherwise src will match layers' name in .psd while invisible layers and groups are ignored.

Currently to avoid get wrong size and performance of pictures, each Photoshop layer that are expected to be outputed should be rasterized before running Lia. It suggests to use Photoshop action to do the repeat works now. And the problem is probably to be resolve in the next version.

What's more, when running Lia, a context with Photoshop information is available in render template. It's helpful in locating element in the viewport, with CSS or JavaScript. Here is the CSS example.

Conf:

module.exports = [{
    src: 'icon*',
    image: 'build/sprite.png',
    style: 'build/sprite.css',
    algorithm: 'left-right',
    padding: 0,
    tmpl: 'css.ejs',
    psd: 'demo.psd'
}]

Template:

<% items.forEach(function(item) { -%>
.<%= item.name %> {
    position: absolute;
    top: <%= item.layer.top + unit %>;
    left: <%= item.layer.left + unit %>;
    width: <%= item.size.width + unit %>;
    height: <%= item.size.height + unit %>;
    background: url('<%= path %>') no-repeat;
    background-size: cover;
    background-position: <%= -item.x + unit %> <%= -item.y + unit %>;
}
<% }) -%>

Output:

.icon1 {
    position: absolute;
    top: 96px;
    left: 96px;
    width: 64px;
    height: 64px;
    background: url('./sprite.png') no-repeat;
    background-size: cover;
    background-position: 0px 0px;
}
.icon2 {
    position: absolute;
    top: 64px;
    left: 64px;
    width: 128px;
    height: 128px;
    background: url('./sprite.png') no-repeat;
    background-size: cover;
    background-position: -64px 0px;
}
...

In addition, to keep correct order of layers from Photoshop, keyframe sprite images' item name is set as id number instead of layer name.

Changelog

• v2.1.0
  • Supports reading .psd directly with option psd
• v2.0.0
  • Easier and stronger template supports with Ejs
  • Remove option.wrap and add option.decimalPlaces
  • In $lia here, layout now be left-right instead of top-down
  • Update default options
  • Stronger test coverage
• v1.2.2
  • Replace Array.prototype.sort with lodash.sortby to fix orders of sprite images, which may be wrong in $lia here
• v1.2.0
  • Use node-images as image engine and thus greatly speed up compilation
• v1.1.1
  • Update for Node v0.12 support
• v1.1.0
  • Fix fatal bug cause by incorrect usage of child_process.execFileSync in windows
  • Add unit test
• v1.0.0
  • Rename from Sprites to Lia
  • Adjust default options
• v0.2.1
  • Add command watch, which be abled to monitor file changes
• v0.1.2
  • Add command now which named here currently, which be abled to build sprite picture in current folder
  • Fix snowball bug, sprite picture will be filter in compilation
• v0.1.1
  • Add parameter tmpl and wrap, which be abled to output json and any format file with sprit coordinats
• v0.0.1:
  • Basic functions

Test

npm i && npm test

License

Copyright (c) 2016 cupools

Licensed under the MIT license.