Google Font provides a subset of Korean, Japanese, and Chinese Slicing Patterns through machine learning.

Font Range helps you to subset using unicode range in Google Fonts.

It has dependencies on the following packages:

pip3 install fonttools[ufo,woff,unicode] zopfli brotli

This project has three types.

• fontRange(): Subset based on unicode-range in the CSS file.
• fontSubset(): Subset based on text or text file.
• fontPipe(): Use fontRange() and fontSubset() to perform multiple subset operations.

// fontRange
fontRange(font_path, css_url_or_path);
fontRange(font_path, css_url_or_path, save_dir);       // Option1
fontRange(font_path, css_url_or_path, { ...options }); // Option2

// fontSubset
fontRange(font_path);
fontRange(font_path, save_dir);       // Option1
fontRange(font_path, { ...options }); // Option2

// fontPipe
fontPipe([
  { font_path },                                      // As `fontSubset(font_path)`
  { font_path, option: { text: "abc" } },             // As `fontSubset(font_path, { text: "abc" })`
  { font_path, option: { textFile: file_path } },     // As `fontSubset(font_path, { textFile: file_path })`
  { font_path, option: { cssFile: css_url_or_path } } // As `fontRange(font_path, css_url_or_path)`
]);
fontPipe([{ font_path1 }, { font_path2 }], "<index>/<total>"); // Sharding option use like `1/2`

The URL of Noto Sans is included in the package.

const targets = {
  weston:   "https://fonts.googleapis.com/css2?family=Noto+Sans&display=swap",
  korean:   "https://fonts.googleapis.com/css2?family=Noto+Sans+KR&display=swap",
  japanese: "https://fonts.googleapis.com/css2?family=Noto+Sans+JP&display=swap",
  chinese:  "https://fonts.googleapis.com/css2?family=Noto+Sans+SC&display=swap",
  chinese_traditional: "https://fonts.googleapis.com/css2?family=Noto+Sans+TC&display=swap",
};

List of options available for all function options.

type Format = "otf" | "ttf" | "woff2" | "woff" | "woff-zopfli";
interface FontDefaultOptionI {
  saveDir:     string;   // Directory to save the generated subset or downloaded CSS
  format:      Format;   // Subset type to create
  nameFormat:  string;   // File name format to create
  logFormat:   string;   // Log format to print
  defaultArgs: string[]; // `pyftsubset` option - default
  etcArgs:     string[]; // `pyftsubset` option - for users
}

• save_dir's default: <font_path>
• format's default: "woff2"
• nameFormat's default: "{NAME}_{INDEX}{EXT}"
• defaultArgs's default:

[
  "--layout-features=*",
  "--glyph-names",
  "--symbol-cmap",
  "--legacy-cmap",
  "--notdef-glyph",
  "--notdef-outline",
  "--recommended-glyphs",
  "--name-legacy",
  "--drop-tables=",
  "--name-IDs=*",
  "--name-languages=*"
]

• etcArgs's default: []

It is designed to be able to do a subset using unicode-range of CSS.

The name of the generated file can be determined from the CSS.

interface FontRangeOptionI extends FontDefaultOptionI {
  fromCSS: "default" | "srcIndex" | "srcName";
}

• default: The index of the file name increases in the generated order
• srcIndex: The index of the file name uses src in CSS #9
  • Based on the first url()
• srcName: The file name uses src in CSS
  • Based on the first url()

It is designed to be able to do a general subset.

By default, all letters are included, but you can set the letters to include:

interface FontSubsetOptionI extends FontDefaultOptionI {
  textFile: string; // From text file
  text:     string; // Letter like `abc`
}

It offers a simple API when doing a large amount of subsets.

Performance is optimized using worker pool and provides sharding for distributed environments.

If cssFile has attributes, it is recognized as fontRange().

interface FontPipeOptionI extends FontRangeOptionI, FontSubsetOptionI {
  cssFile: string;
}

You can control sharing using argument or environment variable.
If both values are used together, argument is applied first.

• Argument: Explicitly used through function.

fontPipe([{ font_path1 }, { font_path2 }], "<index>/<total>");

• Environment Variable: Make it easy to use in CI, npm scripts, ..etc.

SHARD="<index>/<total>"
node subset.js

Licensed under the MIT. See the LICENSE file for details.