Font

Collections

A TrueType or OpenType collection (.ttc, .otc) stores several faces in one file and lets them share tables, typically the glyph data of a CJK family. Its signature is ttcf, and the package reports it as FontFormat::TrueTypeCollection.

Reading

Select a zero-based face when loading:

<?php

use Alto\Font\Font;

$font = Font::fromFile(__DIR__.'/fonts/Collection.ttc', faceIndex: 1);

echo $font->face()->faceIndex;
echo $font->face()->faceCount;

A collection that declares no faces, or an index outside 0 to faceCount - 1, raises InvalidFontException. A collection nested inside a collection raises UnsupportedFontException, and so does a selected face with CFF outlines. Standalone files accept only index zero.

Finding searches the first face of each collection; load another face explicitly with faceIndex.

Writing

A selected face is always written as a standalone font with a rebuilt table directory and checksums; the package does not write collections:

<?php

use Alto\Font\Font;
use Alto\Font\Writer\SfntWriter;

$font = Font::fromFile(__DIR__.'/fonts/Collection.ttc', faceIndex: 1);

new SfntWriter()->write($font, __DIR__.'/output/selected-face.ttf');

Subsetting

Subsetting applies to the selected face only, and the result is a standalone font; see Subsetting.

Requirements and limits

  • A TTC or OTC with glyf faces: read one face, write it standalone, subset it.
  • A WOFF2 collection is rejected explicitly; use the TTC or OTC source.
  • Writing a collection is not available.