alto/font

Font file reading and metadata: parse OpenType/TrueType/WOFF/WOFF2, discover installed fonts, and expose per-glyph facts (metrics, outlines) without any drawing or shaping.

v0.7.0 2026-08-10 00:09 UTC

Requires

• php: >=8.4
• ext-zlib: *

Requires (Dev)

• friendsofphp/php-cs-fixer: ^3.68
• phpstan/phpstan: ^2.1
• phpunit/phpunit: ^12

Suggests

• ext-brotli: Decompresses WOFF2 font data without shelling out to the brotli binary.
• brotli: Provides Brotli decompression for WOFF2 when ext-brotli is not installed.

MIT

• Simon André

Published on Packagist.org on 2026-08-10 00:10 UTC

README

Font file reading and metadata for PHP: parse OpenType/TrueType/WOFF/WOFF2, discover installed fonts, and expose per-glyph facts.

alto/font answers "what is this font, and what are the facts about this glyph" -- metadata, discovery, per-glyph metrics and outlines. It does not shape text, does not apply kerning, and does not draw anything. Turning a string of text into positioned, drawn glyphs is a different package's job (alto/svg-font and friends); this one only reads and reports facts.

use Alto\Font\Font;
use Alto\Font\FontFinder;
use Alto\Font\FontQuery;

$font = Font::fromFile(__DIR__.'/fonts/Inter.ttf');

$font->getDescriptor()->family;      // 'Inter'
$font->face()->unitsPerEm;           // 1000
$font->face()->ascender;             // 968

$glyphId = $font->glyphIdForCodepoint(mb_ord('A'));
$font->glyphMetrics($glyphId)->advanceWidth;
$font->glyphOutline($glyphId);       // raw Contour/PathCommand geometry

$finder = FontFinder::fromDirectories(__DIR__.'/fonts');
$bold = $finder->get(FontQuery::family('Inter')->weight(700));

Features

• Font::fromFile() -- load an OpenType/TrueType/WOFF/WOFF2 font file.
• FontFace -- unitsPerEm, ascender, descender, glyphCount, raw table access.
• FontDescriptor -- family, subfamily, full name, PostScript name, weight, style, stretch, inferred from the name/subfamily strings.
• FontMetadata -- copyright, manufacturer, designer, version, license description and URL, read from the name table.
• Per-glyph facts: glyphIdForCodepoint(), glyphMetrics() (advance width, side bearings), glyphOutline() (contours as generic move/line/quad commands, transformable, not tied to any output format).
• Variable fonts: withVariations() resolves fvar/avar/gvar/HVAR axes and instances into concrete per-instance metrics and outlines.
• Discovery: FontFinder::system() / ::fromDirectories($dirs) / ::fromLocator(), resolving a FontQuery (family/weight/style/stretch) to the best-matching Font via has() / find() / get(). Locator\FontLocatorInterface is the one injectable seam, for tests or custom/non-directory font sources.

Format support

Format	Extension(s)	Support
TrueType (glyf outlines)	.ttf	Supported, including compound glyphs
OpenType with glyf outlines	.otf	Supported
WOFF v1	.woff	Supported (ext-zlib, always available)
WOFF2, null-transform tables	.woff2	Supported only with ext-brotli or the brotli CLI binary on PATH -- without either, throws UnsupportedFontException rather than failing silently or partially
WOFF2 with transformed glyf/loca tables	.woff2	Not supported yet -- rejects cleanly
CFF/CFF2 outlines (Type 2 charstrings)	.otf	Not supported yet -- rejects cleanly
TrueType/OpenType collections	.ttc, .otc	Supported: Font::fromFile($path, faceIndex: $n) selects a face; FontFace::$faceIndex/$faceCount report the file's shape
Compressed (WOFF2) font collections	.woff2	Not supported yet -- rejects cleanly
Color glyph tables (COLR/CPAL, sbix, SVG , CBDT/CBLC)	.ttf, .otf	Not supported yet
Variable fonts (fvar/avar/gvar/HVAR)	.ttf, .otf, .woff, .woff2	Supported for glyf-based outlines

Every unsupported case raises a typed exception (UnsupportedFontException or InvalidFontException) instead of degrading silently.

Installation

composer require alto/font

Development

composer install
composer check       # phpstan + cs-check + test
composer test        # phpunit only
composer cs-fix       # apply coding-standard fixes

License

Alto Font is available under the MIT License.