package:font_subset

Builds or fetches the Flutter font-subset executable (powered by HarfBuzz) across Linux, macOS, and Windows, and provides a Dart API to subset TTF/OTF fonts (for example from a hook/link.dart).

Usage

import 'dart:io';
import 'package:font_subset/font_subset.dart';

Future<void> main() async {
  final result = await subsetFont(
    input: File('fonts/MyIcons.otf'),
    output: File('build/MyIcons.subset.otf'),
    codePoints: const [0xe047],
    optionalCodePoints: const [32],
  );
  print(result.summaryMessage);
}

Build Modes

Configured in pubspec.yaml under hooks.user_defines.font_subset (or via the FONT_SUBSET_BUILD_MODE environment variable):

hooks:
  user_defines:
    font_subset:
      buildMode: fetch # 'fetch', 'checkout', or 'local'

• fetch (default): Downloads prebuilt binaries from GitHub Releases verified against pinned SHA-256 checksums, falling back to local CMake compilation if unavailable.
• checkout: Always compiles font-subset locally from C++ and HarfBuzz sources via CMake (using checkoutPath if specified, or the bundled sources in this package).
• local: Uses a custom prebuilt font-subset binary at localPath.