thorvg_plus 1.0.0

Source-built fork of thorvg for Flutter with full iOS simulator support. Drop-in replacement while upstream thorvg.flutter#22 is unresolved.

thorvg_plus — source-built thorvg for Flutter

thorvg_plus is a source-built fork of the ThorVG Flutter runtime, published on pub.dev as a temporary workaround for thorvg/thorvg.flutter#22. Use it when you need thorvg to link on the iOS Simulator.

The public Dart API matches upstream thorvg 1.0.0 byte-for-byte — Lottie.asset, Lottie.network, and everything else work the same way. Only the native build pipeline differs.

Why this fork exists

Upstream thorvg: ^1.0.0 on pub.dev ships a device-only libthorvg.dylib. Any consumer running flutter run -d <iOS simulator> hits a linker error:

Building for 'iOS-simulator', but linking in dylib
  (…/pub.dev/thorvg-1.0.0/ios/Frameworks/libthorvg.dylib) built for 'iOS'

A local app can work around this with dependency_overrides: thorvg: path: …, but overrides are not transitive through pub.dev — a plugin that depends on thorvg cannot fix the problem for its own consumers.

thorvg_plus removes the prebuilt dylib entirely and builds ThorVG from source on every install, so the compiler produces the right slice for whatever the consumer is targeting.

Scope

The pruned ThorVG tree shipped in this package keeps only what Lottie.* needs at runtime:

• Loaders: lottie, png, jpg, raw.
• Renderer: software engine only.

Removed (via tool/prune_thorvg.sh): SVG / TTF / WebP loaders, GL / WebGPU renderers, savers, tests.

Relation to upstream

• Source: thorvg/thorvg.flutter, tagged at 1.0.0.
• Tracking bug: thorvg.flutter#22 — iOS simulator linker failure.
• Licence: MIT, unchanged — all copyright notices are preserved verbatim.

When upstream lands a fix and releases a patched thorvg, this package will be deprecated in favour of the official one. Switch back as soon as you can — the upstream is the actively maintained renderer.

Install

flutter pub add thorvg_plus

Usage

import 'package:thorvg_plus/thorvg.dart';

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Column(
          children: [
            Lottie.asset('assets/lottie/dancing_star.json'),
            Lottie.network(
              'https://lottie.host/6d7dd6e2-ab92-4e98-826a-2f8430768886/NGnHQ6brWA.json',
            ),
          ],
        ),
      ),
    );
  }
}

Platforms

Platform	Architectures
Android	arm64-v8a, armeabi-v7a, x86_64
iOS	arm64 (device + simulator), x86_64 (simulator)

Regenerate Flutter bindings

Only needed if you modify tvgFlutterLottieAnimation.{h,cpp}:

flutter pub get
flutter pub run ffigen --config ffigen.yaml

License

MIT — see LICENSE. © ThorVG Project.