Skip to content

[Impeller] Text PaintingStyle.stroke still appears to be inferior to Skia implementation. #136688

@greenisles

Description

@greenisles

Is there an existing issue for this?

Steps to reproduce

  1. Create a Flutter app.
  2. Implement text border per the Borders and Stroke example at https://api.flutter.dev/flutter/painting/TextStyle-class.html.
  3. Execute with Impeller.
  4. Execute without Impeller (either by using the flutter run --no-enable-impeller command or by updating the plist file.
  5. Compare results.

Expected results

Expectation is that the Impeller rendering should match the Skia rendering. Please note that I was using Stable channel with even worse Impeller results so tried Beta channel with the documented results here.

Actual results

The border of the Impeller version appears to be misaligned and not as 'crisp' in definition when inspected closely.

The example files show the Skia version has consistently placed borders while the Impeller version has borders that appear to be slightly misaligned to the foreground text.

(impeller)
border_impeller

(skia)
border_skia

Code sample

Code sample

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

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

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // TRY THIS: Try running your application with "flutter run". You'll see
        // the application has a purple toolbar. Then, without quitting the app,
        // try changing the seedColor in the colorScheme below to Colors.green
        // and then invoke "hot reload" (save your changes or press the "hot
        // reload" button in a Flutter-supported IDE, or press "r" if you used
        // the command line to start the app).
        //
        // Notice that the counter didn't reset back to zero; the application
        // state is not lost during the reload. To reset the state, use hot
        // restart instead.
        //
        // This works for code too, not just values: Most code changes can be
        // tested with just a hot reload.
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // TRY THIS: Try changing the color here to a specific color (to
        // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
        // change color while the other colors stay the same.
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          //
          // TRY THIS: Invoke "debug painting" (choose the "Toggle Debug Paint"
          // action in the IDE, or press "p" in the console), to see the
          // wireframe for each widget.
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Stack(
              children: [
                Text('You have pushed the button this many times:',
                  style: TextStyle(fontSize: 30, 
                    fontWeight: FontWeight.bold,
                    foreground: Paint()
                      ..style = PaintingStyle.stroke
                      ..strokeWidth = 2
                      ..color = Colors.red,
                  ),
                ),
                const Text('You have pushed the button this many times:',
                  style: TextStyle(fontSize: 30, 
                    fontWeight: FontWeight.bold, 
                    color: Colors.amber,
                  ),
                ),
              ],
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headlineMedium,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

Screenshots or Video

Screenshots / Video demonstration

[Upload media here]

Logs

Logs
[Paste your logs here]

Flutter Doctor output

Doctor output
[✓] Flutter (Channel beta, 3.16.0-0.2.pre, on macOS 14.0 23A344 darwin-arm64, locale en-NZ)
    • Flutter version 3.16.0-0.2.pre on channel beta at /Users/geoff/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision fe6553b689 (5 days ago), 2023-10-11 19:07:11 -0700
    • Engine revision 249cc9b86c
    • Dart version 3.2.0 (build 3.2.0-210.2.beta)
    • DevTools version 2.28.1

[!] Android toolchain - develop for Android devices (Android SDK version 33.0.1)
    • Android SDK at /Users/geoff/Library/Android/sdk
    ✗ cmdline-tools component is missing
      Run `path/to/sdkmanager --install "cmdline-tools;latest"`
      See https://developer.android.com/studio/command-line for more details.
    ✗ Android license status unknown.
      Run `flutter doctor --android-licenses` to accept the SDK licenses.
      See https://flutter.dev/docs/get-started/install/macos#android-setup for more details.

[✓] Xcode - develop for iOS and macOS (Xcode 15.0)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 15A240d
    • CocoaPods version 1.11.3

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2022.1)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.15+0-b2043.56-8887301)

[✓] IntelliJ IDEA Community Edition (version 2023.1)
    • IntelliJ at /Applications/IntelliJ IDEA CE.app
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart

[✓] VS Code (version 1.83.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.74.0

[✓] Connected device (3 available)            
    • iPad (10th generation) (mobile) • 92CF6F32-017B-456E-A63F-C924E8201348 • ios            • com.apple.CoreSimulator.SimRuntime.iOS-17-0 (simulator)
    • macOS (desktop)                 • macos                                • darwin-arm64   • macOS 14.0 23A344 darwin-arm64
    • Chrome (web)                    • chrome                               • web-javascript • Google Chrome 118.0.5993.70

[✓] Network resources
    • All expected network resources are available.```

</details>

Metadata

Metadata

Assignees

No one assigned

    Labels

    P2Important issues not at the top of the work lista: typographyText rendering, possibly libtxte: impellerImpeller rendering backend issues and features requestsengineflutter/engine related. See also e: labels.found in release: 3.16Found to occur in 3.16has reproducible stepsThe issue has been confirmed reproducible and is ready to work onr: fixedIssue is closed as already fixed in a newer versionslimpellerEngine binary size reduction. go/slimpellerteam-engineOwned by Engine teamtriaged-engineTriaged by Engine team

    Type

    No type

    Projects

    Status

    Done

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions