[Impeller] Inconsistent Transform.scale Text Rendering #121887
Description
Steps to Reproduce
- Ensure that Flutter is running on the master channel at commit 3494c08
- Start iPhone 14 Pro Max Simulator on MacOS
- Execute
flutter run -d iPhone --enable-impelleron the code sample. - Execute
flutter run -d iPhoneon the code sample to compare the difference.
When using the Impeller renderer in combination with Transform.scale, depending on the scale, the letters get rendered very inconsistently, some thinner than others (even at same scale) , some higher / lower then others in terms of baseline, some letter edges even getting cut off sometimes.
Expected results:
Properly consistently rendered text.
Actual results:
Inconsistently rendered text, messed up baselines for a lot of letters, the lowercase "t" in the bottom sentence has different size (even at same scale) when compared to the top sentence "t".
This also happens with other letters at other scales.
Comparison
Code sample
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
@override
Widget build(BuildContext context) {
return const MaterialApp(home: MyHomePage());
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key});
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: Transform.scale(
scale: 0.9,
child: const Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Text(
'The quick brown fox jumps over the lazy dog.',
style: TextStyle(
fontSize: 14,
fontWeight: FontWeight.w500,
letterSpacing: -0.75,
),
),
Text(
'The quick brown fox jumping over the lazy dog.',
style: TextStyle(
fontSize: 14,
fontWeight: FontWeight.w500,
letterSpacing: -0.75,
),
),
],
),
),
),
);
}
}
Logs
[!] Flutter (Channel master, 3.9.0-1.0.pre.33, on macOS 13.3 22E7752300f darwin-arm64, locale en-MK)
• Flutter version 3.9.0-1.0.pre.33 on channel master at /Users/devops/fvm/versions/3494c084481eb11469ee18f2a5e0c1dd90cbe13f
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision 3494c08448 (5 hours ago), 2023-03-03 12:54:23 +0000
• Engine revision 569c62d110
• Dart version 3.0.0 (build 3.0.0-290.0.dev)
• DevTools version 2.22.2
• If those were intentional, you can disregard the above warnings; however it is recommended to use "git" directly to perform update checks and upgrades.
[✓] Android toolchain - develop for Android devices (Android SDK version 33.0.1)
• Android SDK at /Users/devops/Library/Android/sdk
• Platform android-33, build-tools 33.0.1
• Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 11.0.13+0-b1751.21-8125866)
• All Android licenses accepted.
[✓] Xcode - develop for iOS and macOS (Xcode 14.2)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Build 14C18
• CocoaPods version 1.11.3
[✓] Chrome - develop for the web
• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
[✓] Android Studio (version 2021.3)
• 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 11.0.13+0-b1751.21-8125866)
[✓] VS Code (version 1.75.1)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.58.0
[✓] VS Code (version 1.76.0-insider)
• VS Code at /Applications/Visual Studio Code - Insiders.app/Contents
• Flutter extension version 3.60.0
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Labels
Important issues not at the top of the work listUI glitches reported at the engine/skia or impeller rendering levelImpeller rendering backend issues and features requestsflutter/engine related. See also e: labels.Found to occur in 3.9The issue has been confirmed reproducible and is ready to work oniOS applications specificallyIssue is closed as already fixed in a newer version