[Impeller] BlendMode issue due to bad interaction between MaskFilter and the FramebufferBlendContents. #134930
Description
Is there an existing issue for this?
- I have searched the existing issues
- I have read the guide to filing a bug
Steps to reproduce
Run the sample code on iOS.
The bug is Impeller only. It's fine with skia (android).
I've tested it on 3.13.4 and 3.15.0-15.1.pre (beta) and 3.14.0-14.0.pre.337 (master).
Expected results
A green circle with blur like style on the screen.
Actual results
The circle is blurred but not green.
Code sample
Code sample
main.dart
import 'package:flutter/material.dart';
void main() {
runApp(const MainApp());
}
class MainApp extends StatefulWidget {
const MainApp({super.key});
@override
State<MainApp> createState() => _MainAppState();
}
class _MainAppState extends State<MainApp> with SingleTickerProviderStateMixin {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: SizedBox(
height: double.infinity,
width: double.infinity,
child: CustomPaint(
painter: BubbleLayerPainter(),
),
),
),
);
}
}
class BubbleLayerPainter extends CustomPainter {
@override
void paint(Canvas canvas, Size size) {
final colorBlur = Paint()
..style = PaintingStyle.fill
..maskFilter = const MaskFilter.blur(BlurStyle.normal, 60)
..color = Colors.black;
final center = size.center(Offset.zero);
canvas.drawCircle(center, 110, colorBlur);
canvas.drawColor(Colors.grey.withAlpha(255), BlendMode.colorDodge);
final surface = Paint()
..blendMode = BlendMode.screen
..color = Colors.green;
canvas.drawPaint(surface);
}
@override
bool shouldRepaint(BubbleLayerPainter oldDelegate) {
return true;
}
}
Screenshots or Video
Screenshots / Video demonstration
| result on iOS (grey) | result on Android (green) |
|---|---|
 |
 |
Logs
Logs
[Paste your logs here]Flutter Doctor output
Warning is about muti version with fvm.
Doctor output
[!] Flutter (Channel stable, 3.13.4, on macOS 13.4.1 22F770820d darwin-arm64,
locale zh-Hans-CN)
• Flutter version 3.13.4 on channel stable at /Users/zhx/fvm/versions/stable
• Framework revision 367f9ea16b (5 days ago), 2023-09-12 23:27:53 -0500
• Engine revision 9064459a8b
• Dart version 3.1.2
• DevTools version 2.25.0
• Pub download mirror https://pub.flutter-io.cn
• Flutter download mirror https://storage.flutter-io.cn
• 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 32.0.0)
• Android SDK at /Users/zhx/Library/Android/sdk
• Platform android-33, build-tools 32.0.0
• Java binary at: /Applications/Android
Studio.app/Contents/jbr/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build
17.0.6+0-17.0.6b802.4-9586694)
• All Android licenses accepted.
[✓] Xcode - develop for iOS and macOS (Xcode 14.3.1)
• Xcode at /Applications/Xcode_14.3.1.app/Contents/Developer
• Build 14E300c
• CocoaPods version 1.12.1
[✓] Android Studio (version 2022.2)
• 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
17.0.6+0-17.0.6b802.4-9586694)
[✓] VS Code (version 1.82.2)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.73.20230904
[✓] Connected device (1 available)
• macOS (desktop) • macos • darwin-arm64 • macOS 13.4.1 22F770820d
darwin-arm64
[✓] Network resources
• All expected network resources are available.
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High-priority issues 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 3.13Found to occur in 3.14The issue has been confirmed reproducible and is ready to work onIssue is closed as already fixed in a newer versionOwned by Engine team