Significantly worse performance of new RoundedSuperellipse compared to default BorderRadius #167366
Description
Steps to reproduce
- Create a page with many widgets which are using the recently introduced
RoundedSuperellipse - Open this page, go back, open again and you will see noticeable lags
Expected results
Equal performance as when I use the default borderRadius property.
Actual results
Significant worse performance. The raster thread is taking twice as long compared to the default borderRadius. This can be seen also in the video (at the second half I have enabled the performance overlay).
The phone used was an iPhone 14 Pro Max, so not a slow device.
Code sample
Slow code:
DecoratedBox(decoration: ShapeDecoration(shape: RoundedSuperellipseBorder(borderRadius: BorderRadius.circular(16)))Fast code:
DecoratedBox(decoration: BoxDecoration(borderRadius: BorderRadius.circular(16))Screenshots or Video
Screenshots / Video demonstration
Slow raster thread with lags using RoundedSuperellipseBorder (performance overlay enabled in the second half of the video):
ScreenRecording_04-17-2025.20-28-16_1-3.mp4
Normal performance using default BorderRadius (performance overlay enabled in the second half of the video):
ScreenRecording_04-17-2025.20-33-15_1-2.mp4
Flutter Doctor output
Doctor output
[✓] Flutter (Channel master, 3.32.0-1.0.pre.73, on macOS 15.4 24E248 darwin-arm64, locale de-DE) [2,1s]
• Flutter version 3.32.0-1.0.pre.73 on channel master at /Users/felixmittermeier/Documents/flutter
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• Framework revision a7f820163c (6 days ago), 2025-04-11 18:24:16 -0700
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[✓] Android toolchain - develop for Android devices (Android SDK version 35.0.1) [1.558ms]
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• Platform android-35, build-tools 35.0.1
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• Java version OpenJDK Runtime Environment (build 21.0.5+-13047016-b750.29)
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• Xcode at /Applications/Xcode.app/Contents/Developer
• Build 16E140
• CocoaPods version 1.16.2
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• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
[✓] Android Studio (version 2024.3) [9ms]
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• Flutter plugin can be installed from:
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• Java version OpenJDK Runtime Environment (build 21.0.5+-13047016-b750.29)
[✓] VS Code (version 1.99.2) [8ms]
• VS Code at /Applications/Visual Studio Code.app/Contents
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[✓] Connected device (3 available) [5,8s]
• iPhone 14 Pro Max (mobile) • 00008120-00086C192E60C01E • ios • iOS 18.4 22E240
• macOS (desktop) • macos • darwin-arm64 • macOS 15.4 24E248 darwin-arm64
• Chrome (web) • chrome • web-javascript • Google Chrome 135.0.7049.86
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• No issues found!