[ios] Inverse scale transforms results in pixelated blurred poor resolution views
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Description
Description
We have a production app where we have a pinch gesture handler that allows pinch zooming on a map. When the map is zoomed in (scaled up) the child POIs are scaled down to preserve sizing of POIs. Example, if the parent View is scaled by 100 the child POI View is then scaled by 0.01 to counteract the transform and preserve sizing. This works perfectly on Android; however, IOS results in a very pixelated render of the child POI View. It appears on IOS, when a View has nested scale transforms applied such that they are inverse the resulting render is pixelated. On Android the View appears high resolution as expected. (See screenshots below).
See main code in app/{tabs}/index.jsx of repro.
Related:
https://github.com/facebook/react-native/issues/42837
Steps to reproduce
Both Architectures: Paper & Fabric
IOS
- Install dependencies
npm installandnpx pod-install - Run
npx react-native run-iosornpm startand open on ios expo - Notice blurred blue View when it should be a solid red square with blue border (bug)
ANDROID
- Install dependencies
npm install - Run
npx react-native run-android - Notice solid red square with blue border (expected)
React Native Version
0.76.6
Affected Platforms
Runtime - iOS
Output of npx react-native info
System:
OS: macOS 14.6
CPU: (16) arm64 Apple M3 Max
Memory: 145.11 MB / 64.00 GB
Shell:
version: "5.9"
path: /bin/zsh
Binaries:
Node:
version: 18.20.5
path: ~/.nvm/versions/node/v18.20.5/bin/node
Yarn:
version: 1.22.19
path: /usr/local/bin/yarn
npm:
version: 10.8.2
path: ~/.nvm/versions/node/v18.20.5/bin/npm
Watchman: Not Found
Managers:
CocoaPods:
version: 1.15.2
path: /Users/marcbourguignon/.rbenv/shims/pod
SDKs:
iOS SDK:
Platforms:
- DriverKit 24.1
- iOS 18.1
- macOS 15.1
- tvOS 18.1
- visionOS 2.1
- watchOS 11.1
Android SDK: Not Found
IDEs:
Android Studio: 2021.2 AI-212.5712.43.2112.8609683
Xcode:
version: 16.1/16B40
path: /usr/bin/xcodebuild
Languages:
Java:
version: 17.0.4.1
path: /Users/marcbourguignon/.sdkman/candidates/java/current/bin/javac
Ruby:
version: 2.7.5
path: /Users/marcbourguignon/.rbenv/shims/ruby
npmPackages:
"@react-native-community/cli":
installed: 15.1.3
wanted: ^15.1.3
react:
installed: 18.3.1
wanted: 18.3.1
react-native:
installed: 0.76.6
wanted: 0.76.6
react-native-macos: Not Found
npmGlobalPackages:
"*react-native*": Not Found
Android:
hermesEnabled: true
newArchEnabled: false
iOS:
hermesEnabled: true
newArchEnabled: false
Stacktrace or Logs
No crash; rendering bug
Reproducer
https://github.com/wen-kai/expo-sandbox/tree/scale-bug
Screenshots and Videos
Actual (IOS):
Expected (Android):
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the reproducer's app/{tabs}/index.jsx and run the listed iOS steps with React Native 0.76.6 in both Paper and Fabric. Compare the iOS result with Android, focusing on the nested inverse scale transforms. Done means the iOS child view renders as a solid red square with a blue border rather than a blurred, pixelated view.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- ios, javascript, react-native
- Domain
- mobile
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100