[Impeller] Rendering error in blur hash shader due to uniform padding. #161645
Description
Steps to reproduce
I am the developer of blurhash_shader. After upgrading to version 3.27.2 and using the Impeller rendering engine with Vulkan as the backend, I encounter incorrect rendering results.
I have noticed that the higher the computational cost of the shader, the greater the potential errors that may occur. The blurhash can store a different number of color samples, and in the code sample, the blurhash contains 60 colors, which requires looping 60 times in the shader.
Device: Xiaomi Redmi K70
System: Android 15
Vulkan API: 1.3
- Create an empty project.
- Install the blurhash_shader package.
- Use the code sample.
- Run the project on a device that supports Vulkan, using the Impeller rendering engine.
Expected results
Refer to Skia screenshot
Actual results
Refer to Impeller screenshot
Code sample
Code sample
import 'package:blurhash_shader/blurhash_shader.dart';
import 'package:flutter/material.dart';
class ListPage extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("List"),
),
body: GridView.builder(
gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 4,
crossAxisSpacing: 10,
mainAxisSpacing: 10,
),
itemBuilder: (context, index) {
return BlurHash(
r"rLLXc8J7.Ao~9FIAkXITR,_3=|soM_M{bca#kCRj.9adD%IUs,%gi^R*n%-;RjMxtRbwRPkXofkCR3bbnO%Mx]MxRjazWXO@jFtSRjjYbbR5ozs:");
}),
);
}
}Screenshots or Video
Screenshots / Video demonstration
- The message in the old device logs indicates "Known bad Vulkan driver encountered, falling back to OpenGLES," which is displayed the same as with Skia.
| Impeller(Vulkan) | Skia / Impeller(OpenGLES) * |
|---|---|
 |
 |
Logs
Logs
[Paste your logs here]Flutter Doctor output
Doctor output
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 3.27.2, on macOS 15.1.1 24B91 darwin-arm64, locale zh-Hans-US)
[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 16.1)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2024.2)
[✓] VS Code (version 1.96.2)
[✓] Connected device (5 available)
! Error: Browsing on the local area network for **iPad. Ensure the device is unlocked and attached with a cable or associated with the same local area network as this Mac.
The device must be opted into Developer Mode to connect wirelessly. (code -27)
! Error: Browsing on the local area network for ** Ensure the device is unlocked and discoverable via Bluetooth. (code -27)
[✓] Network resources
• No issues found!