flutter/dev/benchmarks/macrobenchmarks/lib
Tong Mu ea1c1bae8f
[Engine] Fast blurring algorithm for RSuperellipse (#169187)
This PR adds a fast blurring algorithm for `RSuperellipse`s with uniform
corner radius, similar to `AttemptDrawBlurredRRect`.

Fixes https://github.com/flutter/flutter/issues/163893. Fixes
https://github.com/flutter/flutter/issues/167366.

This approximate algorithm is implemented by adding additional
retraction to RRect's algorithm. Since they share most the logic, much
effort is made to ensure reasonable code share.

I've also built a playground test `RoundSuperellipseShadowComparison` to
compare the effect between the fast algorithm and the bruteforce
algorithm, and added a macrobenchmark "rsuperellipse_blur".

### Result

The following video shows the reproduction app from
https://github.com/flutter/flutter/issues/167366, which shows much
better framerate on RSE after the PR, almost the same as RRect. (I've
verified that it was much worse without the PR.)


https://github.com/user-attachments/assets/5433af91-c0a1-4b15-9161-cf2280543e27

The following video shows the `RoundSuperellipseShadowComparison`
playground, which compares the fast algorithm (left) against the
bruteforce algorithm (right).

* Pay attention to the cases with small but non zero sigma. They should
be of almost the same shape as those with zero sigma, which skips the
blurring altogether. With this algorithm, the difference between the two
cases are about 1~2 pixel at most.


https://github.com/user-attachments/assets/e26d2d8f-d29e-4db8-9c20-67103d77891c

The following images compare macrobenchmarks "rrect_blur" against the
new "rsuperellipse_blur". (Notice that the avg frame time fluctuates a
lot but at least it shows that they're on par.)

<img width="389" alt="image"
src="https://github.com/user-attachments/assets/67cf4b10-f13f-4e55-bdfd-35d358617f38"
/>

<img width="365" alt="image"
src="https://github.com/user-attachments/assets/6869fa9c-5752-4a11-babe-b6a2d590ebc9"
/>



### Open questions
* Should I improve the code share of shader files? Currently they're not
shared mostly because I'm not sure about its gain and cost.

## Pre-launch Checklist

- [ ] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [ ] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [ ] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [ ] I signed the [CLA].
- [ ] I listed at least one issue that this PR fixes in the description
above.
- [ ] I updated/added relevant documentation (doc comments with `///`).
- [ ] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [ ] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [ ] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

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[Tree Hygiene]:
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2025-05-23 20:20:37 +00:00
..
src [Engine] Fast blurring algorithm for RSuperellipse (#169187) 2025-05-23 20:20:37 +00:00
common.dart [Engine] Fast blurring algorithm for RSuperellipse (#169187) 2025-05-23 20:20:37 +00:00
main.dart [Engine] Fast blurring algorithm for RSuperellipse (#169187) 2025-05-23 20:20:37 +00:00
web_benchmarks_ddc.dart Adding support for macrobenchmarking with "flutter run" (#167692) 2025-04-28 23:39:40 +00:00
web_benchmarks.dart Adding support for macrobenchmarking with "flutter run" (#167692) 2025-04-28 23:39:40 +00:00