[Impeller] small cpu perf for text contents. #166199

jonahwilliams · 2025-03-29T17:50:04Z

Compute scaling matrices once per frame instead of per glyph.
Use index buffer to avoid performing redundant computations for second triangle.

gaaclarke

Code looks good. I think we should switch to triangle strip since we are at it. Not necessary though

gaaclarke · 2025-03-31T16:12:49Z

engine/src/flutter/impeller/entity/contents/text_contents_unittests.cc

@@ -69,12 +69,12 @@ std::shared_ptr<GlyphAtlas> CreateGlyphAtlas(
 }

 Rect PerVertexDataPositionToRect(
-    GlyphAtlasPipeline::VertexShader::PerVertexData data[6]) {
+    GlyphAtlasPipeline::VertexShader::PerVertexData data[4]) {


nit: Since we were refactoring these, it would have been nice to switch to std::array

gaaclarke · 2025-03-31T16:14:33Z

engine/src/flutter/impeller/entity/contents/text_contents.cc

+          indices[j++] = base + 0;
+          indices[j++] = base + 1;
+          indices[j++] = base + 2;
+          indices[j++] = base + 1;
+          indices[j++] = base + 2;
+          indices[j++] = base + 3;


nit: Switching to triangle strip would be more efficient.

The glyph rects aren't connected, so switching to strip would be move overall geometry:

Before: 6 pts
This PR: 4 pts
w/ Strip: 4pts + 4 to break primitive

gaaclarke · 2025-03-31T16:19:00Z

engine/src/flutter/impeller/entity/contents/text_contents.cc

+      index_count * sizeof(uint16_t), alignof(uint16_t), [&](uint8_t* data) {
+        uint16_t* indices = reinterpret_cast<uint16_t*>(data);
+        size_t j = 0;
+        for (auto i = 0u; i < glyph_count; i++) {


This has to loop through everything twice. Why not calculate the index buffer in the ComputeVertexData's loop?

Because of the way the emplace callback works, we can't easy emplace into two buffers at once unless I copy everything. I think this is still OK.

gaaclarke

lgtm, thanks.

This reverts commit 4c85295.

jonahwilliams · 2025-03-31T19:56:14Z

reverted std::array change. We're using different sized arrays in the test, I think templating out all the helper functions is overkill for a unit test

gaaclarke · 2025-03-31T20:21:32Z

reverted std::array change. We're using different sized arrays in the test, I think templating out all the helper functions is overkill for a unit test

All of those functions you changed to std::array require that the size is 4 though. Where was the problem?

gaaclarke · 2025-03-31T20:25:23Z

Ugh, add this to the list of times where std::span would be useful.

jonahwilliams · 2025-03-31T20:27:15Z

They don't all require a size of 4, some need 8 and such...

gaaclarke · 2025-03-31T20:30:34Z

They don't all require a size of 4, some need 8 and such...

The signatures you've changed all had foo[4] in the signature though. We should switch those to std::vector or raw pointers since the [4] is meaningless.

jonahwilliams · 2025-03-31T20:31:39Z

What are we changing to use std::array then, just l values?

gaaclarke · 2025-03-31T20:42:01Z

What are we changing to use std::array then, just l values?

I was thinking the parameters. Here's my concern: when declaring parameters with int foo[4] it's functionally equivalent to int* foo but you get this false sense that it is doing something like std::array<int, 4>. I got bit by this the other day where the code was written fine, but then when it got refactored I was sending in the wrong size array and I got zero compilation or runtime feedback. I just started reading garbage memory and had to figure out why.

So, passing in std::array<int,4> x > std::vector<int> x > int* x, size_t size. I don't think there is every a good reason to use int x[4] actually.

jonahwilliams · 2025-03-31T20:55:25Z

Done

…er#166199)

Roll Flutter from 05b5e7910544 to a0b1b3253416 (37 revisions) flutter/flutter@05b5e79...a0b1b32 2025-04-01 [email protected] Roll Dart SDK from b4d374ec59ec to 4e1f02bc704f (2 revisions) (flutter/flutter#166342) 2025-04-01 [email protected] Trim any text before osascript JSON response (flutter/flutter#166296) 2025-04-01 [email protected] [Gen-l10n] Add `Message.resourceId` and `locale` to all `L10nException` error messages (flutter/flutter#163654) 2025-04-01 [email protected] Add `--ignore-timeouts` flag for `flutter test` command (flutter/flutter#164437) 2025-04-01 [email protected] Update TESTOWNERS username (flutter/flutter#166191) 2025-04-01 [email protected] Roll Skia from 4b07443e6071 to 52cbb917fffd (4 revisions) (flutter/flutter#166329) 2025-04-01 [email protected] Roll Dart SDK from 6b07a09cbd2d to b4d374ec59ec (2 revisions) (flutter/flutter#166321) 2025-04-01 [email protected] [tool] Improve using project files in build targets (flutter/flutter#166211) 2025-04-01 [email protected] Rename FlRenderer to FlCompositorOpenGL (flutter/flutter#166037) 2025-04-01 [email protected] [engine, web_ui] Fix instances of library_private_types_in_public_api (flutter/flutter#166156) 2025-04-01 [email protected] Roll Dart SDK from 509faa921c95 to 6b07a09cbd2d (1 revision) (flutter/flutter#166301) 2025-04-01 [email protected] [Impeller] small cpu perf for text contents. (flutter/flutter#166199) 2025-04-01 [email protected] [android_engine_test] disable old HC mode tests. (flutter/flutter#166293) 2025-04-01 [email protected] [impeller] fixes diagonal antialiased lines (flutter/flutter#166298) 2025-04-01 [email protected] Roll Skia from 5f262bd2cbb4 to 4b07443e6071 (10 revisions) (flutter/flutter#166299) 2025-03-31 [email protected] [Impeller] Directly tessellate conics to linear path segments (flutter/flutter#166165) 2025-03-31 [email protected] [tool] Don't write the .flutter-plugins-dependencies file if it is unchanged (flutter/flutter#166164) 2025-03-31 [email protected] Move `.cxx` directory out of `android/app` (flutter/flutter#166277) 2025-03-31 [email protected] Fix typo in carousel.dart (flutter/flutter#164727) 2025-03-31 [email protected] Roll Dart SDK from c5fa06710bb6 to 509faa921c95 (1 revision) (flutter/flutter#166283) 2025-03-31 [email protected] Public nodes needing paint or layout (flutter/flutter#166148) 2025-03-31 [email protected] [Gen-l10n] Infer placeholder types on both templates and localizations (flutter/flutter#163690) 2025-03-31 [email protected] [Engine][iOS] Cancel animation when recieved `UIKeyboardWillHideNotification` with duration 0.0 (flutter/flutter#164884) 2025-03-31 [email protected] [fuchsia] Remove explicit LogSink and InspectSink routing and use dictionaries instead (flutter/flutter#162780) 2025-03-31 [email protected] Updated to latest AVD to Support Android 16 (API 36) (flutter/flutter#165926) 2025-03-31 [email protected] Feat: Add brightnessOf method for theme (flutter/flutter#163733) 2025-03-31 [email protected] Marks Linux_mokey new_gallery__crane_perf to be flaky (flutter/flutter#165964) 2025-03-31 [email protected] [ Tool ] Correctly select entrypoint target for web build from positional argument list (flutter/flutter#166260) 2025-03-31 [email protected] [Impeller] remove validation warning ignores. (flutter/flutter#166205) 2025-03-31 [email protected] [Impeller] handle shader ordering bug on macOS. (flutter/flutter#165937) 2025-03-31 [email protected] Fix CODEOWNERS for the iOS review team (flutter/flutter#166178) 2025-03-31 [email protected] Remove `<meta content="IE=Edge" http-equiv="X-UA-Compatible">` (flutter/flutter#166252) 2025-03-31 [email protected] Roll Dart SDK from b9c35e05feb5 to c5fa06710bb6 (1 revision) (flutter/flutter#166251) 2025-03-31 [email protected] Roll Skia from 418c68ea5ccb to 5f262bd2cbb4 (2 revisions) (flutter/flutter#166244) 2025-03-31 [email protected] Roll Skia from b6a3bbd1d153 to 418c68ea5ccb (1 revision) (flutter/flutter#166236) 2025-03-31 [email protected] [Impeller] fix min filter for GL external textures. (flutter/flutter#166224) 2025-03-31 [email protected] Roll Skia from 10f4cf9a817d to b6a3bbd1d153 (13 revisions) (flutter/flutter#166231) If this roll has caused a breakage, revert this CL and stop the roller using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC [email protected],[email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose ...

…r#8985) Roll Flutter from 05b5e7910544 to a0b1b3253416 (37 revisions) flutter/flutter@05b5e79...a0b1b32 2025-04-01 [email protected] Roll Dart SDK from b4d374ec59ec to 4e1f02bc704f (2 revisions) (flutter/flutter#166342) 2025-04-01 [email protected] Trim any text before osascript JSON response (flutter/flutter#166296) 2025-04-01 [email protected] [Gen-l10n] Add `Message.resourceId` and `locale` to all `L10nException` error messages (flutter/flutter#163654) 2025-04-01 [email protected] Add `--ignore-timeouts` flag for `flutter test` command (flutter/flutter#164437) 2025-04-01 [email protected] Update TESTOWNERS username (flutter/flutter#166191) 2025-04-01 [email protected] Roll Skia from 4b07443e6071 to 52cbb917fffd (4 revisions) (flutter/flutter#166329) 2025-04-01 [email protected] Roll Dart SDK from 6b07a09cbd2d to b4d374ec59ec (2 revisions) (flutter/flutter#166321) 2025-04-01 [email protected] [tool] Improve using project files in build targets (flutter/flutter#166211) 2025-04-01 [email protected] Rename FlRenderer to FlCompositorOpenGL (flutter/flutter#166037) 2025-04-01 [email protected] [engine, web_ui] Fix instances of library_private_types_in_public_api (flutter/flutter#166156) 2025-04-01 [email protected] Roll Dart SDK from 509faa921c95 to 6b07a09cbd2d (1 revision) (flutter/flutter#166301) 2025-04-01 [email protected] [Impeller] small cpu perf for text contents. (flutter/flutter#166199) 2025-04-01 [email protected] [android_engine_test] disable old HC mode tests. (flutter/flutter#166293) 2025-04-01 [email protected] [impeller] fixes diagonal antialiased lines (flutter/flutter#166298) 2025-04-01 [email protected] Roll Skia from 5f262bd2cbb4 to 4b07443e6071 (10 revisions) (flutter/flutter#166299) 2025-03-31 [email protected] [Impeller] Directly tessellate conics to linear path segments (flutter/flutter#166165) 2025-03-31 [email protected] [tool] Don't write the .flutter-plugins-dependencies file if it is unchanged (flutter/flutter#166164) 2025-03-31 [email protected] Move `.cxx` directory out of `android/app` (flutter/flutter#166277) 2025-03-31 [email protected] Fix typo in carousel.dart (flutter/flutter#164727) 2025-03-31 [email protected] Roll Dart SDK from c5fa06710bb6 to 509faa921c95 (1 revision) (flutter/flutter#166283) 2025-03-31 [email protected] Public nodes needing paint or layout (flutter/flutter#166148) 2025-03-31 [email protected] [Gen-l10n] Infer placeholder types on both templates and localizations (flutter/flutter#163690) 2025-03-31 [email protected] [Engine][iOS] Cancel animation when recieved `UIKeyboardWillHideNotification` with duration 0.0 (flutter/flutter#164884) 2025-03-31 [email protected] [fuchsia] Remove explicit LogSink and InspectSink routing and use dictionaries instead (flutter/flutter#162780) 2025-03-31 [email protected] Updated to latest AVD to Support Android 16 (API 36) (flutter/flutter#165926) 2025-03-31 [email protected] Feat: Add brightnessOf method for theme (flutter/flutter#163733) 2025-03-31 [email protected] Marks Linux_mokey new_gallery__crane_perf to be flaky (flutter/flutter#165964) 2025-03-31 [email protected] [ Tool ] Correctly select entrypoint target for web build from positional argument list (flutter/flutter#166260) 2025-03-31 [email protected] [Impeller] remove validation warning ignores. (flutter/flutter#166205) 2025-03-31 [email protected] [Impeller] handle shader ordering bug on macOS. (flutter/flutter#165937) 2025-03-31 [email protected] Fix CODEOWNERS for the iOS review team (flutter/flutter#166178) 2025-03-31 [email protected] Remove `<meta content="IE=Edge" http-equiv="X-UA-Compatible">` (flutter/flutter#166252) 2025-03-31 [email protected] Roll Dart SDK from b9c35e05feb5 to c5fa06710bb6 (1 revision) (flutter/flutter#166251) 2025-03-31 [email protected] Roll Skia from 418c68ea5ccb to 5f262bd2cbb4 (2 revisions) (flutter/flutter#166244) 2025-03-31 [email protected] Roll Skia from b6a3bbd1d153 to 418c68ea5ccb (1 revision) (flutter/flutter#166236) 2025-03-31 [email protected] [Impeller] fix min filter for GL external textures. (flutter/flutter#166224) 2025-03-31 [email protected] Roll Skia from 10f4cf9a817d to b6a3bbd1d153 (13 revisions) (flutter/flutter#166231) If this roll has caused a breakage, revert this CL and stop the roller using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC [email protected],[email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose ...

[Impeller] small cpu perf for text contents.

62cda0b

github-actions bot added a: text input Entering text in a text field or keyboard related problems engine flutter/engine repository. See also e: labels. e: impeller Impeller rendering backend issues and features requests labels Mar 29, 2025

jonahwilliams requested a review from gaaclarke March 31, 2025 16:10

gaaclarke reviewed Mar 31, 2025

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use std::array.

4c85295

jonahwilliams requested a review from gaaclarke March 31, 2025 16:48

gaaclarke approved these changes Mar 31, 2025

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Revert "use std::array."

e1e5967

This reverts commit 4c85295.

++

b50ba7c

fixed for real.

bdff6c0

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[Impeller] small cpu perf for text contents. #166199

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[Impeller] small cpu perf for text contents. #166199

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