[Flutter GPU] Add explicit draw counts by bdero · Pull Request #186639 · flutter/flutter

bdero · 2026-05-17T10:07:47Z

Moves the vertex and index count off the buffer-binding calls and onto the draw call.

A simple (breaking) change that fixes a very silly design flaw that I built into the API near the very beginning. Moves Flutter GPU draws towards a design that matches virtually all modern graphics APIs, including today's Impeller!
Now is the right time to make changes like this to Flutter GPU, since the API is not yet considered stable.

Before, bindVertexBuffer and bindIndexBuffer each took a count, and a single argument-less draw() guessed vertex versus index based on whether an index buffer happened to be bound.

Sooooo many reasons this was the wrong design:

Wrong object. A draw count belongs on the draw, not on a buffer binding.
Implicit kind. Indexed vs. non-indexed was inferred from what happened to be bound, not stated.
Colliding counts. Vertex and index counts shared one field; the vertex count was dropped when an index buffer was bound.
Slot-0-only. The count came from vertex slot 0; values on other slots were silently ignored.
Opaque draws. draw() told you nothing; you had to trace every bind to know what it drew.
Sticky state. The count leaked across draws in a pass.
Redundant re-binds. Changing only the count forced re-binding the buffer.
No room to grow. Nowhere natural for per-draw params like instanceCount or baseVertex.
Unconventional. WebGPU, Vulkan, Metal, and D3D all put counts on the draw.
Late errors. Bad counts failed at draw() time, far from the mistaken line.

Now:

bindVertexBuffer and bindIndexBuffer only bind buffers.
draw(vertexCount) does a non-indexed draw.
drawIndexed(indexCount) does an indexed draw.

Instanced draws can be landed later via draw and drawIndexed gaining an instanceCount parameter later on, assuming the Impeller-side instancing support in #186653 lands.

Pre-launch Checklist

fluttergithubbot · 2026-05-17T10:08:15Z

An existing Git SHA, 32015b673360111432f7f9ee8eb0edd1da7f8fbe, was detected, and no actions were taken.

To re-trigger presubmits after closing or re-opeing a PR, or pushing a HEAD commit (i.e. with --force) that already was pushed before, push a blank commit (git commit --allow-empty -m "Trigger Build") or rebase to continue.

gemini-code-assist

Code Review

This pull request refactors the Flutter GPU API by moving vertex and index count parameters from the binding methods, such as bindVertexBuffer and bindIndexBuffer, to the draw and drawIndexed methods. These changes are reflected across the Dart API, the C++ implementation, and the native bindings. Feedback suggests strengthening input validation by replacing asserts with RangeError.checkNotNegative in the Dart public API and adding explicit non-negative checks in the C++ layer to prevent potential integer overflow issues when casting signed integers to size_t.

bdero · 2026-05-19T07:18:04Z

FYI @gaaclarke, just realized we technically need Googler review on every PR due to the Google testing requirement. 🙃

auto-submit · 2026-05-19T16:06:30Z

autosubmit label was removed for flutter/flutter/186639, because Pull request flutter/flutter/186639 is not in a mergeable state.

gaaclarke · 2026-05-19T16:19:24Z

@bdero I'm going to let @walley892 handle this one.

walley892

@bdero, LGTM as is and I agree that this more closely matches other graphics APIs.

I'm not super familiar with this part of the codebase, so I left some questions.

walley892 · 2026-05-19T22:19:35Z

    const std::shared_ptr<const impeller::DeviceBuffer>& buffer,
    int offset_in_bytes,
    int length_in_bytes,
-    int vertex_count,


No action - but it looks like this was always unused?

This was read on line 361 (for slot 0 only 🙃)

walley892 · 2026-05-19T22:37:02Z

+    RangeError.checkNotNegative(vertexCount, 'vertexCount');
+    _validateVertexBindings();
+    if (!_draw(vertexCount)) {
+      throw Exception("Failed to append draw");


Is there any possibility/value in bubbling up more descriptive error messages? For example, if I try to use a negative vertexCount - will the only error be Failed to append draw, or is there some other logging inside of flutter_gpu that emits more specific errors?

We do most of these kinds of checks on the Dart API surface today rather than lower down. In this case, just above here there's a RangeError.checkNotNegative line. But we don't catch everything, and it's possible to use the API in invalid ways today that can trigger impeller asserts.

But at some point, I'd like to propose a way to gracefully fail encoding and bubble up Impeller's underlying validation errors for the Flutter GPU case and such.

Issue to improve the error handling situation here: #186768

walley892 · 2026-05-19T22:38:39Z

    render_pass_->SetScissor(scissor.value());
  }

  bool result = render_pass_->Draw().ok();


Following my other comment, I see this just returns a bool and not a status object - are detailed failures emitted anywhere?

Added a followup here #186768

auto-submit · 2026-05-26T23:53:44Z

autosubmit label was removed for flutter/flutter/186639, because - The status or check suite Mac clangd has failed. Please fix the issues identified (or deflake) before re-applying this label.

The status or check suite Mac web_tool_tests has failed. Please fix the issues identified (or deflake) before re-applying this label.

cbracken · 2026-05-27T13:29:47Z

Reason for revert: doesn't compile on mac, or Linux.

Mac:

../../flutter/testing/dart/gpu_shader_reload_test.dart:64:36: Error: Too many positional arguments: 1 allowed, but 2 found.
Try removing the extra positional arguments.
  state.renderPass.bindVertexBuffer(
                                   ^
../../flutter/testing/dart/gpu_shader_reload_test.dart:72:24: Error: Too few positional arguments: 1 required, 0 given.
  state.renderPass.draw();

Linux:

[5064/6842] ACTION //flutter/testing/dart:compile_gpu_shader_reload_test.dart(//build/toolchain/linux:clang_x64)
FAILED: gen/gpu_shader_reload_test.dart.dill 
vpython3 ../../../build/gn_run_binary.py ../../../flutter/prebuilts/linux-x64/dart-sdk/bin/dartaotruntime /b/s/w/ir/cache/builder/engine/src/out/ci/host_release_benchmarks/gen/frontend_server_aot.dart.snapshot -DkFlutterSrcDirectory=/b/s/w/ir/cache/builder/engine/src/flutter -DkFlutterBuildDirectory=/b/s/w/ir/cache/builder/engine/src/out/ci/host_release_benchmarks/gen -DkSkiaGoldWorkDirectory=/b/s/w/ir/cache/builder/engine/src/out/ci/host_release_benchmarks/gen/skia_gold_gpu_shader_reload_test.dart --packages /b/s/w/ir/cache/builder/engine/src/flutter/.dart_tool/package_config.json --sdk-root flutter_patched_sdk --target=flutter --depfile gen/gpu_shader_reload_test.dart.dill.d --output-dill gen/gpu_shader_reload_test.dart.dill ../../../flutter/testing/dart/gpu_shader_reload_test.dart
Command failed: ./../../../flutter/prebuilts/linux-x64/dart-sdk/bin/dartaotruntime /b/s/w/ir/cache/builder/engine/src/out/ci/host_release_benchmarks/gen/frontend_server_aot.dart.snapshot -DkFlutterSrcDirectory=/b/s/w/ir/cache/builder/engine/src/flutter -DkFlutterBuildDirectory=/b/s/w/ir/cache/builder/engine/src/out/ci/host_release_benchmarks/gen -DkSkiaGoldWorkDirectory=/b/s/w/ir/cache/builder/engine/src/out/ci/host_release_benchmarks/gen/skia_gold_gpu_shader_reload_test.dart --packages /b/s/w/ir/cache/builder/engine/src/flutter/.dart_tool/package_config.json --sdk-root flutter_patched_sdk --target=flutter --depfile gen/gpu_shader_reload_test.dart.dill.d --output-dill gen/gpu_shader_reload_test.dart.dill ../../../flutter/testing/dart/gpu_shader_reload_test.dart
exitCode: 254
result 341449f6-a0e5-4e2b-8f52-4cab34a8338f
../../../flutter/testing/dart/gpu_shader_reload_test.dart:64:36: Error: Too many positional arguments: 1 allowed, but 2 found.
Try removing the extra positional arguments.
  state.renderPass.bindVertexBuffer(
                                   ^
../../../flutter/testing/dart/gpu_shader_reload_test.dart:72:24: Error: Too few positional arguments: 1 required, 0 given.
  state.renderPass.draw();
                       ^

cbracken · 2026-05-27T13:32:28Z

Looks like this was added to the merge queue even though presubmits identified a breakage. (I didn't check if it was the same breakage).

Not blaming anyone. I click the "merge when ready" button too, but I always assumed it would NOT merge if presubmits failed. Apparently not. That's a bit surprising.

cbracken · 2026-05-27T13:36:54Z

@bdero sorry for the revert. Ran into this locally when testing a PR of mine then noticed the bots were sad too. :/

I always feel bad about these but it'll get the tree green for round two.

…utter#187170)  Reverts: flutter#186639   Initiated by: cbracken   Reason for reverting: doesn't compile on mac, or Linux. Mac: ``` ../../flutter/testing/dart/gpu_shader_reload_test.dart:64:36: Error: Too many positional arguments: 1 allowed, but 2 found. Try removing the extra positional arguments. state.renderPass.bindVertexBuffer( ^ ../../flutter/testing/dart/gpu_shader_reload_test.dart:72:24: Error: Too few positional arguments: 1 requ   Original PR Author: bdero   Reviewed By: {walley892}   This change reverts the following previous change: Moves the vertex and index count off the buffer-binding calls and onto the draw call. A simple (breaking) change that fixes a very silly design flaw that I built into the API near the very beginning. Moves Flutter GPU draws towards a design that matches virtually all modern graphics APIs, including today's Impeller! Now is the right time to make changes like this to Flutter GPU, since the API is not yet considered stable. Before, `bindVertexBuffer` and `bindIndexBuffer` each took a count, and a single argument-less `draw()` guessed vertex versus index based on whether an index buffer happened to be bound. Sooooo many reasons this was the wrong design: - **Wrong object.** A draw count belongs on the draw, not on a buffer binding. - **Implicit kind.** Indexed vs. non-indexed was inferred from what happened to be bound, not stated. - **Colliding counts.** Vertex and index counts shared one field; the vertex count was dropped when an index buffer was bound. - **Slot-0-only.** The count came from vertex slot 0; values on other slots were silently ignored. - **Opaque draws.** `draw()` told you nothing; you had to trace every bind to know what it drew. - **Sticky state.** The count leaked across draws in a pass. - **Redundant re-binds.** Changing only the count forced re-binding the buffer. - **No room to grow.** Nowhere natural for per-draw params like `instanceCount` or `baseVertex`. - **Unconventional.** WebGPU, Vulkan, Metal, and D3D all put counts on the draw. - **Late errors.** Bad counts failed at `draw()` time, far from the mistaken line. Now: - `bindVertexBuffer` and `bindIndexBuffer` only bind buffers. - `draw(vertexCount)` does a non-indexed draw. - `drawIndexed(indexCount)` does an indexed draw. Instanced draws can be landed later via `draw` and `drawIndexed` gaining an `instanceCount` parameter later on, assuming the Impeller-side instancing support in flutter#186653 lands. ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [AI contribution guidelines] and understand my responsibilities, or I am not using AI tools. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [ ] All existing and new tests are passing.  [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [AI contribution guidelines]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#ai-contribution-guidelines [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md  Co-authored-by: auto-submit[bot] <flutter-engprod-team@google.com>

flutter/flutter@f3a4b98...c8f2f16 2026-05-27 98614782+auto-submit[bot]@users.noreply.github.com Reverts "[Flutter GPU] Add explicit draw counts (#186639)" (flutter/flutter#187170) 2026-05-27 engine-flutter-autoroll@skia.org Roll Dart SDK from 7dcea971af6b to f3db7b7d9801 (2 revisions) (flutter/flutter#187144) 2026-05-27 bdero@google.com [Flutter GPU] Add explicit draw counts (flutter/flutter#186639) 2026-05-27 engine-flutter-autoroll@skia.org Roll Skia from f9db7748563e to fa944af10f91 (1 revision) (flutter/flutter#187139) 2026-05-27 bdero@google.com [Flutter GPU] Flutter GPU ShaderLibrary in-place reload for shader hot reload (flutter/flutter#186793) 2026-05-27 engine-flutter-autoroll@skia.org Roll Skia from a692cbf38952 to f9db7748563e (8 revisions) (flutter/flutter#187135) 2026-05-27 burak.karahan@mail.ru Use local semantics tester in Material button tests (flutter/flutter#186667) 2026-05-27 rmolivares@renzo-olivares.dev Filter out `a: text input` from `team-framework` PR triage (flutter/flutter#187129) 2026-05-27 bkonyi@google.com [Engine] Fix silent buffer mismatch bug in FML Win32 CommandLineFromPlatform (flutter/flutter#187120) 2026-05-27 srawlins@google.com examples: Remove unused parameters (flutter/flutter#185819) 2026-05-27 116356835+AbdeMohlbi@users.noreply.github.com Remove another `String.valueOf` (flutter/flutter#186628) 2026-05-27 alex.medinsh@gmail.com Print trace when skipping flavor-specific and platform-specific assets (flutter/flutter#187045) 2026-05-26 adilhanney@disroot.org Fix `InteractiveViewer` memory leak from undisposed `CurvedAnimation`s (flutter/flutter#185826) 2026-05-26 meylis@divine.video Fix AccessibilityBridge startup crash on vendor-modified Android (flutter/flutter#184630) 2026-05-26 keertip@users.noreply.github.com Update data driven fixes docs (flutter/flutter#186217) 2026-05-26 ahmedsameha1@gmail.com Add more 0x0 size tests part10 (flutter/flutter#186201) 2026-05-26 46920873+gabrimatic@users.noreply.github.com Disable spell check for obscured text (flutter/flutter#186329) 2026-05-26 chris@bracken.jp [iOS] Migrate VSyncClient and DisplayLinkManager to Swift (flutter/flutter#187001) 2026-05-26 bkonyi@google.com [flutter_tools, devicelab] Add safety filesystem guard to tests (flutter/flutter#186748) 2026-05-26 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from Itd2Jq_ZIABH2rW7B... to k9EizfEGJO4WwQN9-... (flutter/flutter#187115) 2026-05-26 engine-flutter-autoroll@skia.org Roll Dart SDK from 00e625453c43 to 7dcea971af6b (1 revision) (flutter/flutter#187117) 2026-05-26 rmacnak@google.com Remove use of deprecated copy_trees. (flutter/flutter#187091) 2026-05-26 15619084+vashworth@users.noreply.github.com Use resolved implementation plugins with SwiftPM (flutter/flutter#187097) 2026-05-26 engine-flutter-autoroll@skia.org Roll Skia from 27a819894f7c to a692cbf38952 (3 revisions) (flutter/flutter#187109) 2026-05-26 engine-flutter-autoroll@skia.org Roll Packages from 69cf959 to fc795e5 (4 revisions) (flutter/flutter#187114) 2026-05-26 mvincentong@gmail.com Handle simctl process exceptions during discovery (flutter/flutter#186501) 2026-05-26 mvincentong@gmail.com Clarify precache enabled platforms help (flutter/flutter#186878) 2026-05-26 bkonyi@google.com [tool] Refactor artifacts.dart to use enhanced enums and reduce duplication (flutter/flutter#187063) 2026-05-26 jason-simmons@users.noreply.github.com Build script updates for syncing engine sources and building artifacts on linux-arm64 (flutter/flutter#186917) 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 boetger@google.com,stuartmorgan@google.com 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 To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

bdero · 2026-05-27T19:33:16Z

@cbracken No worries, thems the rules. This conflicted with a test I added in another change, and both changes just-so-happened to make it into the merge queue at the same time, fair and square. All presubmits were successful on both.

Relands flutter#186639, which was reverted in flutter#187170. The original PR landed clean, but broke the macOS and Linux builds because `engine/src/flutter/testing/dart/gpu_shader_reload_test.dart` (added concurrently by flutter#186793, which was in the merge queue at the same time) still called the old `bindVertexBuffer(view, count)` / `draw()` API. This reland is identical to flutter#186639 plus a one-spot migration of that test to `bindVertexBuffer(view)` + `draw(3)`. --- Moves the vertex and index count off the buffer-binding calls and onto the draw call. A simple (breaking) change that fixes a very silly design flaw that I built into the API near the very beginning. Moves Flutter GPU draws towards a design that matches virtually all modern graphics APIs, including today's Impeller! Now is the right time to make changes like this to Flutter GPU, since the API is not yet considered stable. Before, `bindVertexBuffer` and `bindIndexBuffer` each took a count, and a single argument-less `draw()` guessed vertex versus index based on whether an index buffer happened to be bound. Sooooo many reasons this was the wrong design: - **Wrong object.** A draw count belongs on the draw, not on a buffer binding. - **Implicit kind.** Indexed vs. non-indexed was inferred from what happened to be bound, not stated. - **Colliding counts.** Vertex and index counts shared one field; the vertex count was dropped when an index buffer was bound. - **Slot-0-only.** The count came from vertex slot 0; values on other slots were silently ignored. - **Opaque draws.** `draw()` told you nothing; you had to trace every bind to know what it drew. - **Sticky state.** The count leaked across draws in a pass. - **Redundant re-binds.** Changing only the count forced re-binding the buffer. - **No room to grow.** Nowhere natural for per-draw params like `instanceCount` or `baseVertex`. - **Unconventional.** WebGPU, Vulkan, Metal, and D3D all put counts on the draw. - **Late errors.** Bad counts failed at `draw()` time, far from the mistaken line. Now: - `bindVertexBuffer` and `bindIndexBuffer` only bind buffers. - `draw(vertexCount)` does a non-indexed draw. - `drawIndexed(indexCount)` does an indexed draw. Instanced draws can be landed later via `draw` and `drawIndexed` gaining an `instanceCount` parameter later on, assuming the Impeller-side instancing support in flutter#186653 lands. ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [AI contribution guidelines] and understand my responsibilities, or I am not using AI tools. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [ ] All existing and new tests are passing.  [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [AI contribution guidelines]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#ai-contribution-guidelines [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

cbracken · 2026-05-28T00:17:04Z

This conflicted with a test I added in another change, and both changes just-so-happened to make it into the merge queue at the same time, fair and square. All presubmits were successful on both.

Clearly the answer is "Stop being so productive!" 😂 There should probably be an achievement badge for this.

…r#11795) flutter/flutter@f3a4b98...c8f2f16 2026-05-27 98614782+auto-submit[bot]@users.noreply.github.com Reverts "[Flutter GPU] Add explicit draw counts (#186639)" (flutter/flutter#187170) 2026-05-27 engine-flutter-autoroll@skia.org Roll Dart SDK from 7dcea971af6b to f3db7b7d9801 (2 revisions) (flutter/flutter#187144) 2026-05-27 bdero@google.com [Flutter GPU] Add explicit draw counts (flutter/flutter#186639) 2026-05-27 engine-flutter-autoroll@skia.org Roll Skia from f9db7748563e to fa944af10f91 (1 revision) (flutter/flutter#187139) 2026-05-27 bdero@google.com [Flutter GPU] Flutter GPU ShaderLibrary in-place reload for shader hot reload (flutter/flutter#186793) 2026-05-27 engine-flutter-autoroll@skia.org Roll Skia from a692cbf38952 to f9db7748563e (8 revisions) (flutter/flutter#187135) 2026-05-27 burak.karahan@mail.ru Use local semantics tester in Material button tests (flutter/flutter#186667) 2026-05-27 rmolivares@renzo-olivares.dev Filter out `a: text input` from `team-framework` PR triage (flutter/flutter#187129) 2026-05-27 bkonyi@google.com [Engine] Fix silent buffer mismatch bug in FML Win32 CommandLineFromPlatform (flutter/flutter#187120) 2026-05-27 srawlins@google.com examples: Remove unused parameters (flutter/flutter#185819) 2026-05-27 116356835+AbdeMohlbi@users.noreply.github.com Remove another `String.valueOf` (flutter/flutter#186628) 2026-05-27 alex.medinsh@gmail.com Print trace when skipping flavor-specific and platform-specific assets (flutter/flutter#187045) 2026-05-26 adilhanney@disroot.org Fix `InteractiveViewer` memory leak from undisposed `CurvedAnimation`s (flutter/flutter#185826) 2026-05-26 meylis@divine.video Fix AccessibilityBridge startup crash on vendor-modified Android (flutter/flutter#184630) 2026-05-26 keertip@users.noreply.github.com Update data driven fixes docs (flutter/flutter#186217) 2026-05-26 ahmedsameha1@gmail.com Add more 0x0 size tests part10 (flutter/flutter#186201) 2026-05-26 46920873+gabrimatic@users.noreply.github.com Disable spell check for obscured text (flutter/flutter#186329) 2026-05-26 chris@bracken.jp [iOS] Migrate VSyncClient and DisplayLinkManager to Swift (flutter/flutter#187001) 2026-05-26 bkonyi@google.com [flutter_tools, devicelab] Add safety filesystem guard to tests (flutter/flutter#186748) 2026-05-26 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from Itd2Jq_ZIABH2rW7B... to k9EizfEGJO4WwQN9-... (flutter/flutter#187115) 2026-05-26 engine-flutter-autoroll@skia.org Roll Dart SDK from 00e625453c43 to 7dcea971af6b (1 revision) (flutter/flutter#187117) 2026-05-26 rmacnak@google.com Remove use of deprecated copy_trees. (flutter/flutter#187091) 2026-05-26 15619084+vashworth@users.noreply.github.com Use resolved implementation plugins with SwiftPM (flutter/flutter#187097) 2026-05-26 engine-flutter-autoroll@skia.org Roll Skia from 27a819894f7c to a692cbf38952 (3 revisions) (flutter/flutter#187109) 2026-05-26 engine-flutter-autoroll@skia.org Roll Packages from 69cf959 to fc795e5 (4 revisions) (flutter/flutter#187114) 2026-05-26 mvincentong@gmail.com Handle simctl process exceptions during discovery (flutter/flutter#186501) 2026-05-26 mvincentong@gmail.com Clarify precache enabled platforms help (flutter/flutter#186878) 2026-05-26 bkonyi@google.com [tool] Refactor artifacts.dart to use enhanced enums and reduce duplication (flutter/flutter#187063) 2026-05-26 jason-simmons@users.noreply.github.com Build script updates for syncing engine sources and building artifacts on linux-arm64 (flutter/flutter#186917) 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 boetger@google.com,stuartmorgan@google.com 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 To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

Moves the vertex and index count off the buffer-binding calls and onto the draw call. A simple (breaking) change that fixes a very silly design flaw that I built into the API near the very beginning. Moves Flutter GPU draws towards a design that matches virtually all modern graphics APIs, including today's Impeller! Now is the right time to make changes like this to Flutter GPU, since the API is not yet considered stable. Before, `bindVertexBuffer` and `bindIndexBuffer` each took a count, and a single argument-less `draw()` guessed vertex versus index based on whether an index buffer happened to be bound. Sooooo many reasons this was the wrong design: - **Wrong object.** A draw count belongs on the draw, not on a buffer binding. - **Implicit kind.** Indexed vs. non-indexed was inferred from what happened to be bound, not stated. - **Colliding counts.** Vertex and index counts shared one field; the vertex count was dropped when an index buffer was bound. - **Slot-0-only.** The count came from vertex slot 0; values on other slots were silently ignored. - **Opaque draws.** `draw()` told you nothing; you had to trace every bind to know what it drew. - **Sticky state.** The count leaked across draws in a pass. - **Redundant re-binds.** Changing only the count forced re-binding the buffer. - **No room to grow.** Nowhere natural for per-draw params like `instanceCount` or `baseVertex`. - **Unconventional.** WebGPU, Vulkan, Metal, and D3D all put counts on the draw. - **Late errors.** Bad counts failed at `draw()` time, far from the mistaken line. Now: - `bindVertexBuffer` and `bindIndexBuffer` only bind buffers. - `draw(vertexCount)` does a non-indexed draw. - `drawIndexed(indexCount)` does an indexed draw. Instanced draws can be landed later via `draw` and `drawIndexed` gaining an `instanceCount` parameter later on, assuming the Impeller-side instancing support in flutter#186653 lands. ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [AI contribution guidelines] and understand my responsibilities, or I am not using AI tools. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [ ] All existing and new tests are passing.  [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [AI contribution guidelines]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#ai-contribution-guidelines [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

…utter#187170)  Reverts: flutter#186639   Initiated by: cbracken   Reason for reverting: doesn't compile on mac, or Linux. Mac: ``` ../../flutter/testing/dart/gpu_shader_reload_test.dart:64:36: Error: Too many positional arguments: 1 allowed, but 2 found. Try removing the extra positional arguments. state.renderPass.bindVertexBuffer( ^ ../../flutter/testing/dart/gpu_shader_reload_test.dart:72:24: Error: Too few positional arguments: 1 requ   Original PR Author: bdero   Reviewed By: {walley892}   This change reverts the following previous change: Moves the vertex and index count off the buffer-binding calls and onto the draw call. A simple (breaking) change that fixes a very silly design flaw that I built into the API near the very beginning. Moves Flutter GPU draws towards a design that matches virtually all modern graphics APIs, including today's Impeller! Now is the right time to make changes like this to Flutter GPU, since the API is not yet considered stable. Before, `bindVertexBuffer` and `bindIndexBuffer` each took a count, and a single argument-less `draw()` guessed vertex versus index based on whether an index buffer happened to be bound. Sooooo many reasons this was the wrong design: - **Wrong object.** A draw count belongs on the draw, not on a buffer binding. - **Implicit kind.** Indexed vs. non-indexed was inferred from what happened to be bound, not stated. - **Colliding counts.** Vertex and index counts shared one field; the vertex count was dropped when an index buffer was bound. - **Slot-0-only.** The count came from vertex slot 0; values on other slots were silently ignored. - **Opaque draws.** `draw()` told you nothing; you had to trace every bind to know what it drew. - **Sticky state.** The count leaked across draws in a pass. - **Redundant re-binds.** Changing only the count forced re-binding the buffer. - **No room to grow.** Nowhere natural for per-draw params like `instanceCount` or `baseVertex`. - **Unconventional.** WebGPU, Vulkan, Metal, and D3D all put counts on the draw. - **Late errors.** Bad counts failed at `draw()` time, far from the mistaken line. Now: - `bindVertexBuffer` and `bindIndexBuffer` only bind buffers. - `draw(vertexCount)` does a non-indexed draw. - `drawIndexed(indexCount)` does an indexed draw. Instanced draws can be landed later via `draw` and `drawIndexed` gaining an `instanceCount` parameter later on, assuming the Impeller-side instancing support in flutter#186653 lands. ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [AI contribution guidelines] and understand my responsibilities, or I am not using AI tools. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [ ] All existing and new tests are passing.  [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [AI contribution guidelines]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#ai-contribution-guidelines [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md  Co-authored-by: auto-submit[bot] <flutter-engprod-team@google.com>

Relands flutter#186639, which was reverted in flutter#187170. The original PR landed clean, but broke the macOS and Linux builds because `engine/src/flutter/testing/dart/gpu_shader_reload_test.dart` (added concurrently by flutter#186793, which was in the merge queue at the same time) still called the old `bindVertexBuffer(view, count)` / `draw()` API. This reland is identical to flutter#186639 plus a one-spot migration of that test to `bindVertexBuffer(view)` + `draw(3)`. --- Moves the vertex and index count off the buffer-binding calls and onto the draw call. A simple (breaking) change that fixes a very silly design flaw that I built into the API near the very beginning. Moves Flutter GPU draws towards a design that matches virtually all modern graphics APIs, including today's Impeller! Now is the right time to make changes like this to Flutter GPU, since the API is not yet considered stable. Before, `bindVertexBuffer` and `bindIndexBuffer` each took a count, and a single argument-less `draw()` guessed vertex versus index based on whether an index buffer happened to be bound. Sooooo many reasons this was the wrong design: - **Wrong object.** A draw count belongs on the draw, not on a buffer binding. - **Implicit kind.** Indexed vs. non-indexed was inferred from what happened to be bound, not stated. - **Colliding counts.** Vertex and index counts shared one field; the vertex count was dropped when an index buffer was bound. - **Slot-0-only.** The count came from vertex slot 0; values on other slots were silently ignored. - **Opaque draws.** `draw()` told you nothing; you had to trace every bind to know what it drew. - **Sticky state.** The count leaked across draws in a pass. - **Redundant re-binds.** Changing only the count forced re-binding the buffer. - **No room to grow.** Nowhere natural for per-draw params like `instanceCount` or `baseVertex`. - **Unconventional.** WebGPU, Vulkan, Metal, and D3D all put counts on the draw. - **Late errors.** Bad counts failed at `draw()` time, far from the mistaken line. Now: - `bindVertexBuffer` and `bindIndexBuffer` only bind buffers. - `draw(vertexCount)` does a non-indexed draw. - `drawIndexed(indexCount)` does an indexed draw. Instanced draws can be landed later via `draw` and `drawIndexed` gaining an `instanceCount` parameter later on, assuming the Impeller-side instancing support in flutter#186653 lands. ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [AI contribution guidelines] and understand my responsibilities, or I am not using AI tools. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [ ] All existing and new tests are passing.  [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [AI contribution guidelines]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#ai-contribution-guidelines [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

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[Flutter GPU] Propagate native error detail back through the Dart API #186768

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Reverts "[Flutter GPU] Add explicit draw counts (#186639)" #187170

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Roll Flutter from f3a4b9897834 to c8f2f166323e (29 revisions) flutter/packages#11795

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[Flutter GPU] Add explicit draw counts (reland) #187192

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