Adds external texture devicelab test for windows impeller by gaaclarke · Pull Request #187886 · flutter/flutter

gaaclarke · 2026-06-11T20:44:39Z

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gaaclarke · 2026-06-11T20:45:46Z

+
+#include "flutter/generated_plugin_registrant.h"
+
+class MyTexture {


Most of the code in the runner directory is autogenerated from flutter create. Here is some custom code that is introduced to interface with the external textures API.

gemini-code-assist

Code Review

This pull request adds a new Windows texture impeller test to the CI configuration and introduces a complete Win32 runner example project. The review feedback suggests several key improvements to the C++ implementation, including refactoring MyTexture to use std::vector and std::mutex for safer memory management and thread safety, validating texture dimensions, adding null checks to prevent dereferencing errors, ensuring COM resources are uninitialized on failure, using GetModuleHandleA instead of LoadLibraryA for User32.dll, and simplifying WindowClassRegistrar into a thread-safe static local singleton.

loic-sharma · 2026-06-17T16:49:14Z

+          FlutterDesktopPluginRegistrarRef registrar_ref =
+              flutter_controller_->engine()->GetRegistrarForPlugin("TextureTestPlugin");
+          FlutterDesktopTextureRegistrarRef texture_registrar_ref =
+              FlutterDesktopRegistrarGetTextureRegistrar(registrar_ref);


Oof. I'd consider adding the C++ texture registrar on the C++ engine so that we don't need to drop down to C APIs here? It should be easy to add:

flutter/engine/src/flutter/shell/platform/windows/flutter_windows.cc

Lines 240 to 244 in 8e307e4

FlutterDesktopTextureRegistrarRef FlutterDesktopEngineGetTextureRegistrar(

FlutterDesktopEngineRef engine) {

return HandleForTextureRegistrar(

EngineFromHandle(engine)->texture_registrar());

}

flutter/engine/src/flutter/shell/platform/common/client_wrapper/plugin_registrar.cc

Lines 24 to 27 in a68ab70

auto texture_registrar =

FlutterDesktopRegistrarGetTextureRegistrar(registrar_);

texture_registrar_ =

std::make_unique<TextureRegistrarImpl>(texture_registrar);

flutter/engine/src/flutter/shell/platform/common/client_wrapper/core_implementations.cc

Lines 211 to 282 in 8e307e4

TextureRegistrarImpl::TextureRegistrarImpl(

FlutterDesktopTextureRegistrarRef texture_registrar_ref)

: texture_registrar_ref_(texture_registrar_ref) {}

TextureRegistrarImpl::~TextureRegistrarImpl() = default;

int64_t TextureRegistrarImpl::RegisterTexture(TextureVariant* texture) {

FlutterDesktopTextureInfo info = {};

if (auto pixel_buffer_texture = std::get_if<PixelBufferTexture>(texture)) {

info.type = kFlutterDesktopPixelBufferTexture;

info.pixel_buffer_config.user_data = pixel_buffer_texture;

info.pixel_buffer_config.callback =

[](size_t width, size_t height,

void* user_data) -> const FlutterDesktopPixelBuffer* {

auto texture = static_cast<PixelBufferTexture*>(user_data);

return texture->CopyPixelBuffer(width, height);

};

} else if (auto gpu_surface_texture =

std::get_if<GpuSurfaceTexture>(texture)) {

info.type = kFlutterDesktopGpuSurfaceTexture;

info.gpu_surface_config.struct_size =

sizeof(FlutterDesktopGpuSurfaceTextureConfig);

info.gpu_surface_config.type = gpu_surface_texture->surface_type();

info.gpu_surface_config.user_data = gpu_surface_texture;

info.gpu_surface_config.callback =

[](size_t width, size_t height,

void* user_data) -> const FlutterDesktopGpuSurfaceDescriptor* {

auto texture = static_cast<GpuSurfaceTexture*>(user_data);

return texture->ObtainDescriptor(width, height);

};

} else {

std::cerr << "Attempting to register unknown texture variant." << std::endl;

return -1;

}

int64_t texture_id = FlutterDesktopTextureRegistrarRegisterExternalTexture(

texture_registrar_ref_, &info);

return texture_id;

} // namespace flutter

bool TextureRegistrarImpl::MarkTextureFrameAvailable(int64_t texture_id) {

return FlutterDesktopTextureRegistrarMarkExternalTextureFrameAvailable(

texture_registrar_ref_, texture_id);

}

void TextureRegistrarImpl::UnregisterTexture(int64_t texture_id,

std::function<void()> callback) {

if (callback == nullptr) {

FlutterDesktopTextureRegistrarUnregisterExternalTexture(

texture_registrar_ref_, texture_id, nullptr, nullptr);

return;

}

struct Captures {

std::function<void()> callback;

};

auto captures = new Captures();

captures->callback = std::move(callback);

FlutterDesktopTextureRegistrarUnregisterExternalTexture(

texture_registrar_ref_, texture_id,

[](void* opaque) {

auto captures = reinterpret_cast<Captures*>(opaque);

captures->callback();

delete captures;

},

captures);

}

bool TextureRegistrarImpl::UnregisterTexture(int64_t texture_id) {

UnregisterTexture(texture_id, nullptr);

return true;

}

I created an issue: #188120

It's kind of complicated because we don't want to deviate from the pattern that exists on other platforms too, but the API has already been set to require the usage of the c api.

I'm good with punting, thanks for creating the issue 👍

loic-sharma

Sorry for the late review, I missed this PR. This looks good to me!

However, a nice cleanup would be to add the missing C++ APIs so we don't need to drop down to the low-level C APIs. I don't think that's a blocker though.

This reverts commit 972bc2d.

gaaclarke · 2026-06-17T17:34:57Z

@loic-sharma I need an re-approval since I had merge conflicts. edit: please =)

loic-sharma

Re-LGTM!

mattkae

👍

flutter/flutter@b10d0f1...15963bc 2026-06-18 engine-flutter-autoroll@skia.org Roll Skia from 6e84902d56c3 to 1ae2466c9ea5 (4 revisions) (flutter/flutter#188172) 2026-06-18 engine-flutter-autoroll@skia.org Roll Packages from 6ce00a8 to 4fd05e6 (3 revisions) (flutter/flutter#188171) 2026-06-18 robert.ancell@canonical.com [Linux] Fix vertical offset in composite_layer (flutter/flutter#188145) 2026-06-18 robert.ancell@canonical.com [Linux] Fix incorrect GL datatypes for uniform locations (flutter/flutter#188143) 2026-06-18 engine-flutter-autoroll@skia.org Roll Dart SDK from e05c69222ea4 to 5883736e7670 (2 revisions) (flutter/flutter#188168) 2026-06-18 engine-flutter-autoroll@skia.org Roll Skia from 046277850e8d to 6e84902d56c3 (5 revisions) (flutter/flutter#188165) 2026-06-18 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from or21OEdGtairm6nl9... to 1E2qOlNnC2Ucn-1oV... (flutter/flutter#188162) 2026-06-18 engine-flutter-autoroll@skia.org Roll Skia from 8dd207d443d3 to 046277850e8d (1 revision) (flutter/flutter#188153) 2026-06-18 31859944+LongCatIsLooong@users.noreply.github.com Add entitlements.txt entries for new dart sdk binaries (flutter/flutter#188133) 2026-06-18 engine-flutter-autoroll@skia.org Roll Dart SDK from b670723c5f07 to e05c69222ea4 (1 revision) (flutter/flutter#188146) 2026-06-18 robert.ancell@canonical.com Fix bounds checking in FlAccessibleTextField (flutter/flutter#188137) 2026-06-18 engine-flutter-autoroll@skia.org Roll Skia from f5a2921fe23e to 8dd207d443d3 (2 revisions) (flutter/flutter#188141) 2026-06-18 30870216+gaaclarke@users.noreply.github.com Adds tests for disabling macos impeller (flutter/flutter#188132) 2026-06-17 jlemanski1@gmail.com Improve Flutter Web accessibility: update flt meta viewport tag to align with WCAG 2 guidelines (flutter/flutter#182047) 2026-06-17 engine-flutter-autoroll@skia.org Roll Dart SDK from e39bde5b1bfc to b670723c5f07 (2 revisions) (flutter/flutter#188130) 2026-06-17 engine-flutter-autoroll@skia.org Roll Skia from 066bfbac7282 to f5a2921fe23e (1 revision) (flutter/flutter#188128) 2026-06-17 matt.boetger@gmail.com Support --trace-systrace in release builds on Android (flutter/flutter#186359) 2026-06-17 matt.boetger@gmail.com Isolate compiled dill caches by TargetModel (flutter/flutter#187253) 2026-06-17 98614782+auto-submit[bot]@users.noreply.github.com Reverts "refactor(web): Unify Image on Skwasm and CanvasKit (#187873)" (flutter/flutter#188124) 2026-06-17 matt.kosarek@canonical.com Use a mock EGL manager in windows unittests to avoid flaky rendering calls (flutter/flutter#188078) 2026-06-17 matt.boetger@gmail.com [Android] Remove support for unused manifest flags (flutter/flutter#186021) 2026-06-17 30870216+gaaclarke@users.noreply.github.com Adds windows project switch for enabling impeller (flutter/flutter#188044) 2026-06-17 15619084+vashworth@users.noreply.github.com Skip prefetch SwiftPM dependencies if the project hasn't been migrated to SwiftPM yet (flutter/flutter#187206) 2026-06-17 nshahan@google.com [flutter_tools] Bump dwds to 27.1.2 (flutter/flutter#187951) 2026-06-17 30870216+gaaclarke@users.noreply.github.com Adds external texture devicelab test for windows impeller (flutter/flutter#187886) 2026-06-17 engine-flutter-autoroll@skia.org Roll Skia from 5d19002eb73e to 066bfbac7282 (2 revisions) (flutter/flutter#188118) 2026-06-17 34871572+gmackall@users.noreply.github.com Add note about magnifier issue when using transparent HCPP pv (flutter/flutter#187753) 2026-06-17 30870216+gaaclarke@users.noreply.github.com [linux]: fixes crash when resizing windows (flutter/flutter#187626) 2026-06-17 56400880+adilburaksen@users.noreply.github.com [flutter_tools] Enforce that package-declared asset paths stay within the package (flutter/flutter#187661) 2026-06-17 jason-simmons@users.noreply.github.com Remove canvaskit_cipd_instance from DEPS (flutter/flutter#188073) 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 bmparr@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

…7886) fixes flutter#187795 ## 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. - [x] All existing and new tests are passing. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. If this change needs to override an active code freeze, provide a comment explaining why. The code freeze workflow can be overridden by code reviewers. See pinned issues for any active code freezes with guidance. **Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). Comments from the `gemini-code-assist` bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.  [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

gaaclarke added 2 commits June 11, 2026 13:30

Adds integration test for impeller external textures

d768bf1

removed ico

f790799

flutter-dashboard Bot added the CICD Run CI/CD label Jun 11, 2026

github-actions Bot added d: examples Sample code and demos a: desktop Running on desktop labels Jun 11, 2026

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gaaclarke requested a review from loic-sharma June 11, 2026 22:21

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gaaclarke mentioned this pull request Jun 17, 2026

[windows]: Clean up c/c++ interface for external textures #188120

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Merge branch 'master' into texture-test-windows

aeb31ea

gaaclarke dismissed loic-sharma’s stale review via aeb31ea June 17, 2026 17:25

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fixed bad merge

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gaaclarke added 2 commits June 17, 2026 10:32

Revert "fixed bad merge"

b90ceec

This reverts commit 972bc2d.

fix bad conflict merge

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Merged via the queue into flutter:master with commit 9e9f988 Jun 17, 2026
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		#include "flutter/generated_plugin_registrant.h"

		class MyTexture {

	FlutterDesktopTextureRegistrarRef FlutterDesktopEngineGetTextureRegistrar(
	FlutterDesktopEngineRef engine) {
	return HandleForTextureRegistrar(
	EngineFromHandle(engine)->texture_registrar());
	}

	auto texture_registrar =
	FlutterDesktopRegistrarGetTextureRegistrar(registrar_);
	texture_registrar_ =
	std::make_unique<TextureRegistrarImpl>(texture_registrar);

	TextureRegistrarImpl::TextureRegistrarImpl(
	FlutterDesktopTextureRegistrarRef texture_registrar_ref)
	: texture_registrar_ref_(texture_registrar_ref) {}

	TextureRegistrarImpl::~TextureRegistrarImpl() = default;

	int64_t TextureRegistrarImpl::RegisterTexture(TextureVariant* texture) {
	FlutterDesktopTextureInfo info = {};
	if (auto pixel_buffer_texture = std::get_if<PixelBufferTexture>(texture)) {
	info.type = kFlutterDesktopPixelBufferTexture;
	info.pixel_buffer_config.user_data = pixel_buffer_texture;
	info.pixel_buffer_config.callback =
	[](size_t width, size_t height,
	void* user_data) -> const FlutterDesktopPixelBuffer* {
	auto texture = static_cast<PixelBufferTexture*>(user_data);
	return texture->CopyPixelBuffer(width, height);
	};
	} else if (auto gpu_surface_texture =
	std::get_if<GpuSurfaceTexture>(texture)) {
	info.type = kFlutterDesktopGpuSurfaceTexture;
	info.gpu_surface_config.struct_size =
	sizeof(FlutterDesktopGpuSurfaceTextureConfig);
	info.gpu_surface_config.type = gpu_surface_texture->surface_type();
	info.gpu_surface_config.user_data = gpu_surface_texture;
	info.gpu_surface_config.callback =
	[](size_t width, size_t height,
	void* user_data) -> const FlutterDesktopGpuSurfaceDescriptor* {
	auto texture = static_cast<GpuSurfaceTexture*>(user_data);
	return texture->ObtainDescriptor(width, height);
	};
	} else {
	std::cerr << "Attempting to register unknown texture variant." << std::endl;
	return -1;
	}

	int64_t texture_id = FlutterDesktopTextureRegistrarRegisterExternalTexture(
	texture_registrar_ref_, &info);
	return texture_id;
	} // namespace flutter

	bool TextureRegistrarImpl::MarkTextureFrameAvailable(int64_t texture_id) {
	return FlutterDesktopTextureRegistrarMarkExternalTextureFrameAvailable(
	texture_registrar_ref_, texture_id);
	}

	void TextureRegistrarImpl::UnregisterTexture(int64_t texture_id,
	std::function<void()> callback) {
	if (callback == nullptr) {
	FlutterDesktopTextureRegistrarUnregisterExternalTexture(
	texture_registrar_ref_, texture_id, nullptr, nullptr);
	return;
	}

	struct Captures {
	std::function<void()> callback;
	};
	auto captures = new Captures();
	captures->callback = std::move(callback);
	FlutterDesktopTextureRegistrarUnregisterExternalTexture(
	texture_registrar_ref_, texture_id,
	[](void* opaque) {
	auto captures = reinterpret_cast<Captures*>(opaque);
	captures->callback();
	delete captures;
	},
	captures);
	}

	bool TextureRegistrarImpl::UnregisterTexture(int64_t texture_id) {
	UnregisterTexture(texture_id, nullptr);
	return true;
	}

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gaaclarke commented Jun 11, 2026

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loic-sharma Jun 17, 2026 •

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