[impeller] enable framebuffer blit when available (flutter/engine#56596)

depends on https://github.com/flutter/engine/pull/56573
fixes https://github.com/flutter/flutter/issues/158523

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide] and the [C++,
Objective-C, Java style guides].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I added new tests to check the change I am making or feature I am
adding, or the PR is [test-exempt]. See [testing the engine] for
instructions on writing and running engine tests.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I signed the [CLA].
- [x] 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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[Contributor Guide]:
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[Tree Hygiene]: https://github.com/flutter/flutter/wiki/Tree-hygiene
[test-exempt]:
https://github.com/flutter/flutter/wiki/Tree-hygiene#tests
[Flutter Style Guide]:
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[C++, Objective-C, Java style guides]:
https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style
[testing the engine]:
https://github.com/flutter/flutter/wiki/Testing-the-engine
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/wiki/Tree-hygiene#handling-breaking-changes
[Discord]: https://github.com/flutter/flutter/wiki/Chat

engine/src/flutter/impeller/golden_tests/BUILD.gn

@@ -93,6 +93,7 @@ if (is_mac) {
       "//flutter/impeller/display_list:aiks_unittests_golden",
       "//flutter/impeller/display_list:display_list_unittests_golden",
       "//flutter/impeller/fixtures",
+      "//flutter/impeller/renderer:renderer_unittests_golden",
       "//flutter/third_party/angle:libEGL",
       "//flutter/third_party/angle:libGLESv2",
       "//flutter/third_party/googletest:gtest",

engine/src/flutter/impeller/renderer/BUILD.gn

@@ -96,10 +96,9 @@ impeller_component("renderer") {
   deps = [ "//flutter/fml" ]
 }
 
-impeller_component("renderer_unittests") {
+template("renderer_unittests_component") {
-  testonly = true
+  target_name = invoker.target_name
-
+  predefined_sources = [
-  sources = [
     "blit_pass_unittests.cc",
     "capabilities_unittests.cc",
     "device_buffer_unittests.cc",
@@ -107,20 +106,45 @@ impeller_component("renderer_unittests") {
     "pool_unittests.cc",
     "renderer_unittests.cc",
   ]
-
+  impeller_component(target_name) {
-  deps = [
+    testonly = true
-    ":renderer",
+    if (defined(invoker.defines)) {
-    "../fixtures",
+      defines = invoker.defines
-    "../playground:playground_test",
+    } else {
-    "../tessellator:tessellator_libtess",
+      defines = []
-    "//flutter/testing:testing_lib",
+    }
-  ]
+    sources = predefined_sources
-
+    if (defined(invoker.deps)) {
-  if (impeller_enable_compute) {
+      deps = invoker.deps
-    sources += [ "compute_unittests.cc" ]
+    } else {
+      deps = []
+    }
+    deps += [
+      ":renderer",
+      "../fixtures",
+      "../playground:playground_test",
+      "../tessellator:tessellator_libtess",
+      "//flutter/impeller/display_list:display_list",
+      "//flutter/testing:testing_lib",
+    ]
+    if (defined(invoker.public_configs)) {
+      public_configs = invoker.public_configs
+    }
   }
 }
 
+renderer_unittests_component("renderer_unittests") {
+  deps = [ "//flutter/impeller/display_list:aiks_unittests" ]
+}
+
+renderer_unittests_component("renderer_unittests_golden") {
+  deps = [ "//flutter/impeller/display_list:aiks_unittests_golden" ]
+  defines = [
+    "IMPELLER_GOLDEN_TESTS",
+    "IMPELLER_ENABLE_VALIDATION=1",
+  ]
+}
+
 impeller_component("renderer_dart_unittests") {
   testonly = true
 

engine/src/flutter/impeller/renderer/backend/gles/blit_command_gles.cc

@@ -372,6 +372,8 @@ bool BlitResizeTextureCommandGLES::Encode(const ReactorGLES& reactor) const {
     return false;
   }
 
+  destination->SetCoordinateSystem(source->GetCoordinateSystem());
+
   GLuint read_fbo = GL_NONE;
   GLuint draw_fbo = GL_NONE;
   fml::ScopedCleanupClosure delete_fbos([&gl, &read_fbo, &draw_fbo]() {

engine/src/flutter/impeller/renderer/backend/gles/capabilities_gles.cc

@@ -109,6 +109,10 @@ CapabilitiesGLES::CapabilitiesGLES(const ProcTableGLES& gl) {
     default_glyph_atlas_format_ = PixelFormat::kR8UNormInt;
   }
 
+  if (desc->GetGlVersion().major_version >= 3) {
+    supports_texture_to_texture_blits_ = true;
+  }
+
   supports_framebuffer_fetch_ = desc->HasExtension(kFramebufferFetchExt);
 
   if (desc->HasExtension(kTextureBorderClampExt) ||
@@ -158,10 +162,7 @@ bool CapabilitiesGLES::SupportsSSBO() const {
 }
 
 bool CapabilitiesGLES::SupportsTextureToTextureBlits() const {
-  // TODO(158523): Switch this to true for improved performance
+  return supports_texture_to_texture_blits_;
-  // on GLES 3.0+ devices. Note that this wasn't enabled because
-  // there were some rendering issues on some devices.
-  return false;
 }
 
 bool CapabilitiesGLES::SupportsFramebufferFetch() const {

engine/src/flutter/impeller/renderer/backend/gles/capabilities_gles.h

@@ -131,6 +131,7 @@ class CapabilitiesGLES final
   ISize GetMaximumRenderPassAttachmentSize() const override;
 
  private:
+  bool supports_texture_to_texture_blits_ = false;
   bool supports_framebuffer_fetch_ = false;
   bool supports_decal_sampler_address_mode_ = false;
   bool supports_offscreen_msaa_ = false;

engine/src/flutter/impeller/renderer/backend/gles/test/capabilities_unittests.cc

@@ -17,7 +17,7 @@ TEST(CapabilitiesGLES, CanInitializeWithDefaults) {
 
   EXPECT_FALSE(capabilities->SupportsOffscreenMSAA());
   EXPECT_FALSE(capabilities->SupportsSSBO());
-  EXPECT_FALSE(capabilities->SupportsTextureToTextureBlits());
+  EXPECT_TRUE(capabilities->SupportsTextureToTextureBlits());
   EXPECT_FALSE(capabilities->SupportsFramebufferFetch());
   EXPECT_FALSE(capabilities->SupportsCompute());
   EXPECT_FALSE(capabilities->SupportsComputeSubgroups());

engine/src/flutter/impeller/renderer/blit_pass_unittests.cc

@@ -3,6 +3,9 @@
 // found in the LICENSE file.
 
 #include <cstdint>
+#include "flutter/display_list/dl_builder.h"
+#include "flutter/impeller/display_list/aiks_unittests.h"
+#include "flutter/impeller/display_list/dl_image_impeller.h"
 #include "fml/mapping.h"
 #include "gtest/gtest.h"
 #include "impeller/base/validation.h"
@@ -16,7 +19,12 @@
 namespace impeller {
 namespace testing {
 
-using BlitPassTest = PlaygroundTest;
+using flutter::DisplayListBuilder;
+using flutter::DlColor;
+using flutter::DlImageSampling;
+using flutter::DlPaint;
+
+using BlitPassTest = AiksTest;
 INSTANTIATE_PLAYGROUND_SUITE(BlitPassTest);
 
 TEST_P(BlitPassTest, BlitAcrossDifferentPixelFormatsFails) {
@@ -230,5 +238,36 @@ TEST_P(BlitPassTest, CanResizeTextures) {
   EXPECT_TRUE(context->GetCommandQueue()->Submit({std::move(cmd_buffer)}).ok());
 }
 
+TEST_P(BlitPassTest, CanResizeTexturesPlayground) {
+  auto context = GetContext();
+  auto cmd_buffer = context->CreateCommandBuffer();
+  auto blit_pass = cmd_buffer->CreateBlitPass();
+
+  std::shared_ptr<Texture> src = CreateTextureForFixture("kalimba.jpg");
+
+  TextureDescriptor dst_format;
+  dst_format.storage_mode = StorageMode::kDevicePrivate;
+  dst_format.format = PixelFormat::kR8G8B8A8UNormInt;
+  dst_format.size = {src->GetSize().width / 2, src->GetSize().height};
+  dst_format.usage = TextureUsage::kShaderRead | TextureUsage::kShaderWrite;
+  auto dst = context->GetResourceAllocator()->CreateTexture(dst_format);
+
+  ASSERT_TRUE(dst);
+  ASSERT_TRUE(src);
+
+  EXPECT_TRUE(blit_pass->ResizeTexture(src, dst));
+  EXPECT_TRUE(blit_pass->EncodeCommands(GetContext()->GetResourceAllocator()));
+  EXPECT_TRUE(context->GetCommandQueue()->Submit({std::move(cmd_buffer)}).ok());
+
+  DisplayListBuilder builder;
+  builder.Scale(GetContentScale().x, GetContentScale().y);
+  DlPaint paint;
+  paint.setColor(DlColor::kRed());
+  auto image = DlImageImpeller::Make(dst);
+  builder.DrawImage(image, SkPoint::Make(100.0, 100.0),
+                    DlImageSampling::kNearestNeighbor, &paint);
+  ASSERT_TRUE(OpenPlaygroundHere(builder.Build()));
+}
+
 }  // namespace testing
 }  // namespace impeller

engine/src/flutter/lib/ui/painting/image_decoder_impeller.cc

@@ -243,7 +243,7 @@ DecompressResult ImageDecoderImpeller::DecompressTexture(
       !capabilities->SupportsTextureToTextureBlits()) {
     //----------------------------------------------------------------------------
     /// 2. If the decoded image isn't the requested target size and the src size
-    ///    exceeds the device max texture size, perform a slow CPU reisze.
+    ///    exceeds the device max texture size, perform a slow CPU resize.
     ///
     TRACE_EVENT0("impeller", "SlowCPUDecodeScale");
     const auto scaled_image_info = image_info.makeDimensions(target_size);

engine/src/flutter/shell/platform/android/android_context_gl_impeller.cc

@@ -92,7 +92,7 @@ AndroidContextGLImpeller::AndroidContextGLImpeller(
   }
 
   impeller::egl::ConfigDescriptor desc;
-  desc.api = impeller::egl::API::kOpenGLES2;
+  desc.api = impeller::egl::API::kOpenGLES3;
   desc.color_format = impeller::egl::ColorFormat::kRGBA8888;
   desc.depth_bits = impeller::egl::DepthBits::kTwentyFour;
   desc.stencil_bits = impeller::egl::StencilBits::kEight;
@@ -101,6 +101,12 @@ AndroidContextGLImpeller::AndroidContextGLImpeller(
   desc.surface_type = impeller::egl::SurfaceType::kWindow;
   std::unique_ptr<impeller::egl::Config> onscreen_config =
       display_->ChooseConfig(desc);
+
+  if (!onscreen_config) {
+    desc.api = impeller::egl::API::kOpenGLES2;
+    onscreen_config = display_->ChooseConfig(desc);
+  }
+
   if (!onscreen_config) {
     // Fallback for Android emulator.
     desc.samples = impeller::egl::Samples::kOne;

engine/src/flutter/shell/platform/android/android_context_gl_impeller_unittests.cc

@@ -97,28 +97,38 @@ TEST_F(AndroidContextGLImpellerTest, FallbackForEmulator) {
   auto display = std::make_unique<MockDisplay>();
   EXPECT_CALL(*display, IsValid).WillRepeatedly(Return(true));
   std::unique_ptr<Config> first_result;
-  auto second_result =
+  std::unique_ptr<Config> second_result;
-      std::make_unique<Config>(ConfigDescriptor(), window_egl_config);
   auto third_result =
+      std::make_unique<Config>(ConfigDescriptor(), window_egl_config);
+  auto fourth_result =
       std::make_unique<Config>(ConfigDescriptor(), pbuffer_egl_config);
   EXPECT_CALL(
       *display,
       ChooseConfig(Matcher<ConfigDescriptor>(AllOf(
+          Field(&ConfigDescriptor::api, impeller::egl::API::kOpenGLES3),
           Field(&ConfigDescriptor::samples, impeller::egl::Samples::kFour),
           Field(&ConfigDescriptor::surface_type,
                 impeller::egl::SurfaceType::kWindow)))))
       .WillOnce(Return(ByMove(std::move(first_result))));
+  EXPECT_CALL(
+      *display,
+      ChooseConfig(Matcher<ConfigDescriptor>(AllOf(
+          Field(&ConfigDescriptor::api, impeller::egl::API::kOpenGLES2),
+          Field(&ConfigDescriptor::samples, impeller::egl::Samples::kFour),
+          Field(&ConfigDescriptor::surface_type,
+                impeller::egl::SurfaceType::kWindow)))))
+      .WillOnce(Return(ByMove(std::move(second_result))));
   EXPECT_CALL(
       *display,
       ChooseConfig(Matcher<ConfigDescriptor>(
           AllOf(Field(&ConfigDescriptor::samples, impeller::egl::Samples::kOne),
                 Field(&ConfigDescriptor::surface_type,
                       impeller::egl::SurfaceType::kWindow)))))
-      .WillOnce(Return(ByMove(std::move(second_result))));
+      .WillOnce(Return(ByMove(std::move(third_result))));
   EXPECT_CALL(*display, ChooseConfig(Matcher<ConfigDescriptor>(
                             Field(&ConfigDescriptor::surface_type,
                                   impeller::egl::SurfaceType::kPBuffer))))
-      .WillOnce(Return(ByMove(std::move(third_result))));
+      .WillOnce(Return(ByMove(std::move(fourth_result))));
   ON_CALL(*display, ChooseConfig(_))
       .WillByDefault(Return(ByMove(std::unique_ptr<Config>())));
   auto context =

engine/src/flutter/testing/impeller_golden_tests_output.txt

@@ -951,6 +951,9 @@ impeller_Play_AiksTest_VerticesGeometryUVPositionDataWithTranslate_Vulkan.png
 impeller_Play_AiksTest_VerticesGeometryUVPositionData_Metal.png
 impeller_Play_AiksTest_VerticesGeometryUVPositionData_OpenGLES.png
 impeller_Play_AiksTest_VerticesGeometryUVPositionData_Vulkan.png
+impeller_Play_BlitPassTest_CanResizeTexturesPlayground_Metal.png
+impeller_Play_BlitPassTest_CanResizeTexturesPlayground_OpenGLES.png
+impeller_Play_BlitPassTest_CanResizeTexturesPlayground_Vulkan.png
 impeller_Play_DlGoldenTest_Bug147807_Metal.png
 impeller_Play_DlGoldenTest_Bug147807_OpenGLES.png
 impeller_Play_DlGoldenTest_Bug147807_Vulkan.png