[Impeller] desktop: Add missing dispatch for TextFrameDispatcher in embedder view.

shell/platform/embedder/BUILD.gn

@@ -242,7 +242,8 @@ test_fixtures("fixtures") {
     "fixtures/dpr_noxform.png",
     "fixtures/dpr_xform.png",
     "fixtures/gradient.png",
-    "fixtures/impeller_gl_test.png",
+    "fixtures/impeller_test.png",
+    "fixtures/impeller_text_test.png",
     "fixtures/vk_dpr_noxform.png",
     "fixtures/vk_gradient.png",
     "fixtures/gradient_metal.png",

shell/platform/embedder/embedder_external_view.cc

@@ -137,6 +137,7 @@ bool EmbedderExternalView::Render(const EmbedderRenderTarget& render_target,
 
     impeller::TextFrameDispatcher collector(aiks_context->GetContentContext(),
                                             impeller::Matrix());
+    display_list->Dispatch(collector, sk_cull_rect);
 
     impeller::ExperimentalDlDispatcher impeller_dispatcher(
         aiks_context->GetContentContext(), *impeller_target,

shell/platform/embedder/fixtures/README.md

@@ -71,9 +71,9 @@ $ $ENGINE/out/$TARGET/embedder_unittests --gtest_filter="EmbedderTest.VerifyB143
 # Or, a suite of tests:
 $ $ENGINE/out/$TARGET/embedder_unittests --gtest_filter="EmbedderTest.*"
 
-# 3. Now, copy the output to the golden file:
+# 3. Now, copy the output to the golden file (notice the "actual_" prefix):
 $ cp \
-  $ENGINE/out/$TARGET/gen/flutter/shell/platform/embedder/assets/expectation_verifyb143464703_soft_noxform.png \
+  $ENGINE/out/$TARGET/gen/flutter/shell/platform/embedder/assets/actual_verifyb143464703_soft_noxform.png \
   $ENGINE/flutter/shell/platform/embedder/fixtures/verifyb143464703_soft_noxform.png
 ```
 

shell/platform/embedder/fixtures/main.dart

@@ -1553,7 +1553,7 @@ void render_gradient_retained() {
 
 @pragma('vm:entry-point')
 // ignore: non_constant_identifier_names
-void render_impeller_gl_test() {
+void render_impeller_test() {
   PlatformDispatcher.instance.onBeginFrame = (Duration duration) {
     final SceneBuilder builder = SceneBuilder();
     builder.pushOffset(0.0, 0.0);
@@ -1569,3 +1569,29 @@ void render_impeller_gl_test() {
   };
   PlatformDispatcher.instance.scheduleFrame();
 }
+
+@pragma('vm:entry-point')
+// ignore: non_constant_identifier_names
+void render_impeller_text_test() {
+  PlatformDispatcher.instance.onBeginFrame = (Duration duration) {
+    final SceneBuilder builder = SceneBuilder();
+    builder.pushOffset(0.0, 0.0);
+    final Paint paint = Paint();
+    paint.color = const Color.fromARGB(255, 0, 0, 255);
+    final PictureRecorder baseRecorder = PictureRecorder();
+    final Canvas canvas = Canvas(baseRecorder);
+
+    final ParagraphBuilder paragraphBuilder = ParagraphBuilder(ParagraphStyle(
+      fontFamily: 'sans-serif'
+    ))
+      ..addText('Flutter is the best!');
+    final Paragraph paragraph = paragraphBuilder.build()
+      ..layout(const ParagraphConstraints(width: 400));
+    canvas.drawParagraph(paragraph, const Offset(20, 20));
+
+    builder.addPicture(Offset.zero, baseRecorder.endRecording());
+    builder.pop();
+    PlatformDispatcher.instance.views.first.render(builder.build());
+  };
+  PlatformDispatcher.instance.scheduleFrame();
+}

shell/platform/embedder/tests/embedder_gl_unittests.cc

@@ -4758,7 +4758,7 @@ TEST_F(EmbedderTest, CanRenderWithImpellerOpenGL) {
       });
 
   builder.AddCommandLineArgument("--enable-impeller");
-  builder.SetDartEntrypoint("render_impeller_gl_test");
+  builder.SetDartEntrypoint("render_impeller_test");
   builder.SetOpenGLRendererConfig(SkISize::Make(800, 600));
   builder.SetCompositor();
   builder.SetRenderTargetType(
@@ -4798,7 +4798,7 @@ TEST_F(EmbedderTest, CanRenderWithImpellerOpenGL) {
 
   ASSERT_TRUE(ImageMatchesFixture(
       FixtureNameForBackend(EmbedderTestContextType::kOpenGLContext,
-                            "impeller_gl_test.png"),
+                            "impeller_test.png"),
       rendered_scene));
 
   // The scene will be rendered by the compositor, and the surface present

shell/platform/embedder/tests/embedder_metal_unittests.mm

@@ -614,6 +614,84 @@ void Collect() {
   EXPECT_TRUE(resolve_called);
 }
 
+TEST_F(EmbedderTest, CanRenderWithImpellerMetal) {
+  auto& context = GetEmbedderContext(EmbedderTestContextType::kMetalContext);
+
+  EmbedderConfigBuilder builder(context);
+
+  builder.AddCommandLineArgument("--enable-impeller");
+  builder.SetDartEntrypoint("render_impeller_test");
+  builder.SetMetalRendererConfig(SkISize::Make(800, 600));
+
+  auto rendered_scene = context.GetNextSceneImage();
+
+  auto engine = builder.LaunchEngine();
+  ASSERT_TRUE(engine.is_valid());
+
+  // Send a window metrics events so frames may be scheduled.
+  FlutterWindowMetricsEvent event = {};
+  event.struct_size = sizeof(event);
+  event.width = 800;
+  event.height = 600;
+  event.pixel_ratio = 1.0;
+  ASSERT_EQ(FlutterEngineSendWindowMetricsEvent(engine.get(), &event), kSuccess);
+
+  ASSERT_TRUE(ImageMatchesFixture("impeller_test.png", rendered_scene));
+}
+
+TEST_F(EmbedderTest, CanRenderTextWithImpellerMetal) {
+  auto& context = GetEmbedderContext(EmbedderTestContextType::kMetalContext);
+
+  EmbedderConfigBuilder builder(context);
+
+  builder.AddCommandLineArgument("--enable-impeller");
+  builder.SetDartEntrypoint("render_impeller_text_test");
+  builder.SetMetalRendererConfig(SkISize::Make(800, 600));
+
+  auto rendered_scene = context.GetNextSceneImage();
+
+  auto engine = builder.LaunchEngine();
+  ASSERT_TRUE(engine.is_valid());
+
+  // Send a window metrics events so frames may be scheduled.
+  FlutterWindowMetricsEvent event = {};
+  event.struct_size = sizeof(event);
+  event.width = 800;
+  event.height = 600;
+  event.pixel_ratio = 1.0;
+  ASSERT_EQ(FlutterEngineSendWindowMetricsEvent(engine.get(), &event), kSuccess);
+
+  ASSERT_TRUE(ImageMatchesFixture("impeller_text_test.png", rendered_scene));
+}
+
+TEST_F(EmbedderTest, CanRenderTextWithImpellerAndCompositorMetal) {
+  auto& context = GetEmbedderContext(EmbedderTestContextType::kMetalContext);
+
+  EmbedderConfigBuilder builder(context);
+
+  builder.AddCommandLineArgument("--enable-impeller");
+  builder.SetDartEntrypoint("render_impeller_text_test");
+  builder.SetMetalRendererConfig(SkISize::Make(800, 600));
+  builder.SetCompositor();
+
+  builder.SetRenderTargetType(EmbedderTestBackingStoreProducer::RenderTargetType::kMetalTexture);
+
+  auto rendered_scene = context.GetNextSceneImage();
+
+  auto engine = builder.LaunchEngine();
+  ASSERT_TRUE(engine.is_valid());
+
+  // Send a window metrics events so frames may be scheduled.
+  FlutterWindowMetricsEvent event = {};
+  event.struct_size = sizeof(event);
+  event.width = 800;
+  event.height = 600;
+  event.pixel_ratio = 1.0;
+  ASSERT_EQ(FlutterEngineSendWindowMetricsEvent(engine.get(), &event), kSuccess);
+
+  ASSERT_TRUE(ImageMatchesFixture("impeller_text_test.png", rendered_scene));
+}
+
 }  // namespace testing
 }  // namespace flutter