Reland: [Impeller] Turned on new blur. (#48472)

impeller/aiks/aiks_unittests.cc

@@ -3758,10 +3758,13 @@ TEST_P(AiksTest, GaussianBlurSetsMipCountOnPass) {
   canvas.Restore();
 
   Picture picture = canvas.EndRecordingAsPicture();
-  EXPECT_EQ(1, picture.pass->GetRequiredMipCount());
+  EXPECT_EQ(4, picture.pass->GetRequiredMipCount());
 }
 
 TEST_P(AiksTest, GaussianBlurAllocatesCorrectMipCountRenderTarget) {
+  size_t blur_required_mip_count =
+      GetParam() == PlaygroundBackend::kMetal ? 4 : 1;
+
   Canvas canvas;
   canvas.DrawCircle({100, 100}, 50, {.color = Color::CornflowerBlue()});
   canvas.SaveLayer({}, std::nullopt,
@@ -3782,11 +3785,14 @@ TEST_P(AiksTest, GaussianBlurAllocatesCorrectMipCountRenderTarget) {
     max_mip_count =
         std::max(it->texture->GetTextureDescriptor().mip_count, max_mip_count);
   }
-  EXPECT_EQ(max_mip_count, 1lu);
+  EXPECT_EQ(max_mip_count, blur_required_mip_count);
 }
 
 TEST_P(AiksTest, GaussianBlurMipMapNestedLayer) {
   fml::testing::LogCapture log_capture;
+  size_t blur_required_mip_count =
+      GetParam() == PlaygroundBackend::kMetal ? 4 : 1;
+
   Canvas canvas;
   canvas.DrawPaint({.color = Color::Wheat()});
   canvas.SaveLayer({.blend_mode = BlendMode::kMultiply});
@@ -3809,12 +3815,19 @@ TEST_P(AiksTest, GaussianBlurMipMapNestedLayer) {
     max_mip_count =
         std::max(it->texture->GetTextureDescriptor().mip_count, max_mip_count);
   }
-  EXPECT_EQ(max_mip_count, 1lu);
-  EXPECT_EQ(log_capture.str().find(GaussianBlurFilterContents::kNoMipsError),
-            std::string::npos);
+  EXPECT_EQ(max_mip_count, blur_required_mip_count);
+  if (GetParam() == PlaygroundBackend::kMetal) {
+    EXPECT_EQ(log_capture.str().find(GaussianBlurFilterContents::kNoMipsError),
+              std::string::npos);
+  } else {
+    EXPECT_NE(log_capture.str().find(GaussianBlurFilterContents::kNoMipsError),
+              std::string::npos);
+  }
 }
 
 TEST_P(AiksTest, GaussianBlurMipMapImageFilter) {
+  size_t blur_required_mip_count =
+      GetParam() == PlaygroundBackend::kMetal ? 4 : 1;
   fml::testing::LogCapture log_capture;
   Canvas canvas;
   canvas.SaveLayer(
@@ -3835,9 +3848,14 @@ TEST_P(AiksTest, GaussianBlurMipMapImageFilter) {
     max_mip_count =
         std::max(it->texture->GetTextureDescriptor().mip_count, max_mip_count);
   }
-  EXPECT_EQ(max_mip_count, 1lu);
-  EXPECT_EQ(log_capture.str().find(GaussianBlurFilterContents::kNoMipsError),
-            std::string::npos);
+  EXPECT_EQ(max_mip_count, blur_required_mip_count);
+  if (GetParam() == PlaygroundBackend::kMetal) {
+    EXPECT_EQ(log_capture.str().find(GaussianBlurFilterContents::kNoMipsError),
+              std::string::npos);
+  } else {
+    EXPECT_NE(log_capture.str().find(GaussianBlurFilterContents::kNoMipsError),
+              std::string::npos);
+  }
 }
 
 }  // namespace testing

impeller/entity/contents/filters/directional_gaussian_blur_filter_contents.h

@@ -43,6 +43,9 @@ namespace impeller {
 ///   - `FilterContents::MakeGaussianBlur`
 ///   - //flutter/impeller/entity/shaders/gaussian_blur/gaussian_blur.glsl
 ///
+///\deprecated Previously 2 of these were chained to do 2D blurs, use
+///            \ref GaussianBlurFilterContents instead since it has better
+///            performance.
 class DirectionalGaussianBlurFilterContents final : public FilterContents {
  public:
   DirectionalGaussianBlurFilterContents();

impeller/entity/contents/filters/filter_contents.cc

@@ -50,50 +50,18 @@ std::shared_ptr<FilterContents> FilterContents::MakeDirectionalGaussianBlur(
   return blur;
 }
 
-#ifdef IMPELLER_ENABLE_NEW_GAUSSIAN_FILTER
 const int32_t FilterContents::kBlurFilterRequiredMipCount = 4;
-#else
-const int32_t FilterContents::kBlurFilterRequiredMipCount = 1;
-#endif
 
 std::shared_ptr<FilterContents> FilterContents::MakeGaussianBlur(
     const FilterInput::Ref& input,
     Sigma sigma_x,
     Sigma sigma_y,
     BlurStyle blur_style,
     Entity::TileMode tile_mode) {
-  constexpr bool use_new_filter =
-#ifdef IMPELLER_ENABLE_NEW_GAUSSIAN_FILTER
-      true;
-#else
-      false;
-#endif
-
-  // TODO(https://github.com/flutter/flutter/issues/131580): Remove once the new
-  // blur handles all cases.
-  if (use_new_filter) {
-    auto blur = std::make_shared<GaussianBlurFilterContents>(
-        sigma_x.sigma, sigma_y.sigma, tile_mode);
-    blur->SetInputs({input});
-    return blur;
-  }
-  std::shared_ptr<FilterContents> x_blur = MakeDirectionalGaussianBlur(
-      /*input=*/input,
-      /*sigma=*/sigma_x,
-      /*direction=*/Point(1, 0),
-      /*blur_style=*/BlurStyle::kNormal,
-      /*tile_mode=*/tile_mode,
-      /*is_second_pass=*/false,
-      /*secondary_sigma=*/{});
-  std::shared_ptr<FilterContents> y_blur = MakeDirectionalGaussianBlur(
-      /*input=*/FilterInput::Make(x_blur),
-      /*sigma=*/sigma_y,
-      /*direction=*/Point(0, 1),
-      /*blur_style=*/blur_style,
-      /*tile_mode=*/tile_mode,
-      /*is_second_pass=*/true,
-      /*secondary_sigma=*/sigma_x);
-  return y_blur;
+  auto blur = std::make_shared<GaussianBlurFilterContents>(
+      sigma_x.sigma, sigma_y.sigma, tile_mode);
+  blur->SetInputs({input});
+  return blur;
 }
 
 std::shared_ptr<FilterContents> FilterContents::MakeBorderMaskBlur(

impeller/entity/entity_pass.cc

@@ -256,6 +256,14 @@ static EntityPassTarget CreateRenderTarget(ContentContext& renderer,
   /// What's important is the `StorageMode` of the textures, which cannot be
   /// changed for the lifetime of the textures.
 
+  if (context->GetBackendType() != Context::BackendType::kMetal) {
+    // TODO(https://github.com/flutter/flutter/issues/141495): Implement mip map
+    // generation on vulkan.
+    // TODO(https://github.com/flutter/flutter/issues/141732): Implement mip map
+    // generation on opengles.
+    mip_count = 1;
+  }
+
   RenderTarget target;
   if (context->GetCapabilities()->SupportsOffscreenMSAA()) {
     target = RenderTarget::CreateOffscreenMSAA(