Beef up the test

impeller/display_list/display_list_unittests.cc

@@ -6,6 +6,7 @@
 #include "display_list/display_list_color.h"
 #include "display_list/display_list_color_filter.h"
 #include "display_list/display_list_image_filter.h"
+#include "display_list/display_list_paint.h"
 #include "display_list/display_list_tile_mode.h"
 #include "gtest/gtest.h"
 #include "third_party/imgui/imgui.h"
@@ -294,29 +295,50 @@ TEST_P(DisplayListTest, CanDrawBackdropFilter) {
     if (first_frame) {
       first_frame = false;
       ImGui::SetNextWindowSize({400, 100});
-      ImGui::SetNextWindowPos({300, 550});
+      ImGui::SetNextWindowPos({300, 650});
     }
 
     static float sigma[] = {10, 10};
+    static bool use_bounds = true;
+    static bool draw_circle = true;
 
     ImGui::Begin("Controls");
     ImGui::SliderFloat2("Sigma", sigma, 0, 100);
+    ImGui::Checkbox("Use SaveLayer bounds", &use_bounds);
+    ImGui::Checkbox("Draw child element", &draw_circle);
     ImGui::End();
 
     flutter::DisplayListBuilder builder;
 
+    Vector2 scale = GetContentScale();
+    builder.scale(scale.x, scale.y);
+
     auto filter = flutter::DlBlurImageFilter(sigma[0], sigma[1],
                                              flutter::DlTileMode::kClamp);
 
-    flutter::DlPaint paint;
-    paint.setColor(flutter::DlColor::kRed());
-    builder.drawCircle({100, 100}, 100, paint);
+    std::optional<SkRect> bounds;
+    if (use_bounds) {
+      auto [p1, p2] = IMPELLER_PLAYGROUND_LINE(
+          Point(250, 150), Point(800, 600), 20, Color::White(), Color::White());
+      bounds = SkRect::MakeLTRB(p1.x, p1.y, p2.x, p2.y);
+    }
 
-    auto bounds = SkRect::MakeXYWH(100, 100, 100, 100);
-    builder.saveLayer(&bounds, &paint, &filter);
-    builder.setImageFilter(&filter);
     builder.drawImage(DlImageImpeller::Make(texture), SkPoint::Make(200, 200),
                       SkSamplingOptions{}, true);
+    builder.saveLayer(bounds.has_value() ? &bounds.value() : nullptr, nullptr,
+                      &filter);
+
+    if (draw_circle) {
+      auto circle_center =
+          IMPELLER_PLAYGROUND_POINT(Point(500, 400), 20, Color::Red());
+
+      builder.setStyle(flutter::DlDrawStyle::kStroke);
+      builder.setStrokeCap(flutter::DlStrokeCap::kButt);
+      builder.setStrokeJoin(flutter::DlStrokeJoin::kBevel);
+      builder.setStrokeWidth(10);
+      builder.setColor(flutter::DlColor::kRed().withAlpha(100));
+      builder.drawCircle({circle_center.x, circle_center.y}, 100);
+    }
 
     return builder.Build();
   };

impeller/entity/entity_pass.cc

@@ -8,8 +8,8 @@
 #include <variant>
 
 #include "flutter/fml/logging.h"
+#include "flutter/fml/macros.h"
 #include "flutter/fml/trace_event.h"
-#include "fml/macros.h"
 #include "impeller/base/validation.h"
 #include "impeller/entity/contents/content_context.h"
 #include "impeller/entity/contents/filters/filter_contents.h"