Move checkerboard unit tests onto DisplayList mechanism (flutter#41951)

Part of an ongoing set of efforts to address flutter/flutter#106448

Move the checkerboard layer unit tests onto the DisplayList version of the paint contexts and fix some bugs in the reusability of the DisplayListBuilder that this migration uncovered.

display_list/benchmarking/dl_complexity_helper.h

@@ -120,7 +120,7 @@ class ComplexityCalculatorHelper
 
   void setAntiAlias(bool aa) override { current_paint_.setAntiAlias(aa); }
 
-  void setStyle(DlDrawStyle style) override {
+  void setDrawStyle(DlDrawStyle style) override {
     current_paint_.setDrawStyle(style);
   }
 

display_list/display_list_unittests.cc

@@ -30,6 +30,10 @@ DlOpReceiver& DisplayListBuilderTestingAccessor(DisplayListBuilder& builder) {
   return builder.asReceiver();
 }
 
+DlPaint DisplayListBuilderTestingAttributes(DisplayListBuilder& builder) {
+  return builder.CurrentAttributes();
+}
+
 namespace testing {
 
 static std::vector<testing::DisplayListInvocationGroup> allGroups =
@@ -87,11 +91,49 @@ class DisplayListTestBase : public BaseT {
     return dl;
   }
 
+  static void check_defaults(
+      DisplayListBuilder& builder,
+      const SkRect& cull_rect = DisplayListBuilder::kMaxCullRect) {
+    DlPaint builder_paint = DisplayListBuilderTestingAttributes(builder);
+    DlPaint defaults;
+
+    EXPECT_EQ(builder_paint.isAntiAlias(), defaults.isAntiAlias());
+    EXPECT_EQ(builder_paint.isDither(), defaults.isDither());
+    EXPECT_EQ(builder_paint.isInvertColors(), defaults.isInvertColors());
+    EXPECT_EQ(builder_paint.getColor(), defaults.getColor());
+    EXPECT_EQ(builder_paint.getBlendMode(), defaults.getBlendMode());
+    EXPECT_EQ(builder_paint.getDrawStyle(), defaults.getDrawStyle());
+    EXPECT_EQ(builder_paint.getStrokeWidth(), defaults.getStrokeWidth());
+    EXPECT_EQ(builder_paint.getStrokeMiter(), defaults.getStrokeMiter());
+    EXPECT_EQ(builder_paint.getStrokeCap(), defaults.getStrokeCap());
+    EXPECT_EQ(builder_paint.getStrokeJoin(), defaults.getStrokeJoin());
+    EXPECT_EQ(builder_paint.getColorSource(), defaults.getColorSource());
+    EXPECT_EQ(builder_paint.getColorFilter(), defaults.getColorFilter());
+    EXPECT_EQ(builder_paint.getImageFilter(), defaults.getImageFilter());
+    EXPECT_EQ(builder_paint.getMaskFilter(), defaults.getMaskFilter());
+    EXPECT_EQ(builder_paint.getPathEffect(), defaults.getPathEffect());
+    EXPECT_EQ(builder_paint, defaults);
+    EXPECT_TRUE(builder_paint.isDefault());
+
+    EXPECT_EQ(builder.GetTransform(), SkMatrix());
+    EXPECT_EQ(builder.GetTransformFullPerspective(), SkM44());
+
+    EXPECT_EQ(builder.GetLocalClipBounds(), cull_rect);
+    EXPECT_EQ(builder.GetDestinationClipBounds(), cull_rect);
+
+    EXPECT_EQ(builder.GetSaveCount(), 1);
+  }
+
  private:
   FML_DISALLOW_COPY_AND_ASSIGN(DisplayListTestBase);
 };
 using DisplayListTest = DisplayListTestBase<::testing::Test>;
 
+TEST_F(DisplayListTest, Defaults) {
+  DisplayListBuilder builder;
+  check_defaults(builder);
+}
+
 TEST_F(DisplayListTest, EmptyBuild) {
   DisplayListBuilder builder;
   auto dl = builder.Build();
@@ -117,6 +159,199 @@ TEST_F(DisplayListTest, BuilderCanBeReused) {
   ASSERT_TRUE(dl->Equals(dl2));
 }
 
+TEST_F(DisplayListTest, SaveRestoreRestoresTransform) {
+  SkRect cull_rect = SkRect::MakeLTRB(-10.0f, -10.0f, 500.0f, 500.0f);
+  DisplayListBuilder builder(cull_rect);
+
+  builder.Save();
+  builder.Translate(10.0f, 10.0f);
+  builder.Restore();
+  check_defaults(builder, cull_rect);
+
+  builder.Save();
+  builder.Scale(10.0f, 10.0f);
+  builder.Restore();
+  check_defaults(builder, cull_rect);
+
+  builder.Save();
+  builder.Skew(0.1f, 0.1f);
+  builder.Restore();
+  check_defaults(builder, cull_rect);
+
+  builder.Save();
+  builder.Rotate(45.0f);
+  builder.Restore();
+  check_defaults(builder, cull_rect);
+
+  builder.Save();
+  builder.Transform(SkMatrix::Scale(10.0f, 10.0f));
+  builder.Restore();
+  check_defaults(builder, cull_rect);
+
+  builder.Save();
+  builder.Transform2DAffine(1.0f, 0.0f, 12.0f,  //
+                            0.0f, 1.0f, 35.0f);
+  builder.Restore();
+  check_defaults(builder, cull_rect);
+
+  builder.Save();
+  builder.Transform(SkM44(SkMatrix::Scale(10.0f, 10.0f)));
+  builder.Restore();
+  check_defaults(builder, cull_rect);
+
+  builder.Save();
+  builder.TransformFullPerspective(1.0f, 0.0f, 0.0f, 12.0f,  //
+                                   0.0f, 1.0f, 0.0f, 35.0f,  //
+                                   0.0f, 0.0f, 1.0f, 5.0f,   //
+                                   0.0f, 0.0f, 0.0f, 1.0f);
+  builder.Restore();
+  check_defaults(builder, cull_rect);
+}
+
+TEST_F(DisplayListTest, BuildRestoresTransform) {
+  SkRect cull_rect = SkRect::MakeLTRB(-10.0f, -10.0f, 500.0f, 500.0f);
+  DisplayListBuilder builder(cull_rect);
+
+  builder.Translate(10.0f, 10.0f);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  builder.Scale(10.0f, 10.0f);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  builder.Skew(0.1f, 0.1f);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  builder.Rotate(45.0f);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  builder.Transform(SkMatrix::Scale(10.0f, 10.0f));
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  builder.Transform2DAffine(1.0f, 0.0f, 12.0f,  //
+                            0.0f, 1.0f, 35.0f);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  builder.Transform(SkM44(SkMatrix::Scale(10.0f, 10.0f)));
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  builder.TransformFullPerspective(1.0f, 0.0f, 0.0f, 12.0f,  //
+                                   0.0f, 1.0f, 0.0f, 35.0f,  //
+                                   0.0f, 0.0f, 1.0f, 5.0f,   //
+                                   0.0f, 0.0f, 0.0f, 1.0f);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+}
+
+TEST_F(DisplayListTest, SaveRestoreRestoresClip) {
+  SkRect cull_rect = SkRect::MakeLTRB(-10.0f, -10.0f, 500.0f, 500.0f);
+  DisplayListBuilder builder(cull_rect);
+
+  builder.Save();
+  builder.ClipRect({0.0f, 0.0f, 10.0f, 10.0f});
+  builder.Restore();
+  check_defaults(builder, cull_rect);
+
+  builder.Save();
+  builder.ClipRRect(SkRRect::MakeRectXY({0.0f, 0.0f, 5.0f, 5.0f}, 2.0f, 2.0f));
+  builder.Restore();
+  check_defaults(builder, cull_rect);
+
+  builder.Save();
+  builder.ClipPath(SkPath().addOval({0.0f, 0.0f, 10.0f, 10.0f}));
+  builder.Restore();
+  check_defaults(builder, cull_rect);
+}
+
+TEST_F(DisplayListTest, BuildRestoresClip) {
+  SkRect cull_rect = SkRect::MakeLTRB(-10.0f, -10.0f, 500.0f, 500.0f);
+  DisplayListBuilder builder(cull_rect);
+
+  builder.ClipRect({0.0f, 0.0f, 10.0f, 10.0f});
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  builder.ClipRRect(SkRRect::MakeRectXY({0.0f, 0.0f, 5.0f, 5.0f}, 2.0f, 2.0f));
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  builder.ClipPath(SkPath().addOval({0.0f, 0.0f, 10.0f, 10.0f}));
+  builder.Build();
+  check_defaults(builder, cull_rect);
+}
+
+TEST_F(DisplayListTest, BuildRestoresAttributes) {
+  SkRect cull_rect = SkRect::MakeLTRB(-10.0f, -10.0f, 500.0f, 500.0f);
+  DisplayListBuilder builder(cull_rect);
+  DlOpReceiver& receiver = ToReceiver(builder);
+
+  receiver.setAntiAlias(true);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setDither(true);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setInvertColors(true);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setColor(DlColor::kRed());
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setBlendMode(DlBlendMode::kColorBurn);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setDrawStyle(DlDrawStyle::kStrokeAndFill);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setStrokeWidth(300.0f);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setStrokeMiter(300.0f);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setStrokeCap(DlStrokeCap::kRound);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setStrokeJoin(DlStrokeJoin::kRound);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setColorSource(&kTestSource1);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setColorFilter(&kTestMatrixColorFilter1);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setImageFilter(&kTestBlurImageFilter1);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setMaskFilter(&kTestMaskFilter1);
+  builder.Build();
+  check_defaults(builder, cull_rect);
+
+  receiver.setPathEffect(kTestPathEffect1.get());
+  builder.Build();
+  check_defaults(builder, cull_rect);
+}
+
 TEST_F(DisplayListTest, BuilderBoundsTransformComparedToSkia) {
   const SkRect frame_rect = SkRect::MakeLTRB(10, 10, 100, 100);
   DisplayListBuilder builder(frame_rect);

display_list/dl_builder.cc

@@ -65,15 +65,22 @@ sk_sp<DisplayList> DisplayListBuilder::Build() {
   while (layer_stack_.size() > 1) {
     restore();
   }
+
   size_t bytes = used_;
   int count = render_op_count_;
   size_t nested_bytes = nested_bytes_;
   int nested_count = nested_op_count_;
+  bool compatible = layer_stack_.back().is_group_opacity_compatible();
+  bool is_safe = is_ui_thread_safe_;
+
   used_ = allocated_ = render_op_count_ = op_index_ = 0;
   nested_bytes_ = nested_op_count_ = 0;
   storage_.realloc(bytes);
-  bool compatible = layer_stack_.back().is_group_opacity_compatible();
-  bool is_safe = is_ui_thread_safe_;
+  layer_stack_.pop_back();
+  layer_stack_.emplace_back();
+  tracker_.reset();
+  current_ = DlPaint();
+
   return sk_sp<DisplayList>(
       new DisplayList(std::move(storage_), bytes, count, nested_bytes,
                       nested_count, bounds(), compatible, is_safe, rtree()));
@@ -129,7 +136,7 @@ void DisplayListBuilder::onSetStrokeJoin(DlStrokeJoin join) {
   current_.setStrokeJoin(join);
   Push<SetStrokeJoinOp>(0, 0, join);
 }
-void DisplayListBuilder::onSetStyle(DlDrawStyle style) {
+void DisplayListBuilder::onSetDrawStyle(DlDrawStyle style) {
   current_.setDrawStyle(style);
   Push<SetStyleOp>(0, 0, style);
 }
@@ -346,7 +353,7 @@ void DisplayListBuilder::SetAttributesFromPaint(
     setBlendMode(paint.getBlendMode());
   }
   if (flags.applies_style()) {
-    setStyle(paint.getDrawStyle());
+    setDrawStyle(paint.getDrawStyle());
   }
   if (flags.is_stroked(paint.getDrawStyle())) {
     setStrokeWidth(paint.getStrokeWidth());

display_list/dl_builder.h

@@ -247,6 +247,8 @@ class DisplayListBuilder final : public virtual DlCanvas,
       DisplayListBuilder& builder);
   friend DlOpReceiver& DisplayListBuilderTestingAccessor(
       DisplayListBuilder& builder);
+  friend DlPaint DisplayListBuilderTestingAttributes(
+      DisplayListBuilder& builder);
 
   void SetAttributesFromPaint(const DlPaint& paint,
                               const DisplayListAttributeFlags flags);
@@ -282,9 +284,9 @@ class DisplayListBuilder final : public virtual DlCanvas,
     }
   }
   // |DlOpReceiver|
-  void setStyle(DlDrawStyle style) override {
+  void setDrawStyle(DlDrawStyle style) override {
     if (current_.getDrawStyle() != style) {
-      onSetStyle(style);
+      onSetDrawStyle(style);
     }
   }
   // |DlOpReceiver|
@@ -342,6 +344,8 @@ class DisplayListBuilder final : public virtual DlCanvas,
     }
   }
 
+  DlPaint CurrentAttributes() const { return current_; }
+
   // |DlOpReceiver|
   void save() override { Save(); }
   // Only the |renders_with_attributes()| option will be accepted here. Any
@@ -654,7 +658,7 @@ class DisplayListBuilder final : public virtual DlCanvas,
   void onSetInvertColors(bool invert);
   void onSetStrokeCap(DlStrokeCap cap);
   void onSetStrokeJoin(DlStrokeJoin join);
-  void onSetStyle(DlDrawStyle style);
+  void onSetDrawStyle(DlDrawStyle style);
   void onSetStrokeWidth(SkScalar width);
   void onSetStrokeMiter(SkScalar limit);
   void onSetColor(DlColor color);

display_list/dl_op_receiver.h

@@ -45,7 +45,7 @@ class DlOpReceiver {
   // attributes is not affected by |save| and |restore|.
   virtual void setAntiAlias(bool aa) = 0;
   virtual void setDither(bool dither) = 0;
-  virtual void setStyle(DlDrawStyle style) = 0;
+  virtual void setDrawStyle(DlDrawStyle style) = 0;
   virtual void setColor(DlColor color) = 0;
   virtual void setStrokeWidth(float width) = 0;
   virtual void setStrokeMiter(float limit) = 0;

display_list/dl_op_records.h

@@ -145,7 +145,9 @@ struct SetStyleOp final : DLOp {
 
   const DlDrawStyle style;
 
-  void dispatch(DispatchContext& ctx) const { ctx.receiver.setStyle(style); }
+  void dispatch(DispatchContext& ctx) const {
+    ctx.receiver.setDrawStyle(style);
+  }
 };
 // 4 byte header + 4 byte payload packs into minimum 8 bytes
 struct SetStrokeWidthOp final : DLOp {

display_list/dl_paint.cc

@@ -32,7 +32,8 @@ bool DlPaint::operator==(DlPaint const& other) const {
          Equals(colorSource_, other.colorSource_) &&  //
          Equals(colorFilter_, other.colorFilter_) &&  //
          Equals(imageFilter_, other.imageFilter_) &&  //
-         Equals(maskFilter_, other.maskFilter_);
+         Equals(maskFilter_, other.maskFilter_) &&    //
+         Equals(pathEffect_, other.pathEffect_);
 }
 
 const DlPaint DlPaint::kDefault;