++

Author: jonahwilliams

impeller/aiks/experimental_canvas.cc

@@ -785,9 +785,7 @@ void ExperimentalCanvas::AddClipEntityToCurrentPass(Entity entity) {
 
   // Skip rendering the clip if it is fully contained by the current render
   // target.
-  const std::shared_ptr<ClipContents>& clip_contents =
-      std::static_pointer_cast<ClipContents>(entity.GetContents());
-  if (clip_contents->CanSkip(
+  if (entity.GetContents()->CanSkip(
           render_passes_.back().inline_pass_context->GetTexture()->GetSize(),
           entity.GetTransform())) {
     return;

impeller/entity/contents/clip_contents.h

@@ -25,7 +25,7 @@ class ClipContents final : public Contents {
 
   void SetClipOperation(Entity::ClipOperation clip_op);
 
-  bool CanSkip(ISize render_pass_size, const Matrix& ctm) const;
+  bool CanSkip(ISize render_pass_size, const Matrix& transform) const override;
 
   // |Contents|
   std::optional<Rect> GetCoverage(const Entity& entity) const override;

impeller/entity/contents/contents.cc

@@ -182,4 +182,8 @@ void Contents::SetColorSourceSize(Size size) {
   color_source_size_ = size;
 }
 
+bool Contents::CanSkip(ISize render_pass_size, const Matrix& transform) const {
+  return false;
+}
+
 }  // namespace impeller

impeller/entity/contents/contents.h

@@ -83,6 +83,13 @@ class Contents {
   ///
   void SetCoverageHint(std::optional<Rect> coverage_hint);
 
+  //----------------------------------------------------------------------------
+  /// @brief  Whether this entity can be entirely skipped during rendering.
+  ///
+  /// TODO(jonahwilliams): remove this method which was only added for clipping
+  /// once experimental canvas lands.
+  virtual bool CanSkip(ISize render_pass_size, const Matrix& transform) const;
+
   const std::optional<Rect>& GetCoverageHint() const;
 
   //----------------------------------------------------------------------------

impeller/entity/entity_unittests.cc

@@ -1532,6 +1532,35 @@ TEST_P(EntityTest, ClipContentsShouldRenderIsCorrect) {
   }
 }
 
+TEST_P(EntityTest, ClipContentsCanSkip) {
+  // Intersect Clips can be skipped if the render target coverage is fully
+  // inside of them.
+
+  auto clip = std::make_shared<ClipContents>();
+  clip->SetGeometry(Geometry::MakeRect(Rect::MakeLTRB(0, 0, 100, 100)));
+  clip->SetClipOperation(Entity::ClipOperation::kIntersect);
+
+  // Fully Contained
+  EXPECT_TRUE(clip->CanSkip(ISize::MakeWH(50, 50), {}));
+
+  // Not Intersect
+  clip->SetClipOperation(Entity::ClipOperation::kDifference);
+  EXPECT_FALSE(clip->CanSkip(ISize::MakeWH(50, 50), {}));
+
+  // Not Contained
+  clip->SetClipOperation(Entity::ClipOperation::kIntersect);
+  EXPECT_FALSE(clip->CanSkip(ISize::MakeWH(200, 200), {}));
+
+  // Not Scale Translate
+  clip->SetClipOperation(Entity::ClipOperation::kIntersect);
+  EXPECT_FALSE(
+      clip->CanSkip(ISize::MakeWH(50, 50), Matrix::MakeRotationX(Radians(2))));
+
+  // Not Axis Aligned Rectangle.
+  clip->SetGeometry(Geometry::MakeOval(Rect::MakeLTRB(0, 0, 50, 50)));
+  EXPECT_FALSE(clip->CanSkip(ISize::MakeWH(50, 50), {}));
+}
+
 TEST_P(EntityTest, ClipContentsGetClipCoverageIsCorrect) {
   // Intersection: No stencil coverage, no geometry.
   {