[Impeller] Use direct tessellation geometry for simple clip shapes (f…

…lutter#48959)

This work leverages the recent work to directly tessellate the simple primitives for rendering and uses their geometry classes for equivalent clip primitives.

impeller/aiks/aiks_unittests.cc

@@ -318,6 +318,74 @@ TEST_P(AiksTest, CanRenderClips) {
   ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
 }
 
+TEST_P(AiksTest, CanRenderSimpleClips) {
+  Canvas canvas;
+  canvas.Scale(GetContentScale());
+  Paint paint;
+
+  paint.color = Color::White();
+  canvas.DrawPaint(paint);
+
+  auto draw = [&canvas](const Paint& paint, Scalar x, Scalar y) {
+    canvas.Save();
+    canvas.Translate({x, y});
+    {
+      canvas.Save();
+      canvas.ClipRect(Rect::MakeLTRB(50, 50, 150, 150));
+      canvas.DrawPaint(paint);
+      canvas.Restore();
+    }
+    {
+      canvas.Save();
+      canvas.ClipOval(Rect::MakeLTRB(200, 50, 300, 150));
+      canvas.DrawPaint(paint);
+      canvas.Restore();
+    }
+    {
+      canvas.Save();
+      canvas.ClipRRect(Rect::MakeLTRB(50, 200, 150, 300), {20, 20});
+      canvas.DrawPaint(paint);
+      canvas.Restore();
+    }
+    canvas.Restore();
+  };
+
+  paint.color = Color::Blue();
+  draw(paint, 0, 0);
+
+  std::vector<Color> gradient_colors = {
+      Color{0x1f / 255.0, 0.0, 0x5c / 255.0, 1.0},
+      Color{0x5b / 255.0, 0.0, 0x60 / 255.0, 1.0},
+      Color{0x87 / 255.0, 0x01 / 255.0, 0x60 / 255.0, 1.0},
+      Color{0xac / 255.0, 0x25 / 255.0, 0x53 / 255.0, 1.0},
+      Color{0xe1 / 255.0, 0x6b / 255.0, 0x5c / 255.0, 1.0},
+      Color{0xf3 / 255.0, 0x90 / 255.0, 0x60 / 255.0, 1.0},
+      Color{0xff / 255.0, 0xb5 / 255.0, 0x6b / 250.0, 1.0}};
+  std::vector<Scalar> stops = {
+      0.0,
+      (1.0 / 6.0) * 1,
+      (1.0 / 6.0) * 2,
+      (1.0 / 6.0) * 3,
+      (1.0 / 6.0) * 4,
+      (1.0 / 6.0) * 5,
+      1.0,
+  };
+  auto texture = CreateTextureForFixture("airplane.jpg",
+                                         /*enable_mipmapping=*/true);
+
+  paint.color_source = ColorSource::MakeRadialGradient(
+      {500, 600}, 75, std::move(gradient_colors), std::move(stops),
+      Entity::TileMode::kMirror, {});
+  draw(paint, 0, 300);
+
+  paint.color_source = ColorSource::MakeImage(
+      texture, Entity::TileMode::kRepeat, Entity::TileMode::kRepeat, {},
+      Matrix::MakeTranslation({0, 0}));
+  draw(paint, 300, 0);
+
+  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
+}
+
 TEST_P(AiksTest, CanRenderNestedClips) {
   Canvas canvas;
   Paint paint;

impeller/aiks/canvas.cc

@@ -448,23 +448,34 @@ void Canvas::ClipRect(const Rect& rect, Entity::ClipOperation clip_op) {
   }
 }
 
+void Canvas::ClipOval(const Rect& bounds, Entity::ClipOperation clip_op) {
+  auto geometry = Geometry::MakeOval(bounds);
+  auto& cull_rect = transform_stack_.back().cull_rect;
+  if (clip_op == Entity::ClipOperation::kIntersect &&                      //
+      cull_rect.has_value() &&                                             //
+      geometry->CoversArea(transform_stack_.back().transform, *cull_rect)  //
+  ) {
+    return;  // This clip will do nothing, so skip it.
+  }
+
+  ClipGeometry(geometry, clip_op);
+  switch (clip_op) {
+    case Entity::ClipOperation::kIntersect:
+      IntersectCulling(bounds);
+      break;
+    case Entity::ClipOperation::kDifference:
+      break;
+  }
+}
+
 void Canvas::ClipRRect(const Rect& rect,
                        const Size& corner_radii,
                        Entity::ClipOperation clip_op) {
-  auto path = PathBuilder{}
-                  .SetConvexity(Convexity::kConvex)
-                  .AddRoundedRect(rect, corner_radii)
-                  .SetBounds(rect)
-                  .TakePath();
-
   auto size = rect.GetSize();
   // Does the rounded rect have a flat part on the top/bottom or left/right?
   bool flat_on_TB = corner_radii.width * 2 < size.width;
   bool flat_on_LR = corner_radii.height * 2 < size.height;
-  std::optional<Rect> inner_rect = (flat_on_LR && flat_on_TB)
-                                       ? rect.Expand(-corner_radii)
-                                       : std::make_optional<Rect>();
-  auto geometry = Geometry::MakeFillPath(std::move(path), inner_rect);
+  auto geometry = Geometry::MakeRoundRect(rect, corner_radii);
   auto& cull_rect = transform_stack_.back().cull_rect;
   if (clip_op == Entity::ClipOperation::kIntersect &&                      //
       cull_rect.has_value() &&                                             //

impeller/aiks/canvas.h

@@ -137,6 +137,10 @@ class Canvas {
       const Rect& rect,
       Entity::ClipOperation clip_op = Entity::ClipOperation::kIntersect);
 
+  void ClipOval(
+      const Rect& bounds,
+      Entity::ClipOperation clip_op = Entity::ClipOperation::kIntersect);
+
   void ClipRRect(
       const Rect& rect,
       const Size& corner_radii,

impeller/display_list/dl_dispatcher.cc

@@ -725,22 +725,40 @@ void DlDispatcher::clipRect(const SkRect& rect, ClipOp clip_op, bool is_aa) {
 }
 
 // |flutter::DlOpReceiver|
-void DlDispatcher::clipRRect(const SkRRect& rrect, ClipOp clip_op, bool is_aa) {
+void DlDispatcher::clipRRect(const SkRRect& rrect, ClipOp sk_op, bool is_aa) {
+  auto clip_op = ToClipOperation(sk_op);
   if (rrect.isRect()) {
-    canvas_.ClipRect(skia_conversions::ToRect(rrect.rect()),
-                     ToClipOperation(clip_op));
+    canvas_.ClipRect(skia_conversions::ToRect(rrect.rect()), clip_op);
+  } else if (rrect.isOval()) {
+    canvas_.ClipOval(skia_conversions::ToRect(rrect.rect()), clip_op);
   } else if (rrect.isSimple()) {
     canvas_.ClipRRect(skia_conversions::ToRect(rrect.rect()),
                       skia_conversions::ToSize(rrect.getSimpleRadii()),
-                      ToClipOperation(clip_op));
+                      clip_op);
   } else {
-    canvas_.ClipPath(skia_conversions::ToPath(rrect), ToClipOperation(clip_op));
+    canvas_.ClipPath(skia_conversions::ToPath(rrect), clip_op);
   }
 }
 
 // |flutter::DlOpReceiver|
-void DlDispatcher::clipPath(const SkPath& path, ClipOp clip_op, bool is_aa) {
-  canvas_.ClipPath(skia_conversions::ToPath(path), ToClipOperation(clip_op));
+void DlDispatcher::clipPath(const SkPath& path, ClipOp sk_op, bool is_aa) {
+  auto clip_op = ToClipOperation(sk_op);
+
+  SkRect rect;
+  if (path.isRect(&rect)) {
+    canvas_.ClipRect(skia_conversions::ToRect(rect), clip_op);
+  } else if (path.isOval(&rect)) {
+    canvas_.ClipOval(skia_conversions::ToRect(rect), clip_op);
+  } else {
+    SkRRect rrect;
+    if (path.isRRect(&rrect) && rrect.isSimple()) {
+      canvas_.ClipRRect(skia_conversions::ToRect(rrect.rect()),
+                        skia_conversions::ToSize(rrect.getSimpleRadii()),
+                        clip_op);
+    } else {
+      canvas_.ClipPath(skia_conversions::ToPath(path), clip_op);
+    }
+  }
 }
 
 // |flutter::DlOpReceiver|