tessellation adjustments.

Author: jonahwilliams

impeller/display_list/aiks_dl_unittests.cc

@@ -467,6 +467,7 @@ TEST_P(AiksTest, CanDrawPointsWithTextureMap) {
   ASSERT_TRUE(OpenPlaygroundHere(builder.Build()));
 }
 
+// Regression test for flutter/flutter#152780
 TEST_P(AiksTest, CanDrawScaledPointsLargeScaleSmallRadius) {
   std::vector<SkPoint> point = {
       {0, 0},  //
@@ -487,6 +488,7 @@ TEST_P(AiksTest, CanDrawScaledPointsLargeScaleSmallRadius) {
   ASSERT_TRUE(OpenPlaygroundHere(builder.Build()));
 }
 
+// Regression test for flutter/flutter#152780
 TEST_P(AiksTest, CanDrawScaledPointsSmallScaleLargeRadius) {
   std::vector<SkPoint> point = {
       {0, 0},  //

impeller/entity/geometry/point_field_geometry.cc

@@ -38,7 +38,7 @@ GeometryResult PointFieldGeometry::GetPositionBuffer(
     // point in turn. Note: we intentionally used the original radius here
     // to capture any scaling < 1.0.
     auto generator =
-        renderer.GetTessellator()->FilledCircle(transform, {}, radius_);
+        renderer.GetTessellator()->FilledCircle(transform, {}, radius_, radius);
     FML_DCHECK(generator.GetTriangleType() == PrimitiveType::kTriangleStrip);
     std::vector<Point> circle_vertices;
     circle_vertices.reserve(generator.GetVertexCount());

impeller/tessellator/tessellator.cc

@@ -237,9 +237,10 @@ EllipticalVertexGenerator::EllipticalVertexGenerator(
 EllipticalVertexGenerator Tessellator::FilledCircle(
     const Matrix& view_transform,
     const Point& center,
+    Scalar raw_radius,
     Scalar radius) {
-  size_t divisions =
-      ComputeQuadrantDivisions(view_transform.GetMaxBasisLengthXY() * radius);
+  size_t divisions = ComputeQuadrantDivisions(
+      view_transform.GetMaxBasisLengthXY() * raw_radius);
   return EllipticalVertexGenerator(Tessellator::GenerateFilledCircle,
                                    GetTrigsForDivisions(divisions),
                                    PrimitiveType::kTriangleStrip, 4,
@@ -267,7 +268,7 @@ EllipticalVertexGenerator Tessellator::StrokedCircle(
                                          .half_width = half_width,
                                      });
   } else {
-    return FilledCircle(view_transform, center, radius);
+    return FilledCircle(view_transform, center, radius, radius);
   }
 }
 
@@ -290,7 +291,7 @@ EllipticalVertexGenerator Tessellator::RoundCapLine(
                                          .half_width = -1.0f,
                                      });
   } else {
-    return FilledCircle(view_transform, p0, radius);
+    return FilledCircle(view_transform, p0, radius, radius);
   }
 }
 
@@ -299,7 +300,7 @@ EllipticalVertexGenerator Tessellator::FilledEllipse(
     const Rect& bounds) {
   if (bounds.IsSquare()) {
     return FilledCircle(view_transform, bounds.GetCenter(),
-                        bounds.GetWidth() * 0.5f);
+                        bounds.GetWidth() * 0.5f, bounds.GetWidth() * 0.5f);
   }
   auto max_radius = bounds.GetSize().MaxDimension();
   auto divisions = ComputeQuadrantDivisions(

impeller/tessellator/tessellator.h

@@ -222,8 +222,12 @@ class Tessellator {
   ///          number of sample points to use per quarter circle and the
   ///          returned points are not transformed by it, instead they are
   ///          relative to the coordinate space of the center point.
+  ///
+  ///          The `raw_radius` should be untransformed and unclamped, while
+  ///          `radius` may be rounded up to a minimal pixel size.
   EllipticalVertexGenerator FilledCircle(const Matrix& view_transform,
                                          const Point& center,
+                                         Scalar raw_radius,
                                          Scalar radius);
 
   /// @brief   Create a |VertexGenerator| that can produce vertices for

impeller/tessellator/tessellator_unittests.cc

@@ -140,7 +140,7 @@ TEST(TessellatorTest, CircleVertexCounts) {
   auto tessellator = std::make_shared<Tessellator>();
 
   auto test = [&tessellator](const Matrix& transform, Scalar radius) {
-    auto generator = tessellator->FilledCircle(transform, {}, radius);
+    auto generator = tessellator->FilledCircle(transform, {}, radius, radius);
     size_t quadrant_divisions = generator.GetVertexCount() / 4;
 
     // Confirm the approximation error is within the currently accepted
@@ -177,7 +177,8 @@ TEST(TessellatorTest, FilledCircleTessellationVertices) {
 
   auto test = [&tessellator](const Matrix& transform, const Point& center,
                              Scalar radius) {
-    auto generator = tessellator->FilledCircle(transform, center, radius);
+    auto generator =
+        tessellator->FilledCircle(transform, center, radius, radius);
     EXPECT_EQ(generator.GetTriangleType(), PrimitiveType::kTriangleStrip);
 
     auto vertex_count = generator.GetVertexCount();

testing/impeller_golden_tests_output.txt

@@ -218,6 +218,12 @@ impeller_Play_AiksTest_CanDrawPointsWithTextureMap_Vulkan.png
 impeller_Play_AiksTest_CanDrawPoints_Metal.png
 impeller_Play_AiksTest_CanDrawPoints_OpenGLES.png
 impeller_Play_AiksTest_CanDrawPoints_Vulkan.png
+impeller_Play_AiksTest_CanDrawScaledPointsLargeScaleSmallRadius_Metal.png
+impeller_Play_AiksTest_CanDrawScaledPointsLargeScaleSmallRadius_OpenGLES.png
+impeller_Play_AiksTest_CanDrawScaledPointsLargeScaleSmallRadius_Vulkan.png
+impeller_Play_AiksTest_CanDrawScaledPointsSmallScaleLargeRadius_Metal.png
+impeller_Play_AiksTest_CanDrawScaledPointsSmallScaleLargeRadius_OpenGLES.png
+impeller_Play_AiksTest_CanDrawScaledPointsSmallScaleLargeRadius_Vulkan.png
 impeller_Play_AiksTest_CanEmptyPictureConvertToImage_Metal.png
 impeller_Play_AiksTest_CanEmptyPictureConvertToImage_OpenGLES.png
 impeller_Play_AiksTest_CanEmptyPictureConvertToImage_Vulkan.png