[Impeller] generate stroke vertices into point arena.

impeller/entity/entity_unittests.cc

@@ -2364,6 +2364,45 @@ APPLY_COLOR_FILTER_GRADIENT_TEST(Radial);
 APPLY_COLOR_FILTER_GRADIENT_TEST(Conical);
 APPLY_COLOR_FILTER_GRADIENT_TEST(Sweep);
 
+TEST_P(EntityTest, GiantStrokePathAllocation) {
+  PathBuilder builder{};
+  for (int i = 0; i < 10000; i++) {
+    builder.LineTo(Point(i, i));
+  }
+  Path path = builder.TakePath();
+  auto geom = Geometry::MakeStrokePath(path, /*stroke_width=*/10);
+
+  ContentContext content_context(GetContext(), nullptr);
+  Entity entity;
+
+  auto cmd_buffer = content_context.GetContext()->CreateCommandBuffer();
+
+  RenderTargetAllocator allocator(
+      content_context.GetContext()->GetResourceAllocator());
+
+  auto render_target =
+      allocator.CreateOffscreen(*content_context.GetContext(), {10, 10}, 1);
+  auto pass = cmd_buffer->CreateRenderPass(render_target);
+
+  GeometryResult result =
+      geom->GetPositionBuffer(content_context, entity, *pass);
+
+  // Validate the buffer data overflowed the small buffer
+  EXPECT_GT(result.vertex_buffer.vertex_count, kPointArenaSize);
+
+  // Validate that there are no uninitialized points near the gap.
+  Point* written_data = reinterpret_cast<Point*>(
+      (result.vertex_buffer.vertex_buffer.GetBuffer()->OnGetContents() +
+       result.vertex_buffer.vertex_buffer.GetRange().offset));
+
+  EXPECT_NE(*(written_data + kPointArenaSize - 2), Point(0, 0));
+  EXPECT_NE(*(written_data + kPointArenaSize - 1), Point(0, 0));
+  EXPECT_NE(*(written_data + kPointArenaSize), Point(0, 0));
+  EXPECT_NE(*(written_data + kPointArenaSize + 1), Point(0, 0));
+  EXPECT_NE(*(written_data + kPointArenaSize + 2), Point(0, 0));
+  EXPECT_NE(*(written_data + kPointArenaSize + 3), Point(0, 0));
+}
+
 }  // namespace testing
 }  // namespace impeller
 

impeller/entity/geometry/geometry_unittests.cc

@@ -14,13 +14,13 @@
 #include "impeller/renderer/testing/mocks.h"
 
 inline ::testing::AssertionResult SolidVerticesNear(
-    std::vector<impeller::SolidFillVertexShader::PerVertexData> a,
-    std::vector<impeller::SolidFillVertexShader::PerVertexData> b) {
+    std::vector<impeller::Point> a,
+    std::vector<impeller::Point> b) {
   if (a.size() != b.size()) {
     return ::testing::AssertionFailure() << "Colors length does not match";
   }
   for (auto i = 0u; i < b.size(); i++) {
-    if (!PointNear(a[i].position, b[i].position)) {
+    if (!PointNear(a[i], b[i])) {
       return ::testing::AssertionFailure() << "Positions are not equal.";
     }
   }
@@ -53,13 +53,13 @@ namespace impeller {
 
 class ImpellerEntityUnitTestAccessor {
  public:
-  static std::vector<SolidFillVertexShader::PerVertexData>
-  GenerateSolidStrokeVertices(const Path::Polyline& polyline,
-                              Scalar stroke_width,
-                              Scalar miter_limit,
-                              Join stroke_join,
-                              Cap stroke_cap,
-                              Scalar scale) {
+  static std::vector<Point> GenerateSolidStrokeVertices(
+      const Path::Polyline& polyline,
+      Scalar stroke_width,
+      Scalar miter_limit,
+      Join stroke_join,
+      Cap stroke_cap,
+      Scalar scale) {
     return StrokePathGeometry::GenerateSolidStrokeVertices(
         polyline, stroke_width, miter_limit, stroke_join, stroke_cap, scale);
   }