[Impeller] Remove libtess2 from libflutter.

ci/licenses_golden/licenses_flutter

@@ -40794,6 +40794,8 @@ ORIGIN: ../../../flutter/impeller/tessellator/c/tessellator.h + ../../../flutter
 ORIGIN: ../../../flutter/impeller/tessellator/dart/lib/tessellator.dart + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/tessellator/tessellator.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/tessellator/tessellator.h + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/impeller/tessellator/tessellator_libtess.cc + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/impeller/tessellator/tessellator_libtess.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/toolkit/android/choreographer.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/toolkit/android/choreographer.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/toolkit/android/hardware_buffer.cc + ../../../flutter/LICENSE
@@ -43676,6 +43678,8 @@ FILE: ../../../flutter/impeller/tessellator/c/tessellator.h
 FILE: ../../../flutter/impeller/tessellator/dart/lib/tessellator.dart
 FILE: ../../../flutter/impeller/tessellator/tessellator.cc
 FILE: ../../../flutter/impeller/tessellator/tessellator.h
+FILE: ../../../flutter/impeller/tessellator/tessellator_libtess.cc
+FILE: ../../../flutter/impeller/tessellator/tessellator_libtess.h
 FILE: ../../../flutter/impeller/toolkit/android/choreographer.cc
 FILE: ../../../flutter/impeller/toolkit/android/choreographer.h
 FILE: ../../../flutter/impeller/toolkit/android/hardware_buffer.cc

impeller/geometry/BUILD.gn

@@ -87,7 +87,7 @@ executable("geometry_benchmarks") {
   deps = [
     ":geometry",
     "../entity",
-    "../tessellator",
+    "../tessellator:tessellator_libtess",
     "//flutter/benchmarking",
   ]
 }

impeller/geometry/geometry_benchmarks.cc

@@ -10,6 +10,7 @@
 #include "impeller/geometry/path.h"
 #include "impeller/geometry/path_builder.h"
 #include "impeller/tessellator/tessellator.h"
+#include "impeller/tessellator/tessellator_libtess.h"
 
 namespace impeller {
 
@@ -37,7 +38,7 @@ Path CreateQuadratic(bool closed);
 Path CreateRRect();
 }  // namespace
 
-static Tessellator tess;
+static TessellatorLibtess tess;
 
 template <class... Args>
 static void BM_Polyline(benchmark::State& state, Args&&... args) {

impeller/renderer/BUILD.gn

@@ -135,6 +135,7 @@ impeller_component("renderer_unittests") {
     ":renderer",
     "../fixtures",
     "../playground:playground_test",
+    "../tessellator:tessellator_libtess",
     "//flutter/testing:testing_lib",
   ]
 

impeller/renderer/renderer_unittests.cc

@@ -24,21 +24,18 @@
 #include "impeller/fixtures/sepia.frag.h"
 #include "impeller/fixtures/sepia.vert.h"
 #include "impeller/fixtures/swizzle.frag.h"
-#include "impeller/fixtures/test_texture.frag.h"
-#include "impeller/fixtures/test_texture.vert.h"
 #include "impeller/fixtures/texture.frag.h"
 #include "impeller/fixtures/texture.vert.h"
 #include "impeller/geometry/path_builder.h"
 #include "impeller/playground/playground_test.h"
-#include "impeller/renderer/command.h"
 #include "impeller/renderer/command_buffer.h"
 #include "impeller/renderer/pipeline_builder.h"
 #include "impeller/renderer/pipeline_library.h"
 #include "impeller/renderer/render_pass.h"
 #include "impeller/renderer/render_target.h"
 #include "impeller/renderer/renderer.h"
 #include "impeller/renderer/vertex_buffer_builder.h"
-#include "impeller/tessellator/tessellator.h"
+#include "impeller/tessellator/tessellator_libtess.h"
 #include "third_party/imgui/imgui.h"
 
 // TODO(zanderso): https://github.com/flutter/flutter/issues/127701
@@ -394,7 +391,7 @@ TEST_P(RendererTest, CanRenderInstanced) {
   VertexBufferBuilder<VS::PerVertexData> builder;
 
   ASSERT_EQ(Tessellator::Result::kSuccess,
-            Tessellator{}.Tessellate(
+            TessellatorLibtess{}.Tessellate(
                 PathBuilder{}
                     .AddRect(Rect::MakeXYWH(10, 10, 100, 100))
                     .TakePath(FillType::kOdd),

impeller/tessellator/BUILD.gn

@@ -15,6 +15,21 @@ impeller_component("tessellator") {
   deps = [
     "../core",
     "//flutter/fml",
+  ]
+}
+
+impeller_component("tessellator_libtess") {
+  sources = [
+    "tessellator_libtess.cc",
+    "tessellator_libtess.h",
+  ]
+
+  public_deps = [ "../geometry" ]
+
+  deps = [
+    ":tessellator",
+    "../core",
+    "//flutter/fml",
     "//third_party/libtess2",
   ]
 }
@@ -30,11 +45,11 @@ impeller_component("tessellator_shared") {
   sources = [
     "c/tessellator.cc",
     "c/tessellator.h",
-    "tessellator.cc",
-    "tessellator.h",
   ]
 
   deps = [
+    ":tessellator",
+    ":tessellator_libtess",
     "../core",
     "../geometry",
     "//flutter/fml",
@@ -50,7 +65,7 @@ impeller_component("tessellator_unittests") {
   testonly = true
   sources = [ "tessellator_unittests.cc" ]
   deps = [
-    ":tessellator",
+    ":tessellator_libtess",
     "../geometry:geometry_asserts",
     "//flutter/testing",
   ]

impeller/tessellator/c/tessellator.cc

@@ -6,6 +6,8 @@
 
 #include <vector>
 
+#include "impeller/tessellator/tessellator_libtess.h"
+
 namespace impeller {
 PathBuilder* CreatePathBuilder() {
   return new PathBuilder();
@@ -42,7 +44,7 @@ struct Vertices* Tessellate(PathBuilder* builder,
                             Scalar tolerance) {
   auto path = builder->CopyPath(static_cast<FillType>(fill_type));
   std::vector<float> points;
-  if (Tessellator{}.Tessellate(
+  if (TessellatorLibtess{}.Tessellate(
           path, tolerance,
           [&points](const float* vertices, size_t vertices_count,
                     const uint16_t* indices, size_t indices_count) {

impeller/tessellator/c/tessellator.h

@@ -8,7 +8,6 @@
 #include <cstdint>
 
 #include "impeller/geometry/path_builder.h"
-#include "impeller/tessellator/tessellator.h"
 
 #ifdef _WIN32
 #define IMPELLER_API __declspec(dllexport)

impeller/tessellator/tessellator.cc

@@ -4,166 +4,15 @@
 
 #include "impeller/tessellator/tessellator.h"
 
-#include "third_party/libtess2/Include/tesselator.h"
-
 namespace impeller {
 
-static void* HeapAlloc(void* userData, unsigned int size) {
-  return malloc(size);
-}
-
-static void* HeapRealloc(void* userData, void* ptr, unsigned int size) {
-  return realloc(ptr, size);
-}
-
-static void HeapFree(void* userData, void* ptr) {
-  free(ptr);
-}
-
-// Note: these units are "number of entities" for bucket size and not in KB.
-static const TESSalloc kAlloc = {
-    HeapAlloc, HeapRealloc, HeapFree, 0, /* =userData */
-    16,                                  /* =meshEdgeBucketSize */
-    16,                                  /* =meshVertexBucketSize */
-    16,                                  /* =meshFaceBucketSize */
-    16,                                  /* =dictNodeBucketSize */
-    16,                                  /* =regionBucketSize */
-    0                                    /* =extraVertices */
-};
-
 Tessellator::Tessellator()
-    : point_buffer_(std::make_unique<std::vector<Point>>()),
-      c_tessellator_(nullptr, &DestroyTessellator) {
+    : point_buffer_(std::make_unique<std::vector<Point>>()) {
   point_buffer_->reserve(2048);
-  TESSalloc alloc = kAlloc;
-  {
-    // libTess2 copies the TESSalloc despite the non-const argument.
-    CTessellator tessellator(::tessNewTess(&alloc), &DestroyTessellator);
-    c_tessellator_ = std::move(tessellator);
-  }
 }
 
 Tessellator::~Tessellator() = default;
 
-static int ToTessWindingRule(FillType fill_type) {
-  switch (fill_type) {
-    case FillType::kOdd:
-      return TESS_WINDING_ODD;
-    case FillType::kNonZero:
-      return TESS_WINDING_NONZERO;
-  }
-  return TESS_WINDING_ODD;
-}
-
-Tessellator::Result Tessellator::Tessellate(const Path& path,
-                                            Scalar tolerance,
-                                            const BuilderCallback& callback) {
-  if (!callback) {
-    return Result::kInputError;
-  }
-
-  point_buffer_->clear();
-  auto polyline =
-      path.CreatePolyline(tolerance, std::move(point_buffer_),
-                          [this](Path::Polyline::PointBufferPtr point_buffer) {
-                            point_buffer_ = std::move(point_buffer);
-                          });
-
-  auto fill_type = path.GetFillType();
-
-  if (polyline.points->empty()) {
-    return Result::kInputError;
-  }
-
-  auto tessellator = c_tessellator_.get();
-  if (!tessellator) {
-    return Result::kTessellationError;
-  }
-
-  constexpr int kVertexSize = 2;
-  constexpr int kPolygonSize = 3;
-
-  //----------------------------------------------------------------------------
-  /// Feed contour information to the tessellator.
-  ///
-  static_assert(sizeof(Point) == 2 * sizeof(float));
-  for (size_t contour_i = 0; contour_i < polyline.contours.size();
-       contour_i++) {
-    size_t start_point_index, end_point_index;
-    std::tie(start_point_index, end_point_index) =
-        polyline.GetContourPointBounds(contour_i);
-
-    ::tessAddContour(tessellator,  // the C tessellator
-                     kVertexSize,  //
-                     polyline.points->data() + start_point_index,  //
-                     sizeof(Point),                                //
-                     end_point_index - start_point_index           //
-    );
-  }
-
-  //----------------------------------------------------------------------------
-  /// Let's tessellate.
-  ///
-  auto result = ::tessTesselate(tessellator,                   // tessellator
-                                ToTessWindingRule(fill_type),  // winding
-                                TESS_POLYGONS,                 // element type
-                                kPolygonSize,                  // polygon size
-                                kVertexSize,                   // vertex size
-                                nullptr  // normal (null is automatic)
-  );
-
-  if (result != 1) {
-    return Result::kTessellationError;
-  }
-
-  int element_item_count = tessGetElementCount(tessellator) * kPolygonSize;
-
-  // We default to using a 16bit index buffer, but in cases where we generate
-  // more tessellated data than this can contain we need to fall back to
-  // dropping the index buffer entirely. Instead code could instead switch to
-  // a uint32 index buffer, but this is done for simplicity with the other
-  // fast path above.
-  if (element_item_count < USHRT_MAX) {
-    int vertex_item_count = tessGetVertexCount(tessellator);
-    auto vertices = tessGetVertices(tessellator);
-    auto elements = tessGetElements(tessellator);
-
-    // libtess uses an int index internally due to usage of -1 as a sentinel
-    // value.
-    std::vector<uint16_t> indices(element_item_count);
-    for (int i = 0; i < element_item_count; i++) {
-      indices[i] = static_cast<uint16_t>(elements[i]);
-    }
-    if (!callback(vertices, vertex_item_count, indices.data(),
-                  element_item_count)) {
-      return Result::kInputError;
-    }
-  } else {
-    std::vector<Point> points;
-    std::vector<float> data;
-
-    int vertex_item_count = tessGetVertexCount(tessellator) * kVertexSize;
-    auto vertices = tessGetVertices(tessellator);
-    points.reserve(vertex_item_count);
-    for (int i = 0; i < vertex_item_count; i += 2) {
-      points.emplace_back(vertices[i], vertices[i + 1]);
-    }
-
-    int element_item_count = tessGetElementCount(tessellator) * kPolygonSize;
-    auto elements = tessGetElements(tessellator);
-    data.reserve(element_item_count);
-    for (int i = 0; i < element_item_count; i++) {
-      data.emplace_back(points[elements[i]].x);
-      data.emplace_back(points[elements[i]].y);
-    }
-    if (!callback(data.data(), element_item_count, nullptr, 0u)) {
-      return Result::kInputError;
-    }
-  }
-
-  return Result::kSuccess;
-}
-
 Path::Polyline Tessellator::CreateTempPolyline(const Path& path,
                                                Scalar tolerance) {
   FML_DCHECK(point_buffer_);
@@ -239,12 +88,6 @@ std::vector<Point> Tessellator::TessellateConvex(const Path& path,
   return output;
 }
 
-void DestroyTessellator(TESStesselator* tessellator) {
-  if (tessellator != nullptr) {
-    ::tessDeleteTess(tessellator);
-  }
-}
-
 static constexpr int kPrecomputedDivisionCount = 1024;
 static int kPrecomputedDivisions[kPrecomputedDivisionCount] = {
     // clang-format off