Improve getting non-overlapping rectangles from RTree

BUILD.gn

@@ -116,6 +116,7 @@ group("flutter") {
     public_deps += [
       "//flutter/display_list:display_list_benchmarks",
       "//flutter/display_list:display_list_builder_benchmarks",
+      "//flutter/display_list:display_list_region_benchmarks",
       "//flutter/fml:fml_benchmarks",
       "//flutter/impeller/geometry:geometry_benchmarks",
       "//flutter/lib/ui:ui_benchmarks",

ci/licenses_golden/excluded_files

@@ -39,6 +39,7 @@
 ../../../flutter/display_list/effects/dl_image_filter_unittests.cc
 ../../../flutter/display_list/effects/dl_mask_filter_unittests.cc
 ../../../flutter/display_list/effects/dl_path_effect_unittests.cc
+../../../flutter/display_list/geometry/dl_region_unittests.cc
 ../../../flutter/display_list/geometry/dl_rtree_unittests.cc
 ../../../flutter/display_list/skia/dl_sk_conversions_unittests.cc
 ../../../flutter/display_list/skia/dl_sk_paint_dispatcher_unittests.cc

ci/licenses_golden/licenses_flutter

@@ -714,6 +714,7 @@ ORIGIN: ../../../flutter/display_list/benchmarking/dl_complexity_gl.h + ../../..
 ORIGIN: ../../../flutter/display_list/benchmarking/dl_complexity_helper.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/display_list/benchmarking/dl_complexity_metal.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/display_list/benchmarking/dl_complexity_metal.h + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/display_list/benchmarking/dl_region_benchmarks.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/display_list/display_list.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/display_list/display_list.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/display_list/dl_attributes.h + ../../../flutter/LICENSE
@@ -748,6 +749,8 @@ ORIGIN: ../../../flutter/display_list/effects/dl_path_effect.cc + ../../../flutt
 ORIGIN: ../../../flutter/display_list/effects/dl_path_effect.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/display_list/effects/dl_runtime_effect.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/display_list/effects/dl_runtime_effect.h + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/display_list/geometry/dl_region.cc + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/display_list/geometry/dl_region.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/display_list/geometry/dl_rtree.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/display_list/geometry/dl_rtree.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/display_list/image/dl_image.cc + ../../../flutter/LICENSE
@@ -3380,6 +3383,7 @@ FILE: ../../../flutter/display_list/benchmarking/dl_complexity_gl.h
 FILE: ../../../flutter/display_list/benchmarking/dl_complexity_helper.h
 FILE: ../../../flutter/display_list/benchmarking/dl_complexity_metal.cc
 FILE: ../../../flutter/display_list/benchmarking/dl_complexity_metal.h
+FILE: ../../../flutter/display_list/benchmarking/dl_region_benchmarks.cc
 FILE: ../../../flutter/display_list/display_list.cc
 FILE: ../../../flutter/display_list/display_list.h
 FILE: ../../../flutter/display_list/dl_attributes.h
@@ -3414,6 +3418,8 @@ FILE: ../../../flutter/display_list/effects/dl_path_effect.cc
 FILE: ../../../flutter/display_list/effects/dl_path_effect.h
 FILE: ../../../flutter/display_list/effects/dl_runtime_effect.cc
 FILE: ../../../flutter/display_list/effects/dl_runtime_effect.h
+FILE: ../../../flutter/display_list/geometry/dl_region.cc
+FILE: ../../../flutter/display_list/geometry/dl_region.h
 FILE: ../../../flutter/display_list/geometry/dl_rtree.cc
 FILE: ../../../flutter/display_list/geometry/dl_rtree.h
 FILE: ../../../flutter/display_list/image/dl_image.cc

display_list/BUILD.gn

@@ -57,6 +57,8 @@ source_set("display_list") {
     "effects/dl_path_effect.h",
     "effects/dl_runtime_effect.cc",
     "effects/dl_runtime_effect.h",
+    "geometry/dl_region.cc",
+    "geometry/dl_region.h",
     "geometry/dl_rtree.cc",
     "geometry/dl_rtree.h",
     "image/dl_image.cc",
@@ -112,6 +114,7 @@ if (enable_unittests) {
       "effects/dl_image_filter_unittests.cc",
       "effects/dl_mask_filter_unittests.cc",
       "effects/dl_path_effect_unittests.cc",
+      "geometry/dl_region_unittests.cc",
       "geometry/dl_rtree_unittests.cc",
       "skia/dl_sk_conversions_unittests.cc",
       "skia/dl_sk_paint_dispatcher_unittests.cc",
@@ -182,6 +185,18 @@ if (enable_unittests) {
       "//flutter/testing:testing_lib",
     ]
   }
+
+  executable("display_list_region_benchmarks") {
+    testonly = true
+
+    sources = [ "benchmarking/dl_region_benchmarks.cc" ]
+
+    deps = [
+      ":display_list_fixtures",
+      "//flutter/benchmarking",
+      "//flutter/testing:testing_lib",
+    ]
+  }
 }
 
 fixtures_location("display_list_benchmarks_fixtures") {

display_list/benchmarking/dl_region_benchmarks.cc

@@ -0,0 +1,92 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "flutter/benchmarking/benchmarking.h"
+
+#include "flutter/display_list/geometry/dl_region.h"
+#include "third_party/skia/include/core/SkRegion.h"
+
+#include <random>
+
+class SkRegionAdapter {
+ public:
+  void addRect(const SkIRect& rect) { region_.op(rect, SkRegion::kUnion_Op); }
+
+  std::vector<SkIRect> getRects() {
+    std::vector<SkIRect> rects;
+    SkRegion::Iterator it(region_);
+    while (!it.done()) {
+      rects.push_back(it.rect());
+      it.next();
+    }
+    return rects;
+  }
+
+ private:
+  SkRegion region_;
+};
+
+class DlRegionAdapter {
+ public:
+  void addRect(const SkIRect& rect) { rects_.push_back(rect); }
+
+  std::vector<SkIRect> getRects() {
+    flutter::DlRegion region(std::move(rects_));
+    return region.getRects(false);
+  }
+
+ private:
+  std::vector<SkIRect> rects_;
+};
+
+template <typename Region>
+void RunRegionBenchmark(benchmark::State& state, int maxSize) {
+  while (state.KeepRunning()) {
+    std::random_device d;
+    std::seed_seq seed{2, 1, 3};
+    std::mt19937 rng(seed);
+
+    std::uniform_int_distribution pos(0, 4000);
+    std::uniform_int_distribution size(1, maxSize);
+
+    Region region;
+
+    for (int i = 0; i < 2000; ++i) {
+      SkIRect rect =
+          SkIRect::MakeXYWH(pos(rng), pos(rng), size(rng), size(rng));
+      region.addRect(rect);
+    }
+
+    auto vec2 = region.getRects();
+  }
+}
+
+namespace flutter {
+
+static void BM_RegionBenchmarkSkRegion(benchmark::State& state, int maxSize) {
+  RunRegionBenchmark<SkRegionAdapter>(state, maxSize);
+}
+
+static void BM_RegionBenchmarkDlRegion(benchmark::State& state, int maxSize) {
+  RunRegionBenchmark<DlRegionAdapter>(state, maxSize);
+}
+
+BENCHMARK_CAPTURE(BM_RegionBenchmarkDlRegion, Tiny, 30)
+    ->Unit(benchmark::kMicrosecond);
+BENCHMARK_CAPTURE(BM_RegionBenchmarkSkRegion, Tiny, 30)
+    ->Unit(benchmark::kMicrosecond);
+BENCHMARK_CAPTURE(BM_RegionBenchmarkDlRegion, Small, 100)
+    ->Unit(benchmark::kMicrosecond);
+BENCHMARK_CAPTURE(BM_RegionBenchmarkSkRegion, Small, 100)
+    ->Unit(benchmark::kMicrosecond);
+BENCHMARK_CAPTURE(BM_RegionBenchmarkDlRegion, Medium, 400)
+    ->Unit(benchmark::kMicrosecond);
+BENCHMARK_CAPTURE(BM_RegionBenchmarkSkRegion, Medium, 400)
+    ->Unit(benchmark::kMicrosecond);
+BENCHMARK_CAPTURE(BM_RegionBenchmarkDlRegion, Large, 1500)
+    ->Unit(benchmark::kMicrosecond);
+BENCHMARK_CAPTURE(BM_RegionBenchmarkSkRegion, Large, 1500)
+    ->Unit(benchmark::kMicrosecond);
+
+}  // namespace flutter

display_list/dl_builder.cc

@@ -1106,7 +1106,8 @@ void DisplayListBuilder::DrawDisplayList(const sk_sp<DisplayList> display_list,
     case BoundsAccumulatorType::kRTree:
       auto rtree = display_list->rtree();
       if (rtree) {
-        std::list<SkRect> rects = rtree->searchAndConsolidateRects(bounds);
+        std::list<SkRect> rects =
+            rtree->searchAndConsolidateRects(bounds, false);
         for (const SkRect& rect : rects) {
           // TODO (https://github.com/flutter/flutter/issues/114919): Attributes
           // are not necessarily `kDrawDisplayListFlags`.