flow/layers/transform_layer_unittests.cc - mirrors/engine - Git at Google

 // 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/flow/layers/transform_layer.h"

 #include "flutter/flow/testing/diff_context_test.h"
 #include "flutter/flow/testing/layer_test.h"
 #include "flutter/flow/testing/mock_layer.h"
 #include "flutter/fml/macros.h"

 namespace flutter {
 namespace testing {

 using TransformLayerTest = LayerTest;

 #ifndef NDEBUG
 TEST_F(TransformLayerTest, PaintingEmptyLayerDies) {
   auto layer = std::make_shared<TransformLayer>(SkMatrix());  // identity

   layer->Preroll(preroll_context());
   EXPECT_EQ(layer->paint_bounds(), SkRect::MakeEmpty());
   EXPECT_EQ(layer->child_paint_bounds(), SkRect::MakeEmpty());
   EXPECT_FALSE(layer->needs_painting(paint_context()));

   EXPECT_DEATH_IF_SUPPORTED(layer->Paint(paint_context()),
                             "needs_painting\\(context\\)");
 }

 TEST_F(TransformLayerTest, PaintBeforePrerollDies) {
   SkPath child_path;
   child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
   auto mock_layer = std::make_shared<MockLayer>(child_path, DlPaint());
   auto layer = std::make_shared<TransformLayer>(SkMatrix());  // identity
   layer->Add(mock_layer);

   EXPECT_DEATH_IF_SUPPORTED(layer->Paint(paint_context()),
                             "needs_painting\\(context\\)");
 }
 #endif

 TEST_F(TransformLayerTest, Identity) {
   SkPath child_path;
   child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
   SkRect cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
   auto mock_layer = std::make_shared<MockLayer>(child_path, DlPaint());
   auto layer = std::make_shared<TransformLayer>(SkMatrix());  // identity
   layer->Add(mock_layer);

   preroll_context()->state_stack.set_preroll_delegate(cull_rect);
   layer->Preroll(preroll_context());
   EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
   EXPECT_EQ(layer->paint_bounds(), mock_layer->paint_bounds());
   EXPECT_EQ(layer->child_paint_bounds(), mock_layer->paint_bounds());
   EXPECT_TRUE(mock_layer->needs_painting(paint_context()));
   EXPECT_TRUE(layer->needs_painting(paint_context()));
   EXPECT_EQ(mock_layer->parent_matrix(), SkMatrix());  // identity
   EXPECT_EQ(mock_layer->parent_cull_rect(), cull_rect);
   EXPECT_EQ(mock_layer->parent_mutators().stack_count(), 0u);
   EXPECT_EQ(mock_layer->parent_mutators(), MutatorsStack());

   layer->Paint(display_list_paint_context());
   DisplayListBuilder expected_builder;
   /* (Transform)layer::Paint */ {
     expected_builder.Save();
     {
       expected_builder.Transform(SkMatrix());
       /* mock_layer::Paint */ {
         expected_builder.DrawPath(child_path, DlPaint());
       }
     }
     expected_builder.Restore();
   }
   EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
 }

 TEST_F(TransformLayerTest, Simple) {
   SkPath child_path;
   child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
   SkMatrix initial_transform = SkMatrix::Translate(-0.5f, -0.5f);
   SkRect local_cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
   SkRect device_cull_rect = initial_transform.mapRect(local_cull_rect);
   SkMatrix layer_transform = SkMatrix::Translate(2.5f, 2.5f);
   SkMatrix inverse_layer_transform;
   EXPECT_TRUE(layer_transform.invert(&inverse_layer_transform));

   auto mock_layer = std::make_shared<MockLayer>(child_path, DlPaint());
   auto layer = std::make_shared<TransformLayer>(layer_transform);
   layer->Add(mock_layer);

   preroll_context()->state_stack.set_preroll_delegate(device_cull_rect,
                                                       initial_transform);
   layer->Preroll(preroll_context());
   EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
   EXPECT_EQ(layer->paint_bounds(),
             layer_transform.mapRect(mock_layer->paint_bounds()));
   EXPECT_EQ(layer->child_paint_bounds(), mock_layer->paint_bounds());
   EXPECT_TRUE(mock_layer->needs_painting(paint_context()));
   EXPECT_TRUE(layer->needs_painting(paint_context()));
   EXPECT_EQ(mock_layer->parent_matrix(),
             SkMatrix::Concat(initial_transform, layer_transform));
   EXPECT_EQ(mock_layer->parent_cull_rect(),
             inverse_layer_transform.mapRect(local_cull_rect));
   EXPECT_EQ(mock_layer->parent_mutators(),
             std::vector({Mutator(layer_transform)}));

   layer->Paint(display_list_paint_context());
   DisplayListBuilder expected_builder;
   /* (Transform)layer::Paint */ {
     expected_builder.Save();
     {
       expected_builder.Transform(layer_transform);
       /* mock_layer::Paint */ {
         expected_builder.DrawPath(child_path, DlPaint());
       }
     }
     expected_builder.Restore();
   }
   EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
 }

 TEST_F(TransformLayerTest, SimpleM44) {
   SkPath child_path;
   child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
   SkMatrix initial_transform = SkMatrix::Translate(-0.5f, -0.5f);
   SkRect local_cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
   SkRect device_cull_rect = initial_transform.mapRect(local_cull_rect);
   SkMatrix layer_transform = SkMatrix::Translate(2.5f, 3.5f);
   SkMatrix inverse_layer_transform;
   EXPECT_TRUE(layer_transform.invert(&inverse_layer_transform));

   auto mock_layer = std::make_shared<MockLayer>(child_path, DlPaint());
   auto layer = std::make_shared<TransformLayer>(SkM44::Translate(2.5f, 3.5f));
   layer->Add(mock_layer);

   preroll_context()->state_stack.set_preroll_delegate(device_cull_rect,
                                                       initial_transform);
   layer->Preroll(preroll_context());
   EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
   EXPECT_EQ(layer->paint_bounds(),
             layer_transform.mapRect(mock_layer->paint_bounds()));
   EXPECT_EQ(layer->child_paint_bounds(), mock_layer->paint_bounds());
   EXPECT_TRUE(mock_layer->needs_painting(paint_context()));
   EXPECT_TRUE(layer->needs_painting(paint_context()));
   EXPECT_EQ(mock_layer->parent_matrix(),
             SkMatrix::Concat(initial_transform, layer_transform));
   EXPECT_EQ(mock_layer->parent_cull_rect(),
             inverse_layer_transform.mapRect(local_cull_rect));
   EXPECT_EQ(mock_layer->parent_mutators(),
             std::vector({Mutator(layer_transform)}));

   layer->Paint(display_list_paint_context());
   DisplayListBuilder expected_builder;
   /* (Transform)layer::Paint */ {
     expected_builder.Save();
     {
       expected_builder.Transform(layer_transform);
       /* mock_layer::Paint */ {
         expected_builder.DrawPath(child_path, DlPaint());
       }
     }
     expected_builder.Restore();
   }
   EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
 }

 TEST_F(TransformLayerTest, ComplexM44) {
   SkPath child_path;
   child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
   SkMatrix initial_transform = SkMatrix::Translate(-0.5f, -0.5f);
   SkRect local_cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
   SkRect device_cull_rect = initial_transform.mapRect(local_cull_rect);
   SkM44 layer_transform44 = SkM44();
   layer_transform44.preTranslate(2.5f, 2.5f);
   // 20 degrees around the X axis
   layer_transform44.preConcat(SkM44::Rotate({1.0f, 0.0f, 0.0f}, M_PI / 9.0f));
   // 10 degrees around the Y axis
   layer_transform44.preConcat(SkM44::Rotate({0.0f, 1.0f, 0.0f}, M_PI / 18.0f));
   SkMatrix layer_transform = layer_transform44.asM33();
   SkMatrix inverse_layer_transform;
   EXPECT_TRUE(layer_transform.invert(&inverse_layer_transform));

   auto mock_layer = std::make_shared<MockLayer>(child_path, DlPaint());
   auto layer = std::make_shared<TransformLayer>(layer_transform44);
   layer->Add(mock_layer);

   preroll_context()->state_stack.set_preroll_delegate(device_cull_rect,
                                                       initial_transform);
   layer->Preroll(preroll_context());
   EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
   EXPECT_EQ(layer->paint_bounds(),
             layer_transform.mapRect(mock_layer->paint_bounds()));
   EXPECT_EQ(layer->child_paint_bounds(), mock_layer->paint_bounds());
   EXPECT_TRUE(mock_layer->needs_painting(paint_context()));
   EXPECT_TRUE(layer->needs_painting(paint_context()));
   EXPECT_EQ(mock_layer->parent_matrix(),
             SkMatrix::Concat(initial_transform, layer_transform));
   EXPECT_EQ(mock_layer->parent_cull_rect(),
             inverse_layer_transform.mapRect(local_cull_rect));
   EXPECT_EQ(mock_layer->parent_mutators(),
             std::vector({Mutator(layer_transform)}));

   layer->Paint(display_list_paint_context());
   DisplayListBuilder expected_builder;
   /* (Transform)layer::Paint */ {
     expected_builder.Save();
     {
       expected_builder.Transform(layer_transform44);
       /* mock_layer::Paint */ {
         expected_builder.DrawPath(child_path, DlPaint());
       }
     }
     expected_builder.Restore();
   }
   EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
 }

 TEST_F(TransformLayerTest, Nested) {
   SkPath child_path;
   child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
   SkMatrix initial_transform = SkMatrix::Translate(-0.5f, -0.5f);
   SkRect local_cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
   SkRect device_cull_rect = initial_transform.mapRect(local_cull_rect);
   SkMatrix layer1_transform = SkMatrix::Translate(2.5f, 2.5f);
   SkMatrix layer2_transform = SkMatrix::Translate(3.5f, 3.5f);
   SkMatrix inverse_layer1_transform, inverse_layer2_transform;
   EXPECT_TRUE(layer1_transform.invert(&inverse_layer1_transform));
   EXPECT_TRUE(layer2_transform.invert(&inverse_layer2_transform));

   auto mock_layer = std::make_shared<MockLayer>(child_path, DlPaint());
   auto layer1 = std::make_shared<TransformLayer>(layer1_transform);
   auto layer2 = std::make_shared<TransformLayer>(layer2_transform);
   layer1->Add(layer2);
   layer2->Add(mock_layer);

   preroll_context()->state_stack.set_preroll_delegate(device_cull_rect,
                                                       initial_transform);
   layer1->Preroll(preroll_context());
   EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
   EXPECT_EQ(layer2->paint_bounds(),
             layer2_transform.mapRect(mock_layer->paint_bounds()));
   EXPECT_EQ(layer2->child_paint_bounds(), mock_layer->paint_bounds());
   EXPECT_EQ(layer1->paint_bounds(),
             layer1_transform.mapRect(layer2->paint_bounds()));
   EXPECT_EQ(layer1->child_paint_bounds(), layer2->paint_bounds());
   EXPECT_TRUE(mock_layer->needs_painting(paint_context()));
   EXPECT_TRUE(layer2->needs_painting(paint_context()));
   EXPECT_TRUE(layer1->needs_painting(paint_context()));
   EXPECT_EQ(
       mock_layer->parent_matrix(),
       SkMatrix::Concat(SkMatrix::Concat(initial_transform, layer1_transform),
                        layer2_transform));
   EXPECT_EQ(mock_layer->parent_cull_rect(),
             inverse_layer2_transform.mapRect(
                 inverse_layer1_transform.mapRect(local_cull_rect)));
   EXPECT_EQ(
       mock_layer->parent_mutators(),
       std::vector({Mutator(layer1_transform), Mutator(layer2_transform)}));

   layer1->Paint(display_list_paint_context());
   DisplayListBuilder expected_builder;
   /* (Transform)layer1::Paint */ {
     expected_builder.Save();
     {
       expected_builder.Transform(layer1_transform);
       /* (Transform)layer1::Paint */ {
         expected_builder.Save();
         {
           expected_builder.Transform(layer2_transform);
           /* mock_layer::Paint */ {
             expected_builder.DrawPath(child_path, DlPaint());
           }
         }
         expected_builder.Restore();
       }
     }
     expected_builder.Restore();
   }
   EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
 }

 TEST_F(TransformLayerTest, NestedSeparated) {
   SkPath child_path;
   child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
   SkMatrix initial_transform = SkMatrix::Translate(-0.5f, -0.5f);
   SkRect local_cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
   SkRect device_cull_rect = initial_transform.mapRect(local_cull_rect);
   SkMatrix layer1_transform = SkMatrix::Translate(2.5f, 2.5f);
   SkMatrix layer2_transform = SkMatrix::Translate(3.5f, 3.5f);
   SkMatrix inverse_layer1_transform, inverse_layer2_transform;
   EXPECT_TRUE(layer1_transform.invert(&inverse_layer1_transform));
   EXPECT_TRUE(layer2_transform.invert(&inverse_layer2_transform));
   DlPaint child_paint1(DlColor::kBlue());
   DlPaint child_paint2(DlColor::kGreen());

   auto mock_layer1 = std::make_shared<MockLayer>(child_path, child_paint1);
   auto mock_layer2 = std::make_shared<MockLayer>(child_path, child_paint2);
   auto layer1 = std::make_shared<TransformLayer>(layer1_transform);
   auto layer2 = std::make_shared<TransformLayer>(layer2_transform);
   layer1->Add(mock_layer1);
   layer1->Add(layer2);
   layer2->Add(mock_layer2);

   preroll_context()->state_stack.set_preroll_delegate(device_cull_rect,
                                                       initial_transform);
   layer1->Preroll(preroll_context());
   SkRect layer1_child_bounds = layer2->paint_bounds();
   layer1_child_bounds.join(mock_layer1->paint_bounds());
   SkRect expected_layer1_bounds = layer1_child_bounds;
   layer1_transform.mapRect(&expected_layer1_bounds);

   EXPECT_EQ(mock_layer2->paint_bounds(), child_path.getBounds());
   EXPECT_EQ(layer2->paint_bounds(),
             layer2_transform.mapRect(mock_layer2->paint_bounds()));
   EXPECT_EQ(layer2->child_paint_bounds(), mock_layer2->paint_bounds());
   EXPECT_EQ(mock_layer1->paint_bounds(), child_path.getBounds());
   EXPECT_EQ(layer1->paint_bounds(), expected_layer1_bounds);
   EXPECT_EQ(layer1->child_paint_bounds(), layer1_child_bounds);
   EXPECT_TRUE(mock_layer2->needs_painting(paint_context()));
   EXPECT_TRUE(layer2->needs_painting(paint_context()));
   EXPECT_TRUE(mock_layer1->needs_painting(paint_context()));
   EXPECT_TRUE(layer1->needs_painting(paint_context()));
   EXPECT_EQ(mock_layer1->parent_matrix(),
             SkMatrix::Concat(initial_transform, layer1_transform));
   EXPECT_EQ(
       mock_layer2->parent_matrix(),
       SkMatrix::Concat(SkMatrix::Concat(initial_transform, layer1_transform),
                        layer2_transform));
   EXPECT_EQ(mock_layer1->parent_cull_rect(),
             inverse_layer1_transform.mapRect(local_cull_rect));
   EXPECT_EQ(mock_layer2->parent_cull_rect(),
             inverse_layer2_transform.mapRect(
                 inverse_layer1_transform.mapRect(local_cull_rect)));
   EXPECT_EQ(mock_layer1->parent_mutators(),
             std::vector({Mutator(layer1_transform)}));
   EXPECT_EQ(
       mock_layer2->parent_mutators(),
       std::vector({Mutator(layer1_transform), Mutator(layer2_transform)}));

   layer1->Paint(display_list_paint_context());
   DisplayListBuilder expected_builder;
   /* (Transform)layer1::Paint */ {
     expected_builder.Save();
     {
       expected_builder.Transform(layer1_transform);
       /* mock_layer::Paint */ {
         expected_builder.DrawPath(child_path, child_paint1);
       }
       /* (Transform)layer1::Paint */ {
         expected_builder.Save();
         {
           expected_builder.Transform(layer2_transform);
           /* mock_layer::Paint */ {
             expected_builder.DrawPath(child_path, child_paint2);
           }
         }
         expected_builder.Restore();
       }
     }
     expected_builder.Restore();
   }
   EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
 }

 TEST_F(TransformLayerTest, OpacityInheritance) {
   auto path1 = SkPath().addRect({10, 10, 30, 30});
   auto mock1 = MockLayer::MakeOpacityCompatible(path1);
   auto transform1 = std::make_shared<TransformLayer>(SkMatrix::Scale(2, 2));
   transform1->Add(mock1);

   // TransformLayer will pass through compatibility from a compatible child
   PrerollContext* context = preroll_context();
   transform1->Preroll(context);
   EXPECT_EQ(context->renderable_state_flags,
             LayerStateStack::kCallerCanApplyOpacity);

   auto path2 = SkPath().addRect({40, 40, 50, 50});
   auto mock2 = MockLayer::MakeOpacityCompatible(path2);
   transform1->Add(mock2);

   // TransformLayer will pass through compatibility from multiple
   // non-overlapping compatible children
   transform1->Preroll(context);
   EXPECT_EQ(context->renderable_state_flags,
             LayerStateStack::kCallerCanApplyOpacity);

   auto path3 = SkPath().addRect({20, 20, 40, 40});
   auto mock3 = MockLayer::MakeOpacityCompatible(path3);
   transform1->Add(mock3);

   // TransformLayer will not pass through compatibility from multiple
   // overlapping children even if they are individually compatible
   transform1->Preroll(context);
   EXPECT_EQ(context->renderable_state_flags, 0);

   auto transform2 = std::make_shared<TransformLayer>(SkMatrix::Scale(2, 2));
   transform2->Add(mock1);
   transform2->Add(mock2);

   // Double check first two children are compatible and non-overlapping
   transform2->Preroll(context);
   EXPECT_EQ(context->renderable_state_flags,
             LayerStateStack::kCallerCanApplyOpacity);

   auto path4 = SkPath().addRect({60, 60, 70, 70});
   auto mock4 = MockLayer::Make(path4);
   transform2->Add(mock4);

   // The third child is non-overlapping, but not compatible so the
   // TransformLayer should end up incompatible
   transform2->Preroll(context);
   EXPECT_EQ(context->renderable_state_flags, 0);
 }

 TEST_F(TransformLayerTest, OpacityInheritancePainting) {
   auto path1 = SkPath().addRect({10, 10, 30, 30});
   auto mock1 = MockLayer::MakeOpacityCompatible(path1);
   auto path2 = SkPath().addRect({40, 40, 50, 50});
   auto mock2 = MockLayer::MakeOpacityCompatible(path2);
   auto transform = SkMatrix::Scale(2, 2);
   auto transform_layer = std::make_shared<TransformLayer>(transform);
   transform_layer->Add(mock1);
   transform_layer->Add(mock2);

   // TransformLayer will pass through compatibility from multiple
   // non-overlapping compatible children
   PrerollContext* context = preroll_context();
   transform_layer->Preroll(context);
   EXPECT_EQ(context->renderable_state_flags,
             LayerStateStack::kCallerCanApplyOpacity);

   int opacity_alpha = 0x7F;
   SkPoint offset = SkPoint::Make(10, 10);
   auto opacity_layer = std::make_shared<OpacityLayer>(opacity_alpha, offset);
   opacity_layer->Add(transform_layer);
   opacity_layer->Preroll(context);
   EXPECT_TRUE(opacity_layer->children_can_accept_opacity());

   DisplayListBuilder expected_builder;
   /* opacity_layer paint */ {
     expected_builder.Save();
     {
       expected_builder.Translate(offset.fX, offset.fY);
       /* transform_layer paint */ {
         expected_builder.Save();
         expected_builder.Transform(transform);
         /* child layer1 paint */ {
           expected_builder.DrawPath(path1, DlPaint().setAlpha(opacity_alpha));
         }
         /* child layer2 paint */ {
           expected_builder.DrawPath(path2, DlPaint().setAlpha(opacity_alpha));
         }
         expected_builder.Restore();
       }
     }
     expected_builder.Restore();
   }

   opacity_layer->Paint(display_list_paint_context());
   EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
 }

 using TransformLayerLayerDiffTest = DiffContextTest;

 TEST_F(TransformLayerLayerDiffTest, Transform) {
   auto path1 = SkPath().addRect(SkRect::MakeLTRB(0, 0, 50, 50));
   auto m1 = std::make_shared<MockLayer>(path1);

   auto transform1 =
       std::make_shared<TransformLayer>(SkMatrix::Translate(10, 10));
   transform1->Add(m1);

   MockLayerTree t1;
   t1.root()->Add(transform1);

   auto damage = DiffLayerTree(t1, MockLayerTree());
   EXPECT_EQ(damage.frame_damage, SkIRect::MakeLTRB(10, 10, 60, 60));

   auto transform2 =
       std::make_shared<TransformLayer>(SkMatrix::Translate(20, 20));
   transform2->Add(m1);
   transform2->AssignOldLayer(transform1.get());

   MockLayerTree t2;
   t2.root()->Add(transform2);

   damage = DiffLayerTree(t2, t1);
   EXPECT_EQ(damage.frame_damage, SkIRect::MakeLTRB(10, 10, 70, 70));

   auto transform3 =
       std::make_shared<TransformLayer>(SkMatrix::Translate(20, 20));
   transform3->Add(m1);
   transform3->AssignOldLayer(transform2.get());

   MockLayerTree t3;
   t3.root()->Add(transform3);

   damage = DiffLayerTree(t3, t2);
   EXPECT_EQ(damage.frame_damage, SkIRect::MakeEmpty());
 }

 TEST_F(TransformLayerLayerDiffTest, TransformNested) {
   auto path1 = SkPath().addRect(SkRect::MakeLTRB(0, 0, 50, 50));
   auto m1 = CreateContainerLayer(std::make_shared<MockLayer>(path1));
   auto m2 = CreateContainerLayer(std::make_shared<MockLayer>(path1));
   auto m3 = CreateContainerLayer(std::make_shared<MockLayer>(path1));

   auto transform1 = std::make_shared<TransformLayer>(SkMatrix::Scale(2.0, 2.0));

   auto transform1_1 =
       std::make_shared<TransformLayer>(SkMatrix::Translate(10, 10));
   transform1_1->Add(m1);
   transform1->Add(transform1_1);

   auto transform1_2 =
       std::make_shared<TransformLayer>(SkMatrix::Translate(100, 100));
   transform1_2->Add(m2);
   transform1->Add(transform1_2);

   auto transform1_3 =
       std::make_shared<TransformLayer>(SkMatrix::Translate(200, 200));
   transform1_3->Add(m3);
   transform1->Add(transform1_3);

   MockLayerTree l1;
   l1.root()->Add(transform1);

   auto damage = DiffLayerTree(l1, MockLayerTree());
   EXPECT_EQ(damage.frame_damage, SkIRect::MakeLTRB(20, 20, 500, 500));

   auto transform2 = std::make_shared<TransformLayer>(SkMatrix::Scale(2.0, 2.0));

   auto transform2_1 =
       std::make_shared<TransformLayer>(SkMatrix::Translate(10, 10));
   transform2_1->Add(m1);
   transform2_1->AssignOldLayer(transform1_1.get());
   transform2->Add(transform2_1);

   // Offset 1px from transform1_2 so that they're not the same
   auto transform2_2 =
       std::make_shared<TransformLayer>(SkMatrix::Translate(100, 101));
   transform2_2->Add(m2);
   transform2_2->AssignOldLayer(transform1_2.get());
   transform2->Add(transform2_2);

   auto transform2_3 =
       std::make_shared<TransformLayer>(SkMatrix::Translate(200, 200));
   transform2_3->Add(m3);
   transform2_3->AssignOldLayer(transform1_3.get());
   transform2->Add(transform2_3);

   MockLayerTree l2;
   l2.root()->Add(transform2);

   damage = DiffLayerTree(l2, l1);

   // transform2 has not transform1 assigned as old layer, so it should be
   // invalidated completely
   EXPECT_EQ(damage.frame_damage, SkIRect::MakeLTRB(20, 20, 500, 500));

   // now diff the tree properly, the only difference being transform2_2 and
   // transform_2_1
   transform2->AssignOldLayer(transform1.get());
   damage = DiffLayerTree(l2, l1);

   EXPECT_EQ(damage.frame_damage, SkIRect::MakeLTRB(200, 200, 300, 302));
 }

 }  // namespace testing
 }  // namespace flutter
	// 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/flow/layers/transform_layer.h"

	#include "flutter/flow/testing/diff_context_test.h"
	#include "flutter/flow/testing/layer_test.h"
	#include "flutter/flow/testing/mock_layer.h"
	#include "flutter/fml/macros.h"

	namespace flutter {
	namespace testing {

	using TransformLayerTest = LayerTest;

	#ifndef NDEBUG
	TEST_F(TransformLayerTest, PaintingEmptyLayerDies) {
	auto layer = std::make_shared<TransformLayer>(SkMatrix()); // identity

	layer->Preroll(preroll_context());
	EXPECT_EQ(layer->paint_bounds(), SkRect::MakeEmpty());
	EXPECT_EQ(layer->child_paint_bounds(), SkRect::MakeEmpty());
	EXPECT_FALSE(layer->needs_painting(paint_context()));

	EXPECT_DEATH_IF_SUPPORTED(layer->Paint(paint_context()),
	"needs_painting\\(context\\)");
	}

	TEST_F(TransformLayerTest, PaintBeforePrerollDies) {
	SkPath child_path;
	child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
	auto mock_layer = std::make_shared<MockLayer>(child_path, DlPaint());
	auto layer = std::make_shared<TransformLayer>(SkMatrix()); // identity
	layer->Add(mock_layer);

	EXPECT_DEATH_IF_SUPPORTED(layer->Paint(paint_context()),
	"needs_painting\\(context\\)");
	}
	#endif

	TEST_F(TransformLayerTest, Identity) {
	SkPath child_path;
	child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
	SkRect cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
	auto mock_layer = std::make_shared<MockLayer>(child_path, DlPaint());
	auto layer = std::make_shared<TransformLayer>(SkMatrix()); // identity
	layer->Add(mock_layer);

	preroll_context()->state_stack.set_preroll_delegate(cull_rect);
	layer->Preroll(preroll_context());
	EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
	EXPECT_EQ(layer->paint_bounds(), mock_layer->paint_bounds());
	EXPECT_EQ(layer->child_paint_bounds(), mock_layer->paint_bounds());
	EXPECT_TRUE(mock_layer->needs_painting(paint_context()));
	EXPECT_TRUE(layer->needs_painting(paint_context()));
	EXPECT_EQ(mock_layer->parent_matrix(), SkMatrix()); // identity
	EXPECT_EQ(mock_layer->parent_cull_rect(), cull_rect);
	EXPECT_EQ(mock_layer->parent_mutators().stack_count(), 0u);
	EXPECT_EQ(mock_layer->parent_mutators(), MutatorsStack());

	layer->Paint(display_list_paint_context());
	DisplayListBuilder expected_builder;
	/* (Transform)layer::Paint */ {
	expected_builder.Save();
	{
	expected_builder.Transform(SkMatrix());
	/* mock_layer::Paint */ {
	expected_builder.DrawPath(child_path, DlPaint());
	}
	}
	expected_builder.Restore();
	}
	EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
	}

	TEST_F(TransformLayerTest, Simple) {
	SkPath child_path;
	child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
	SkMatrix initial_transform = SkMatrix::Translate(-0.5f, -0.5f);
	SkRect local_cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
	SkRect device_cull_rect = initial_transform.mapRect(local_cull_rect);
	SkMatrix layer_transform = SkMatrix::Translate(2.5f, 2.5f);
	SkMatrix inverse_layer_transform;
	EXPECT_TRUE(layer_transform.invert(&inverse_layer_transform));

	auto mock_layer = std::make_shared<MockLayer>(child_path, DlPaint());
	auto layer = std::make_shared<TransformLayer>(layer_transform);
	layer->Add(mock_layer);

	preroll_context()->state_stack.set_preroll_delegate(device_cull_rect,
	initial_transform);
	layer->Preroll(preroll_context());
	EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
	EXPECT_EQ(layer->paint_bounds(),
	layer_transform.mapRect(mock_layer->paint_bounds()));
	EXPECT_EQ(layer->child_paint_bounds(), mock_layer->paint_bounds());
	EXPECT_TRUE(mock_layer->needs_painting(paint_context()));
	EXPECT_TRUE(layer->needs_painting(paint_context()));
	EXPECT_EQ(mock_layer->parent_matrix(),
	SkMatrix::Concat(initial_transform, layer_transform));
	EXPECT_EQ(mock_layer->parent_cull_rect(),
	inverse_layer_transform.mapRect(local_cull_rect));
	EXPECT_EQ(mock_layer->parent_mutators(),
	std::vector({Mutator(layer_transform)}));

	layer->Paint(display_list_paint_context());
	DisplayListBuilder expected_builder;
	/* (Transform)layer::Paint */ {
	expected_builder.Save();
	{
	expected_builder.Transform(layer_transform);
	/* mock_layer::Paint */ {
	expected_builder.DrawPath(child_path, DlPaint());
	}
	}
	expected_builder.Restore();
	}
	EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
	}

	TEST_F(TransformLayerTest, SimpleM44) {
	SkPath child_path;
	child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
	SkMatrix initial_transform = SkMatrix::Translate(-0.5f, -0.5f);
	SkRect local_cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
	SkRect device_cull_rect = initial_transform.mapRect(local_cull_rect);
	SkMatrix layer_transform = SkMatrix::Translate(2.5f, 3.5f);
	SkMatrix inverse_layer_transform;
	EXPECT_TRUE(layer_transform.invert(&inverse_layer_transform));

	auto mock_layer = std::make_shared<MockLayer>(child_path, DlPaint());
	auto layer = std::make_shared<TransformLayer>(SkM44::Translate(2.5f, 3.5f));
	layer->Add(mock_layer);

	preroll_context()->state_stack.set_preroll_delegate(device_cull_rect,
	initial_transform);
	layer->Preroll(preroll_context());
	EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
	EXPECT_EQ(layer->paint_bounds(),
	layer_transform.mapRect(mock_layer->paint_bounds()));
	EXPECT_EQ(layer->child_paint_bounds(), mock_layer->paint_bounds());
	EXPECT_TRUE(mock_layer->needs_painting(paint_context()));
	EXPECT_TRUE(layer->needs_painting(paint_context()));
	EXPECT_EQ(mock_layer->parent_matrix(),
	SkMatrix::Concat(initial_transform, layer_transform));
	EXPECT_EQ(mock_layer->parent_cull_rect(),
	inverse_layer_transform.mapRect(local_cull_rect));
	EXPECT_EQ(mock_layer->parent_mutators(),
	std::vector({Mutator(layer_transform)}));

	layer->Paint(display_list_paint_context());
	DisplayListBuilder expected_builder;
	/* (Transform)layer::Paint */ {
	expected_builder.Save();
	{
	expected_builder.Transform(layer_transform);
	/* mock_layer::Paint */ {
	expected_builder.DrawPath(child_path, DlPaint());
	}
	}
	expected_builder.Restore();
	}
	EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
	}

	TEST_F(TransformLayerTest, ComplexM44) {
	SkPath child_path;
	child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
	SkMatrix initial_transform = SkMatrix::Translate(-0.5f, -0.5f);
	SkRect local_cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
	SkRect device_cull_rect = initial_transform.mapRect(local_cull_rect);
	SkM44 layer_transform44 = SkM44();
	layer_transform44.preTranslate(2.5f, 2.5f);
	// 20 degrees around the X axis
	layer_transform44.preConcat(SkM44::Rotate({1.0f, 0.0f, 0.0f}, M_PI / 9.0f));
	// 10 degrees around the Y axis
	layer_transform44.preConcat(SkM44::Rotate({0.0f, 1.0f, 0.0f}, M_PI / 18.0f));
	SkMatrix layer_transform = layer_transform44.asM33();
	SkMatrix inverse_layer_transform;
	EXPECT_TRUE(layer_transform.invert(&inverse_layer_transform));

	auto mock_layer = std::make_shared<MockLayer>(child_path, DlPaint());
	auto layer = std::make_shared<TransformLayer>(layer_transform44);
	layer->Add(mock_layer);

	preroll_context()->state_stack.set_preroll_delegate(device_cull_rect,
	initial_transform);
	layer->Preroll(preroll_context());
	EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
	EXPECT_EQ(layer->paint_bounds(),
	layer_transform.mapRect(mock_layer->paint_bounds()));
	EXPECT_EQ(layer->child_paint_bounds(), mock_layer->paint_bounds());
	EXPECT_TRUE(mock_layer->needs_painting(paint_context()));
	EXPECT_TRUE(layer->needs_painting(paint_context()));
	EXPECT_EQ(mock_layer->parent_matrix(),
	SkMatrix::Concat(initial_transform, layer_transform));
	EXPECT_EQ(mock_layer->parent_cull_rect(),
	inverse_layer_transform.mapRect(local_cull_rect));
	EXPECT_EQ(mock_layer->parent_mutators(),
	std::vector({Mutator(layer_transform)}));

	layer->Paint(display_list_paint_context());
	DisplayListBuilder expected_builder;
	/* (Transform)layer::Paint */ {
	expected_builder.Save();
	{
	expected_builder.Transform(layer_transform44);
	/* mock_layer::Paint */ {
	expected_builder.DrawPath(child_path, DlPaint());
	}
	}
	expected_builder.Restore();
	}
	EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
	}

	TEST_F(TransformLayerTest, Nested) {
	SkPath child_path;
	child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
	SkMatrix initial_transform = SkMatrix::Translate(-0.5f, -0.5f);
	SkRect local_cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
	SkRect device_cull_rect = initial_transform.mapRect(local_cull_rect);
	SkMatrix layer1_transform = SkMatrix::Translate(2.5f, 2.5f);
	SkMatrix layer2_transform = SkMatrix::Translate(3.5f, 3.5f);
	SkMatrix inverse_layer1_transform, inverse_layer2_transform;
	EXPECT_TRUE(layer1_transform.invert(&inverse_layer1_transform));
	EXPECT_TRUE(layer2_transform.invert(&inverse_layer2_transform));

	auto mock_layer = std::make_shared<MockLayer>(child_path, DlPaint());
	auto layer1 = std::make_shared<TransformLayer>(layer1_transform);
	auto layer2 = std::make_shared<TransformLayer>(layer2_transform);
	layer1->Add(layer2);
	layer2->Add(mock_layer);

	preroll_context()->state_stack.set_preroll_delegate(device_cull_rect,
	initial_transform);
	layer1->Preroll(preroll_context());
	EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
	EXPECT_EQ(layer2->paint_bounds(),
	layer2_transform.mapRect(mock_layer->paint_bounds()));
	EXPECT_EQ(layer2->child_paint_bounds(), mock_layer->paint_bounds());
	EXPECT_EQ(layer1->paint_bounds(),
	layer1_transform.mapRect(layer2->paint_bounds()));
	EXPECT_EQ(layer1->child_paint_bounds(), layer2->paint_bounds());
	EXPECT_TRUE(mock_layer->needs_painting(paint_context()));
	EXPECT_TRUE(layer2->needs_painting(paint_context()));
	EXPECT_TRUE(layer1->needs_painting(paint_context()));
	EXPECT_EQ(
	mock_layer->parent_matrix(),
	SkMatrix::Concat(SkMatrix::Concat(initial_transform, layer1_transform),
	layer2_transform));
	EXPECT_EQ(mock_layer->parent_cull_rect(),
	inverse_layer2_transform.mapRect(
	inverse_layer1_transform.mapRect(local_cull_rect)));
	EXPECT_EQ(
	mock_layer->parent_mutators(),
	std::vector({Mutator(layer1_transform), Mutator(layer2_transform)}));

	layer1->Paint(display_list_paint_context());
	DisplayListBuilder expected_builder;
	/* (Transform)layer1::Paint */ {
	expected_builder.Save();
	{
	expected_builder.Transform(layer1_transform);
	/* (Transform)layer1::Paint */ {
	expected_builder.Save();
	{
	expected_builder.Transform(layer2_transform);
	/* mock_layer::Paint */ {
	expected_builder.DrawPath(child_path, DlPaint());
	}
	}
	expected_builder.Restore();
	}
	}
	expected_builder.Restore();
	}
	EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
	}

	TEST_F(TransformLayerTest, NestedSeparated) {
	SkPath child_path;
	child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
	SkMatrix initial_transform = SkMatrix::Translate(-0.5f, -0.5f);
	SkRect local_cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
	SkRect device_cull_rect = initial_transform.mapRect(local_cull_rect);
	SkMatrix layer1_transform = SkMatrix::Translate(2.5f, 2.5f);
	SkMatrix layer2_transform = SkMatrix::Translate(3.5f, 3.5f);
	SkMatrix inverse_layer1_transform, inverse_layer2_transform;
	EXPECT_TRUE(layer1_transform.invert(&inverse_layer1_transform));
	EXPECT_TRUE(layer2_transform.invert(&inverse_layer2_transform));
	DlPaint child_paint1(DlColor::kBlue());
	DlPaint child_paint2(DlColor::kGreen());

	auto mock_layer1 = std::make_shared<MockLayer>(child_path, child_paint1);
	auto mock_layer2 = std::make_shared<MockLayer>(child_path, child_paint2);
	auto layer1 = std::make_shared<TransformLayer>(layer1_transform);
	auto layer2 = std::make_shared<TransformLayer>(layer2_transform);
	layer1->Add(mock_layer1);
	layer1->Add(layer2);
	layer2->Add(mock_layer2);

	preroll_context()->state_stack.set_preroll_delegate(device_cull_rect,
	initial_transform);
	layer1->Preroll(preroll_context());
	SkRect layer1_child_bounds = layer2->paint_bounds();
	layer1_child_bounds.join(mock_layer1->paint_bounds());
	SkRect expected_layer1_bounds = layer1_child_bounds;
	layer1_transform.mapRect(&expected_layer1_bounds);

	EXPECT_EQ(mock_layer2->paint_bounds(), child_path.getBounds());
	EXPECT_EQ(layer2->paint_bounds(),
	layer2_transform.mapRect(mock_layer2->paint_bounds()));
	EXPECT_EQ(layer2->child_paint_bounds(), mock_layer2->paint_bounds());
	EXPECT_EQ(mock_layer1->paint_bounds(), child_path.getBounds());
	EXPECT_EQ(layer1->paint_bounds(), expected_layer1_bounds);
	EXPECT_EQ(layer1->child_paint_bounds(), layer1_child_bounds);
	EXPECT_TRUE(mock_layer2->needs_painting(paint_context()));
	EXPECT_TRUE(layer2->needs_painting(paint_context()));
	EXPECT_TRUE(mock_layer1->needs_painting(paint_context()));
	EXPECT_TRUE(layer1->needs_painting(paint_context()));
	EXPECT_EQ(mock_layer1->parent_matrix(),
	SkMatrix::Concat(initial_transform, layer1_transform));
	EXPECT_EQ(
	mock_layer2->parent_matrix(),
	SkMatrix::Concat(SkMatrix::Concat(initial_transform, layer1_transform),
	layer2_transform));
	EXPECT_EQ(mock_layer1->parent_cull_rect(),
	inverse_layer1_transform.mapRect(local_cull_rect));
	EXPECT_EQ(mock_layer2->parent_cull_rect(),
	inverse_layer2_transform.mapRect(
	inverse_layer1_transform.mapRect(local_cull_rect)));
	EXPECT_EQ(mock_layer1->parent_mutators(),
	std::vector({Mutator(layer1_transform)}));
	EXPECT_EQ(
	mock_layer2->parent_mutators(),
	std::vector({Mutator(layer1_transform), Mutator(layer2_transform)}));

	layer1->Paint(display_list_paint_context());
	DisplayListBuilder expected_builder;
	/* (Transform)layer1::Paint */ {
	expected_builder.Save();
	{
	expected_builder.Transform(layer1_transform);
	/* mock_layer::Paint */ {
	expected_builder.DrawPath(child_path, child_paint1);
	}
	/* (Transform)layer1::Paint */ {
	expected_builder.Save();
	{
	expected_builder.Transform(layer2_transform);
	/* mock_layer::Paint */ {
	expected_builder.DrawPath(child_path, child_paint2);
	}
	}
	expected_builder.Restore();
	}
	}
	expected_builder.Restore();
	}
	EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
	}

	TEST_F(TransformLayerTest, OpacityInheritance) {
	auto path1 = SkPath().addRect({10, 10, 30, 30});
	auto mock1 = MockLayer::MakeOpacityCompatible(path1);
	auto transform1 = std::make_shared<TransformLayer>(SkMatrix::Scale(2, 2));
	transform1->Add(mock1);

	// TransformLayer will pass through compatibility from a compatible child
	PrerollContext* context = preroll_context();
	transform1->Preroll(context);
	EXPECT_EQ(context->renderable_state_flags,
	LayerStateStack::kCallerCanApplyOpacity);

	auto path2 = SkPath().addRect({40, 40, 50, 50});
	auto mock2 = MockLayer::MakeOpacityCompatible(path2);
	transform1->Add(mock2);

	// TransformLayer will pass through compatibility from multiple
	// non-overlapping compatible children
	transform1->Preroll(context);
	EXPECT_EQ(context->renderable_state_flags,
	LayerStateStack::kCallerCanApplyOpacity);

	auto path3 = SkPath().addRect({20, 20, 40, 40});
	auto mock3 = MockLayer::MakeOpacityCompatible(path3);
	transform1->Add(mock3);

	// TransformLayer will not pass through compatibility from multiple
	// overlapping children even if they are individually compatible
	transform1->Preroll(context);
	EXPECT_EQ(context->renderable_state_flags, 0);

	auto transform2 = std::make_shared<TransformLayer>(SkMatrix::Scale(2, 2));
	transform2->Add(mock1);
	transform2->Add(mock2);

	// Double check first two children are compatible and non-overlapping
	transform2->Preroll(context);
	EXPECT_EQ(context->renderable_state_flags,
	LayerStateStack::kCallerCanApplyOpacity);

	auto path4 = SkPath().addRect({60, 60, 70, 70});
	auto mock4 = MockLayer::Make(path4);
	transform2->Add(mock4);

	// The third child is non-overlapping, but not compatible so the
	// TransformLayer should end up incompatible
	transform2->Preroll(context);
	EXPECT_EQ(context->renderable_state_flags, 0);
	}

	TEST_F(TransformLayerTest, OpacityInheritancePainting) {
	auto path1 = SkPath().addRect({10, 10, 30, 30});
	auto mock1 = MockLayer::MakeOpacityCompatible(path1);
	auto path2 = SkPath().addRect({40, 40, 50, 50});
	auto mock2 = MockLayer::MakeOpacityCompatible(path2);
	auto transform = SkMatrix::Scale(2, 2);
	auto transform_layer = std::make_shared<TransformLayer>(transform);
	transform_layer->Add(mock1);
	transform_layer->Add(mock2);

	// TransformLayer will pass through compatibility from multiple
	// non-overlapping compatible children
	PrerollContext* context = preroll_context();
	transform_layer->Preroll(context);
	EXPECT_EQ(context->renderable_state_flags,
	LayerStateStack::kCallerCanApplyOpacity);

	int opacity_alpha = 0x7F;
	SkPoint offset = SkPoint::Make(10, 10);
	auto opacity_layer = std::make_shared<OpacityLayer>(opacity_alpha, offset);
	opacity_layer->Add(transform_layer);
	opacity_layer->Preroll(context);
	EXPECT_TRUE(opacity_layer->children_can_accept_opacity());

	DisplayListBuilder expected_builder;
	/* opacity_layer paint */ {
	expected_builder.Save();
	{
	expected_builder.Translate(offset.fX, offset.fY);
	/* transform_layer paint */ {
	expected_builder.Save();
	expected_builder.Transform(transform);
	/* child layer1 paint */ {
	expected_builder.DrawPath(path1, DlPaint().setAlpha(opacity_alpha));
	}
	/* child layer2 paint */ {
	expected_builder.DrawPath(path2, DlPaint().setAlpha(opacity_alpha));
	}
	expected_builder.Restore();
	}
	}
	expected_builder.Restore();
	}

	opacity_layer->Paint(display_list_paint_context());
	EXPECT_TRUE(DisplayListsEQ_Verbose(display_list(), expected_builder.Build()));
	}

	using TransformLayerLayerDiffTest = DiffContextTest;

	TEST_F(TransformLayerLayerDiffTest, Transform) {
	auto path1 = SkPath().addRect(SkRect::MakeLTRB(0, 0, 50, 50));
	auto m1 = std::make_shared<MockLayer>(path1);

	auto transform1 =
	std::make_shared<TransformLayer>(SkMatrix::Translate(10, 10));
	transform1->Add(m1);

	MockLayerTree t1;
	t1.root()->Add(transform1);

	auto damage = DiffLayerTree(t1, MockLayerTree());
	EXPECT_EQ(damage.frame_damage, SkIRect::MakeLTRB(10, 10, 60, 60));

	auto transform2 =
	std::make_shared<TransformLayer>(SkMatrix::Translate(20, 20));
	transform2->Add(m1);
	transform2->AssignOldLayer(transform1.get());

	MockLayerTree t2;
	t2.root()->Add(transform2);

	damage = DiffLayerTree(t2, t1);
	EXPECT_EQ(damage.frame_damage, SkIRect::MakeLTRB(10, 10, 70, 70));

	auto transform3 =
	std::make_shared<TransformLayer>(SkMatrix::Translate(20, 20));
	transform3->Add(m1);
	transform3->AssignOldLayer(transform2.get());

	MockLayerTree t3;
	t3.root()->Add(transform3);

	damage = DiffLayerTree(t3, t2);
	EXPECT_EQ(damage.frame_damage, SkIRect::MakeEmpty());
	}

	TEST_F(TransformLayerLayerDiffTest, TransformNested) {
	auto path1 = SkPath().addRect(SkRect::MakeLTRB(0, 0, 50, 50));
	auto m1 = CreateContainerLayer(std::make_shared<MockLayer>(path1));
	auto m2 = CreateContainerLayer(std::make_shared<MockLayer>(path1));
	auto m3 = CreateContainerLayer(std::make_shared<MockLayer>(path1));

	auto transform1 = std::make_shared<TransformLayer>(SkMatrix::Scale(2.0, 2.0));

	auto transform1_1 =
	std::make_shared<TransformLayer>(SkMatrix::Translate(10, 10));
	transform1_1->Add(m1);
	transform1->Add(transform1_1);

	auto transform1_2 =
	std::make_shared<TransformLayer>(SkMatrix::Translate(100, 100));
	transform1_2->Add(m2);
	transform1->Add(transform1_2);

	auto transform1_3 =
	std::make_shared<TransformLayer>(SkMatrix::Translate(200, 200));
	transform1_3->Add(m3);
	transform1->Add(transform1_3);

	MockLayerTree l1;
	l1.root()->Add(transform1);

	auto damage = DiffLayerTree(l1, MockLayerTree());
	EXPECT_EQ(damage.frame_damage, SkIRect::MakeLTRB(20, 20, 500, 500));

	auto transform2 = std::make_shared<TransformLayer>(SkMatrix::Scale(2.0, 2.0));

	auto transform2_1 =
	std::make_shared<TransformLayer>(SkMatrix::Translate(10, 10));
	transform2_1->Add(m1);
	transform2_1->AssignOldLayer(transform1_1.get());
	transform2->Add(transform2_1);

	// Offset 1px from transform1_2 so that they're not the same
	auto transform2_2 =
	std::make_shared<TransformLayer>(SkMatrix::Translate(100, 101));
	transform2_2->Add(m2);
	transform2_2->AssignOldLayer(transform1_2.get());
	transform2->Add(transform2_2);

	auto transform2_3 =
	std::make_shared<TransformLayer>(SkMatrix::Translate(200, 200));
	transform2_3->Add(m3);
	transform2_3->AssignOldLayer(transform1_3.get());
	transform2->Add(transform2_3);

	MockLayerTree l2;
	l2.root()->Add(transform2);

	damage = DiffLayerTree(l2, l1);

	// transform2 has not transform1 assigned as old layer, so it should be
	// invalidated completely
	EXPECT_EQ(damage.frame_damage, SkIRect::MakeLTRB(20, 20, 500, 500));

	// now diff the tree properly, the only difference being transform2_2 and
	// transform_2_1
	transform2->AssignOldLayer(transform1.get());
	damage = DiffLayerTree(l2, l1);

	EXPECT_EQ(damage.frame_damage, SkIRect::MakeLTRB(200, 200, 300, 302));
	}

	} // namespace testing
	} // namespace flutter