Implement PaintArtifactCompositor::mightOverlap.

third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositorTest.cpp

 // Copyright 2016 The Chromium 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 "platform/graphics/compositing/PaintArtifactCompositor.h"
 
 #include "base/test/test_simple_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "cc/layers/layer.h"
 #include "cc/test/fake_compositor_frame_sink.h"
@@ skipping 548 matching lines @@
 TEST_F(PaintArtifactCompositorTestWithPropertyTrees,
        ForeignLayerPassesThrough) {
   scoped_refptr<cc::Layer> layer = cc::Layer::Create();
 
   TestPaintArtifact testArtifact;
   testArtifact
       .chunk(TransformPaintPropertyNode::root(), ClipPaintPropertyNode::root(),
              EffectPaintPropertyNode::root())
       .rectDrawing(FloatRect(0, 0, 100, 100), Color::white);
   testArtifact.chunk(defaultPaintChunkProperties())
-      .foreignLayer(FloatPoint(50, 100), IntSize(400, 300), layer);
+      .foreignLayer(FloatPoint(50, 60), IntSize(400, 300), layer);

[chrishtr, 2016/12/29 19:35:13]

Changed this to ensure overlap.

   testArtifact
       .chunk(TransformPaintPropertyNode::root(), ClipPaintPropertyNode::root(),
              EffectPaintPropertyNode::root())
       .rectDrawing(FloatRect(0, 0, 100, 100), Color::gray);
 
   const PaintArtifact& artifact = testArtifact.build();
 
   ASSERT_EQ(3u, artifact.paintChunks().size());
   PaintArtifactCompositor::PendingLayer pendingLayer1(
       artifact.paintChunks()[0]);
   // Foreign layers can't merge.
   EXPECT_FALSE(PaintArtifactCompositor::canMergeInto(
       artifact, artifact.paintChunks()[1], pendingLayer1));
   PaintArtifactCompositor::PendingLayer pendingLayer2(
       artifact.paintChunks()[1]);
   EXPECT_FALSE(PaintArtifactCompositor::canMergeInto(
       artifact, artifact.paintChunks()[2], pendingLayer2));
 
   update(artifact);
 
   ASSERT_EQ(3u, contentLayerCount());
   EXPECT_EQ(layer, contentLayerAt(1));
   EXPECT_EQ(gfx::Size(400, 300), layer->bounds());
-  EXPECT_EQ(translation(50, 100), layer->screen_space_transform());
+  EXPECT_EQ(translation(50, 60), layer->screen_space_transform());
 }
 
 TEST_F(PaintArtifactCompositorTestWithPropertyTrees, EffectTreeConversion) {
   RefPtr<EffectPaintPropertyNode> effect1 =
       createOpacityOnlyEffect(EffectPaintPropertyNode::root(), 0.5);
   RefPtr<EffectPaintPropertyNode> effect2 =
       createOpacityOnlyEffect(effect1, 0.3);
   RefPtr<EffectPaintPropertyNode> effect3 =
       createOpacityOnlyEffect(EffectPaintPropertyNode::root(), 0.2);
 
@@ skipping 670 matching lines @@
     rectsWithColor.push_back(
         RectWithColor(FloatRect(20, 30, 10, 20), Color(Color::black)));
     rectsWithColor.push_back(
         RectWithColor(FloatRect(0, 0, 200, 300), Color::gray));
 
     const cc::Layer* layer = contentLayerAt(0);
     EXPECT_THAT(layer->GetPicture(), Pointee(drawsRectangles(rectsWithColor)));
   }
 }
 
+TEST_F(PaintArtifactCompositorTestWithPropertyTrees, OverlapTransform) {
+  RefPtr<TransformPaintPropertyNode> transform =
+      TransformPaintPropertyNode::create(
+          TransformPaintPropertyNode::root(),
+          TransformationMatrix().translate(50, 50), FloatPoint3D(100, 100, 0),
+          false, 0, CompositingReason3DTransform);
+
+  TestPaintArtifact testArtifact;
+  testArtifact.chunk(defaultPaintChunkProperties())
+      .rectDrawing(FloatRect(0, 0, 100, 100), Color::white);
+  testArtifact
+      .chunk(transform.get(), ClipPaintPropertyNode::root(),
+             EffectPaintPropertyNode::root())
+      .rectDrawing(FloatRect(0, 0, 100, 100), Color::black);
+  testArtifact.chunk(defaultPaintChunkProperties())
+      .rectDrawing(FloatRect(0, 0, 200, 300), Color::gray);
+
+  const PaintArtifact& artifact = testArtifact.build();
+
+  ASSERT_EQ(3u, artifact.paintChunks().size());
+  PaintArtifactCompositor::PendingLayer pendingLayer(artifact.paintChunks()[0]);
+  EXPECT_FALSE(PaintArtifactCompositor::canMergeInto(
+      artifact, artifact.paintChunks()[1], pendingLayer));
+
+  PaintArtifactCompositor::PendingLayer pendingLayer2(
+      artifact.paintChunks()[1]);
+  EXPECT_FALSE(PaintArtifactCompositor::canMergeInto(
+      artifact, artifact.paintChunks()[2], pendingLayer2));
+
+  GeometryMapper geometryMapper;
+  EXPECT_TRUE(PaintArtifactCompositor::mightOverlap(
+      artifact.paintChunks()[2], pendingLayer2, geometryMapper));
+
+  update(artifact);
+
+  // The third paint chunk overlaps the second but can't merge due to
+  // incompatible transform. The second paint chunk can't merge into the first
+  // due to a direct compositing reason.
+  ASSERT_EQ(3u, contentLayerCount());
+}
+
+TEST_F(PaintArtifactCompositorTestWithPropertyTrees, MightOverlap) {
+  PaintChunk paintChunk;
+  paintChunk.properties = defaultPaintChunkProperties();
+  paintChunk.bounds = FloatRect(0, 0, 100, 100);
+
+  PaintChunk paintChunk2;
+  paintChunk.properties = defaultPaintChunkProperties();
+  paintChunk2.bounds = FloatRect(0, 0, 100, 100);
+
+  GeometryMapper geometryMapper;
+  PaintArtifactCompositor::PendingLayer pendingLayer(paintChunk);
+  EXPECT_TRUE(PaintArtifactCompositor::mightOverlap(paintChunk2, pendingLayer,
+                                                    geometryMapper));
+
+  RefPtr<TransformPaintPropertyNode> transform =
+      TransformPaintPropertyNode::create(
+          TransformPaintPropertyNode::root(),
+          TransformationMatrix().translate(99, 0), FloatPoint3D(100, 100, 0),
+          false);
+
+  paintChunk2.properties.propertyTreeState.setTransform(transform.get());
+
+  EXPECT_TRUE(PaintArtifactCompositor::mightOverlap(paintChunk2, pendingLayer,
+                                                    geometryMapper));
+
+  RefPtr<TransformPaintPropertyNode> transform2 =
+      TransformPaintPropertyNode::create(
+          TransformPaintPropertyNode::root(),
+          TransformationMatrix().translate(100, 0), FloatPoint3D(100, 100, 0),
+          false);
+  paintChunk2.properties.propertyTreeState.setTransform(transform2.get());
+
+  EXPECT_FALSE(PaintArtifactCompositor::mightOverlap(paintChunk2, pendingLayer,
+                                                     geometryMapper));
+}
+
 TEST_F(PaintArtifactCompositorTestWithPropertyTrees, PendingLayer) {
   PaintChunk chunk1;
   chunk1.properties.propertyTreeState = PropertyTreeState(
       TransformPaintPropertyNode::root(), ClipPaintPropertyNode::root(),
       EffectPaintPropertyNode::root(), ScrollPaintPropertyNode::root());
   chunk1.properties.backfaceHidden = true;
   chunk1.knownToBeOpaque = true;
   chunk1.bounds = FloatRect(0, 0, 30, 40);
 
   PaintArtifactCompositor::PendingLayer pendingLayer(chunk1);
@@ skipping 47 matching lines @@
   chunk2.properties.propertyTreeState = chunk1.properties.propertyTreeState;
   chunk2.properties.propertyTreeState.setTransform(transform);
   chunk2.bounds = FloatRect(0, 0, 50, 60);
   GeometryMapper geometryMapper;
   pendingLayer.add(chunk2, &geometryMapper);
 
   EXPECT_FLOAT_RECT_EQ(FloatRect(0, 0, 70, 85), pendingLayer.bounds);
 }
 
 }  // namespace blink