Skip paint chunks with effectively invisible opacity.

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 <memory>
 
 #include "base/test/test_simple_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 125 matching lines @@
     return paint_artifact_compositor_->GetExtraDataForTesting()
         ->content_layers.size();
   }
 
   cc::Layer* ContentLayerAt(unsigned index) {
     return paint_artifact_compositor_->GetExtraDataForTesting()
         ->content_layers[index]
         .get();
   }
 
+  void AddSimpleRectChunk(TestPaintArtifact& artifact) {
+    artifact
+        .Chunk(TransformPaintPropertyNode::Root(),
+               ClipPaintPropertyNode::Root(), EffectPaintPropertyNode::Root())
+        .RectDrawing(FloatRect(100, 100, 200, 100), Color::kBlack);
+  }
+
+  void CreateSimpleArtifactWithOpacity(TestPaintArtifact& artifact,
+                                       float opacity,
+                                       bool include_preceding_chunk,
+                                       bool include_subsequent_chunk) {
+    if (include_preceding_chunk)
+      AddSimpleRectChunk(artifact);
+    RefPtr<EffectPaintPropertyNode> effect =
+        CreateOpacityOnlyEffect(EffectPaintPropertyNode::Root(), opacity);
+    artifact
+        .Chunk(TransformPaintPropertyNode::Root(),
+               ClipPaintPropertyNode::Root(), effect)
+        .RectDrawing(FloatRect(0, 0, 100, 100), Color::kBlack);
+    if (include_subsequent_chunk)
+      AddSimpleRectChunk(artifact);
+    Update(artifact.Build());
+  }
+
  private:
   std::unique_ptr<PaintArtifactCompositor> paint_artifact_compositor_;
   scoped_refptr<base::TestSimpleTaskRunner> task_runner_;
   base::ThreadTaskRunnerHandle task_runner_handle_;
   std::unique_ptr<WebLayerTreeViewWithCompositorFrameSink> web_layer_tree_view_;
 };
 
 TEST_F(PaintArtifactCompositorTestWithPropertyTrees, EmptyPaintArtifact) {
   PaintArtifact empty_artifact;
   Update(empty_artifact);
@@ skipping 1912 matching lines @@
   CompositorElementIdSet composited_element_ids;
   Update(artifact.Build(), composited_element_ids);
 
   EXPECT_EQ(2u, composited_element_ids.size());
   EXPECT_TRUE(
       composited_element_ids.Contains(transform->GetCompositorElementId()));
   EXPECT_TRUE(
       composited_element_ids.Contains(effect->GetCompositorElementId()));
 }
 
+TEST_F(PaintArtifactCompositorTestWithPropertyTrees, SkipChunkWithOpacityZero) {
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0, false, false);
+    ASSERT_EQ(0u, ContentLayerCount());
+  }
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0, true, false);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0, true, true);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0, false, true);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+}
+
+TEST_F(PaintArtifactCompositorTestWithPropertyTrees, SkipChunkWithTinyOpacity) {
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0.0003f, false, false);
+    ASSERT_EQ(0u, ContentLayerCount());
+  }
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0.0003f, true, false);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0.0003f, true, true);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0.0003f, false, true);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+}
+
+TEST_F(PaintArtifactCompositorTestWithPropertyTrees,
+       DontSkipChunkWithMinimumOpacity) {
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0.0004f, false, false);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0.0004f, true, false);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0.0004f, true, true);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0.0004f, false, true);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+}
+
+TEST_F(PaintArtifactCompositorTestWithPropertyTrees,
+       DontSkipChunkWithAboveMinimumOpacity) {
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0.3f, false, false);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0.3f, true, false);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0.3f, true, true);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+  {
+    TestPaintArtifact artifact;
+    CreateSimpleArtifactWithOpacity(artifact, 0.3f, false, true);
+    ASSERT_EQ(1u, ContentLayerCount());
+  }
+}
+
 }  // namespace blink