Implement interest rects for synchronized paint.

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMappingTest.cpp

Index: third_party/WebKit/Source/core/layout/compositing/CompositedLayerMappingTest.cpp
diff --git a/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMappingTest.cpp b/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMappingTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..f7b15eccd4e1ff7ed31cbff34b33b5af6a0313c8
--- /dev/null
+++ b/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMappingTest.cpp
@@ -0,0 +1,174 @@
+// Copyright 2014 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 "config.h"
+#include "core/layout/compositing/CompositedLayerMapping.h"
+
+#include "core/frame/FrameView.h"
+#include "core/layout/LayoutBoxModelObject.h"
+#include "core/layout/LayoutTestHelper.h"
+#include "core/paint/PaintLayer.h"
+#include <gtest/gtest.h>
+
+namespace blink {
+
+class CompositedLayerMappingTest : public RenderingTest {
+public:
+    CompositedLayerMappingTest()
+        : m_originalSlimmingPaintSynchronizedPaintingEnabled(RuntimeEnabledFeatures::slimmingPaintSynchronizedPaintingEnabled()) { }
+
+protected:
+    IntRect computeInterestRect(const GraphicsLayer* graphicsLayer, LayoutObject* owningLayoutObject)
+    {
+        return CompositedLayerMapping::computeInterestRect(graphicsLayer, owningLayoutObject);
+    }
+
+private:
+    void SetUp() override
+    {
+        RuntimeEnabledFeatures::setSlimmingPaintSynchronizedPaintingEnabled(true);
+
+        RenderingTest::SetUp();
+        enableCompositing();
+        GraphicsLayer::setDrawDebugRedFillForTesting(false);
+    }
+
+    void TearDown() override
+    {
+        GraphicsLayer::setDrawDebugRedFillForTesting(true);
+        RuntimeEnabledFeatures::setSlimmingPaintSynchronizedPaintingEnabled(m_originalSlimmingPaintSynchronizedPaintingEnabled);
+    }
+
+    bool m_originalSlimmingPaintSynchronizedPaintingEnabled;
+};
+
+static void printRect(IntRect rect)
+{
+    fprintf(stderr, "[x=%d y=%d maxX=%d maxY=%d]\n", rect.x(), rect.y(), rect.maxX(), rect.maxY());
+}
+
+static bool checkRectsEqual(const IntRect& expected, const IntRect& actual)
+{
+    if (expected != actual) {
+        fprintf(stderr, "Expected: ");
+        printRect(expected);
+        fprintf(stderr, "Actual: ");
+        printRect(actual);
+        return false;
+    }
+    return true;
+}
+
+TEST_F(CompositedLayerMappingTest, SimpleInterestRect)
+{
+    setBodyInnerHTML("<div id='target' style='width: 200px; height: 200px; will-change: transform'></div>");
+
+    document().view()->updateAllLifecyclePhases();
+    Element* element = document().getElementById("target");
+    PaintLayer* paintLayer = toLayoutBoxModelObject(element->layoutObject())->layer();
+    ASSERT_TRUE(!!paintLayer->graphicsLayerBacking());
+    EXPECT_TRUE(checkRectsEqual(IntRect(0, 0, 200, 200), computeInterestRect(paintLayer->graphicsLayerBacking(), paintLayer->layoutObject())));
+}
+
+TEST_F(CompositedLayerMappingTest, TallLayerInterestRect)
+{
+    setBodyInnerHTML("<div id='target' style='width: 200px; height: 10000px; will-change: transform'></div>");
+
+    document().view()->updateAllLifecyclePhases();
+    Element* element = document().getElementById("target");
+    PaintLayer* paintLayer = toLayoutBoxModelObject(element->layoutObject())->layer();
+    ASSERT_TRUE(paintLayer->graphicsLayerBacking());
+    // Screen-space visible content rect is [8, 8, 200, 600]. Mapping back to local, adding 4000px in all directions, then
+    // clipping, yields this rect.
+    EXPECT_TRUE(checkRectsEqual(IntRect(0, 0, 200, 4592), computeInterestRect(paintLayer->graphicsLayerBacking(), paintLayer->layoutObject())));
+}
+
+TEST_F(CompositedLayerMappingTest, RotatedInterestRect)
+{
+    setBodyInnerHTML("<div id='target' style='width: 200px; height: 200px; will-change: transform; transform: rotateZ(45deg)'></div>");
+
+    document().view()->updateAllLifecyclePhases();
+    Element* element = document().getElementById("target");
+    PaintLayer* paintLayer = toLayoutBoxModelObject(element->layoutObject())->layer();
+    ASSERT_TRUE(!!paintLayer->graphicsLayerBacking());
+    EXPECT_TRUE(checkRectsEqual(IntRect(0, 0, 200, 200), computeInterestRect(paintLayer->graphicsLayerBacking(), paintLayer->layoutObject())));
+}
+
+TEST_F(CompositedLayerMappingTest, RotatedTallInterestRect)
+{
+    setBodyInnerHTML("<div id='target' style='width: 200px; height: 10000px; will-change: transform; transform: rotateZ(45deg)'></div>");
+
+    document().view()->updateAllLifecyclePhases();
+    Element* element = document().getElementById("target");
+    PaintLayer* paintLayer = toLayoutBoxModelObject(element->layoutObject())->layer();
+    ASSERT_TRUE(!!paintLayer->graphicsLayerBacking());
+    EXPECT_TRUE(checkRectsEqual(IntRect(0, 0, 200, 5536), computeInterestRect(paintLayer->graphicsLayerBacking(), paintLayer->layoutObject())));
+}
+
+TEST_F(CompositedLayerMappingTest, WideLayerInterestRect)
+{
+    setBodyInnerHTML("<div id='target' style='width: 10000px; height: 200px; will-change: transform'></div>");
+
+    document().view()->updateAllLifecyclePhases();
+    Element* element = document().getElementById("target");
+    PaintLayer* paintLayer = toLayoutBoxModelObject(element->layoutObject())->layer();
+    ASSERT_TRUE(!!paintLayer->graphicsLayerBacking());
+    // Screen-space visible content rect is [8, 8, 800, 200] (the screen is 800x600).
+    // Mapping back to local, adding 4000px in all directions, then clipping, yields this rect.
+    EXPECT_TRUE(checkRectsEqual(IntRect(0, 0, 4792, 200), computeInterestRect(paintLayer->graphicsLayerBacking(), paintLayer->layoutObject())));
+}
+
+TEST_F(CompositedLayerMappingTest, FixedPositionInterestRect)
+{
+    setBodyInnerHTML("<div id='target' style='width: 300px; height: 400px; will-change: transform; position: fixed; top: 100px; left: 200px;'></div>");
+
+    document().view()->updateAllLifecyclePhases();
+    Element* element = document().getElementById("target");
+    PaintLayer* paintLayer = toLayoutBoxModelObject(element->layoutObject())->layer();
+    ASSERT_TRUE(!!paintLayer->graphicsLayerBacking());
+    EXPECT_TRUE(checkRectsEqual(IntRect(0, 0, 300, 400), computeInterestRect(paintLayer->graphicsLayerBacking(), paintLayer->layoutObject())));
+}
+
+TEST_F(CompositedLayerMappingTest, LayerOffscreenInterestRect)
+{
+    setBodyInnerHTML(
+        "<div id='target' style='width: 200px; height: 200px; will-change: transform; position: absolute; top: 9000px; left: 0px;'>"
+        "</div>");
+
+    document().view()->updateAllLifecyclePhases();
+    Element* element = document().getElementById("target");
+    PaintLayer* paintLayer = toLayoutBoxModelObject(element->layoutObject())->layer();
+    ASSERT_TRUE(!!paintLayer->graphicsLayerBacking());
+    // Offscreen layers are painted as usual.
+    fprintf(stderr, "\nTest:\n");
+    EXPECT_TRUE(checkRectsEqual(IntRect(0, 0, 200, 200), computeInterestRect(paintLayer->graphicsLayerBacking(), paintLayer->layoutObject())));
+}
+
+TEST_F(CompositedLayerMappingTest, ScrollingLayerInterestRect)
+{
+    setBodyInnerHTML("<div id='target' style='width: 200px; height: 200px; will-change: transform; overflow: scroll'>"
+        "<div style='width: 100px; height: 10000px'></div></div>");
+
+    document().view()->updateAllLifecyclePhases();
+    Element* element = document().getElementById("target");
+    PaintLayer* paintLayer = toLayoutBoxModelObject(element->layoutObject())->layer();
+    ASSERT_TRUE(paintLayer->graphicsLayerBacking());
+    // Offscreen layers are painted as usual.
+    EXPECT_TRUE(checkRectsEqual(IntRect(0, 0, 200, 4592), computeInterestRect(paintLayer->graphicsLayerBackingForScrolling(), paintLayer->layoutObject())));
+}
+
+TEST_F(CompositedLayerMappingTest, ClippedBigLayer)
+{
+    setBodyInnerHTML("<div style='width: 1px; height: 1px; overflow: hidden'>"
+        "<div id='target' style='width: 10000px; height: 10000px; will-change: transform'></div></div>");
+
+    document().view()->updateAllLifecyclePhases();
+    Element* element = document().getElementById("target");
+    PaintLayer* paintLayer = toLayoutBoxModelObject(element->layoutObject())->layer();
+    ASSERT_TRUE(paintLayer->graphicsLayerBacking());
+    // Offscreen layers are painted as usual.
+    EXPECT_TRUE(checkRectsEqual(IntRect(0, 0, 4001, 4001), computeInterestRect(paintLayer->graphicsLayerBacking(), paintLayer->layoutObject())));
+}
+
+} // namespace blink