Repaint on interest rect change

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

 // 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);
     }
 
+    bool interestRectChangedEnoughToRepaint(const IntSize& layerSize, const IntRect& previousInterestRect, const IntRect& newInterestRect)
+    {
+        return CompositedLayerMapping::interestRectChangedEnoughToRepaint(layerSize, previousInterestRect, newInterestRect);
+    }
+
 private:
     void SetUp() override
     {
         RuntimeEnabledFeatures::setSlimmingPaintSynchronizedPaintingEnabled(true);
 
         RenderingTest::SetUp();
         enableCompositing();
         GraphicsLayer::setDrawDebugRedFillForTesting(false);
     }
 
@@ skipping 159 matching lines @@
         "<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())));
 }
 
+TEST_F(CompositedLayerMappingTest, InterestRectChangedEnoughToRepaint)

[chrishtr, 2015/10/29 16:34:42]

Please copy the exact tests from here:

https://code.google.com/p/chromium/codesearch#chromium/src/cc/playback/displa...

so we know the algorithms are the same.

[Xianzhu, 2015/10/29 17:17:27]

Done.

+{
+    IntSize layerSize(2000, 2000);
+    EXPECT_FALSE(interestRectChangedEnoughToRepaint(layerSize, IntRect(), IntRect()));
+    EXPECT_TRUE(interestRectChangedEnoughToRepaint(layerSize, IntRect(), IntRect(0, 0, 100, 100)));
+    EXPECT_FALSE(interestRectChangedEnoughToRepaint(layerSize, IntRect(100, 100, 100, 100), IntRect(100, 100, 50, 50)));
+    EXPECT_FALSE(interestRectChangedEnoughToRepaint(layerSize, IntRect(100, 100, 100, 100), IntRect(50, 50, 500, 500)));
+    EXPECT_TRUE(interestRectChangedEnoughToRepaint(layerSize, IntRect(100, 100, 100, 100), IntRect(50, 50, 800, 600)));
+    EXPECT_TRUE(interestRectChangedEnoughToRepaint(layerSize, IntRect(100, 100, 100, 100), IntRect(0, 0, 200, 200)));
+    EXPECT_TRUE(interestRectChangedEnoughToRepaint(layerSize, IntRect(1000, 1000, 900, 900), IntRect(1000, 1000, 1000, 1000)));
+}
+
 } // namespace blink