Mark layers that can use LCD text based on layer transform and opacity.

cc/layer_tree_host_common_unittest.cc

Index: cc/layer_tree_host_common_unittest.cc
diff --git a/cc/layer_tree_host_common_unittest.cc b/cc/layer_tree_host_common_unittest.cc
index 228ce2b6e5b7cf4cc4e8f5a6a7bf61e73cde12c3..9c4d72f9ad242b5634584e95d4427aef226ffb1c 100644
--- a/cc/layer_tree_host_common_unittest.cc
+++ b/cc/layer_tree_host_common_unittest.cc
@@ -4045,4 +4045,120 @@ TEST(LayerTreeHostCommonTest, verifySubtreeSearch)
     EXPECT_EQ(0, LayerTreeHostCommon::findLayerInSubtree(root.get(), nonexistentId));
 }
 
+TEST(LayerTreeHostCommonTest, verifyCanUseLCDTextForSingleLayer)
+{
+    scoped_refptr<Layer> root = Layer::create();
+
+    // Case 1: Identity transform.
+    WebTransformationMatrix identityMatrix;
+    setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(1, 1), false);
+    executeCalculateDrawTransformsAndVisibility(root.get());
+    EXPECT_EQ(LayerTreeHostCommon::canUseLCDText(), root->canUseLCDText());
+
+    // Case 2: Integral translation.
+    WebTransformationMatrix integralTranslation;
+    integralTranslation.translate(1, 2);
+    root->setTransform(integralTranslation);
+    executeCalculateDrawTransformsAndVisibility(root.get());
+    EXPECT_EQ(LayerTreeHostCommon::canUseLCDText(), root->canUseLCDText());
+
+    // Case 3: Non-integral translation.
+    WebTransformationMatrix nonIntegralTranslation;
+    nonIntegralTranslation.translate(1.5, 2.5);
+    root->setTransform(nonIntegralTranslation);
+    executeCalculateDrawTransformsAndVisibility(root.get());
+    EXPECT_EQ(false, root->canUseLCDText());
+
+    // Case 4: Rotation.
+    WebTransformationMatrix rotation;
+    rotation.rotate(10);
+    root->setTransform(rotation);
+    executeCalculateDrawTransformsAndVisibility(root.get());
+    EXPECT_EQ(false, root->canUseLCDText());
+
+    // Case 5: Scale.
+    WebTransformationMatrix scale;
+    scale.scale(2);
+    root->setTransform(scale);
+    executeCalculateDrawTransformsAndVisibility(root.get());
+    EXPECT_EQ(false, root->canUseLCDText());
+
+    // Case 6: Skew.
+    WebTransformationMatrix skew;
+    skew.skewX(10);
+    root->setTransform(skew);
+    executeCalculateDrawTransformsAndVisibility(root.get());
+    EXPECT_EQ(false, root->canUseLCDText());
+
+    // Case 7: Translucent.
+    root->setTransform(identityMatrix);
+    root->setOpacity(0.5);

[danakj, 2012/11/07 18:15:00]

The root layer owns a render surface, so this isn't testing what you are
expecting it to test. Can you make a child layer of the root, and do this entire
test on that child instead?

[alokp, 2012/11/08 22:34:07]

Done.

+    executeCalculateDrawTransformsAndVisibility(root.get());
+    EXPECT_EQ(false, root->canUseLCDText());
+
+    // Case 8: Restore transform and opacity.
+    root->setTransform(identityMatrix);
+    root->setOpacity(1);
+    executeCalculateDrawTransformsAndVisibility(root.get());
+    EXPECT_EQ(LayerTreeHostCommon::canUseLCDText(), root->canUseLCDText());
+}
+
+TEST(LayerTreeHostCommonTest, verifyCanUseLCDTextForLayerTree)

[danakj, 2012/11/07 18:15:00]

Seems like this is testing "...ForRenderSurface" more than "...ForLayerTree"?

[alokp, 2012/11/08 22:34:07]

Done.

+{
+    scoped_refptr<Layer> root = Layer::create();

[danakj, 2012/11/07 18:15:00]

Can you make a child of the root, that owns a render surface
(setForceRenderSurface(true)), and test with that instead of testing the root
layer? That will more directly mimic real life.

[alokp, 2012/11/08 22:34:07]

Done.

+    scoped_refptr<Layer> child = Layer::create();
+    root->addChild(child.get());
+
+    // Case 1: Identity transform.
+    WebTransformationMatrix identityMatrix;
+    setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(1, 1), false);
+    setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(1, 1), false);
+    executeCalculateDrawTransformsAndVisibility(root.get());
+    EXPECT_EQ(LayerTreeHostCommon::canUseLCDText(), root->canUseLCDText());
+    EXPECT_EQ(LayerTreeHostCommon::canUseLCDText(), child->canUseLCDText());
+
+    // Case 2: Integral translation.
+    WebTransformationMatrix integralTranslation;
+    integralTranslation.translate(1, 2);
+    root->setTransform(integralTranslation);
+    executeCalculateDrawTransformsAndVisibility(root.get());
+    EXPECT_EQ(LayerTreeHostCommon::canUseLCDText(), root->canUseLCDText());
+    EXPECT_EQ(LayerTreeHostCommon::canUseLCDText(), child->canUseLCDText());
+
+    // Case 3: Render surface cannot use LCD text.
+    root->setOpacity(0.5);
+    executeCalculateDrawTransformsAndVisibility(root.get());
+    EXPECT_EQ(false, root->canUseLCDText());
+    EXPECT_EQ(false, child->canUseLCDText());
+
+    // Case 4: Restore opacity.
+    root->setOpacity(1);
+    executeCalculateDrawTransformsAndVisibility(root.get());
+    EXPECT_EQ(LayerTreeHostCommon::canUseLCDText(), root->canUseLCDText());
+    EXPECT_EQ(LayerTreeHostCommon::canUseLCDText(), child->canUseLCDText());
+
+    // Case 5: Child layer cannot use LCD text.
+    WebTransformationMatrix scale;
+    scale.scale(2);
+    child->setTransform(scale);
+    executeCalculateDrawTransformsAndVisibility(root.get());
+    EXPECT_EQ(LayerTreeHostCommon::canUseLCDText(), root->canUseLCDText());
+    EXPECT_EQ(false, child->canUseLCDText());
+}
+
+TEST(LayerTreeHostCommonTest, verifyCanUseLCDTextWithAnimation)
+{
+    scoped_refptr<Layer> root = Layer::create();

[danakj, 2012/11/07 18:15:00]

Again, please use a child of the root to be more robust.

[alokp, 2012/11/08 22:34:07]

Done.

+
+    WebTransformationMatrix identityMatrix;
+    setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(1, 1), false);
+    root->setOpacity(0.9f);
+    root->setCanUseLCDText(true);
+    addOpacityTransitionToController(*(root->layerAnimationController()), 10, 0.9f, 0.1f, false);
+    executeCalculateDrawTransformsAndVisibility(root.get());
+    // Text AA should not be adjusted while animation is active.
+    // LCD text remains enabled even when it should not be.
+    EXPECT_EQ(true, root->canUseLCDText());
+}
+
 }  // anonymous namespace