cc: Fix computation of layer backfacing-ness when using property trees
When using property trees, layers whose transform is tested for
backfacing-ness might not have up-to-date draw properties (e.g.,
such layers might not draw content). This means that instead of
using the layer's draw_transform() draw property, we need to
call DrawTransformFromPropertyTrees.
BUG=553580
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel
Review URL: https://codereview.chromium.org/1422453007
Cr-Commit-Position: refs/heads/master@{#358683}
diff --git a/cc/trees/layer_tree_host_common.cc b/cc/trees/layer_tree_host_common.cc
index 649f6c2..345182c 100644
--- a/cc/trees/layer_tree_host_common.cc
+++ b/cc/trees/layer_tree_host_common.cc
@@ -445,14 +445,22 @@
return layer->Is3dSorted();
}
-static bool IsLayerBackFaceVisible(LayerImpl* layer) {
+static bool IsLayerBackFaceVisible(LayerImpl* layer,
+ bool use_property_trees,
+ const TransformTree& transform_tree) {
// The current W3C spec on CSS transforms says that backface visibility should
// be determined differently depending on whether the layer is in a "3d
// rendering context" or not. For Chromium code, we can determine whether we
// are in a 3d rendering context by checking if the parent preserves 3d.
- if (LayerIsInExisting3DRenderingContext(layer))
- return layer->draw_transform().IsBackFaceVisible();
+ if (LayerIsInExisting3DRenderingContext(layer)) {
+ if (use_property_trees) {
+ return DrawTransformFromPropertyTrees(layer, transform_tree)
+ .IsBackFaceVisible();
+ } else {
+ return layer->draw_transform().IsBackFaceVisible();
+ }
+ }
// In this case, either the layer establishes a new 3d rendering context, or
// is not in a 3d rendering context at all.
@@ -519,7 +527,10 @@
layer_rect_in_target_space, layer->draw_transform());
}
-static bool LayerShouldBeSkipped(LayerImpl* layer, bool layer_is_drawn) {
+static bool LayerShouldBeSkipped(LayerImpl* layer,
+ bool layer_is_drawn,
+ bool use_property_trees,
+ const TransformTree& transform_tree) {
// Layers can be skipped if any of these conditions are met.
// - is not drawn due to it or one of its ancestors being hidden (or having
// no copy requests).
@@ -553,7 +564,8 @@
// The layer should not be drawn if (1) it is not double-sided and (2) the
// back of the layer is known to be facing the screen.
if (!backface_test_layer->double_sided() &&
- IsLayerBackFaceVisible(backface_test_layer))
+ IsLayerBackFaceVisible(backface_test_layer, use_property_trees,
+ transform_tree))
return true;
return false;
@@ -2542,7 +2554,9 @@
size_t descendants_size = descendants->size();
- bool layer_should_be_skipped = LayerShouldBeSkipped(layer, layer_is_drawn);
+ bool layer_should_be_skipped =
+ LayerShouldBeSkipped(layer, layer_is_drawn, use_property_trees,
+ property_trees->transform_tree);
if (!layer_should_be_skipped) {
MarkLayerWithRenderSurfaceLayerListId(layer,
current_render_surface_layer_list_id);
diff --git a/cc/trees/layer_tree_host_common_unittest.cc b/cc/trees/layer_tree_host_common_unittest.cc
index e42460d..5e862ef 100644
--- a/cc/trees/layer_tree_host_common_unittest.cc
+++ b/cc/trees/layer_tree_host_common_unittest.cc
@@ -6067,6 +6067,48 @@
.size());
}
+TEST_F(LayerTreeHostCommonTest, DoNotIncludeBackfaceInvisibleLayers) {
+ LayerImpl* root = root_layer();
+ LayerImpl* child = AddChild<LayerImpl>(root);
+ LayerImpl* grand_child = AddChild<LayerImpl>(child);
+ grand_child->SetDrawsContent(true);
+
+ child->SetDoubleSided(false);
+ grand_child->SetUseParentBackfaceVisibility(true);
+
+ gfx::Transform identity_transform;
+ SetLayerPropertiesForTesting(root, identity_transform, gfx::Point3F(),
+ gfx::PointF(), gfx::Size(50, 50), false, true,
+ true);
+ SetLayerPropertiesForTesting(child, identity_transform, gfx::Point3F(),
+ gfx::PointF(), gfx::Size(30, 30), false, true,
+ false);
+ SetLayerPropertiesForTesting(grand_child, identity_transform, gfx::Point3F(),
+ gfx::PointF(), gfx::Size(20, 20), false, true,
+ false);
+
+ ExecuteCalculateDrawProperties(root);
+
+ EXPECT_EQ(1u, render_surface_layer_list_impl()->size());
+ EXPECT_EQ(grand_child, render_surface_layer_list_impl()
+ ->at(0)
+ ->render_surface()
+ ->layer_list()[0]);
+ gfx::Transform rotation_transform = identity_transform;
+ rotation_transform.RotateAboutXAxis(180.0);
+
+ child->SetTransform(rotation_transform);
+ child->layer_tree_impl()->property_trees()->needs_rebuild = true;
+
+ ExecuteCalculateDrawProperties(root);
+ EXPECT_EQ(1u, render_surface_layer_list_impl()->size());
+ EXPECT_EQ(0u, render_surface_layer_list_impl()
+ ->at(0)
+ ->render_surface()
+ ->layer_list()
+ .size());
+}
+
TEST_F(LayerTreeHostCommonTest, ClippedByScrollParent) {
// Checks that the simple case (being clipped by a scroll parent that would
// have been processed before you anyhow) results in the right clips.
