cc: Apply occlusion before creating quads in SurfaceLayerImpl.

This makes the AppendQuads method query occlusion directly and subtract
it from the quads it would create before they are created, skipping
quads that are completely occluded and avoiding a malloc/free for them.

Depends on: https://codereview.chromium.org/201153021/

R=jamesr@chromium.org, jamesr
BUG=344962

Review URL: https://codereview.chromium.org/205123002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@258364 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 72 insertions, 2 deletions

diff --git a/cc/cc_tests.gyp b/cc/cc_tests.gyp
index d7e6e72..c593e9e 100644
--- a/cc/cc_tests.gyp
+++ b/cc/cc_tests.gyp
@@ -43,6 +43,7 @@
       'layers/render_surface_unittest.cc',
       'layers/scrollbar_layer_unittest.cc',
       'layers/solid_color_layer_impl_unittest.cc',
+      'layers/surface_layer_impl_unittest.cc',
       'layers/texture_layer_unittest.cc',
       'layers/texture_layer_impl_unittest.cc',
       'layers/tiled_layer_impl_unittest.cc',
diff --git a/cc/layers/surface_layer_impl.cc b/cc/layers/surface_layer_impl.cc
index ffeae2a..2f98805 100644
--- a/cc/layers/surface_layer_impl.cc
+++ b/cc/layers/surface_layer_impl.cc
@@ -46,9 +46,12 @@ void SurfaceLayerImpl::AppendQuads(QuadSink* quad_sink,
 
   scoped_ptr<SurfaceDrawQuad> quad = SurfaceDrawQuad::Create();
   gfx::Rect quad_rect(content_bounds());
-  gfx::Rect visible_quad_rect(quad_rect);
+  gfx::Rect visible_quad_rect = quad_sink->UnoccludedContentRect(
+      quad_rect, draw_properties().target_space_transform);
+  if (visible_quad_rect.IsEmpty())
+    return;
   quad->SetNew(shared_quad_state, quad_rect, visible_quad_rect, surface_id_);
-  quad_sink->MaybeAppend(quad.PassAs<DrawQuad>());
+  quad_sink->Append(quad.PassAs<DrawQuad>());
 }
 
 void SurfaceLayerImpl::GetDebugBorderProperties(SkColor* color,
diff --git a/cc/layers/surface_layer_impl_unittest.cc b/cc/layers/surface_layer_impl_unittest.cc
new file mode 100644
index 0000000..86e3e49c
--- /dev/null
+++ b/cc/layers/surface_layer_impl_unittest.cc
@@ -0,0 +1,66 @@
+// 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 "cc/layers/surface_layer_impl.h"
+
+#include "cc/test/layer_test_common.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cc {
+namespace {
+
+TEST(SurfaceLayerImplTest, Occlusion) {
+  gfx::Size layer_size(1000, 1000);
+  gfx::Size viewport_size(1000, 1000);
+
+  LayerTestCommon::LayerImplTest impl;
+
+  SurfaceLayerImpl* surface_layer_impl =
+      impl.AddChildToRoot<SurfaceLayerImpl>();
+  surface_layer_impl->SetAnchorPoint(gfx::PointF());
+  surface_layer_impl->SetBounds(layer_size);
+  surface_layer_impl->SetContentBounds(layer_size);
+  surface_layer_impl->SetDrawsContent(true);
+  surface_layer_impl->SetSurfaceId(9);
+
+  impl.CalcDrawProps(viewport_size);
+
+  {
+    SCOPED_TRACE("No occlusion");
+    gfx::Rect occluded;
+    impl.AppendQuadsWithOcclusion(surface_layer_impl, occluded);
+
+    LayerTestCommon::VerifyQuadsExactlyCoverRect(impl.quad_list(),
+                                                 gfx::Rect(layer_size));
+    EXPECT_EQ(1u, impl.quad_list().size());
+  }
+
+  {
+    SCOPED_TRACE("Full occlusion");
+    gfx::Rect occluded(surface_layer_impl->visible_content_rect());
+    impl.AppendQuadsWithOcclusion(surface_layer_impl, occluded);
+
+    LayerTestCommon::VerifyQuadsExactlyCoverRect(impl.quad_list(), gfx::Rect());
+    EXPECT_EQ(impl.quad_list().size(), 0u);
+  }
+
+  {
+    SCOPED_TRACE("Partial occlusion");
+    gfx::Rect occluded(200, 0, 800, 1000);
+    impl.AppendQuadsWithOcclusion(surface_layer_impl, occluded);
+
+    size_t partially_occluded_count = 0;
+    LayerTestCommon::VerifyQuadsCoverRectWithOcclusion(
+        impl.quad_list(),
+        gfx::Rect(layer_size),
+        occluded,
+        &partially_occluded_count);
+    // The layer outputs one quad, which is partially occluded.
+    EXPECT_EQ(1u, impl.quad_list().size());
+    EXPECT_EQ(1u, partially_occluded_count);
+  }
+}
+
+}  // namespace
+}  // namespace cc