Split picture layer quads to allow removing more occluded area.

cc/trees/occlusion_unittest.cc

 // 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/trees/occlusion.h"
 
 #include <stddef.h>
 
+#include "cc/base/region.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace cc {
 namespace {
 
 TEST(OcclusionTest, HasOcclusion) {
   Occlusion empty;
   EXPECT_FALSE(empty.HasOcclusion());
 
   empty = Occlusion(
@@ skipping 244 matching lines @@
   EXPECT_EQ(gfx::Rect(20, 20), full_query_result_down);
 
   gfx::Rect half_query_result_left =
       some_occluded_left.GetUnoccludedContentRect(gfx::Rect(10, 0, 10, 20));
   gfx::Rect half_query_result_down =
       some_occluded_down.GetUnoccludedContentRect(gfx::Rect(10, 0, 10, 20));
   EXPECT_EQ(gfx::Rect(10, 0, 10, 10), half_query_result_left);
   EXPECT_EQ(gfx::Rect(10, 0, 10, 10), half_query_result_down);
 }
 
+TEST(OcclusionTest, OccludeContentRegionScaled) {
+  gfx::Transform half_scale;
+  half_scale.Scale(0.5, 0.5);
+
+  gfx::Transform double_scale;
+  double_scale.Scale(2, 2);
+
+  Occlusion some_occluded_half(half_scale, SimpleEnclosedRegion(5, 5),
+                               SimpleEnclosedRegion(5, 5, 5, 5));
+  Occlusion some_occluded_double(double_scale, SimpleEnclosedRegion(20, 20),
+                                 SimpleEnclosedRegion(19, 20, 21, 20));
+
+  Region region_half(gfx::Rect(5, 0, 15, 20));
+  some_occluded_half.OccludeContentRegion(&region_half);
+
+  Region result_region;
+  // Top right and bottom left rectangles should remain.
+  result_region.Union(gfx::Rect(10, 0, 10, 10));
+  result_region.Union(gfx::Rect(5, 10, 5, 10));
+  EXPECT_EQ(result_region.ToString(), region_half.ToString());
+
+  // The result should be the same as above, as the additional half-pixel
+  // occlusion should be ignored.
+  Region region_double(gfx::Rect(5, 0, 15, 20));
+  some_occluded_double.OccludeContentRegion(&region_double);
+  EXPECT_EQ(result_region.ToString(), region_double.ToString());
+}
+
+TEST(OcclusionTest, OccludeContentRegionRotate) {
+  gfx::Transform rotate_transform;
+  // Extremely small rotation.
+  rotate_transform.Rotate(1);
+
+  Occlusion occlusion(rotate_transform, SimpleEnclosedRegion(10, 10),
+                      SimpleEnclosedRegion(10, 10, 10, 10));
+
+  Region region(gfx::Rect(1, 1, 1, 1));
+  Region occluded_region(region);
+  occlusion.OccludeContentRegion(&occluded_region);
+
+  // Transform isn't axis-aligned, so no occlusion should be done.
+  EXPECT_EQ(region.ToString(), occluded_region.ToString());
+}
+
 }  // namespace
 }  // namespace cc