cc: Add PictureLayerTilingSet to manage PictureLayerTiling

cc/picture_layer_tiling_unittest.cc

Index: cc/picture_layer_tiling_unittest.cc
diff --git a/cc/picture_layer_tiling_unittest.cc b/cc/picture_layer_tiling_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..03bd9aadb19d29f4e3b66b937cebed9e34fbda57
--- /dev/null
+++ b/cc/picture_layer_tiling_unittest.cc
@@ -0,0 +1,121 @@
+// Copyright 2012 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/picture_layer_tiling.h"
+
+#include "cc/test/fake_picture_layer_tiling_client.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gfx/size_conversions.h"
+
+namespace cc {
+
+class PictureLayerTilingIteratorTest : public testing::Test {
+ public:
+  PictureLayerTilingIteratorTest() {}
+  virtual ~PictureLayerTilingIteratorTest() {}
+
+  void Initialize(gfx::Size tile_size,
+                  float contents_scale,
+                  gfx::Size layer_bounds) {
+    client_.SetTileSize(tile_size);
+    tiling_ = PictureLayerTiling::Create(contents_scale, tile_size);
+    tiling_->SetClient(&client_);
+    tiling_->SetLayerBounds(layer_bounds);
+  }
+
+  void VerifyTilesExactlyCoverRect(float rect_scale, gfx::Rect rect) {
+    // Iterators are not valid if this ratio is too large (i.e. the
+    // tiling is too high-res for a low-res destination rect.)  This is an
+    // artifact of snapping geometry to integer coordinates and then mapping
+    // back to floating point texture coordinates.
+    float dest_to_contents_scale = tiling_->contents_scale() / rect_scale;
+    ASSERT_LE(dest_to_contents_scale, 2.0);
+
+    Region remaining = rect;
+    for (PictureLayerTiling::Iterator iter(tiling_.get(), rect_scale, rect);
+         iter;
+         ++iter) {
+
+      // Geometry cannot overlap previous geometry at all
+      gfx::Rect geometry = iter.geometry_rect();
+      EXPECT_TRUE(rect.Contains(geometry));
+      EXPECT_TRUE(remaining.Contains(geometry));
+      remaining.Subtract(geometry);
+
+      // Sanity check that texture coords are within the texture rect.
+      gfx::RectF texture_rect = iter.texture_rect();
+      EXPECT_GE(texture_rect.x(), 0);
+      EXPECT_GE(texture_rect.y(), 0);
+      EXPECT_LE(texture_rect.right(), client_.TileSize().width());
+      EXPECT_LE(texture_rect.bottom(), client_.TileSize().height());
+
+      EXPECT_EQ(iter.texture_size(), client_.TileSize());
+    }
+
+    // The entire rect must be filled by geometry from the tiling.
+    EXPECT_TRUE(remaining.IsEmpty());
+  }
+
+ protected:
+  FakePictureLayerTilingClient client_;
+  scoped_ptr<PictureLayerTiling> tiling_;
+
+  DISALLOW_COPY_AND_ASSIGN(PictureLayerTilingIteratorTest);
+};
+
+TEST_F(PictureLayerTilingIteratorTest, IteratorCoversLayerBoundsNoScale) {
+  Initialize(gfx::Size(100, 100), 1, gfx::Size(1099, 801));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect());
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 1099, 801));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(52, 83, 789, 412));
+
+  // With borders, a size of 3x3 = 1 pixel of content.
+  Initialize(gfx::Size(3, 3), 1, gfx::Size(10, 10));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 1, 1));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 2, 2));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(1, 1, 2, 2));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(3, 2, 5, 2));
+}
+
+TEST_F(PictureLayerTilingIteratorTest, IteratorCoversLayerBoundsTilingScale) {
+  Initialize(gfx::Size(200, 100), 2.0f, gfx::Size(1005, 2010));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect());
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 1005, 2010));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(50, 112, 512, 381));
+
+  Initialize(gfx::Size(3, 3), 2.0f, gfx::Size(10, 10));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect());
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 1, 1));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 2, 2));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(1, 1, 2, 2));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(3, 2, 5, 2));
+
+  Initialize(gfx::Size(100, 200), 0.5f, gfx::Size(1005, 2010));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 1005, 2010));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(50, 112, 512, 381));
+
+  Initialize(gfx::Size(150, 250), 0.37f, gfx::Size(1005, 2010));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 1005, 2010));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(50, 112, 512, 381));
+
+  Initialize(gfx::Size(312, 123), 0.01f, gfx::Size(1005, 2010));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 1005, 2010));
+  VerifyTilesExactlyCoverRect(1, gfx::Rect(50, 112, 512, 381));
+}
+
+TEST_F(PictureLayerTilingIteratorTest, IteratorCoversLayerBoundsBothScale) {
+  Initialize(gfx::Size(50, 50), 4.0f, gfx::Size(800, 600));
+  VerifyTilesExactlyCoverRect(2.0f, gfx::Rect());
+  VerifyTilesExactlyCoverRect(2.0f, gfx::Rect(0, 0, 1600, 1200));
+  VerifyTilesExactlyCoverRect(2.0f, gfx::Rect(512, 365, 253, 182));
+
+  float scale = 6.7f;
+  gfx::Size bounds(800, 600);
+  gfx::Rect full_rect(gfx::ToCeiledSize(gfx::ScaleSize(bounds, scale)));
+  Initialize(gfx::Size(256, 512), 5.2f, bounds);
+  VerifyTilesExactlyCoverRect(scale, full_rect);
+  VerifyTilesExactlyCoverRect(scale, gfx::Rect(2014, 1579, 867, 1033));
+}
+
+}  // namespace cc