cc: Implement tile iteration order based on pyramid sequence. [old]

cc/base/tiling_data.h

Index: cc/base/tiling_data.h
diff --git a/cc/base/tiling_data.h b/cc/base/tiling_data.h
index 3c3937db81541378eb71cdae42ca419e07af0bf0..f0d85674c7cd8fc18a701117730ea045a7f1b75c 100644
--- a/cc/base/tiling_data.h
+++ b/cc/base/tiling_data.h
@@ -9,6 +9,7 @@
 
 #include "base/logging.h"
 #include "cc/base/cc_export.h"
+#include "cc/base/pyramid_sequence.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 
@@ -50,6 +51,16 @@ class CC_EXPORT TilingData {
   // Return the highest tile index whose border texels include src_position.
   int LastBorderTileXIndexFromSrcCoord(int src_position) const;
   int LastBorderTileYIndexFromSrcCoord(int src_position) const;
+  // Return the virtual tile index, assuming tiling size to be infinite in all
+  // quadrants.
+  int TileVirtualXIndexFromSrcCoord(int src_position) const;
+  int TileVirtualYIndexFromSrcCoord(int src_position) const;
+  // Return the virtual around tile indices around the given rect.
+  void TileVirtualAroundIndices(const gfx::Rect& center_rect,
+                                int* around_left,
+                                int* around_right,
+                                int* around_top,
+                                int* around_bottom) const;
 
   gfx::Rect ExpandRectIgnoringBordersToTileBounds(const gfx::Rect& rect) const;
   gfx::Rect ExpandRectToTileBounds(const gfx::Rect& rect) const;
@@ -148,32 +159,17 @@ class CC_EXPORT TilingData {
                              const gfx::Rect& consider_rect,
                              const gfx::Rect& ignore_rect,
                              const gfx::Rect& center_rect);
-    SpiralDifferenceIterator& operator++();
-
-   private:
-    bool valid_column() const {
-      return index_x_ >= consider_left_ && index_x_ <= consider_right_;
-    }
-    bool valid_row() const {
-      return index_y_ >= consider_top_ && index_y_ <= consider_bottom_;
-    }
+    SpiralDifferenceIterator(const SpiralDifferenceIterator& other);
+    SpiralDifferenceIterator(SpiralDifferenceIterator&& other);
+    ~SpiralDifferenceIterator();
 
-    int current_step_count() const {
-      return (direction_ == UP || direction_ == DOWN) ? vertical_step_count_
-                                                      : horizontal_step_count_;
-    }
-
-    bool needs_direction_switch() const;
-    void switch_direction();
+    SpiralDifferenceIterator& operator=(const SpiralDifferenceIterator& other);
+    SpiralDifferenceIterator& operator=(SpiralDifferenceIterator&& other);
 
-    enum Direction { UP, LEFT, DOWN, RIGHT };
+    SpiralDifferenceIterator& operator++();
 
-    Direction direction_;
-    int delta_x_;
-    int delta_y_;
-    int current_step_;
-    int horizontal_step_count_;
-    int vertical_step_count_;
+   private:
+    TopDownPyramidSequence pyramid_sequence_;
   };
 
   class CC_EXPORT ReverseSpiralDifferenceIterator
@@ -184,41 +180,20 @@ class CC_EXPORT TilingData {
                                     const gfx::Rect& consider_rect,
                                     const gfx::Rect& ignore_rect,
                                     const gfx::Rect& center_rect);
-    ReverseSpiralDifferenceIterator& operator++();
+    ReverseSpiralDifferenceIterator(
+        const ReverseSpiralDifferenceIterator& other);
+    ReverseSpiralDifferenceIterator(ReverseSpiralDifferenceIterator&& other);
+    ~ReverseSpiralDifferenceIterator();
 
-   private:
-    bool in_around_rect() const {
-      return index_x_ >= around_left_ && index_x_ <= around_right_ &&
-             index_y_ >= around_top_ && index_y_ <= around_bottom_;
-    }
-    bool valid_column() const {
-      return index_x_ >= consider_left_ && index_x_ <= consider_right_;
-    }
-    bool valid_row() const {
-      return index_y_ >= consider_top_ && index_y_ <= consider_bottom_;
-    }
-
-    int current_step_count() const {
-      return (direction_ == UP || direction_ == DOWN) ? vertical_step_count_
-                                                      : horizontal_step_count_;
-    }
-
-    bool needs_direction_switch() const;
-    void switch_direction();
-
-    int around_left_;
-    int around_top_;
-    int around_right_;
-    int around_bottom_;
+    ReverseSpiralDifferenceIterator& operator=(
+        const ReverseSpiralDifferenceIterator& other);
+    ReverseSpiralDifferenceIterator& operator=(
+        ReverseSpiralDifferenceIterator&& other);
 
-    enum Direction { LEFT, UP, RIGHT, DOWN };
+    ReverseSpiralDifferenceIterator& operator++();
 
-    Direction direction_;
-    int delta_x_;
-    int delta_y_;
-    int current_step_;
-    int horizontal_step_count_;
-    int vertical_step_count_;
+   private:
+    BottomUpPyramidSequence pyramid_sequence_;
   };
 
  private: