cc: Reduce duplicated tiling data difference iterator code

cc/base/tiling_data.h

 // Copyright 2010 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.
 
 #ifndef CC_BASE_TILING_DATA_H_
 #define CC_BASE_TILING_DATA_H_
 
 #include <utility>
 
 #include "base/basictypes.h"
@@ skipping 83 matching lines @@
              const gfx::Rect& consider_rect,
              bool include_borders);
     Iterator& operator++();
 
    private:
     int left_;
     int right_;
     int bottom_;
   };
 
-  // Iterate through all indices whose bounds (not including borders) intersect
-  // with |consider| but which also do not intersect with |ignore|.
-  class CC_EXPORT DifferenceIterator : public BaseIterator {
-   public:
-    DifferenceIterator(const TilingData* tiling_data,
-                       const gfx::Rect& consider_rect,
-                       const gfx::Rect& ignore_rect);
-    DifferenceIterator& operator++();
+  class CC_EXPORT BaseDifferenceIterator : public BaseIterator {
+   protected:
+    BaseDifferenceIterator();
+    BaseDifferenceIterator(const TilingData* tiling_data,
+                           const gfx::Rect& consider_rect,
+                           const gfx::Rect& ignore_rect);
 
-   private:
+    bool HasConsiderRect() const;
+    bool in_consider_rect() const {
+      return index_x_ >= consider_left_ && index_x_ <= consider_right_ &&
+             index_y_ >= consider_top_ && index_y_ <= consider_bottom_;
+    }
     bool in_ignore_rect() const {
-     return index_x_ >= ignore_left_ && index_x_ <= ignore_right_ &&
-       index_y_ >= ignore_top_ && index_y_ <= ignore_bottom_;
+      return index_x_ >= ignore_left_ && index_x_ <= ignore_right_ &&
+             index_y_ >= ignore_top_ && index_y_ <= ignore_bottom_;
     }
 
     int consider_left_;
     int consider_top_;
     int consider_right_;
     int consider_bottom_;
     int ignore_left_;
     int ignore_top_;
     int ignore_right_;
     int ignore_bottom_;
   };
 
+  // Iterate through all indices whose bounds (not including borders) intersect
+  // with |consider| but which also do not intersect with |ignore|.
+  class CC_EXPORT DifferenceIterator : public BaseDifferenceIterator {
+   public:
+    DifferenceIterator(const TilingData* tiling_data,
+                       const gfx::Rect& consider_rect,
+                       const gfx::Rect& ignore_rect);
+    DifferenceIterator& operator++();
+  };
+
   // Iterate through all indices whose bounds + border intersect with
   // |consider| but which also do not intersect with |ignore|. The iterator
   // order is a counterclockwise spiral around the given center.
-  class CC_EXPORT SpiralDifferenceIterator : public BaseIterator {
+  class CC_EXPORT SpiralDifferenceIterator : public BaseDifferenceIterator {
    public:
     SpiralDifferenceIterator();
     SpiralDifferenceIterator(const TilingData* tiling_data,
                              const gfx::Rect& consider_rect,
                              const gfx::Rect& ignore_rect,
                              const gfx::Rect& center_rect);
     SpiralDifferenceIterator& operator++();
 
    private:
-    bool in_consider_rect() const {
-      return index_x_ >= consider_left_ && index_x_ <= consider_right_ &&
-             index_y_ >= consider_top_ && index_y_ <= consider_bottom_;
-    }
-    bool in_ignore_rect() const {
-      return index_x_ >= ignore_left_ && index_x_ <= ignore_right_ &&
-             index_y_ >= ignore_top_ && index_y_ <= ignore_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 consider_left_;
-    int consider_top_;
-    int consider_right_;
-    int consider_bottom_;
-    int ignore_left_;
-    int ignore_top_;
-    int ignore_right_;
-    int ignore_bottom_;
-
     enum Direction { UP, LEFT, DOWN, RIGHT };
 
     Direction direction_;
     int delta_x_;
     int delta_y_;
     int current_step_;
     int horizontal_step_count_;
     int vertical_step_count_;
   };
 
-  class CC_EXPORT ReverseSpiralDifferenceIterator : public BaseIterator {
+  class CC_EXPORT ReverseSpiralDifferenceIterator
+      : public BaseDifferenceIterator {
    public:
     ReverseSpiralDifferenceIterator();
     ReverseSpiralDifferenceIterator(const TilingData* tiling_data,
                                     const gfx::Rect& consider_rect,
                                     const gfx::Rect& ignore_rect,
                                     const gfx::Rect& center_rect);
     ReverseSpiralDifferenceIterator& operator++();
 
    private:
-    bool in_consider_rect() const {
-      return index_x_ >= consider_left_ && index_x_ <= consider_right_ &&
-             index_y_ >= consider_top_ && index_y_ <= consider_bottom_;
-    }
     bool in_around_rect() const {
       return index_x_ >= around_left_ && index_x_ <= around_right_ &&
              index_y_ >= around_top_ && index_y_ <= around_bottom_;
     }
-    bool in_ignore_rect() const {
-      return index_x_ >= ignore_left_ && index_x_ <= ignore_right_ &&
-             index_y_ >= ignore_top_ && index_y_ <= ignore_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 consider_left_;
-    int consider_top_;
-    int consider_right_;
-    int consider_bottom_;
     int around_left_;
     int around_top_;
     int around_right_;
     int around_bottom_;
-    int ignore_left_;
-    int ignore_top_;
-    int ignore_right_;
-    int ignore_bottom_;
 
     enum Direction { LEFT, UP, RIGHT, DOWN };
 
     Direction direction_;
     int delta_x_;
     int delta_y_;
     int current_step_;
     int horizontal_step_count_;
     int vertical_step_count_;
   };
@@ skipping 13 matching lines @@
   int border_texels_;
 
   // These are computed values.
   int num_tiles_x_;
   int num_tiles_y_;
 };
 
 }  // namespace cc
 
 #endif  // CC_BASE_TILING_DATA_H_