Initial pass at integrating Differ into the chromoting host code....

remoting/host/differ.h

 // Copyright (c) 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 REMOTING_HOST_DIFFER_H_
 #define REMOTING_HOST_DIFFER_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/scoped_ptr.h"
 #include "gfx/rect.h"
+#include "remoting/base/types.h"
 
 namespace remoting {
 
-typedef std::vector<gfx::Rect> DirtyRects;
 typedef uint8 DiffInfo;
 
 // Size (in pixels) of each square block used for diffing.
 // This must be a multiple of sizeof(uint64).
 static const int kBlockSize = 32;
 
 class Differ {
  public:
   // Create a differ that operates on bitmaps with the specified width, height
   // and bytes_per_pixel.
-  Differ(int width, int height, int bytes_per_pixel);
+  Differ(int width, int height, int bytes_per_pixel, int stride);
 
   // Given the previous and current screen buffer, calculate the set of
   // rectangles that enclose all the changed pixels in the new screen.
   void CalcDirtyRects(const void* prev_buffer, const void* curr_buffer,
-                      DirtyRects* rects);
+                      InvalidRects* rects);
 
   // Identify all of the blocks that contain changed pixels.
   void MarkDirtyBlocks(const void* prev_buffer, const void* curr_buffer);
 
   // Diff a small block of image and return non-zero if there is a diff.
   // Currently, this just returns 0 or 1, but this may change in the future
   // to return the number of pixels changed.
   DiffInfo DiffBlock(const uint8* prev_buffer, const uint8* curr_buffer,
                      int stride);
 
   // Diff a small block of image and return non-zero if there is a diff.
   // This checks only the part of the block specified by the width and
   // height parameters.
   // This is much slower than DiffBlock() since it cannot assume that the
   // full block is being checked.
   // If we force the capturer to always return images whose width/height are
   // multiples of kBlockSize, then this will never be called.
   DiffInfo DiffPartialBlock(const uint8* prev_buffer, const uint8* curr_buffer,
                             int stride, int width, int height);
 
   // After the dirty blocks have been identified, this routine merges adjacent
   // blocks into larger rectangular units.
   // The goal is to minimize the number of rects that cover the dirty blocks,
   // although it is not required to calc the absolute minimum of rects.
-  void MergeBlocks(DirtyRects* rects);
+  void MergeBlocks(InvalidRects* rects);
 
   // Allow tests to access our private parts.
   friend class DifferTest;
 
  private:
   // Dimensions of screen.
   int width_;
   int height_;
 
   // Number of bytes for each pixel in source and dest bitmap.
+  // (Yes, they must match.)
   int bytes_per_pixel_;
 
-  // Number of bytes in each row of the image.
+  // Number of bytes in each row of the image (AKA: stride).
   int bytes_per_row_;
 
   // Diff information for each block in the image.
   scoped_array<DiffInfo> diff_info_;
 
   // Dimensions and total size of diff info array.
   int diff_info_width_;
   int diff_info_height_;
   int diff_info_size_;
 
   DISALLOW_COPY_AND_ASSIGN(Differ);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_DIFFER_H_