Add DesktopFrame rotation functions

webrtc/modules/desktop_capture/desktop_frame.h

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_DESKTOP_CAPTURE_DESKTOP_FRAME_H_
 #define WEBRTC_MODULES_DESKTOP_CAPTURE_DESKTOP_FRAME_H_
 
 #include <memory>
 
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/modules/desktop_capture/desktop_geometry.h"
 #include "webrtc/modules/desktop_capture/desktop_region.h"
+#include "webrtc/modules/desktop_capture/rgba_color.h"
 #include "webrtc/modules/desktop_capture/shared_memory.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 // DesktopFrame represents a video frame captured from the screen.
 class DesktopFrame {
  public:
   // DesktopFrame objects always hold RGBA data.
   static const int kBytesPerPixel = 4;
+  static_assert(kBytesPerPixel == sizeof(RgbaColor),
+                "A pixel in DesktopFrame should be safe to be represented by a "
+                "RgbaColor");
 
   virtual ~DesktopFrame();
 
   // Size of the frame.
   const DesktopSize& size() const { return size_; }
 
   // Distance in the buffer between two neighboring rows in bytes.
   int stride() const { return stride_; }
 
   // Data buffer used for the frame.
@@ skipping 22 matching lines @@
   void CopyPixelsFrom(const uint8_t* src_buffer,
                       int src_stride,
                       const DesktopRect& dest_rect);
   void CopyPixelsFrom(const DesktopFrame& src_frame,
                       const DesktopVector& src_pos,
                       const DesktopRect& dest_rect);
 
   // A helper to return the data pointer of a frame at the specified position.
   uint8_t* GetFrameDataAtPos(const DesktopVector& pos) const;
 
+  // Whether current instance equals to the |other| in both size() and data().
+  bool DataEquals(const DesktopFrame& other) const;
+
+  // Paints the pixel at |pos| with |color|. This should be for test purpose
+  // only. This function triggers check failure if pos is out of current
+  // DesktopFrame.
+  void Paint(DesktopVector pos, RgbaColor color);

[Sergey Ulanov, 2016/11/15 02:28:10]

Do we really need this function here? RgbaColor is currently marked as
tests-only (see the comments in the header) and I'd prefer to keep it restricted
to tests. If you use this function only in tests then maybe add make it a static
function in a separate test_utils file. Same applies for DataEquals() and
Clear().

[Hzj_jie, 2016/11/15 05:17:02]

Sure. Updated.

+
+  // Clears DesktopFrame by set entire data() buffer into 0. This should be for
+  // test purpose only.
+  void Clear();
+
  protected:
   DesktopFrame(DesktopSize size,
                int stride,
                uint8_t* data,
                SharedMemory* shared_memory);
 
   // Ownership of the buffers is defined by the classes that inherit from this
   // class. They must guarantee that the buffer is not deleted before the frame
   // is deleted.
   uint8_t* const data_;
@@ skipping 43 matching lines @@
   ~SharedMemoryDesktopFrame() override;
 
  private:
   RTC_DISALLOW_COPY_AND_ASSIGN(SharedMemoryDesktopFrame);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_DESKTOP_CAPTURE_DESKTOP_FRAME_H_