DirectX based screen capturer logic

webrtc/modules/desktop_capture/desktop_geometry.cc

 /*
  *  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.
  */
 
@@ skipping 26 matching lines @@
   }
 }
 
 void DesktopRect::Translate(int32_t dx, int32_t dy) {
   left_ += dx;
   top_ += dy;
   right_ += dx;
   bottom_ += dy;
 }
 
+DesktopRect DesktopRect::Expand(uint32_t padding,
+                                const DesktopSize& size) const {
+  int32_t l = left() - padding;
+  int32_t t = top() - padding;
+  int32_t r = right() + padding;
+  int32_t b = bottom() + padding;
+  if (l < 0) l = 0;
+  if (t < 0) t = 0;
+  if (r > size.width()) r = size.width();
+  if (b > size.height()) b = size.height();
+  return DesktopRect(l, t, r, b);
+}
+
 }  // namespace webrtc