Add DesktopFrame rotation functions

webrtc/modules/desktop_capture/desktop_frame_rotation.cc

Index: webrtc/modules/desktop_capture/desktop_frame_rotation.cc
diff --git a/webrtc/modules/desktop_capture/desktop_frame_rotation.cc b/webrtc/modules/desktop_capture/desktop_frame_rotation.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c7dce061bd5c694b5a3188bf8ff8082883c4799d
--- /dev/null
+++ b/webrtc/modules/desktop_capture/desktop_frame_rotation.cc
@@ -0,0 +1,110 @@
+/*
+ *  Copyright (c) 2016 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.
+ */
+
+#include "webrtc/modules/desktop_capture/desktop_frame_rotation.h"
+
+#include <string.h>
+
+#include "webrtc/base/checks.h"
+#include "third_party/libyuv/include/libyuv/rotate_argb.h"
+
+namespace webrtc {
+
+namespace {
+
+libyuv::RotationMode ToLibyuvRotationMode(Rotation rotation) {
+  switch (rotation) {
+    case Rotation::CLOCK_WISE_0:
+      return libyuv::kRotate0;
+    case Rotation::CLOCK_WISE_90:
+      return libyuv::kRotate90;
+    case Rotation::CLOCK_WISE_180:
+      return libyuv::kRotate180;
+    case Rotation::CLOCK_WISE_270:
+      return libyuv::kRotate270;
+  }
+  RTC_NOTREACHED();
+  return libyuv::kRotate0;
+}
+
+}  // namespace
+
+Rotation ReverseRotation(Rotation rotation) {
+  switch (rotation) {
+    case Rotation::CLOCK_WISE_0:
+      return rotation;
+    case Rotation::CLOCK_WISE_90:
+      return Rotation::CLOCK_WISE_270;
+    case Rotation::CLOCK_WISE_180:
+      return Rotation::CLOCK_WISE_180;
+    case Rotation::CLOCK_WISE_270:
+      return Rotation::CLOCK_WISE_90;
+  }
+  RTC_NOTREACHED();
+  return Rotation::CLOCK_WISE_0;
+}
+
+DesktopSize RotateSize(DesktopSize size, Rotation rotation) {
+  switch (rotation) {
+    case Rotation::CLOCK_WISE_0:
+    case Rotation::CLOCK_WISE_180:
+      return size;
+    case Rotation::CLOCK_WISE_90:
+    case Rotation::CLOCK_WISE_270:
+      return DesktopSize(size.height(), size.width());
+  }
+  RTC_NOTREACHED();
+  return DesktopSize();
+}
+
+DesktopRect RotateRect(DesktopRect rect, DesktopSize size, Rotation rotation) {
+  switch (rotation) {
+    case Rotation::CLOCK_WISE_0:
+      return rect;
+    case Rotation::CLOCK_WISE_90:
+      return DesktopRect::MakeXYWH(size.height() - rect.bottom(), rect.left(),
+                                   rect.height(), rect.width());
+    case Rotation::CLOCK_WISE_180:
+      return DesktopRect::MakeXYWH(size.width() - rect.right(),
+                                   size.height() - rect.bottom(), rect.width(),
+                                   rect.height());
+    case Rotation::CLOCK_WISE_270:
+      return DesktopRect::MakeXYWH(rect.top(), size.width() - rect.right(),
+                                   rect.height(), rect.width());
+  }
+  RTC_NOTREACHED();
+  return DesktopRect();
+}
+
+
+void RotateDesktopFrame(const DesktopFrame& source,
+                        const DesktopRect& source_rect,
+                        const Rotation& rotation,
+                        DesktopFrame* target) {
+  RTC_DCHECK(target);
+  // The rectangle in |target|.
+  const DesktopRect target_rect =
+      RotateRect(source_rect, source.size(), rotation);
+  RTC_DCHECK(DesktopRect::MakeSize(target->size()).ContainsRect(target_rect));

[Sergey Ulanov, 2016/11/21 21:01:12]

Also DCHECK that |source_rect| is inside |source|?

[Hzj_jie, 2016/11/21 23:33:30]

Done.

+
+  if (target_rect.is_empty()) {
+    return;
+  }
+
+  target->mutable_updated_region()->AddRect(target_rect);
+  int result = libyuv::ARGBRotate(
+       source.GetFrameDataAtPos(source_rect.top_left()), source.stride(),
+       target->GetFrameDataAtPos(target_rect.top_left()), target->stride(),
+       source_rect.width(), source_rect.height(),
+       ToLibyuvRotationMode(rotation));
+  RTC_DCHECK_EQ(result, 0);
+}
+
+}  // namespace webrtc