[Chromoting] Improve DirectX capturer to support multiple outputs

webrtc/modules/desktop_capture/win/dxgi_adapter_duplicator.h

+/*
+ *  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.
+ */
+
+#ifndef MODULES_DESKTOP_CAPTURE_WIN_DXGI_ADAPTER_DUPLICATOR_H_
+#define MODULES_DESKTOP_CAPTURE_WIN_DXGI_ADAPTER_DUPLICATOR_H_
+
+#include <wrl/client.h>
+
+#include <vector>
+
+#include "webrtc/modules/desktop_capture/desktop_frame.h"
+#include "webrtc/modules/desktop_capture/desktop_geometry.h"
+#include "webrtc/modules/desktop_capture/desktop_region.h"
+#include "webrtc/modules/desktop_capture/win/d3d_device.h"
+#include "webrtc/modules/desktop_capture/win/dxgi_context.h"
+#include "webrtc/modules/desktop_capture/win/dxgi_output_duplicator.h"
+
+namespace webrtc {
+
+// A container of DxgiOutputDuplicators to duplicate monitors attached to a
+// single video card.
+class DxgiAdapterDuplicator {
+ public:
+  // Creates an instance of DxgiAdapterDuplicator from a D3dDevice. Only
+  // DxgiDuplicatorContainer can create an instance.
+  explicit DxgiAdapterDuplicator(const D3dDevice& device);
+
+  // To allow this class to work with vector.
+  DxgiAdapterDuplicator(DxgiAdapterDuplicator&& other);
+
+  // Initializes the DxgiAdapterDuplicator from a D3dDevice.
+  bool Initialize();
+
+  // Sequential calls Duplicate function of all the DxgiOutputDuplicators owned
+  // by this instance.
+  bool Duplicate(DxgiContext* context,
+                 DesktopFrame* target,
+                 const DesktopFrame* last_frame);
+
+  // Captures one screen and writes into target. If id < 0 or greater than
+  // screen_count(), this function returns false.
+  bool Duplicate(DxgiContext* context,
+                 int id,
+                 DesktopFrame* target,
+                 const DesktopFrame* last_frame);
+
+  // Returns desktop rect covered by this DxgiAdapterDuplicator.
+  DesktopRect desktop_rect() const { return desktop_rect_; }
+
+  // Returns the size of one screen owned by this DxgiAdapterDuplicator. If id
+  // is less than zero, or greater than screen_count(), this function returns
+  // an empty DesktopRect.
+  DesktopRect ScreenRect(int id) const;
+
+  // Returns the count of screens owned by this DxgiAdapterDuplicator. i.e. the
+  // size of duplicators_. These screens can be retrieved by an interger in the
+  // range of [0, screen_count()).
+  int screen_count() const { return static_cast<int>(duplicators_.size()); }
+
+ private:
+  friend class DxgiDuplicatorContainer;
+
+  bool DoInitialize();
+
+  void Setup(DxgiContext* context);
+
+  void Unregister(const DxgiContext* const context);
+
+  const D3dDevice device_;
+  std::vector<DxgiOutputDuplicator> duplicators_;
+  DesktopRect desktop_rect_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_DESKTOP_CAPTURE_WIN_DXGI_ADAPTER_DUPLICATOR_H_