[Chromoting] Improve DirectX capturer to support multiple outputs

webrtc/modules/desktop_capture/win/dxgi_adapter_duplicator.cc

+/*
+ *  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/win/dxgi_adapter_duplicator.h"
+
+#include <comdef.h>
+#include <DXGI.h>
+
+#include <algorithm>
+
+#include "webrtc/base/logging.h"
+
+namespace webrtc {
+
+using Microsoft::WRL::ComPtr;
+
+namespace {
+
+bool IsValidRect(const RECT& rect) {
+  return rect.left >= 0 && rect.top >= 0 &&
+         rect.right > rect.left && rect.bottom > rect.top;
+}
+
+}  // namespace
+
+bool DxgiAdapterDuplicator::Initialize(const D3dDevice& device) {
+  if (DoInitialize(device)) {
+    return true;
+  }
+  duplicators_.clear();
+  return false;
+}
+
+bool DxgiAdapterDuplicator::DoInitialize(const D3dDevice& device) {
+  for (int i = 0;; i++) {
+    ComPtr<IDXGIOutput> output;
+    _com_error error = device.dxgi_adapter()->EnumOutputs(
+        i, output.GetAddressOf());
+    if (error.Error() == DXGI_ERROR_NOT_FOUND) {
+      break;
+    }
+
+    if (error.Error() != S_OK || !output) {
+      LOG(LS_WARNING) << "IDXGIAdapter::EnumOutputs returns an unexpected "
+                         "result " << error.ErrorMessage() << " with error code"
+                      << error.Error();
+      return false;
+    }
+
+    DXGI_OUTPUT_DESC desc;
+    error = _com_error(output->GetDesc(&desc));
+    if (error.Error() == S_OK) {
+      if (desc.AttachedToDesktop && IsValidRect(desc.DesktopCoordinates)) {
+        ComPtr<IDXGIOutput1> output1;
+        error = _com_error(output.As(&output1));
+        if (error.Error() != S_OK || !output1) {
+          LOG(LS_WARNING) << "Failed to convert IDXGIOutput to IDXGIOutput1, "
+                             "this usually means the system does not support "
+                             "DirectX 11";
+          return false;
+        }
+        duplicators_.emplace_back(device, output1, desc);
+        if (!duplicators_.back().Initialize()) {
+          return false;
+        }
+        if (desktop_rect_.is_empty()) {
+          desktop_rect_ = duplicators_.back().desktop_rect();
+        } else {
+          const DesktopRect& left = desktop_rect_;
+          const DesktopRect& right = duplicators_.back().desktop_rect();
+          desktop_rect_ = DesktopRect::MakeLTRB(
+              std::min(left.left(), right.left()),
+              std::min(left.top(), right.top()),
+              std::max(left.right(), right.right()),
+              std::max(left.bottom(), right.bottom()));
+        }
+      }
+    } else {
+      LOG(LS_WARNING) << "Failed to get output description of device " << i
+                      << ", ignore.";
+    }
+  }
+  return true;
+}
+
+bool DxgiAdapterDuplicator::Duplicate(DesktopFrame* target,
+                                      const DesktopFrame* last_frame) {
+  for (auto& duplicator : duplicators_) {
+    if (!duplicator.Duplicate(
+        target, last_frame, duplicator.desktop_rect().top_left())) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool DxgiAdapterDuplicator::Duplicate(int id,
+                                      DesktopFrame* target,
+                                      const DesktopFrame* last_frame) {
+  if (id < 0 || id >= static_cast<int>(duplicators_.size())) {
+    return false;
+  }
+  return duplicators_[id].Duplicate(target, last_frame, DesktopVector());
+}
+
+DesktopRect DxgiAdapterDuplicator::ScreenRect(int id) const {
+  if (id < 0 || id >= static_cast<int>(duplicators_.size())) {
+    return DesktopRect();
+  }
+  return duplicators_[id].desktop_rect();
+}
+
+}  // namespace webrtc