[feat] add Windows DXGI/GDI screen capture with WGC→DXGI→GDI fallback support

src/screen_capturer/windows/screen_capturer_dxgi.h

@@ -0,0 +1,79 @@
+/*
+ * @Author: DI JUNKUN
+ * @Date: 2026-02-27
+ * Copyright (c) 2026 by DI JUNKUN, All Rights Reserved.
+ */
+
+#ifndef _SCREEN_CAPTURER_DXGI_H_
+#define _SCREEN_CAPTURER_DXGI_H_
+
+#include <Windows.h>
+#include <d3d11.h>
+#include <dxgi1_2.h>
+#include <wrl/client.h>
+
+#include <atomic>
+#include <functional>
+#include <memory>
+#include <mutex>
+#include <string>
+#include <thread>
+#include <vector>
+
+#include "rd_log.h"
+#include "screen_capturer.h"
+
+namespace crossdesk {
+
+class ScreenCapturerDxgi : public ScreenCapturer {
+ public:
+  ScreenCapturerDxgi();
+  ~ScreenCapturerDxgi();
+
+ public:
+  int Init(const int fps, cb_desktop_data cb) override;
+  int Destroy() override;
+  int Start(bool show_cursor) override;
+  int Stop() override;
+
+  int Pause(int monitor_index) override;
+  int Resume(int monitor_index) override;
+
+  int SwitchTo(int monitor_index) override;
+
+  std::vector<DisplayInfo> GetDisplayInfoList() override {
+    return display_info_list_;
+  }
+
+ private:
+  bool InitializeDxgi();
+  void EnumerateDisplays();
+  bool CreateDuplicationForMonitor(int monitor_index);
+  void CaptureLoop();
+  void ReleaseDuplication();
+
+ private:
+  std::vector<DisplayInfo> display_info_list_;
+  std::vector<Microsoft::WRL::ComPtr<IDXGIOutput>> outputs_;
+
+  Microsoft::WRL::ComPtr<IDXGIFactory1> dxgi_factory_;
+  Microsoft::WRL::ComPtr<ID3D11Device> d3d_device_;
+  Microsoft::WRL::ComPtr<ID3D11DeviceContext> d3d_context_;
+  Microsoft::WRL::ComPtr<IDXGIOutputDuplication> duplication_;
+  Microsoft::WRL::ComPtr<ID3D11Texture2D> staging_;
+
+  std::atomic<bool> running_{false};
+  std::atomic<bool> paused_{false};
+  std::atomic<int> monitor_index_{0};
+  std::atomic<bool> show_cursor_{true};
+  std::thread thread_;
+  int fps_ = 60;
+  cb_desktop_data callback_ = nullptr;
+
+  unsigned char* nv12_frame_ = nullptr;
+  int nv12_width_ = 0;
+  int nv12_height_ = 0;
+};
+}  // namespace crossdesk
+
+#endif