Add wgc demo

record_desktop_wgc.h

@@ -0,0 +1,65 @@
+#pragma once
+
+#include <Windows.h>
+
+#include "export.h"
+#include "record_desktop.h"
+
+namespace am {
+class record_desktop_wgc : public record_desktop,
+                           public wgc_session::wgc_session_observer {
+  class wgc_session_module {
+    using func_type_is_supported = bool (*)();
+    using func_type_create_session = wgc_session *(*)();
+
+   public:
+    wgc_session_module() {
+      module_ = ::LoadLibraryA("WGC.dll");
+      if (module_) {
+        func_is_supported_ = (func_type_is_supported)::GetProcAddress(
+            module_, "wgc_is_supported");
+        func_create_session_ = (func_type_create_session)::GetProcAddress(
+            module_, "wgc_create_session");
+      }
+    }
+    ~wgc_session_module() {
+      if (module_) ::FreeModule(module_);
+    }
+
+    bool is_supported() const {
+      return func_create_session_ && func_is_supported_();
+    }
+
+    wgc_session *create_session() const {
+      if (!func_create_session_) return nullptr;
+
+      return func_create_session_();
+    }
+
+   private:
+    HMODULE module_ = nullptr;
+    func_type_is_supported func_is_supported_ = nullptr;
+    func_type_create_session func_create_session_ = nullptr;
+  };
+
+ public:
+  record_desktop_wgc();
+  ~record_desktop_wgc();
+
+  int init(const RECORD_DESKTOP_RECT &rect, const int fps) override;
+
+  int start() override;
+  int pause() override;
+  int resume() override;
+  int stop() override;
+
+  void on_frame(const wgc_session::wgc_session_frame &frame) override;
+
+ protected:
+  void clean_up() override;
+
+ private:
+  wgc_session *session_ = nullptr;
+  wgc_session_module module_;
+};
+}  // namespace am