Add wgc demo

demo/Win32MonitorEnumeration.h

@@ -0,0 +1,50 @@
+#pragma once
+#include <dwmapi.h>
+
+struct Monitor {
+public:
+  Monitor(nullptr_t) {}
+  Monitor(HMONITOR hmonitor, std::wstring &className, bool isPrimary) {
+    m_hmonitor = hmonitor;
+    m_className = className;
+    m_bIsPrimary = isPrimary;
+  }
+
+  HMONITOR Hmonitor() const noexcept { return m_hmonitor; }
+  std::wstring ClassName() const noexcept { return m_className; }
+  bool IsPrimary() const noexcept { return m_bIsPrimary; }
+
+private:
+  HMONITOR m_hmonitor;
+  std::wstring m_className;
+  bool m_bIsPrimary;
+};
+
+BOOL WINAPI EnumMonitorProc(HMONITOR hmonitor, HDC hdc, LPRECT lprc,
+                            LPARAM data) {
+
+  MONITORINFOEX info_ex;
+  info_ex.cbSize = sizeof(MONITORINFOEX);
+
+  GetMonitorInfo(hmonitor, &info_ex);
+
+  if (info_ex.dwFlags == DISPLAY_DEVICE_MIRRORING_DRIVER)
+    return true;
+
+  auto monitors = ((std::vector<Monitor> *)data);
+  std::wstring name = info_ex.szDevice;
+  auto monitor =
+      Monitor(hmonitor, name, info_ex.dwFlags & MONITORINFOF_PRIMARY);
+
+  monitors->emplace_back(monitor);
+
+  return true;
+}
+
+std::vector<Monitor> EnumerateMonitors() {
+  std::vector<Monitor> monitors;
+
+  ::EnumDisplayMonitors(NULL, NULL, EnumMonitorProc, (LPARAM)&monitors);
+
+  return monitors;
+}