Modify and restore NVIDIA control panel settings

Namely:
- Power profile for sunshine.exe
- Global OpenGL/Vulkan DXGI swapchain

src/platform/windows/nvprefs/nvapi_opensource_wrapper.cpp

@@ -0,0 +1,128 @@
+#include "nvprefs_common.h"
+
+#include <nvapi_interface.h>
+
+namespace {
+
+  std::map<const char *, void *> interfaces;
+  HMODULE dll = NULL;
+
+  template <typename Func, typename... Args>
+  NvAPI_Status
+  call_interface(const char *name, Args... args) {
+    auto func = (Func *) interfaces[name];
+
+    if (!func) {
+      return interfaces.empty() ? NVAPI_API_NOT_INITIALIZED : NVAPI_NOT_SUPPORTED;
+    }
+
+    return func(args...);
+  }
+
+}  // namespace
+
+#undef NVAPI_INTERFACE
+#define NVAPI_INTERFACE NvAPI_Status __cdecl
+
+extern void *
+nvapi_QueryInterface(NvU32 id);
+
+NVAPI_INTERFACE
+NvAPI_Initialize() {
+  if (dll) return NVAPI_OK;
+
+#ifdef _WIN64
+  auto dll_name = "nvapi64.dll";
+#else
+  auto dll_name = "nvapi.dll";
+#endif
+
+  if ((dll = LoadLibraryEx(dll_name, NULL, LOAD_LIBRARY_SEARCH_SYSTEM32))) {
+    if (auto query_interface = (decltype(nvapi_QueryInterface) *) GetProcAddress(dll, "nvapi_QueryInterface")) {
+      for (const auto &item : nvapi_interface_table) {
+        interfaces[item.func] = query_interface(item.id);
+      }
+      return NVAPI_OK;
+    }
+  }
+
+  NvAPI_Unload();
+  return NVAPI_LIBRARY_NOT_FOUND;
+}
+
+NVAPI_INTERFACE
+NvAPI_Unload() {
+  if (dll) {
+    interfaces.clear();
+    FreeLibrary(dll);
+    dll = NULL;
+  }
+  return NVAPI_OK;
+}
+
+NVAPI_INTERFACE
+NvAPI_GetErrorMessage(NvAPI_Status nr, NvAPI_ShortString szDesc) {
+  return call_interface<decltype(NvAPI_GetErrorMessage)>("NvAPI_GetErrorMessage", nr, szDesc);
+}
+
+// This is only a subset of NvAPI_DRS_* functions, more can be added if needed
+
+NVAPI_INTERFACE
+NvAPI_DRS_CreateSession(NvDRSSessionHandle *phSession) {
+  return call_interface<decltype(NvAPI_DRS_CreateSession)>("NvAPI_DRS_CreateSession", phSession);
+}
+
+NVAPI_INTERFACE
+NvAPI_DRS_DestroySession(NvDRSSessionHandle hSession) {
+  return call_interface<decltype(NvAPI_DRS_DestroySession)>("NvAPI_DRS_DestroySession", hSession);
+}
+
+NVAPI_INTERFACE
+NvAPI_DRS_LoadSettings(NvDRSSessionHandle hSession) {
+  return call_interface<decltype(NvAPI_DRS_LoadSettings)>("NvAPI_DRS_LoadSettings", hSession);
+}
+
+NVAPI_INTERFACE
+NvAPI_DRS_SaveSettings(NvDRSSessionHandle hSession) {
+  return call_interface<decltype(NvAPI_DRS_SaveSettings)>("NvAPI_DRS_SaveSettings", hSession);
+}
+
+NVAPI_INTERFACE
+NvAPI_DRS_CreateProfile(NvDRSSessionHandle hSession, NVDRS_PROFILE *pProfileInfo, NvDRSProfileHandle *phProfile) {
+  return call_interface<decltype(NvAPI_DRS_CreateProfile)>("NvAPI_DRS_CreateProfile", hSession, pProfileInfo, phProfile);
+}
+
+NVAPI_INTERFACE
+NvAPI_DRS_FindProfileByName(NvDRSSessionHandle hSession, NvAPI_UnicodeString profileName, NvDRSProfileHandle *phProfile) {
+  return call_interface<decltype(NvAPI_DRS_FindProfileByName)>("NvAPI_DRS_FindProfileByName", hSession, profileName, phProfile);
+}
+
+NVAPI_INTERFACE
+NvAPI_DRS_CreateApplication(NvDRSSessionHandle hSession, NvDRSProfileHandle hProfile, NVDRS_APPLICATION *pApplication) {
+  return call_interface<decltype(NvAPI_DRS_CreateApplication)>("NvAPI_DRS_CreateApplication", hSession, hProfile, pApplication);
+}
+
+NVAPI_INTERFACE
+NvAPI_DRS_GetApplicationInfo(NvDRSSessionHandle hSession, NvDRSProfileHandle hProfile, NvAPI_UnicodeString appName, NVDRS_APPLICATION *pApplication) {
+  return call_interface<decltype(NvAPI_DRS_GetApplicationInfo)>("NvAPI_DRS_GetApplicationInfo", hSession, hProfile, appName, pApplication);
+}
+
+NVAPI_INTERFACE
+NvAPI_DRS_SetSetting(NvDRSSessionHandle hSession, NvDRSProfileHandle hProfile, NVDRS_SETTING *pSetting) {
+  return call_interface<decltype(NvAPI_DRS_SetSetting)>("NvAPI_DRS_SetSetting", hSession, hProfile, pSetting);
+}
+
+NVAPI_INTERFACE
+NvAPI_DRS_GetSetting(NvDRSSessionHandle hSession, NvDRSProfileHandle hProfile, NvU32 settingId, NVDRS_SETTING *pSetting) {
+  return call_interface<decltype(NvAPI_DRS_GetSetting)>("NvAPI_DRS_GetSetting", hSession, hProfile, settingId, pSetting);
+}
+
+NVAPI_INTERFACE
+NvAPI_DRS_DeleteProfileSetting(NvDRSSessionHandle hSession, NvDRSProfileHandle hProfile, NvU32 settingId) {
+  return call_interface<decltype(NvAPI_DRS_DeleteProfileSetting)>("NvAPI_DRS_DeleteProfileSetting", hSession, hProfile, settingId);
+}
+
+NVAPI_INTERFACE
+NvAPI_DRS_GetBaseProfile(NvDRSSessionHandle hSession, NvDRSProfileHandle *phProfile) {
+  return call_interface<decltype(NvAPI_DRS_GetBaseProfile)>("NvAPI_DRS_GetBaseProfile", hSession, phProfile);
+}