NVAPI establish application profile that disables GSync, FXAA, and sharpening

NvAPIThing.cpp

// This goes in the header file, which probably isn't necessary unless you're exporting the function from a DLL
__declspec(dllexport) NvAPI_Status (__stdcall EstablishNvApiApplicationProfile)(
    const wchar_t* wszProfileName,       // "Paint.NET"
    const wchar_t* wszAppName,           // EXE file path, or Package Family Name
    const wchar_t* wszUserFriendlyName   // EXE file name, or Package Family Name
    );

// CPP file
#include "nvapi/nvapi.h"
#include "nvapi/NvApiDriverSettings.h"
#pragma comment(lib, "nvapi64.lib")

static void SetNVUString(NvAPI_UnicodeString& nvStr, const wchar_t* wcStr)
{
    memset(nvStr, 0, sizeof(NvU16) * NVAPI_UNICODE_STRING_MAX);
    wcscpy_s(reinterpret_cast<wchar_t*>(nvStr), NVAPI_UNICODE_STRING_MAX, wcStr);
}

static NvAPI_Status SetSimpleNvDRSSetting(
    NvDRSSessionHandle hSession,
    NvDRSProfileHandle hProfile,
    NvU32 settingId,
    NVDRS_SETTING_TYPE settingType,
    NvU32 u32CurrentValue)
{
    NVDRS_SETTING nvSetting = { 0 };
    nvSetting.version = NVDRS_SETTING_VER;
    nvSetting.settingId = settingId;
    nvSetting.settingType = settingType;
    nvSetting.u32CurrentValue = u32CurrentValue;

    return NvAPI_DRS_SetSetting(hSession, hProfile, &nvSetting);
}

NvAPI_Status (__stdcall EstablishNvApiApplicationProfile)(
    const wchar_t* wszProfileName,
    const wchar_t* wszAppName,
    const wchar_t* wszUserFriendlyName)
{
    if (wszProfileName == NULL || wszAppName == NULL || wszUserFriendlyName == NULL)
    {
        return NVAPI_INVALID_POINTER;
    }

    NvAPI_Status status = NVAPI_OK;
    bool initialized = false;

    if (NV_SUCCEEDED(status))
    {
        status = NvAPI_Initialize();
        if (NV_SUCCEEDED(status))
        {
            initialized = true;
        }
    }

    NvDRSSessionHandle hSession = 0;
    if (NV_SUCCEEDED(status))
    {
        status = NvAPI_DRS_CreateSession(&hSession);
    }

    if (NV_SUCCEEDED(status))
    {
        status = NvAPI_DRS_LoadSettings(hSession);
    }

    // Find or create the profile
    NvDRSProfileHandle hProfile = 0;
    if (NV_SUCCEEDED(status))
    {
        NVDRS_APPLICATION nvApplication = { 0 };
        nvApplication.version = NVDRS_APPLICATION_VER;

        NvAPI_UnicodeString nvsAppName;
        SetNVUString(nvsAppName, wszAppName);

        // try to look up the profile by appName (path to EXE)
        status = NvAPI_DRS_FindApplicationByName(
            hSession,
            nvsAppName,
            &hProfile,
            &nvApplication);

        if (NV_FAILED(status))
        {
            NvAPI_UnicodeString nvsProfileName;
            SetNVUString(nvsProfileName, wszProfileName);

            // try to look up profile by the profile's name ("Paint.NET")
            status = NvAPI_DRS_FindProfileByName(
                hSession,
                nvsProfileName,
                &hProfile);

            if (NV_FAILED(status))
            {
                NVDRS_PROFILE nvProfile = { 0 };
                nvProfile.version = NVDRS_PROFILE_VER;
                nvProfile.isPredefined = 0;
                SetNVUString(nvProfile.profileName, wszProfileName);

                // create a new profile
                status = NvAPI_DRS_CreateProfile(
                    hSession,
                    &nvProfile,
                    &hProfile);
            }

            // add our EXE to whichever profile we've got
            if (NV_SUCCEEDED(status))
            {
                NVDRS_APPLICATION nvApplication2 = { 0 };
                nvApplication2.version = NVDRS_APPLICATION_VER;
                nvApplication2.isPredefined = 0;

                SetNVUString(nvApplication2.appName, wszAppName);
                SetNVUString(nvApplication2.userFriendlyName, wszUserFriendlyName);
                SetNVUString(nvApplication2.launcher, L"");
                SetNVUString(nvApplication2.fileInFolder, L"");

                status = NvAPI_DRS_CreateApplication(
                    hSession,
                    hProfile,
                    &nvApplication2);
            }
        }
    }

    // This is out here for easier debugging. Errors while setting individual settings are
    // ignored in order to avoid derailing the whole process.
    NvAPI_Status setSettingStatus = NVAPI_OK;

    // Turn off "image sharpening" in the profile. This setting really messes up how the UI looks.
    // TODO: did this change in the latest driver versions? removed or renamed? (dec 2020)
    if (NV_SUCCEEDED(status))
    {
        setSettingStatus = SetSimpleNvDRSSetting(
            hSession,
            hProfile,
            0x00598928,
            NVDRS_DWORD_TYPE,
            0);
    }

    // Turn off GSYNC, which doesn't work well for windowed applications
    // "GSYNC - Application State" set to "Force Off"
    // In the NVCPL, the "Monitor Technology" setting will then be greyed out and say "Not supported for this application".
    // This is the same profile that Microsoft Visual Studio uses, and it's a WPF app that would also have problems with
    // GSYNC. WPA (Windows Performance Analyzer), another WPF app, has the same problems if you don't modify its NVCP settings.
    if (NV_SUCCEEDED(status))
    {
        setSettingStatus = SetSimpleNvDRSSetting(
            hSession,
            hProfile,
            VRR_APP_OVERRIDE_ID,
            NVDRS_DWORD_TYPE,
            VRR_APP_OVERRIDE_FORCE_OFF);
    }

    // Disallow FXAA
    if (NV_SUCCEEDED(status))
    {
        setSettingStatus = SetSimpleNvDRSSetting(
            hSession,
            hProfile,
            FXAA_ALLOW_ID,
            NVDRS_DWORD_TYPE,
            FXAA_ALLOW_DISALLOWED);
    }

    if (NV_SUCCEEDED(status))
    {
        status = NvAPI_DRS_SaveSettings(hSession);
    }

    if (hSession != NULL)
    {
        status = NvAPI_DRS_DestroySession(hSession);
        hSession = NULL;
    }

    if (initialized)
    {
        (void)NvAPI_Unload();
    }

    return status;
}