IDirectDraw::GetMonitorFrequency
HRESULT GetMonitorFrequency(LPDWORD lpdwFrequency);
Returns the frequency of the monitor being driven by the DirectDraw object. The frequency value is returned in Hz multiplied by 100. For example, 60Hz is returned as 6000.
·Returns DD_OK if successful, or one of the following error values otherwise:
DDERR_INVALIDOBJECT DDERR_INVALIDPARAMS
lpdwFrequency
Address of the doubleword to be filled in with the monitor frequency.