The IDirectInputDevice8::GetEffectInfo method can be used to retrieve information about the device's support for an effect whose globally unique identifier (GUID) is known. It retrieves the same information that is returned in the DIEffectInfo structure during enumeration. For more information, see Effect Enumeration.
The following code fetches information about an effect whose GUID is stored in the EffectGuid variable, and determines whether the direction of the effect can be changed without stopping and restarting it:
DIEFFECTINFO diEffectInfo; diEffectInfo.dwSize = sizeof(DIEFFECTINFO); g_lpdid->GetEffectInfo(&diEffectInfo, EffectGuid); if (diEffectInfo.dwDynamicParams & DIEP_DIRECTION) { // Can reset parameter dynamically }