IDirectDraw::GetVerticalBlankStatus
HRESULT GetVerticalBlankStatus(LPBOOL lpbIsInVB);
Returns the status of the vertical blank.
·Returns DD_OK if successful, or one of the following error values otherwise:
DDERR_INVALIDOBJECT DDERR_INVALIDPARAMS
lpbIsInVB
Address of the BOOL to be filled in with the status of the vertical blank.
This method will set the passed BOOL to TRUE if a vertical blank is occurring and to FALSE otherwise. To synchronize with the vertical blank, use the IDirectDraw::WaitForVerticalBlank method.