DWORD GetFlipStatus(
PDD_GETFLIPSTATUSDATA lpGetFlipStatus
);
GetFlipStatus queries the driver for its flip status.
GetFlipStatus returns a DDHAL_DRIVER_Xxx callback code that indicates how the driver handled the call. These return codes are defined in ddrawint.h.
The driver should report its flip status based on the flag set in the dwFlags member of lpGetFlipStatus. If the driver is busy and cannot otherwise perform a flip at this time, it should set the ddRVal member to DDERR_WASSTILLDRAWING; otherwise, the driver should set ddRVal to DD_OK.