typedef struct _DD_WAITFORVERTICALBLANKDATA{
PDD_DIRECTDRAW_GLOBAL lpDD;
DWORD dwFlags;
DWORD bIsInVB;
DWORD hEvent;
HRESULT ddRVal;
VOID * WaitForVerticalBlank;
} DD_WAITFORVERTICALBLANKDATA;
The DD_WAITFORVERTICALBLANKDATA structure is passed to the DirectDraw hardware interface’s WaitForVerticalBlank object callback.
Members
lpDD
Pointer to the DD_DIRECTDRAW_GLOBAL structure that describes the driver.
dwFlags
Specifies how the driver should handle the vertical blank. This field can be one of the following values:
| Value | Meaning |
| DDWAITVB_I_TESTVB | Driver should simply return the current status of the vertical blank. |
| DDWAITVB_BLOCKBEGIN | Driver should return from WaitForVerticalBlank only when the vertical blank interval begins. |
| DDWAITVB_BLOCKEND | Driver should return from WaitForVerticalBlank only when the vertical blank interval ends and display begins. |
bIsInVB
Specifies the raster state of the device. A value of TRUE indicates that the device is in a vertical blank; FALSE means that it is not.
hEvent
Handle to the event that the driver should trigger when the specified vertical blank status occurs. This is not currently supported by Windows NT.
ddRVal
Location in which the driver returns a DirectDraw status return code. The status codes are defined in ddraw.h.
WaitForVerticalBlank
Unused by Windows NT.