IDirectDraw4::WaitForVerticalBlank (Windows CE 5.0)
This method helps the application synchronize itself with the vertical-blank interval.
HRESULT WaitForVerticalBlank(DWORDdwFlags,HANDLE hEvent);
Parameters
- dwFlags
Determines how long to wait for the vertical blank. The following table shows the possible flags.Flag Description DDWAITVB_BLOCKBEGIN Returns when the vertical-blank interval begins. DDWAITVB_BLOCKBEGINEVENT Triggers an event when the vertical blank begins. This value is not supported.
DDWAITVB_BLOCKEND Returns when the vertical-blank interval ends and the display begins. - hEvent
Handle of the event to be triggered when the vertical blank begins. This parameter is not currently used.
Return Values
If the method succeeds, the return value is DD_OK.
If the method fails, the return value may be one of the following error values:
| DDERR_INVALIDOBJECT |
| DDERR_INVALIDPARAMS |
| DDERR_UNSUPPORTED |
| DDERR_WASSTILLDRAWING |
Remarks
In a preemptive multithreaded environment, it is unlikely that the IDirectDraw4::WaitForVerticalBlank method can synchronize with the vertical-blank interval.
Instead, use appropriate wait flags to time blits and flips.
Requirements
OS Versions: Windows CE 2.12 and later. Version 2.12 requires DXPAK 1.0 or later.
Header: Ddraw.h.
Link Library: Ddraw.lib.
See Also
IDirectDraw4::GetVerticalBlankStatus | IDirectDraw4::GetScanLine
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