IDirectDraw::WaitForVerticalBlank (Windows Embedded CE 6.0)

1/6/2010

This method helps the application synchronize itself with the vertical-blank interval.

Syntax

HRESULT WaitForVerticalBlank(
  DWORD dwFlags, 
  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_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 Value

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:

For more information on these error codes see DirectDraw Return Values.

Remarks

In a preemptive multithreaded environment, it is unlikely that the IDirectDraw::WaitForVerticalBlank method can synchronize with the vertical-blank interval.

Instead, use appropriate wait flags to time blits and flips.

Requirements

See Also

Reference

IDirectDraw
IDirectDraw::GetVerticalBlankStatus
IDirectDraw::GetScanLine