Important:
This is retired content. This content is outdated and is no longer being maintained. It is provided as a courtesy for individuals who are still using these technologies. This content may contain URLs that were valid when originally published, but now link to sites or pages that no longer exist.
A version of this page is also available for
4/8/2010

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:

DDERR_INVALIDOBJECT

DDERR_INVALIDPARAMS

DDERR_UNSUPPORTED

DDERR_WASSTILLDRAWING

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

Remarks

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

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

Requirements

Header ddraw.h
Library ddraw.lib
Windows Embedded CE Windows Embedded CE 6.0 and later
Windows Mobile Pocket PC for Windows Mobile Version 5.0 and later, Smartphone for Windows Mobile Version 5.0 and later

See Also