Compartilhar via


IDirectDraw::WaitForVerticalBlank (Compact 2013)

3/26/2014

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 WaitForVerticalBlank method can synchronize with the vertical-blank interval.

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

Requirements

Header

ddraw.h

Library

ddraw.lib

See Also

Reference

IDirectDraw
DirectDraw Reference
DirectDraw Interfaces
IDirectDraw::GetVerticalBlankStatus
IDirectDraw::GetScanLine

Other Resources

DirectDraw