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IDirectDraw4::WaitForVerticalBlank

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

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_BLOCKBEGINEVENT Triggers an event when the vertical blank begins. This value is not currently 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 will be able to accurately synchronize with the vertical-blank interval. Instead, you should 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

 Last updated on Thursday, April 08, 2004

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