### IDirectDrawSurface3::UpdateOverlayDisplay

The IDirectDrawSurface3::UpdateOverlayDisplay method repaints the rectangles in the dirty rectangle list of all active overlays. This clears the dirty rectangle list. This method is for software emulation onlyžit does nothing if the hardware supports overlays.

HRESULT UpdateOverlayDisplay(

DWORD dwFlags

);

##### Parameters

dwFlags
  Type of update to perform. One of the following flags:

  DDOVER_REFRESHDIRTYRECTS
  | Updates the overlay display using the list of dirty rectangles previously constructed for this destination. This clears the dirty rectangle list.
  DDOVER_REFRESHALL
  | Ignores the dirty rectangle list and updates the overlay display completely. This clears the dirty rectangle list.

##### 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_INVALIDSURFACETYPE
DDERR_UNSUPPORTED

##### Remarks

This method is not currently implemented.

##### See Also

IDirectDrawSurface3::AddOverlayDirtyRect