HRESULT Unlock(LPVOID lpSurfaceData);
Notifies DirectDraw that the direct surface manipulations are complete.
·Returns DD_OK if successful, or one of the following error values otherwise:
| DDERR_GENERIC | DDERR_INVALIDOBJECT |
| DDERR_INVALIDPARAMS | DDERR_INVALIDRECT |
| DDERR_NOTLOCKED | DDERR_SURFACELOST |
lpSurfaceData
Address of a pointer returned by the IDirectDrawSurface::Lock method. Since it is possible to call IDirectDrawSurface::Lock multiple times for the same surface with different destination rectangles, this pointer ties the calls to the IDirectDrawSurface::Lock and IDirectDrawSurface::Unlock methods together.