The IDirect3DViewport2::AddLight method adds the specified light to the list of Direct3DLight objects associated with this viewport.
HRESULT AddLight(
LPDIRECT3DLIGHT lpDirect3DLight
);
Parameters
lpDirect3DLight
Address of the Direct3DLight object that should be associated with this Direct3DDevice object.
Return Values
If the method succeeds, the return value is D3D_OK.
If the method fails, the return value may be one of the following values:
DDERR_INVALIDOBJECT 
DDERR_INVALIDPARAMS 
Remarks
This method is unchanged from its implementation in the IDirect3DViewport interface.
QuickInfo
  Windows NT: Use version 5.0 or later.
  Windows: Use Windows 95 or later. Available as a redistributable for Windows 95.
  Windows CE: Unsupported.
  Header: Declared in d3d.h.
  Import Library: Use ddraw.lib.