Retrieves the viewport parameters currently set for the device.
HRESULT GetViewport( D3DVIEWPORT9 * pViewport );
If the method succeeds, the return value is D3D_OK. D3DERR_INVALIDCALL is returned if the pViewport parameter is invalid.
Typically, methods that return state will not work on a device that is created using D3DCREATE_PUREDEVICE. This method however, will work even on a pure device.
Header: Declared in D3d9.h.