Gets the fixed vertex function declaration.
HRESULT GetFVF( DWORD * pFVF );
If the method succeeds, the return value is D3D_OK. If the method fails, the return value can be D3DERR_INVALIDCALL.
The fixed vertex function declaration is a set of FVF flags that determine how vertices processed by the fixed function pipeline will be used.
Header: Declared in D3d9.h.