Retrieves a declaration describing the vertices in the mesh.
HRESULT GetDeclaration( D3DVERTEXELEMENT9 Declaration[MAX_FVF_DECL_SIZE] );
If the method succeeds, the return value is D3D_OK. If the method fails, the return value can be D3DERR_INVALIDCALL.
The array of elements includes the D3DDECL_END macro, which ends the declaration.
Header: Declared in D3dx9mesh.h.