IDirect3DResource9::GetType
DX9 vtable[10] → D3DRESOURCETYPE
IDirect3DResource9::GetType is a method of the COM interface IDirect3DResource9 in Direct3D 9. Its function pointer sits at vtable index 10 — the zero-based slot in that interface's virtual method table, counted from QueryInterface and including every entry inherited from a base interface. It takes no parameters and returns D3DRESOURCETYPE.
COM methods are reached through that table rather than by an exported name, so the slot index is what a wrapper, an interface hook or a disassembly listing has to resolve against.