IDirectDrawSurface3::SetSurfaceDesc

DDraw vtable[39] → HRESULT

IDirectDrawSurface3::SetSurfaceDesc is a method of the COM interface IDirectDrawSurface3 in DirectDraw. Its function pointer sits at vtable index 39 — 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 2 parameters (surface_desc, flags) and returns HRESULT.

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. The parameter order and types below are the ones this interface declares.