IDirectDraw7::WaitForVerticalBlank

DDraw vtable[22] → HRESULT

IDirectDraw7::WaitForVerticalBlank is a method of the COM interface IDirectDraw7 in DirectDraw. Its function pointer sits at vtable index 22 — 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 (dwFlags, hEvent) 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.