typedef HRESULT (WINAPI* LPD3DENUMTEXTUREFORMATSCALLBACK)
(LPDDSURFACEDESC lpDdsd, LPVOID lpUserArg);
Prototype definition for the callback function to enumerate texture formats.
lpDdsd
Address of the DirectDrawSurface object containing the texture information.
lpUserArg
Address of application-defined data passed to this callback function.
When determining the order in which to call callback functions, the system searches the objects highest in the hierarchy first, and then calls their callback functions in the order in which they were created.