let register_com ~prefix name args ?more f =
let name = Printf.sprintf "%s_%s" prefix name in
let f args =
match !last_active_multiclip with
None -> ()
| Some mc -> f mc args
in
let c = {
Cam_commands.com_name = name ;
com_args = args ;
com_more_args = more ;
com_f = f ;
}
in
Cam_commands.register c