Non ho capito bene l'indentazione ma è una cosa del genere
codice:
subroutine raypacket (from, to)
   stack calls
   push(calls, (from, to))
   while not empty(calls) do
     (from, to) = pop(calls)
     if from = to then raytraverse(from)  //problema banale 
     if from-to=1 then raytraverse(to); raytraverse(from) // problema banale
     else
      destination1=raytraverse(from)
      destination2=raytraverse(to)
      if destination1=destination2 then
        if from - to > 1 then linear_interpolate_distance(from,to)
      else begin
        push(calls, (from+(to-from)/2+1,to))
        push(calls, (from,from+(to-from)/2))
      end
     end
   end