sorry, the scanner's not using a c_scan... I just call it scanner. I'm using c_trace. Still, the solutions seem to be similar.
setting the sun non-passable and then back to passable: will that hurt any other c_move? and how about frame rate etc? is it fast? cause then this would be a great and simple idea.

linked list -> will do. exactly what I'm looking for. Do you remember if it's double-linked though? it wouldn't be terrible if not, it would just simplify things.