returns true if the face is contained in the general-polygon set,
and false otherwise.
bool
f.visited ()
returns true if the face has been visited, and false otherwise.
This is used internally by the some of the operations of the
General_polygon_set_2 class that traverse the arrangement faces.
Modifiers
void
f.set_contained ( bool flag)
marks the face as contained (if flag is true), or as a hole
(if it is false).
void
f.set_visited ( bool flag)
marks the face as visited (if flag is true), or as not visited
(if it is false). This is used internally by the some of the
operations of the General_polygon_set_2 class that traverse the
arrangement faces.
