+ virtual void set_steps (Points const &, bool stepped);
+ virtual void compute_bounding_box () const;
+
+ bool covers (Duple const &) const;
+ /**
+ * Set the distance at which a point will be considered to be covered
+ * by the line. For the definition of "distance" see
+ * utils.cc:distance_to_segment_squared()
+ */
+ void set_covers_threshold (double);
+
+ void set_fill_y1 (double);
+
+private:
+ double _threshold;
+ double _y1;