+ void set_state(State s) { set_state(s, s); }
+ void clear_state(State s) { set_state(s, NORMAL); }
+ void set_state(State, State);
+
+ void rebuild();
+ virtual void rebuild_special(const Part &, CachedPart &) { }
+
+public:
+ void render(GL::Renderer &) const;
+protected:
+ virtual void render_special(const Part &, GL::Renderer &) const { }