2 interval.hh -- part of flowerlib
4 (c) 1996--2004 Han-Wen Nienhuys
11 #include "flower-proto.hh"
13 #include "drul-array.hh"
15 /* A T interval. This represents the closed interval [left,right].
16 No invariants. T must be a totally ordered ring (with division, anyway ..)
17 At instantiation, the function infinity () has to be defined explicitely. */
19 struct Interval_t : public Drul_array<T>
22 Drul_array<T>::elem_ref;
25 static String T_to_string (T arg);
30 elem_ref (RIGHT) += t;
35 elem_ref (RIGHT) += t;
38 T distance (T t) const
41 return T (t - elem (RIGHT));
42 else if (t < elem (LEFT))
43 return T (elem (LEFT) - t);
49 *this and h are comparable
51 void unite (Interval_t<T> h);
52 void intersect (Interval_t<T> h);
55 elem_ref(LEFT) = elem (LEFT) <? p;
56 elem_ref(RIGHT) = elem (RIGHT) >? p;
64 TODO: strip hungarian suffix.
66 bool is_empty () const
68 return elem (LEFT) > elem (RIGHT);
70 bool superset (Interval_t<T> const&) const;
75 Interval_t (T m, T M) : Drul_array<T> (m,M)
78 Interval_t<T> &operator -= (T r) {
83 Interval_t<T> &operator += (T r) {
88 Interval_t<T> &operator *= (T r) {
92 elem_ref (RIGHT) *= r;
100 Real linear_combination (Real x) const
102 Drul_array<Real> da (elem (LEFT), elem (RIGHT));
103 return ::linear_combination (da, x);
105 String to_string () const;
119 elem_ref (LEFT) = elem (RIGHT);
120 elem_ref (RIGHT) = t;
126 inclusion ordering. Crash if not comparable.
129 int Interval__compare (const Interval_t<T>&,Interval_t<T> const&);
132 Inclusion ordering. return -2 if not comparable
136 _Interval__compare (const Interval_t<T>&a,Interval_t<T> const&b);
143 #include "compare.hh"
145 TEMPLATE_INSTANTIATE_COMPARE (Interval_t<T>&, Interval__compare, template<class T>);
150 intersection (Interval_t<T> a, Interval_t<T> const&b)
159 Interval_t<T> operator + (T a,Interval_t<T> i)
167 Interval_t<T> operator - (Interval_t<T> i, T a)
175 Interval_t<T> operator - (T a,Interval_t<T> i)
184 Interval_t<T> operator + (Interval_t<T> i,T a){
190 Interval_t<T> operator * (T a,Interval_t<T> i)
198 Interval_t<T> operator * (Interval_t<T> i,T a){
205 Interval_t<T>::center () const
207 assert (!is_empty ());
208 return (elem (LEFT) + elem (RIGHT)) / T (2);
211 // again? see flower-proto.hh
212 typedef Interval_t<Real> Interval;
213 typedef Interval_t<int> Slice; // weird name
216 #endif // INTERVAL_HH