2 interval.hh -- part of flowerlib
4 (c) 1996--2006 Han-Wen Nienhuys
12 #include "std-string.hh"
14 #include "flower-proto.hh"
15 #include "drul-array.hh"
17 /* A T interval. This represents the closed interval [left,right].
18 No invariants. T must be a totally ordered ring (with division, anyway ..)
19 At instantiation, the function infinity () has to be defined explicitely. */
21 struct Interval_t : public Drul_array<T>
24 Drul_array<T>::elem_ref;
27 static std::string T_to_string (T arg);
32 elem_ref (RIGHT) += t;
37 elem_ref (RIGHT) += t;
40 T distance (T t) const
43 return T (t - elem (RIGHT));
44 else if (t < elem (LEFT))
45 return T (elem (LEFT) - t);
51 *this and h are comparable
53 void unite (Interval_t<T> h);
54 void intersect (Interval_t<T> h);
57 elem_ref (LEFT) = min (elem (LEFT), p);
58 elem_ref (RIGHT) = max (elem (RIGHT), p);
66 TODO: strip hungarian suffix.
68 bool is_empty () const
70 return elem (LEFT) > elem (RIGHT);
72 bool superset (Interval_t<T> const &) const;
77 Interval_t (Drul_array<T> const &src)
82 Interval_t (T m, T M) : Drul_array<T> (m, M)
85 Interval_t<T> &operator -= (T r)
91 Interval_t<T> &operator += (T r)
94 elem_ref (RIGHT) += r;
97 Interval_t<T> &operator *= (T r)
101 elem_ref (LEFT) *= r;
102 elem_ref (RIGHT) *= r;
109 Real linear_combination (Real x) const
111 Drul_array<Real> da (elem (LEFT), elem (RIGHT));
112 return ::linear_combination (da, x);
114 std::string to_string () const;
116 bool contains (T r) const;
122 elem_ref (RIGHT) = r;
128 elem_ref (LEFT) = elem (RIGHT);
129 elem_ref (RIGHT) = t;
132 static int left_comparison (Interval_t<T> const &a, Interval_t<T> const &b)
134 return sign (a[LEFT] - b[RIGHT]);
139 inclusion ordering. Crash if not comparable.
142 int Interval__compare (const Interval_t<T> &, Interval_t<T> const &);
145 Inclusion ordering. return -2 if not comparable
149 _Interval__compare (const Interval_t<T> &a, Interval_t<T> const &b);
155 #include "compare.hh"
157 TEMPLATE_INSTANTIATE_COMPARE (Interval_t<T> &, Interval__compare, template<class T>);
161 intersection (Interval_t<T> a, Interval_t<T> const &b)
169 Interval_t<T> operator + (T a, Interval_t<T> i)
177 Interval_t<T> operator - (Interval_t<T> i, T a)
185 Interval_t<T> operator - (T a, Interval_t<T> i)
194 Interval_t<T> operator + (Interval_t<T> i, T a)
201 Interval_t<T> operator * (T a, Interval_t<T> i)
209 Interval_t<T> operator * (Interval_t<T> i, T a)
216 Interval_t<T>::center () const
218 assert (!is_empty ());
219 return (elem (LEFT) + elem (RIGHT)) / T (2);
222 typedef Interval_t<Real> Interval;
223 typedef Interval_t<int> Slice; // weird name
226 #endif // INTERVAL_HH