/*
interval.hh -- part of flowerlib
-
- (c) 1996 Han-Wen Nienhuys
+
+ (c) 1996--2006 Han-Wen Nienhuys
*/
#ifndef INTERVAL_HH
#define INTERVAL_HH
-#include <assert.h>
+#include <math.h>
+
#include "flower-proto.hh"
-#include "real.hh"
#include "drul-array.hh"
-/** a T interval. this represents the closed interval [left,right].
- No invariants. T must be a totally ordered ring (with division, anyway ..)
- At instantiation, the function infinity () has to be defined explicitely.
-
- */
+/* A T interval. This represents the closed interval [left,right].
+ No invariants. T must be a totally ordered ring (with division, anyway ..)
+ At instantiation, the function infinity () has to be defined explicitely. */
template<class T>
-struct Interval_t : public Drul_array<T> {
+struct Interval_t : public Drul_array<T>
+{
+ Drul_array<T>::elem;
+ Drul_array<T>::elem_ref;
- /* ************** */
-
- static T infinity () ;
- static String T_to_str (T arg);
- T center () { return (elem (LEFT) + elem (RIGHT)) / T (2);}
+ static T infinity ();
+ static String T_to_string (T arg);
+ T center () const;
void translate (T t)
- {
- elem (LEFT) += t;
- elem (RIGHT) += t;
- }
-
+ {
+ elem_ref (LEFT) += t;
+ elem_ref (RIGHT) += t;
+ }
+ void widen (T t)
+ {
+ elem_ref (LEFT) -= t;
+ elem_ref (RIGHT) += t;
+ }
+
+ T distance (T t) const
+ {
+ if (t > elem (RIGHT))
+ return T (t - elem (RIGHT));
+ else if (t < elem (LEFT))
+ return T (elem (LEFT) - t);
+ else
+ return T (0);
+ }
/**
- PRE
- *this and h are comparable
- */
+ PRE
+ *this and h are comparable
+ */
void unite (Interval_t<T> h);
void intersect (Interval_t<T> h);
-
+ void add_point (T p)
+ {
+ elem_ref (LEFT) = min (elem (LEFT), p);
+ elem_ref (RIGHT) = max (elem (RIGHT), p);
+ }
T length () const;
- void set_empty () ;
- bool empty_b () const { return elem (LEFT) > elem (RIGHT); }
- bool contains_b (Interval_t<T> const&) const;
- Interval_t () {
+ T delta () const;
+ void set_empty ();
+ void set_full ();
+
+ /*
+ TODO: strip hungarian suffix.
+ */
+ bool is_empty () const
+ {
+ return elem (LEFT) > elem (RIGHT);
+ }
+ bool superset (Interval_t<T> const &) const;
+ Interval_t ()
+ {
set_empty ();
}
- Interval_t (T m, T M) : Drul_array<T> (m,M)
- {}
- Interval_t<T> &operator -= (T r) {
+ Interval_t (Drul_array<T> const &src)
+ : Drul_array<T> (src)
+ {
+ }
+
+ Interval_t (T m, T M) : Drul_array<T> (m, M)
+ {
+ }
+ Interval_t<T> &operator -= (T r)
+ {
*this += -r;
return *this;
}
- Interval_t<T> &operator += (T r) {
- elem (LEFT) += r;
- elem (RIGHT) +=r;
+ Interval_t<T> &operator += (T r)
+ {
+ elem_ref (LEFT) += r;
+ elem_ref (RIGHT) += r;
return *this;
}
- Interval_t<T> &operator *= (T r) {
- if (!empty_b ())
+ Interval_t<T> &operator *= (T r)
+ {
+ if (!is_empty ())
{
- elem (LEFT) *= r;
- elem (RIGHT) *= r;
- if (r < T (0)) {
- T t = elem (LEFT);
- elem (LEFT) = elem (RIGHT);
- elem (RIGHT) = t;
- }
+ elem_ref (LEFT) *= r;
+ elem_ref (RIGHT) *= r;
+ if (r < T (0))
+ swap ();
}
return *this;
}
- Real linear_combination (Real x) const {
- return ((1.0 - x) * Real (elem (LEFT)) + (x + 1.0) * Real (elem (RIGHT))) * 0.5;
+ Real linear_combination (Real x) const
+ {
+ Drul_array<Real> da (elem (LEFT), elem (RIGHT));
+ return ::linear_combination (da, x);
}
- String str () const;
- void print () const;
- bool elem_b (T r);
- void negate () {
+ String to_string () const;
+
+ bool contains (T r) const;
+ void negate ()
+ {
T r = -elem (LEFT);
T l = -elem (RIGHT);
- elem (LEFT) = l;
- elem (RIGHT) =r;
+ elem_ref (LEFT) = l;
+ elem_ref (RIGHT) = r;
+ }
+
+ void swap ()
+ {
+ T t = elem (LEFT);
+ elem_ref (LEFT) = elem (RIGHT);
+ elem_ref (RIGHT) = t;
}
-};
+ static int left_comparison (Interval_t<T> const &a, Interval_t<T> const &b)
+ {
+ return sign (a[LEFT] - b[RIGHT]);
+ }
+};
/**
- inclusion ordering. Crash if not comparable.
- */
+ inclusion ordering. Crash if not comparable.
+*/
template<class T>
-int Interval__compare (const Interval_t<T>&,Interval_t<T> const&);
+int Interval__compare (const Interval_t<T> &, Interval_t<T> const &);
/**
Inclusion ordering. return -2 if not comparable
- */
+*/
template<class T>
int
-_Interval__compare (const Interval_t<T>&a,Interval_t<T> const&b);
-
+_Interval__compare (const Interval_t<T> &a, Interval_t<T> const &b);
/*
INLINE
- */
+*/
#include "compare.hh"
-TEMPLATE_INSTANTIATE_COMPARE (Interval_t<T>&, Interval__compare, template<class T>);
-
+TEMPLATE_INSTANTIATE_COMPARE (Interval_t<T> &, Interval__compare, template<class T>);
template<class T>
inline Interval_t<T>
-intersection (Interval_t<T> a, Interval_t<T> const&b)
+intersection (Interval_t<T> a, Interval_t<T> const &b)
{
a.intersect (b);
return a;
-
}
template<class T>
inline
-Interval_t<T> operator + (T a,Interval_t<T> i)
+Interval_t<T> operator + (T a, Interval_t<T> i)
{
i += a;
return i;
template<class T>
inline
-Interval_t<T> operator - (T a,Interval_t<T> i)
+Interval_t<T> operator - (T a, Interval_t<T> i)
{
i.negate ();
i += a;
template<class T>
inline
-Interval_t<T> operator + (Interval_t<T> i,T a){
- return a+i;
+Interval_t<T> operator + (Interval_t<T> i, T a)
+{
+ return a + i;
}
template<class T>
inline
-Interval_t<T> operator * (T a,Interval_t<T> i)
+Interval_t<T> operator * (T a, Interval_t<T> i)
{
i *= a;
return i;
template<class T>
inline
-Interval_t<T> operator * (Interval_t<T> i,T a){
- return a*i;
+Interval_t<T> operator * (Interval_t<T> i, T a)
+{
+ return a * i;
+}
+
+template<class T>
+inline T
+Interval_t<T>::center () const
+{
+ assert (!is_empty ());
+ return (elem (LEFT) + elem (RIGHT)) / T (2);
}
-// again? see flower-proto.hh
typedef Interval_t<Real> Interval;
typedef Interval_t<int> Slice; // weird name