X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=flower%2Finclude%2Finterval.hh;h=9808bfaef652768c93d8bb97dd0b1f02716fd030;hb=5b4b0d6e9a197e8f9eb085b7c2ad78b8be3e5cfc;hp=d236759219e1f66887b988b4111cfb1739bda840;hpb=6a1295eaacbc3e6b5a7ce19f7f942b23f8d7f2ff;p=lilypond.git

diff --git a/flower/include/interval.hh b/flower/include/interval.hh
index d236759219..9808bfaef6 100644
--- a/flower/include/interval.hh
+++ b/flower/include/interval.hh
@@ -1,120 +1,162 @@
 /*
   interval.hh -- part of flowerlib
-  
-  (c) 1996 Han-Wen Nienhuys
+
+  (c) 1996--2008 Han-Wen Nienhuys
 */
 
 #ifndef INTERVAL_HH
 #define INTERVAL_HH
 
-#include <assert.h> 
-#include "fproto.hh"
-#include "real.hh"
+#include <math.h>
 
+#include "flower-proto.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 {
-  T left, right;
-
-  /* ************** */
-    
-  static T infinity() ;
-    
-  T center() { return (left + right) / T(2);}
-  void translate (T t) {
-    left += t;
-    right += t;
-  }
-  T& idx (int j) {
-    if (j==-1)
-      return left;
-    else if (j==1)
-      return right;
-    else
-      assert (false);
-    return left;		
+struct Interval_t : public Drul_array<T>
+{
+  Drul_array<T>::at;
+
+  static T infinity ();
+  static string T_to_string (T arg);
+  T center () const;
+  void translate (T t)
+  {
+    at (LEFT) += t;
+    at (RIGHT) += t;
   }
-  T& operator[](int j) {
-    return idx (j);
+  void widen (T t)
+  {
+    at (LEFT) -= t;
+    at (RIGHT) += t;
   }
-  T operator[](int j) const {
-    return ((Interval_t<T> *)this)->idx (j);
+
+  T distance (T t) const
+  {
+    if (t > at (RIGHT))
+      return T (t - at (RIGHT));
+    else if (t < at (LEFT))
+      return T (at (LEFT) - t);
+    else
+      return T (0);
   }
-  T &max() { return right;}
-  T max() const { return right;}
-  T min() const{ return left; }
-  T &min(){ return left; }
   /**
-    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)
+  {
+    at (LEFT) = min (at (LEFT), p);
+    at (RIGHT) = max (at (RIGHT), p);
+  }
+  T length () const;
+  T delta () const;
+  void set_empty ();
+  void set_full ();
+
+  bool is_empty () const
+  {
+    return at (LEFT) > at (RIGHT);
+  }
+  bool superset (Interval_t<T> const &) const;
+  Interval_t ()
+  {
+    set_empty ();
+  }
+  Interval_t (Drul_array<T> const &src)
+    : Drul_array<T> (src)
+  {
+  }
 
-  T length() const;
-  void set_empty() ;
-  bool empty_b() const { return left > right; }
-  bool contains_b (Interval_t<T> const&) const;
-  Interval_t() {
-    set_empty();
+  Interval_t (T m, T M) : Drul_array<T> (m, M)
+  {
   }
-  Interval_t (T m, T M) {
-    left =m;
-    right = M;
+  Interval_t<T> &operator -= (T r)
+  {
+    *this += -r;
+    return *this;
   }
-  Interval_t<T> &operator += (T r) {
-    left += r;
-    right +=r;
+
+  Interval_t<T> &operator += (T r)
+  {
+    at (LEFT) += r;
+    at (RIGHT) += r;
     return *this;
   }
-  Interval_t<T> &operator *=(T r) {
-    left *= r;
-    right *= r;
-    if (r < T(0)) {
-      T t = left;
-      left = right;
-      right = t;
-    }
+  Interval_t<T> &operator *= (T r)
+  {
+    if (!is_empty ())
+      {
+	at (LEFT) *= r;
+	at (RIGHT) *= r;
+	if (r < T (0))
+	  swap ();
+      }
     return *this;
   }
-  String str() const;    
-  void print () const;
-  bool elt_b (T r);
+
+  Real linear_combination (Real x) const;
+  string to_string () const;
+
+  bool contains (T r) const;
+  void negate ()
+  {
+    T r = -at (LEFT);
+    T l = -at (RIGHT);
+    at (LEFT) = l;
+    at (RIGHT) = r;
+  }
+
+  void swap ()
+  {
+    T t = at (LEFT);
+    at (LEFT) = at (RIGHT);
+    at (RIGHT) = t;
+  }
+
+  static bool left_less (Interval_t<T> const &a, Interval_t<T> const &b)
+  {
+    return a[LEFT] < b[RIGHT];
+  }
 };
 
+/**
+   inclusion ordering. Crash if not  comparable.
+*/
+template<class T>
+int Interval__compare (const Interval_t<T> &, Interval_t<T> const &);
 
 /**
-  inclusion ordering. Crash if not comparable.
-  */
+   Inclusion ordering.  return -2 if not comparable
+*/
 template<class T>
-int Interval__compare (const Interval_t<T>&,Interval_t<T> const&);
+int
+_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;
@@ -122,30 +164,54 @@ Interval_t<T> operator +(T a,Interval_t<T> 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)
+{
+  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 *= a;
+  i.negate ();
+  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;
 }
 
-typedef Interval_t<Real> Interval;
-
+template<class T>
+inline
+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;
+}
 
+template<class T>
+inline T
+Interval_t<T>::center () const
+{
+  assert (!is_empty ());
+  return (at (LEFT) + at (RIGHT)) / T (2);
+}
 
-#endif // INTERVAL_HH
+typedef Interval_t<Real> Interval;
+typedef Interval_t<int> Slice;	// weird name
 
 
+#endif // INTERVAL_HH