X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=flower%2Finclude%2Finterval.hh;h=9808bfaef652768c93d8bb97dd0b1f02716fd030;hb=5b4b0d6e9a197e8f9eb085b7c2ad78b8be3e5cfc;hp=aae16381dbef62ed5133b332d49714d8260b5070;hpb=01ddcb81463d7a68530971100469d3e2baf8c94b;p=lilypond.git

diff --git a/flower/include/interval.hh b/flower/include/interval.hh
index aae16381db..9808bfaef6 100644
--- a/flower/include/interval.hh
+++ b/flower/include/interval.hh
@@ -1,125 +1,217 @@
 /*
   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
-  */
+/* 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;
-
-    /* ************** */
-    
-    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;		
-    }
-    T& operator[](int j) {
-	return idx(j);
-    }
-    T operator[](int j) const {
-	return ((Interval_t<T> *)this)->idx(j);
-    }
-    T &max() { return right;}
-    T max()const { return right;}
-    T min()const{ return left; }
-    T &min(){ return left; }
-    /**
-      PRE
-      *this and h are comparable
-      */
-    void unite(Interval_t<T> h);
-    void intersect(Interval_t<T> h);
-
-    T length() const;
-    void set_empty() ;
-    bool empty() const { return left > right; }
-    Interval_t() {
-	set_empty();
-    }
-    Interval_t(T m, T M) {
-	left =m;
-	right = M;
-    }
-    Interval_t<T> &operator += (T r) {
-	left += r;
-	right +=r;
-	return *this;
-    }
-    String str() const;    
-    bool elt_q(T r);
+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;
+  }
+  void widen (T t)
+  {
+    at (LEFT) -= t;
+    at (RIGHT) += t;
+  }
+
+  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);
+  }
+  /**
+     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)
+  {
+  }
+
+  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)
+  {
+    at (LEFT) += r;
+    at (RIGHT) += r;
+    return *this;
+  }
+  Interval_t<T> &operator *= (T r)
+  {
+    if (!is_empty ())
+      {
+	at (LEFT) *= r;
+	at (RIGHT) *= r;
+	if (r < T (0))
+	  swap ();
+      }
+    return *this;
+  }
+
+  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;
-    
+  a.intersect (b);
+  return a;
 }
 
+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 +(T a,Interval_t<T> i )
+Interval_t<T> operator - (Interval_t<T> i, T a)
 {
-    i += a;
-    return 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 - (T a, Interval_t<T> i)
+{
+  i.negate ();
+  i += a;
+  return i;
 }
 
-typedef Interval_t<Real> Interval;
+template<class T>
+inline
+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)
+{
+  i *= a;
+  return i;
+}
 
-#define Interval__instantiate(T) template struct Interval_t<T>;\
-  template  int Interval__compare(const Interval_t<T>&,Interval_t<T> const&)
+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