1 files changed, 58 insertions, 0 deletions
diff --git a/flower/interval.hh b/flower/interval.hh
new file mode 100644
index 0000000000..950945ca87
--- /dev/null
+++ b/flower/interval.hh
@@ -0,0 +1,58 @@
+/*
+  interval.hh -- part of flowerlib
+  
+  (c) 1996 Han-Wen Nienhuys
+*/
+
+#ifndef INTERVAL_HH
+#define INTERVAL_HH
+
+#include <assert.h> 
+#include "real.hh"
+
+
+/// a Real interval
+struct Interval {
+    Real min, max;
+
+    void translate(Real t) {
+	min += t;
+	max += t;
+    }
+    Real operator[](int j) {
+	if (j==-1)
+	    return min;
+	else if (j==1)
+	    return max;
+	else
+	    assert(false);
+	    return 0.0;
+		
+    }
+    void unite(Interval h) {
+	if (h.min<min)
+	    min = h.min;
+	if (h.max>max)
+	    max = h.max;
+    }
+    Real length() const;
+    void set_empty() ;
+    bool empty() { return min > max; }
+    Interval() {
+	set_empty();
+    }
+    Interval(Real m, Real M) {
+	min =m;
+	max = M;
+    }
+    Interval &operator += (Real r) {
+	min += r;
+	max +=r;
+	return *this;
+    }
+};
+
+
+#endif // INTERVAL_HH
+
+