1 files changed, 8 insertions, 0 deletions
diff --git a/src/value.h b/src/value.h
index f9bd99b..4d8346f 100644
--- a/src/value.h
+++ b/src/value.h
@@ -3,6 +3,7 @@
 
 #include <vector>
 #include <string>
+#include <algorithm>
 
 // Workaround for https://bugreports.qt-project.org/browse/QTBUG-22829
 #ifndef Q_MOC_RUN
@@ -39,6 +40,13 @@ public:
         this->end == other.end;
     }
 
+    /// inverse begin/end if begin is upper than end
+    void normalize() {
+		if (end < begin) {
+			std::swap(begin,end);
+		}
+	}
+
     double begin;
     double step;
     double end;