Index: DamEngine/trunk/src/Deltares.DamEngine.Data/Geometry/GeometryGenerator.cs
===================================================================
diff -u -r5217 -r5218
--- DamEngine/trunk/src/Deltares.DamEngine.Data/Geometry/GeometryGenerator.cs	(.../GeometryGenerator.cs)	(revision 5217)
+++ DamEngine/trunk/src/Deltares.DamEngine.Data/Geometry/GeometryGenerator.cs	(.../GeometryGenerator.cs)	(revision 5218)
@@ -1049,16 +1049,21 @@
         bool flag2 = Routines2D.DoesPointExistInLine(headPoint1, endPoint1, endPoint2, 0.001);
         bool flag3 = Routines2D.DoesPointExistInLine(headPoint2, endPoint2, headPoint1, 0.001);
         bool flag4 = Routines2D.DoesPointExistInLine(headPoint2, endPoint2, endPoint1, 0.001);
-        double num1 = !headPoint1.Z.IsNearEqual(endPoint1.Z) ? (headPoint1.X - endPoint1.X) / (headPoint1.Z - endPoint1.Z) : double.MaxValue;
-        double num2 = !headPoint2.Z.IsNearEqual(endPoint2.Z) ? (headPoint2.X - endPoint2.X) / (headPoint2.Z - endPoint2.Z) : double.MaxValue;
-        if (Math.Abs(Math.Abs(num1) - Math.Abs(num2)) > 5E-12)
+        double slope1 = !headPoint1.Z.IsNearEqual(endPoint1.Z) ? (headPoint1.X - endPoint1.X) / (headPoint1.Z - endPoint1.Z) : double.MaxValue;
+        double slope2 = !headPoint2.Z.IsNearEqual(endPoint2.Z) ? (headPoint2.X - endPoint2.X) / (headPoint2.Z - endPoint2.Z) : double.MaxValue;
+        if (Math.Abs(Math.Abs(slope1) - Math.Abs(slope2)) > 5E-12)
         {
+            // The lines are not parallel
             if (flag1 && flag2)
             {
+                // When both headPoint2 and endPoint2 are (almost) on line1, then flag point that is closest to line1
+                // When the distance is the same, flag endPoint2
                 DetermineFlagValuesWithDistanceToLine(headPoint2, endPoint2, headPoint1, endPoint1, ref flag1, ref flag2);
             }
             if (flag3 && flag4)
             {
+                // When both headPoint1 and endPoint1 are (almost) on line2, then flag point that is closest to line2
+                // When the distance is the same, flag endPoint1
                 DetermineFlagValuesWithDistanceToLine(headPoint1, endPoint1, headPoint2, endPoint2, ref flag3, ref flag4);
             }
         }
@@ -1067,14 +1072,19 @@
         bool flag6 = Routines2D.DetermineIfPointsCoincide(headPoint1.X, headPoint1.Z, endPoint2.X, endPoint2.Z, 0.001);
         bool flag7 = Routines2D.DetermineIfPointsCoincide(endPoint1.X, endPoint1.Z, headPoint2.X, headPoint2.Z, 0.001);
         bool flag8 = Routines2D.DetermineIfPointsCoincide(endPoint1.X, endPoint1.Z, endPoint2.X, endPoint2.Z, 0.001);
-        if (Math.Abs(Math.Abs(num1) - Math.Abs(num2)) > 5E-12)
+        if (Math.Abs(Math.Abs(slope1) - Math.Abs(slope2)) > 5E-12)
         {
+            // The lines are not parallel
             if (flag5 && flag7)
             {
+                // When both headPoint1 and endPoint1 (almost) coincide with headPoint2, then flag point that is closest to headPoint2
+                // When the distance is the same, flag endPoint1
                 DetermineFlagValuesWithDistanceBetweenPoints(headPoint1, endPoint1, headPoint2, ref flag5, ref flag7);
             }
             if (flag6 && flag8)
             {
+                // When both headPoint1 and endPoint1 (almost) coincide with endPoint2, then flag point that is closest to endPoint2
+                // When the distance is the same, flag endPoint1
                 DetermineFlagValuesWithDistanceBetweenPoints(headPoint1, endPoint1, endPoint2, ref flag6, ref flag8);
             }
         }
@@ -1179,13 +1189,13 @@
             flagB = false;
     }
 
-    private static void DetermineFlagValuesWithDistanceToLine(Point2D point1, Point2D point2, Point2D headPoint, Point2D endPoint,
+    private static void DetermineFlagValuesWithDistanceToLine(Point2D point1, Point2D point2, Point2D linePoint1, Point2D linePoint2,
                                                               ref bool flagA,  ref bool flagB)
     {
         double distancePoint1ToLine = Routines2D.CalculateDistanceToLine(point1.X, point1.Z, 
-                                                                         headPoint.X, headPoint.Z, endPoint.X, endPoint.Z);
+                                                                         linePoint1.X, linePoint1.Z, linePoint2.X, linePoint2.Z);
         double distancePoint2ToLine = Routines2D.CalculateDistanceToLine(point2.X, point2.Z, 
-                                                                         headPoint.X, headPoint.Z, endPoint.X, endPoint.Z);
+                                                                         linePoint1.X, linePoint1.Z, linePoint2.X, linePoint2.Z);
         if (distancePoint1ToLine > distancePoint2ToLine)
             flagA = false;
         else