--- a/cmd/isoareas/main.go	Fri Sep 27 17:13:29 2019 +0200
+++ b/cmd/isoareas/main.go	Fri Sep 27 17:26:43 2019 +0200
@@ -315,32 +315,8 @@
 					segment:
 						for e := pb.open.Front(); e != nil; e = e.Next() {
 							line := e.Value.(octree.LineStringZ)
-							first, last := line[0], line[len(line)-1]
-
-							front, back := curr[0], curr[len(curr)-1]
-
-							if back.EpsEquals(first) {
-								curr = append(curr, line[1:]...)
-								pb.open.Remove(e)
-								goto segment
-							}
-
-							if back.EpsEquals(last) {
-								line.Reverse()
-								curr = append(curr, line[1:]...)
-								pb.open.Remove(e)
-								goto segment
-							}
-
-							if front.EpsEquals(last) {
-								curr = append(line, curr[1:]...)
-								pb.open.Remove(e)
-								goto segment
-							}
-
-							if front.EpsEquals(first) {
-								line.Reverse()
-								curr = append(line, curr[1:]...)
+							if nline := glue(curr, line); nline != nil {
+								curr = nline
 								pb.open.Remove(e)
 								goto segment
 							}