Isochrones: Reduce number of different sites for edge-based routing

ratrun · Oct 23, 2024 · 49139dd · 49139dd
1 parent cc45cf0
commit 49139dd
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/core/src/main/java/com/graphhopper/isochrone/algorithm/JTSTriangulator.java b/core/src/main/java/com/graphhopper/isochrone/algorithm/JTSTriangulator.java
@@ -63,6 +63,10 @@ public Result triangulate(Snap snap, QueryGraph queryGraph, ShortestPathTree sho
                 PointList innerPoints = edge.fetchWayGeometry(FetchMode.PILLAR_ONLY);
                 if (innerPoints.size() > 0) {
                     int midIndex = innerPoints.size() / 2;
+                    if (innerPoints.size() % 2 == 0 && edge.get(EdgeIteratorState.REVERSE_STATE))
+                        // For edge-based routing we might have explored the same edge in two different directions.
+                        // Here we make sure we only include the **same** point twice instead of two different ones.
+                        midIndex -= 1;
                     double lat2 = innerPoints.getLat(midIndex);
                     double lon2 = innerPoints.getLon(midIndex);
                     Coordinate site2 = new Coordinate(lon2, lat2);