Do not remove first edge of shortest path

onthegomap · Nov 9, 2024 · 49df8b4 · 49df8b4
1 parent 2076034
commit 49df8b4
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Showing 2 changed files with 4 additions and 3 deletions.
diff --git a/planetiler-core/src/main/java/com/onthegomap/planetiler/util/LoopLineMerger.java b/planetiler-core/src/main/java/com/onthegomap/planetiler/util/LoopLineMerger.java
@@ -101,7 +101,7 @@ private void removeLoops() {
     List<Edge> removedEdges = new ArrayList<>();
     for (var node : output) {
       for (var edge : List.copyOf(node.getEdges())) {
-        if (removedEdges.contains(edge)) {
+        if (removedEdges.contains(edge) || removedEdges.contains(edge.reversed)) {
           continue;
         }
         if (edge.from == edge.to && edge.length <= loopMinLength) {
@@ -113,8 +113,9 @@ private void removeLoops() {
         try {
           var allPaths = findAllPaths(edge.from, edge.to, loopMinLength);
           if (allPaths.size() > 1) {
+            var firstEdgeShortestPath = allPaths.get(0).getFirst();
             for (var path : allPaths.subList(1, allPaths.size())) {
-              if (path.size() > 0) {
+              if (path.size() > 0 && !firstEdgeShortestPath.equals(path.get(0))) {
                 removedEdges.add(path.get(0));
                 path.get(0).remove();
               }

diff --git a/planetiler-core/src/test/java/com/onthegomap/planetiler/util/LoopLineMergerTest.java b/planetiler-core/src/test/java/com/onthegomap/planetiler/util/LoopLineMergerTest.java
@@ -259,7 +259,7 @@ void testMergeCarriagewaysWithTwoSplits() {
   @Test
   void testRealWorldHarkingen() {
     var merger = new LoopLineMerger()
-      .setMinLength(0)
+      .setMinLength(4 * 0.0625)
       .setLoopMinLength(8 * 0.0625);
 
     merger.add(newLineString(99.185791015625,109.83056640625, 99.202392578125,109.8193359375, 99.21337890625,109.810302734375, 99.222412109375,109.8017578125, 99.229736328125,109.793701171875, 99.241943359375,109.779541015625));