follow-up on ef14e59: order also holes when creating final result, fo…

…r deterministic output
onthegomap · Mar 14, 2023 · f71ee5c · f71ee5c
1 parent b7f9ad7
commit f71ee5c
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Showing 2 changed files with 18 additions and 1 deletion.
diff --git a/planetiler-core/src/main/java/com/onthegomap/planetiler/reader/osm/OsmMultipolygon.java b/planetiler-core/src/main/java/com/onthegomap/planetiler/reader/osm/OsmMultipolygon.java
@@ -72,7 +72,7 @@ private Ring(Polygon geom) {
     public Polygon toPolygon() {
       return GeoUtils.JTS_FACTORY.createPolygon(
         geom.getExteriorRing(),
-        holes.stream().map(ring -> ring.geom.getExteriorRing()).toArray(LinearRing[]::new)
+        holes.stream().sorted(BY_AREA_DESCENDING).map(ring -> ring.geom.getExteriorRing()).toArray(LinearRing[]::new)
       );
     }
 

diff --git a/planetiler-core/src/test/java/com/onthegomap/planetiler/reader/osm/OsmMultipolygonTest.java b/planetiler-core/src/test/java/com/onthegomap/planetiler/reader/osm/OsmMultipolygonTest.java
@@ -260,6 +260,23 @@ void testSimplePolygonWithMultipleHoles() throws GeometryException {
     );
   }
 
+  @Test
+  void testSimplePolygonWithMultipleHolesOrdering() throws GeometryException {
+    testBuildMultipolygon(
+      List.of(
+        rectangleNodes(0, 10),
+        rectangleNodes(3, 5),
+        rectangleNodes(1, 2),
+        rectangleNodes(6, 9)
+      ),
+      newPolygon(
+        rectangleCoordList(0, 10),
+        List.of(rectangleCoordList(6, 9), rectangleCoordList(3, 5), rectangleCoordList(1, 2))
+      ),
+      true
+    );
+  }
+
   public List<Node> rectangleNodes(double xMin, double yMin, double xMax, double yMax) {
     var startEnd = node(xMin, yMin);
     return List.of(startEnd, node(xMax, yMin), node(xMax, yMax), node(xMin, yMax), startEnd);