Merge pull request HSLdevcom#127 from HSLdevcom/fix-proper-multipolygons

Break multipolygons into multiple areas
lassetyr · Mar 10, 2017 · 84d137b · 84d137b
2 parents 45caca6 + f16c8c8
commit 84d137b
Showing 1 changed file with 24 additions and 4 deletions.
diff --git a/src/main/java/org/opentripplanner/graph_builder/module/osm/OSMDatabase.java b/src/main/java/org/opentripplanner/graph_builder/module/osm/OSMDatabase.java
@@ -35,6 +35,7 @@ the License, or (at your option) any later version.
 import org.slf4j.LoggerFactory;
 
 import java.util.*;
+import java.util.stream.Collectors;
 
 public class OSMDatabase implements OpenStreetMapContentHandler {
 
@@ -661,10 +662,29 @@ private void processMultipolygonRelations() {
                 }
             }
             processedAreas.add(relation);
-            try {
-                newArea(new Area(relation, outerWays, innerWays, nodesById));
-            } catch (Area.AreaConstructionException|Ring.RingConstructionException e) {
-                continue;
+
+            Map<Ring, OSMWay> wayForRing = new HashMap<>();
+            List<List<Ring>> groups = new ArrayList<>();;
+            for (OSMWay way : outerWays) {
+                Ring ring = new Ring(way.getNodeRefs(), nodesById);
+                wayForRing.put(ring, way);
+                for (List<Ring> group : groups) {
+                    if (ring.toJtsPolygon().intersects(group.get(0).toJtsPolygon())) {
+                        group.add(ring);
+                        break;
+                    }
+                }
+                groups.add(new ArrayList<>(Collections.singletonList(ring)));
+            }
+
+            for (List<Ring> group : groups) {
+                try {
+                    List<OSMWay> outerRingWays = group.stream().map(wayForRing::get)
+                        .collect(Collectors.toList());
+                    newArea(new Area(relation, outerRingWays, innerWays, nodesById));
+                } catch (Area.AreaConstructionException|Ring.RingConstructionException e) {
+                    continue;
+                }
             }
 
             for (OSMRelationMember member : relation.getMembers()) {