Match only features within distance limit

Without this change an edge can be matched to a feature if their bounding boxes overlap, even if they are far apart.

src/main/java/com/conveyal/r5/analyst/scenario/ShapefileLts.java

@@ -4,7 +4,6 @@
 import com.conveyal.analysis.datasource.DataSourceException;
 import com.conveyal.file.FileStorageFormat;
 import com.conveyal.file.FileStorageKey;
-import com.conveyal.r5.rastercost.ElevationLoader;
 import com.conveyal.r5.shapefile.ShapefileMatcher;
 import com.conveyal.r5.transit.TransportNetwork;
 import com.conveyal.r5.transit.TransportNetworkCache;
@@ -24,8 +23,6 @@
  */
 public class ShapefileLts extends Modification {
 
-    public String ltsDataSource;
-
     /**
      * ID of the linear shapefile DataSource containing bicycle LTS to be matched to streets.
      * We must assume its type because the workers don't have access to the DataStore metadata.
@@ -35,6 +32,8 @@ public class ShapefileLts extends Modification {
     /** The name of the numeric attribute within the ltsDataSource containing LTS values from 1-4. */
     public String ltsAttribute = "lts";
 
+    public double matchLimitMeters = 3.0;
+
     private FileStorageKey fileStorageKey;
 
     private File localFile;
@@ -61,7 +60,7 @@ public boolean apply (TransportNetwork network) {
         network.streetLayer.edgeStore.flags = new TIntArrayList(network.streetLayer.edgeStore.flags);
         ShapefileMatcher shapefileMatcher = new ShapefileMatcher(network.streetLayer);
         try {
-            shapefileMatcher.match(localFile.getAbsolutePath(), ltsAttribute);
+            shapefileMatcher.match(localFile.getAbsolutePath(), ltsAttribute, matchLimitMeters);
         } catch (Exception e) {
             addError(ExceptionUtils.shortAndLongString(e));
         }

src/main/java/com/conveyal/r5/shapefile/ShapefileMatcher.java

@@ -1,14 +1,17 @@
 package com.conveyal.r5.shapefile;
 
+import com.conveyal.r5.common.SphericalDistanceLibrary;
 import com.conveyal.r5.streets.EdgeStore;
 import com.conveyal.r5.streets.StreetLayer;
 import com.conveyal.r5.util.LambdaCounter;
 import com.conveyal.r5.util.ShapefileReader;
 import org.locationtech.jts.algorithm.distance.DiscreteHausdorffDistance;
+import org.locationtech.jts.geom.Coordinate;
 import org.locationtech.jts.geom.Envelope;
 import org.locationtech.jts.geom.LineString;
 import org.locationtech.jts.geom.MultiLineString;
 import org.locationtech.jts.index.strtree.STRtree;
+import org.locationtech.jts.operation.distance.DistanceOp;
 import org.opengis.feature.simple.SimpleFeature;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -18,7 +21,6 @@
 import java.util.List;
 import java.util.stream.IntStream;
 
-import static com.conveyal.r5.streets.EdgeStore.intToLts;
 import static com.conveyal.r5.streets.EdgeStore.EdgeFlag.BIKE_LTS_EXPLICIT;
 
 /**
@@ -59,6 +61,8 @@ public class ShapefileMatcher {
     private StreetLayer streets;
     private int ltsAttributeIndex = -1;
 
+    private double matchLimitMeters;
+
     public ShapefileMatcher (StreetLayer streets) {
         this.streets = streets;
     }
@@ -72,12 +76,15 @@ public ShapefileMatcher (StreetLayer streets) {
      * OSM_INFERRED, OSM_EXPLICIT, SHAPEFILE_MATCH etc. This could also apply to things like speeds and slopes.
      * The values could be retained only for the duration of network building unless we have a reason to keep them.
      */
-    public void match (String shapefileName, String attributeName) {
+    public void match (String shapefileName, String attributeName, double matchLimitMeters) {
         try {
             indexFeatures(shapefileName, attributeName);
         } catch (Throwable t) {
             throw new RuntimeException("Could not load and index shapefile.", t);
         }
+
+        this.matchLimitMeters = matchLimitMeters;
+
         LOG.info("Matching edges and setting bike LTS flags...");
         // Even single-threaded this is pretty fast for small extracts, but it's readily paralellized.
         final LambdaCounter edgePairCounter =
@@ -107,19 +114,23 @@ public void match (String shapefileName, String attributeName) {
                 streets.edgeStore.nEdgePairs() - edgePairCounter.getCount());
     }
 
-    // Match metric is currently Hausdorff distance, eventually replace with something that accounts for overlap length.
+    // For features within the given matchLimitMeters, choose the closest based on Hausdorff distance.
+    // This could eventually be replaced with something that accounts for overlap length.
     private SimpleFeature findBestMatch (LineString edgeGeometry) {
         SimpleFeature bestFeature = null;
         double bestDistance = Double.POSITIVE_INFINITY;
         List<SimpleFeature> features = featureIndex.query(edgeGeometry.getEnvelopeInternal());
         for (SimpleFeature feature : features) {
-            // Note that we're using unprojected coordinates so x distance is exaggerated realtive to y.
-            DiscreteHausdorffDistance dhd = new DiscreteHausdorffDistance(extractLineString(feature), edgeGeometry);
-            double distance = dhd.distance();
-            // distance = overlap(extractLineString(feature), edgeGeometry);
-            if (bestDistance > distance) {
-                bestDistance = distance;
-                bestFeature = feature;
+            Coordinate[] nearestPoints = new DistanceOp(extractLineString(feature), edgeGeometry).nearestPoints();
+            if (SphericalDistanceLibrary.fastDistance(nearestPoints[0], nearestPoints[1]) < matchLimitMeters) {
+                // Note that we're using unprojected coordinates so x distance is exaggerated relative to y.
+                DiscreteHausdorffDistance dhd = new DiscreteHausdorffDistance(extractLineString(feature), edgeGeometry);
+                double distance = dhd.distance();
+                // distance = overlap(extractLineString(feature), edgeGeometry);
+                if (bestDistance > distance) {
+                    bestDistance = distance;
+                    bestFeature = feature;
+                }
             }
         }
         return bestFeature;

src/main/java/com/conveyal/r5/shapefile/ShapefileMatcherMain.java

@@ -21,7 +21,7 @@ public class ShapefileMatcherMain {
     public static void main (String[] args) throws Throwable {
         StreetLayer streetLayer = loadStreetLayer();
         ShapefileMatcher shapefileMatcher = new ShapefileMatcher(streetLayer);
-        shapefileMatcher.match(SHAPE_FILE, SHAPE_FILE_ATTRIBUTE);
+        shapefileMatcher.match(SHAPE_FILE, SHAPE_FILE_ATTRIBUTE, 2.0);
     }
 
     private static StreetLayer loadStreetLayer () {