refactored waypoint-matching into map-access-layer

brouter-mapaccess/src/main/java/btools/mapaccess/WaypointMatcherImpl.java

@@ -0,0 +1,157 @@
+package btools.mapaccess;
+
+import java.util.List;
+
+import btools.codec.WaypointMatcher;
+import btools.mapaccess.OsmNode;
+import btools.mapaccess.OsmNodePairSet;
+import btools.util.CheapRuler;
+
+/**
+ * the WaypointMatcher is feeded by the decoder with geoemtries of ways that are
+ * already check for allowed access according to the current routing profile
+ *
+ * It matches these geometries against the list of waypoints to find the best
+ * match for each waypoint
+ */
+public final class WaypointMatcherImpl implements WaypointMatcher
+{
+  private List<MatchedWaypoint> waypoints;
+  private OsmNodePairSet islandPairs;
+
+  private int lonStart;
+  private int latStart;
+  private int lonTarget;
+  private int latTarget;
+  private boolean anyUpdate;
+  private int lonLast;
+  private int latLast;
+
+  public WaypointMatcherImpl( List<MatchedWaypoint> waypoints, double maxDistance, OsmNodePairSet islandPairs )
+  {
+    this.waypoints = waypoints;
+    this.islandPairs = islandPairs;
+    for ( MatchedWaypoint mwp : waypoints )
+    {
+      mwp.radius = maxDistance;
+    }
+  }
+
+  private void checkSegment( int lon1, int lat1, int lon2, int lat2 )
+  {
+    // todo: bounding-box pre-filter
+
+    double[] lonlat2m = CheapRuler.getLonLatToMeterScales( (lat1+lat2) >> 1 );
+    double dlon2m = lonlat2m[0];
+    double dlat2m = lonlat2m[1];
+
+    double dx = ( lon2 - lon1 ) * dlon2m;
+    double dy = ( lat2 - lat1 ) * dlat2m;
+    double d = Math.sqrt( dy * dy + dx * dx );
+
+    if ( d == 0. )
+      return;
+
+    for ( MatchedWaypoint mwp : waypoints )
+    {
+      OsmNode wp = mwp.waypoint;
+
+      double x1 = ( lon1 - wp.ilon ) * dlon2m;
+      double y1 = ( lat1 - wp.ilat ) * dlat2m;
+      double x2 = ( lon2 - wp.ilon ) * dlon2m;
+      double y2 = ( lat2 - wp.ilat ) * dlat2m;
+      double r12 = x1 * x1 + y1 * y1;
+      double r22 = x2 * x2 + y2 * y2;
+      double radius = Math.abs( r12 < r22 ? y1 * dx - x1 * dy : y2 * dx - x2 * dy ) / d;
+
+      if ( radius < mwp.radius )
+      {
+        double s1 = x1 * dx + y1 * dy;
+        double s2 = x2 * dx + y2 * dy;
+
+        if ( s1 < 0. )
+        {
+          s1 = -s1;
+          s2 = -s2;
+        }
+        if ( s2 > 0. )
+        {
+          radius = Math.sqrt( s1 < s2 ? r12 : r22 );
+          if ( radius > mwp.radius )
+            continue;
+        }
+        // new match for that waypoint
+        mwp.radius = radius; // shortest distance to way
+        mwp.hasUpdate = true;
+        anyUpdate = true;
+        // calculate crosspoint
+        if ( mwp.crosspoint == null )
+          mwp.crosspoint = new OsmNode();
+        if ( s2 < 0. )
+        {
+          double wayfraction = -s2 / ( d * d );
+          double xm = x2 - wayfraction * dx;
+          double ym = y2 - wayfraction * dy;
+          mwp.crosspoint.ilon = (int) ( xm / dlon2m + wp.ilon );
+          mwp.crosspoint.ilat = (int) ( ym / dlat2m + wp.ilat );
+        }
+        else if ( s1 > s2 )
+        {
+          mwp.crosspoint.ilon = lon2;
+          mwp.crosspoint.ilat = lat2;
+        }
+        else
+        {
+          mwp.crosspoint.ilon = lon1;
+          mwp.crosspoint.ilat = lat1;
+        }
+      }
+    }
+  }
+
+  @Override
+  public boolean start( int ilonStart, int ilatStart, int ilonTarget, int ilatTarget )
+  {
+    if ( islandPairs.size() > 0 )
+    {
+      long n1 = ( (long) ilonStart ) << 32 | ilatStart;
+      long n2 = ( (long) ilonTarget ) << 32 | ilatTarget;
+      if ( islandPairs.hasPair( n1, n2 ) )
+      {
+        return false;
+      }
+    }
+    lonLast = lonStart = ilonStart;
+    latLast = latStart = ilatStart;
+    lonTarget = ilonTarget;
+    latTarget = ilatTarget;
+    anyUpdate = false;
+    return true;
+  }
+
+  @Override
+  public void transferNode( int ilon, int ilat )
+  {
+    checkSegment( lonLast, latLast, ilon, ilat );
+    lonLast = ilon;
+    latLast = ilat;
+  }
+
+  @Override
+  public void end()
+  {
+    checkSegment( lonLast, latLast, lonTarget, latTarget );
+    if ( anyUpdate )
+    {
+      for ( MatchedWaypoint mwp : waypoints )
+      {
+        if ( mwp.hasUpdate )
+        {
+          mwp.hasUpdate = false;
+          mwp.node1 = new OsmNode( lonStart, latStart );
+          mwp.node2 = new OsmNode( lonTarget, latTarget );
+        }
+      }
+    }
+  }
+}