Added new nearestPointOnLine default and custom distance unit (#1058)

mapbox · Jun 25, 2019 · faa62bf · faa62bf
1 parent a4b4f05
commit faa62bf
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Showing 2 changed files with 54 additions and 10 deletions.
diff --git a/services-turf/src/main/java/com/mapbox/turf/TurfMisc.java b/services-turf/src/main/java/com/mapbox/turf/TurfMisc.java
@@ -2,6 +2,8 @@
 
 import android.support.annotation.FloatRange;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
 import com.mapbox.geojson.Feature;
 import com.mapbox.geojson.LineString;
 import com.mapbox.geojson.Point;
@@ -207,7 +209,6 @@ public static LineString lineSliceAlong(@NonNull LineString line,
     return LineString.fromLngLats(slice);
   }
 
-
   /**
    * Takes a {@link Point} and a {@link LineString} and calculates the closest Point on the
    * LineString.
@@ -219,25 +220,46 @@ public static LineString lineSliceAlong(@NonNull LineString line,
    */
   @NonNull
   public static Feature nearestPointOnLine(@NonNull Point pt, @NonNull List<Point> coords) {
+    return nearestPointOnLine(pt, coords, null);
+  }
+
+  /**
+   * Takes a {@link Point} and a {@link LineString} and calculates the closest Point on the
+   * LineString.
+   *
+   * @param pt point to snap from
+   * @param coords line to snap to
+   * @param units one of the units found inside {@link TurfConstants.TurfUnitCriteria}
+   *              can be degrees, radians, miles, or kilometers
+   * @return closest point on the line to point
+   * @since 4.9.0
+   */
+  @NonNull
+  public static Feature nearestPointOnLine(@NonNull Point pt, @NonNull List<Point> coords,
+                                           @Nullable @TurfConstants.TurfUnitCriteria String units) {
 
     if (coords.size() < 2) {
       throw new TurfException("Turf nearestPointOnLine requires a List of Points "
-        + "made up of at least 2 coordinates.");
+          + "made up of at least 2 coordinates.");
+    }
+
+    if (units == null) {
+      units = TurfConstants.UNIT_KILOMETERS;
     }
 
     Feature closestPt = Feature.fromGeometry(
-      Point.fromLngLat(Double.POSITIVE_INFINITY, Double.POSITIVE_INFINITY));
+        Point.fromLngLat(Double.POSITIVE_INFINITY, Double.POSITIVE_INFINITY));
     closestPt.addNumberProperty("dist", Double.POSITIVE_INFINITY);
 
     for (int i = 0; i < coords.size() - 1; i++) {
       Feature start = Feature.fromGeometry(coords.get(i));
       Feature stop = Feature.fromGeometry(coords.get(i + 1));
       //start
       start.addNumberProperty("dist", TurfMeasurement.distance(
-        pt, (Point) start.geometry(), TurfConstants.UNIT_MILES));
+        pt, (Point) start.geometry(), units));
       //stop
       stop.addNumberProperty("dist", TurfMeasurement.distance(
-        pt, (Point) stop.geometry(), TurfConstants.UNIT_MILES));
+        pt, (Point) stop.geometry(), units));
       //perpendicular
       double heightDistance = Math.max(
         start.properties().get("dist").getAsDouble(),
@@ -246,11 +268,9 @@ public static Feature nearestPointOnLine(@NonNull Point pt, @NonNull List<Point>
       double direction = TurfMeasurement.bearing((Point) start.geometry(),
         (Point) stop.geometry());
       Feature perpendicularPt1 = Feature.fromGeometry(
-        TurfMeasurement.destination(pt, heightDistance, direction + 90,
-          TurfConstants.UNIT_MILES));
+        TurfMeasurement.destination(pt, heightDistance, direction + 90, units));
       Feature perpendicularPt2 = Feature.fromGeometry(
-        TurfMeasurement.destination(pt, heightDistance, direction - 90,
-          TurfConstants.UNIT_MILES));
+        TurfMeasurement.destination(pt, heightDistance, direction - 90, units));
       LineIntersectsResult intersect = lineIntersects(
         ((Point) perpendicularPt1.geometry()).longitude(),
         ((Point) perpendicularPt1.geometry()).latitude(),
@@ -267,7 +287,7 @@ public static Feature nearestPointOnLine(@NonNull Point pt, @NonNull List<Point>
         intersectPt = Feature.fromGeometry(
           Point.fromLngLat(intersect.horizontalIntersection(), intersect.verticalIntersection()));
         intersectPt.addNumberProperty("dist", TurfMeasurement.distance(pt,
-          (Point) intersectPt.geometry(), TurfConstants.UNIT_MILES));
+          (Point) intersectPt.geometry(), units));
       }
 
       if ((double) start.getNumberProperty("dist")

diff --git a/services-turf/src/test/java/com/mapbox/turf/TurfMiscTest.java b/services-turf/src/test/java/com/mapbox/turf/TurfMiscTest.java
@@ -345,6 +345,30 @@ public void testTurfPointOnLinePointsOnSidesOfLines() throws TurfException {
     }
   }
 
+  @Test
+  public void testTurfPointOnLinePointsOnSidesOfLinesCustomUnit() throws TurfException {
+    List<Point> line = new ArrayList<>();
+    line.add(Point.fromLngLat(-122.45616137981413, 37.72125936929241));
+    line.add(Point.fromLngLat(-122.45717525482178, 37.718242366859215));
+    Point first = line.get(0);
+    Point last = line.get(1);
+
+    List<Point> pts = new ArrayList<>();
+    pts.add(Point.fromLngLat(-122.45702505111694, 37.71881098149625));
+    pts.add(Point.fromLngLat(-122.45733618736267, 37.719235317933844));
+    pts.add(Point.fromLngLat(-122.45686411857605, 37.72027068864082));
+    pts.add(Point.fromLngLat(-122.45652079582213, 37.72063561093274));
+
+    for (Point pt : pts) {
+      Feature snappedFeature = TurfMisc.nearestPointOnLine(pt, line, TurfConstants.UNIT_MILES);
+      Point snapped = (Point) snappedFeature.geometry();
+      // pt did not snap to first vertex
+      assertNotEquals(snapped, first);
+      // pt did not snap to last vertex
+      assertNotEquals(snapped, last);
+    }
+  }
+
   @Test
   public void testLineSliceAlongLine1() throws IOException, TurfException {
     Feature line1 = Feature.fromJson(loadJsonFixture(LINE_SLICE_ALONG_LINE_ONE));