How to use

inside

method

in

com.mapbox.turf.TurfJoins

/**
 * Takes a {@link Point} and a {@link Polygon} and determines if the point resides inside the
 * polygon. The polygon can be convex or concave. The function accounts for holes.
 *
 * @param point   which you'd like to check if inside the polygon
 * @param polygon which you'd like to check if the points inside
 * @return true if the Point is inside the Polygon; false if the Point is not inside the Polygon
 * @see <a href="http://turfjs.org/docs/#inside">Turf Inside documentation</a>
 * @since 1.3.0
 */
public static boolean inside(Point point, Polygon polygon) {
 // This API needs to get better
 List<List<Point>> coordinates = polygon.coordinates();
 List<List<List<Point>>> multiCoordinates = new ArrayList<>();
 multiCoordinates.add(coordinates);
 return inside(point, MultiPolygon.fromLngLats(multiCoordinates));
}

/**
 * Takes a {@link FeatureCollection} of {@link Point} and a {@link FeatureCollection} of
 * {@link Polygon} and returns the points that fall within the polygons.
 *
 * @param points   input points.
 * @param polygons input polygons.
 * @return points that land within at least one polygon.
 * @since 1.3.0
 */
public static FeatureCollection pointsWithinPolygon(FeatureCollection points,
                          FeatureCollection polygons) {
 ArrayList<Feature> features = new ArrayList<>();
 for (int i = 0; i < polygons.features().size(); i++) {
  for (int j = 0; j < points.features().size(); j++) {
   Point point = (Point) points.features().get(j).geometry();
   boolean isInside
    = TurfJoins.inside(point, (Polygon) polygons.features().get(i).geometry());
   if (isInside) {
    features.add(Feature.fromGeometry(point));
   }
  }
 }
 return FeatureCollection.fromFeatures(features);
}

@Test
public void testPolyWithHole() throws TurfException, IOException {
 Point ptInHole = Point.fromLngLat(-86.69208526611328, 36.20373274711739);
 Point ptInPoly = Point.fromLngLat(-86.72229766845702, 36.20258997094334);
 Point ptOutsidePoly = Point.fromLngLat(-86.75079345703125, 36.18527313913089);
 Feature polyHole = Feature.fromJson(loadJsonFixture(POLY_WITH_HOLE_FIXTURE));
 assertFalse(TurfJoins.inside(ptInHole, (Polygon) polyHole.geometry()));
 assertTrue(TurfJoins.inside(ptInPoly, (Polygon) polyHole.geometry()));
 assertFalse(TurfJoins.inside(ptOutsidePoly, (Polygon) polyHole.geometry()));
}

@Test
public void testMultipolygonWithHole() throws TurfException, IOException {
 Point ptInHole = Point.fromLngLat(-86.69208526611328, 36.20373274711739);
 Point ptInPoly = Point.fromLngLat(-86.72229766845702, 36.20258997094334);
 Point ptInPoly2 = Point.fromLngLat(-86.75079345703125, 36.18527313913089);
 Point ptOutsidePoly = Point.fromLngLat(-86.75302505493164, 36.23015046460186);
 Feature multiPolyHole = Feature.fromJson(loadJsonFixture(MULTIPOLY_WITH_HOLE_FIXTURE));
 assertFalse(TurfJoins.inside(ptInHole, (MultiPolygon) multiPolyHole.geometry()));
 assertTrue(TurfJoins.inside(ptInPoly, (MultiPolygon) multiPolyHole.geometry()));
 assertTrue(TurfJoins.inside(ptInPoly2, (MultiPolygon) multiPolyHole.geometry()));
 assertFalse(TurfJoins.inside(ptOutsidePoly, (MultiPolygon) multiPolyHole.geometry()));
}

Point ptOut = Point.fromLngLat(140, 150);
assertTrue(TurfJoins.inside(ptIn, poly));
assertFalse(TurfJoins.inside(ptOut, poly));
ptOut = Point.fromLngLat(25, 50);
assertTrue(TurfJoins.inside(ptIn, concavePoly));
assertFalse(TurfJoins.inside(ptOut, concavePoly));

@Test
public void testInputPositions() throws IOException, TurfException {
 Point ptInPoly = Point.fromLngLat(-86.72229766845702, 36.20258997094334);
 Point ptOutsidePoly = Point.fromLngLat(-86.75079345703125, 36.18527313913089);
 Feature polyHole = Feature.fromJson(loadJsonFixture(POLY_WITH_HOLE_FIXTURE));
 Polygon polygon = (Polygon) polyHole.geometry();
 assertTrue(TurfJoins.inside(ptInPoly, polygon));
 assertFalse(TurfJoins.inside(ptOutsidePoly, polygon));
}