兔子-判断点在多边形内

private boolean IsPointInPolygon(List<LatLng> poly, LatLng pt) {
    int i, j;
    boolean c = false;
    for (i = 0, j = poly.size() - 1; i < poly.size(); j = i++) {
      if ((((poly.get(i).latitude <= pt.latitude) && (pt.latitude < poly
          .get(j).latitude)) || ((poly.get(j).latitude <= pt.latitude) && (pt.latitude < poly
          .get(i).latitude)))
          && (pt.longitude < (poly.get(j).longitude - poly.get(i).longitude)
              * (pt.latitude - poly.get(i).latitude)
              / (poly.get(j).latitude - poly.get(i).latitude)
              + poly.get(i).longitude)) {
        c = !c;
      }
    }
    return c;
  }