static Geometry densify(Geometry geom, CoordinateReferenceSystem crs, double maxAreaError)
      throws FactoryException, TransformException {
    // basic checks
    if (maxAreaError <= 0) {
      throw new IllegalArgumentException("maxAreaError must be greater than 0");
    }
    if (!(geom instanceof Polygon) && !(geom instanceof MultiPolygon)) {
      throw new IllegalArgumentException("Geom must be poligonal");
    }
    if (crs == null) {
      throw new IllegalArgumentException("CRS cannot be set to null");
    }
    double previousArea = 0.0;
    CoordinateReferenceSystem targetCRS = CRS.parseWKT(ECKERT_IV_WKT);
    MathTransform firstTransform = CRS.findMathTransform(crs, targetCRS);
    GeometryFactory geomFactory = new GeometryFactory();
    int ngeom = geom.getNumGeometries();
    Geometry densifiedGeometry = geom;
    double areaError = 1.0d;
    int maxIterate = 0;
    do {
      double max = 0;
      maxIterate++;
      // check the maximum side length of the densifiedGeometry
      for (int j = 0; j < ngeom; j++) {
        Geometry geometry = densifiedGeometry.getGeometryN(j);
        Coordinate[] coordinates = geometry.getCoordinates();
        int n = coordinates.length;
        for (int i = 0; i < (n - 1); i++) {
          Coordinate[] coords = new Coordinate[2];
          coords[0] = coordinates[i];
          coords[1] = coordinates[i + 1];
          LineString lineString = geomFactory.createLineString(coords);
          if (lineString.getLength() > max) max = lineString.getLength();
        }
      }

      // calculate the denified geometry
      densifiedGeometry = Densifier.densify(densifiedGeometry, max / 2);

      // reproject densifiedGeometry to Eckert IV
      Geometry targetGeometry = JTS.transform(densifiedGeometry, firstTransform);
      double nextArea = targetGeometry.getArea();

      // evaluate the current error
      areaError = Math.abs(previousArea - nextArea) / nextArea;
      //      logger3.info("AREA ERROR"+areaError);
      previousArea = nextArea;
      // check whether the current error is greater than the maximum allowed
    } while (areaError > maxAreaError && maxIterate < 10);
    return densifiedGeometry;
  }
Beispiel #2
0
 /**
  * Densify a geometry using the given distance tolerance.
  *
  * @param geometry Geometry
  * @param tolerance Distance tolerance
  * @return Densified geometry
  */
 public static Geometry densify(Geometry geometry, double tolerance) {
   if (geometry == null) {
     return null;
   }
   return Densifier.densify(geometry, tolerance);
 }