Java Code Examples for org.locationtech.jts.geom.Geometry#getCentroid()

private void drawTrackPointConnections0(Rendering rendering) {
    // todo - get these styles from vector data node.  (nf)
    rendering.getGraphics().setPaint(strokePaint);
    float scalingFactor = (float) rendering.getViewport().getViewToModelTransform().getScaleX();
    float effectiveStrokeWidth = (float) (scalingFactor * STROKE_WIDTH);
    float effectiveDash = Math.max(1.0F, scalingFactor * 5.0F);
    float effectiveMeterLimit = Math.max(1.0F, scalingFactor * 10.0F);
    BasicStroke basicStroke = new BasicStroke(effectiveStrokeWidth,
                                              BasicStroke.CAP_SQUARE,
                                              BasicStroke.JOIN_MITER,
                                              effectiveMeterLimit,
                                              new float[]{
                                                      effectiveDash,
                                                      effectiveDash},
                                              0.0f);
    rendering.getGraphics().setStroke(basicStroke);

    // FeatureCollection.toArray() returns the feature in original order
    // todo - must actually sort using some (timestamp) attribute (nf)
    SimpleFeature[] features = getVectorDataNode().getFeatureCollection().toArray(new SimpleFeature[0]);
    double lastX = 0;
    double lastY = 0;
    for (int i = 0; i < features.length; i++) {
        SimpleFeature feature = features[i];
        Geometry geometry = (Geometry) feature.getDefaultGeometry();
        org.locationtech.jts.geom.Point centroid = geometry.getCentroid();
        try {
            final Point2D.Double sceneCoords = new Point2D.Double(centroid.getX(), centroid.getY());
            final Point2D.Double modelCoords = new Point2D.Double();
            sceneTransformProvider.getSceneToModelTransform().transform(sceneCoords, modelCoords);
            if (i > 0) {
                rendering.getGraphics().draw(new Line2D.Double(lastX, lastY, centroid.getX(), centroid.getY()));
            }
            lastX = modelCoords.getX();
            lastY = modelCoords.getY();
        } catch (TransformException e) {
            //continue loop
        }
    }
}
 

public double getAreaSimple(final Geometry polygon) throws Exception {
  final Point centroid = polygon.getCentroid();
  final CoordinateReferenceSystem equalAreaCRS = lookupUtmCrs(centroid.getY(), centroid.getX());

  final MathTransform transform =
      CRS.findMathTransform(DefaultGeographicCRS.WGS84, equalAreaCRS, true);

  final Geometry transformedPolygon = JTS.transform(polygon, transform);

  return transformedPolygon.getArea() * SQM_2_SQKM;
}
 

public double getAreaDensify(final Geometry polygon) throws Exception {
  final Point centroid = polygon.getCentroid();
  final CoordinateReferenceSystem equalAreaCRS = lookupUtmCrs(centroid.getY(), centroid.getX());

  final double vertexSpacing = polygon.getLength() / densifyVertexCount;
  final Geometry densePolygon = Densifier.densify(polygon, vertexSpacing);

  final MathTransform transform =
      CRS.findMathTransform(DefaultGeographicCRS.WGS84, equalAreaCRS, true);

  final Geometry transformedPolygon = JTS.transform(densePolygon, transform);

  return transformedPolygon.getArea() * SQM_2_SQKM;
}
 

private static Geometry convert(
    final Geometry value,
    final Class<? extends Geometry> shapeClass) {
  if (shapeClass.isInstance(value)) {
    return value;
  }
  if (shapeClass.isAssignableFrom(Point.class)) {
    return value.getCentroid();
  }
  final Geometry hull = value.convexHull();
  if (shapeClass.isInstance(hull)) {
    return hull;
  }
  return null;
}
 

@Override
public Point getCentroid(final SimpleFeature anObject) {
  final FeatureGeometryHandler handler =
      new FeatureGeometryHandler(anObject.getDefaultGeometryProperty().getDescriptor());
  final Geometry geometry = handler.toIndexValue(anObject).getGeometry();
  final int srid = SimpleFeatureGeometryExtractor.getSRID(anObject);
  final Point point = geometry.getCentroid();
  point.setSRID(srid);
  return point;
}
 

/**
 * If the given object is a JTS geometry, returns its centroid. Otherwise returns {@code null}.
 */
@Override
final Object tryGetCentroid(final Object geometry) {
    if (geometry instanceof Geometry) {
        final Geometry jts = (Geometry) geometry;
        final Point centroid = jts.getCentroid();
        copyMetadata(jts, centroid);
        return centroid;
    }
    return null;
}
 

public static GeoPoint getCentroidFromGeom(Geometry geom) {
    Geometry geom_centroid = geom.getCentroid();
    return new GeoPoint(geom_centroid.getCoordinate().y, geom_centroid.getCoordinate().x);
}
 

public static long hashCentroid(final Geometry geometry) {
  final Point centroid = geometry.getCentroid();
  return Double.doubleToLongBits(centroid.getX()) + Double.doubleToLongBits(centroid.getY() * 31);
}