/*
* This is part of Geomajas, a GIS framework, http://www.geomajas.org/.
*
* Copyright 2008-2011 Geosparc nv, http://www.geosparc.com/, Belgium.
*
* The program is available in open source according to the GNU Affero
* General Public License. All contributions in this program are covered
* by the Geomajas Contributors License Agreement. For full licensing
* details, see LICENSE.txt in the project root.
*/
package org.geomajas.gwt.client.spatial.geometry;
import org.geomajas.geometry.Coordinate;
import org.geomajas.gwt.client.spatial.Bbox;
import org.geomajas.layer.LayerType;
/**
* MultiPolygon client-side GWT object.
*
* @author Pieter De Graef
*/
public class MultiPolygon extends AbstractGeometry {
private static final long serialVersionUID = -5493083055951288577L;
private Polygon[] polygons;
// -------------------------------------------------------------------------
// Constructor
// -------------------------------------------------------------------------
MultiPolygon(int srid, int precision) {
super(srid, precision);
}
MultiPolygon(int srid, int precision, Polygon[] polygons) {
super(srid, precision);
this.polygons = polygons;
}
// -------------------------------------------------------------------------
// Geometry implementation:
// -------------------------------------------------------------------------
/**
* Create a copy of this geometry and return it.
*/
public Object clone() {
return getGeometryFactory().createMultiPolygon(polygons);
}
public Geometry getGeometryN(int n) {
if (isEmpty()) {
return null;
}
if (n >= 0 && n < polygons.length) {
return polygons[n];
}
return this;
}
/**
* Return the number of polygons.
*/
public int getNumGeometries() {
if (isEmpty()) {
return 0;
}
return polygons.length;
}
Polygon[] getPolygons() {
return polygons;
}
void setPolygons(Polygon[] polygons) {
this.polygons = polygons;
}
/**
* Return the sum of all the points of all the polygons in this MultiPolygon.
*/
public int getNumPoints() {
if (isEmpty()) {
return 0;
}
int total = 0;
for (Polygon polygon : polygons) {
total += polygon.getNumPoints();
}
return total;
}
/**
* Return the added number of polygon area's.
*/
public double getArea() {
double area = 0;
if (!isEmpty()) {
for (Polygon polygon : polygons) {
area += polygon.getArea();
}
}
return area;
}
/**
* Return the total length.
*/
public double getLength() {
double len = 0;
if (!isEmpty()) {
for (Polygon polygon : polygons) {
len += polygon.getLength();
}
}
return len;
}
/**
* The centroid is also known as the "center of gravity" or the "center of mass".
*
* @return Return the center point.
*/
public Coordinate getCentroid() {
if (isEmpty()) {
return null;
}
double sumX = 0;
double sumY = 0;
double totalLength = 0;
Coordinate[] coordinates = new Coordinate[polygons.length];
for (int i = 0; i < polygons.length; i++) {
coordinates[i] = polygons[i].getCentroid();
}
for (int i = 0; i < coordinates.length - 1; i++) {
double length = coordinates[i].distance(coordinates[i + 1]);
totalLength += length;
double midx = (coordinates[i].getX() + coordinates[i + 1].getX()) / 2;
sumX += length * midx;
double midy = (coordinates[i].getY() + coordinates[i + 1].getY()) / 2;
sumY += length * midy;
}
return new Coordinate(sumX / totalLength, sumY / totalLength);
}
/**
* Return the minimal distance between this coordinate and any vertex of the geometry.
*
* @return Return the minimal distance
*/
public double getDistance(Coordinate coordinate) {
double distance = Double.MAX_VALUE;
if (!isEmpty()) {
for (Polygon polygon : polygons) {
double d = polygon.getDistance(coordinate);
if (d < distance) {
distance = d;
}
}
}
return distance;
}
/**
* Checks all it's polygons for validity.
*/
public boolean isValid() {
if (!isEmpty()) {
for (int i = 0; i < polygons.length; i++) {
if (!polygons[i].isValid()) {
return false;
}
for (int j = i + 1; j < polygons.length; j++) {
if (polygons[i].intersects(polygons[j])) {
return false;
}
}
}
}
return true;
}
public boolean isEmpty() {
return (polygons == null || polygons.length == 0);
}
/**
* Return the closest bounding box around the geometry.
*/
public Bbox getBounds() {
Bbox bounds = null;
if (!isEmpty()) {
for (Polygon polygon : polygons) {
if (bounds == null) {
bounds = polygon.getBounds();
} else {
bounds = bounds.union(polygon.getBounds());
}
}
}
return bounds;
}
public Coordinate getCoordinate() {
if (isEmpty()) {
return null;
}
return polygons[0].getCoordinate();
}
/**
* Return the concatenated array of all coordinates of all polygons in this MultiPolygon geometry.
*/
public Coordinate[] getCoordinates() {
if (isEmpty()) {
return null;
}
Coordinate[] coordinates = new Coordinate[getNumPoints()];
int count = 0;
for (Polygon polygon : polygons) {
Coordinate[] polyCoords = polygon.getCoordinates();
for (Coordinate polyCoord : polyCoords) {
coordinates[count++] = polyCoord;
}
}
return coordinates;
}
public LayerType getLayerType() {
return LayerType.MULTIPOLYGON;
}
public String toWkt() {
if (isEmpty()) {
return "MULTIPOLYGON(EMPTY)";
}
String wkt = "MULTIPOLYGON(";
for (int i = 0; i < polygons.length; i++) {
String lineWkt = polygons[i].toWkt();
if (i > 0) {
wkt += ",";
}
wkt += lineWkt.substring(lineWkt.indexOf("("));
}
return wkt + ")";
}
}