/**
* Buffer polygons by buffering the individual boundary segments and either unioning or
* differencing them.
*
* @param g
* @param distance
* @return the buffer geometry
*/
public static Geometry bufferBySegments(Geometry g, double distance) {
Geometry segs = LineHandlingFunctions.extractSegments(g);
double posDist = Math.abs(distance);
Geometry segBuf = bufferByComponents(segs, posDist);
if (distance < 0.0) return g.difference(segBuf);
return g.union(segBuf);
}
private GeometryCollection editGeometryCollection(
GeometryCollection collection, GeometryEditorOperation operation) {
// first edit the entire collection
// MD - not sure why this is done - could just check original collection?
GeometryCollection collectionForType = (GeometryCollection) operation.edit(collection, factory);
// edit the component geometries
ArrayList geometries = new ArrayList();
for (int i = 0; i < collectionForType.getNumGeometries(); i++) {
Geometry geometry = edit(collectionForType.getGeometryN(i), operation);
if (geometry == null || geometry.isEmpty()) {
continue;
}
geometries.add(geometry);
}
if (collectionForType.getClass() == MultiPoint.class) {
return factory.createMultiPoint((Point[]) geometries.toArray(new Point[] {}));
}
if (collectionForType.getClass() == MultiLineString.class) {
return factory.createMultiLineString((LineString[]) geometries.toArray(new LineString[] {}));
}
if (collectionForType.getClass() == MultiPolygon.class) {
return factory.createMultiPolygon((Polygon[]) geometries.toArray(new Polygon[] {}));
}
return factory.createGeometryCollection((Geometry[]) geometries.toArray(new Geometry[] {}));
}
static double area(Collection geoms) {
double area = 0.0;
for (Iterator i = geoms.iterator(); i.hasNext(); ) {
Geometry geom = (Geometry) i.next();
area += geom.getArea();
}
return area;
}
private static Polygon findPolygonContaining(Geometry geom, Coordinate pt) {
PointLocator locator = new PointLocator();
for (int i = 0; i < geom.getNumGeometries(); i++) {
Polygon poly = (Polygon) geom.getGeometryN(i);
int loc = locator.locate(pt, poly);
if (loc == Location.INTERIOR) return poly;
}
return null;
}
/**
* Gets a {@link LineString} which is a minimum diameter
*
* @return a {@link LineString} which is a minimum diameter
*/
public LineString getDiameter() {
computeMinimumDiameter();
// return empty linestring if no minimum width calculated
if (minWidthPt == null) return inputGeom.getFactory().createLineString((Coordinate[]) null);
Coordinate basePt = minBaseSeg.project(minWidthPt);
return inputGeom.getFactory().createLineString(new Coordinate[] {basePt, minWidthPt});
}
/**
* Edit the input {@link Geometry} with the given edit operation. Clients can create subclasses of
* {@link GeometryEditorOperation} or {@link CoordinateOperation} to perform required
* modifications.
*
* @param geometry the Geometry to edit
* @param operation the edit operation to carry out
* @return a new {@link Geometry} which is the result of the editing (which may be empty)
*/
public Geometry edit(Geometry geometry, GeometryEditorOperation operation) {
// nothing to do
if (geometry == null) return null;
Geometry result = editInternal(geometry, operation);
if (isUserDataCopied) {
result.setUserData(geometry.getUserData());
}
return result;
}
public static Geometry componentBuffers(Geometry g, double distance) {
List bufs = new ArrayList();
for (Iterator it = new GeometryCollectionIterator(g); it.hasNext(); ) {
Geometry comp = (Geometry) it.next();
if (comp instanceof GeometryCollection) continue;
bufs.add(comp.buffer(distance));
}
return FunctionsUtil.getFactoryOrDefault(g)
.createGeometryCollection(GeometryFactory.toGeometryArray(bufs));
}
public static Geometry bufferByChains(Geometry g, double distance, int maxChainSize) {
if (maxChainSize <= 0)
throw new IllegalArgumentException(
"Maximum Chain Size must be specified as an input parameter");
Geometry segs = LineHandlingFunctions.extractChains(g, maxChainSize);
double posDist = Math.abs(distance);
Geometry segBuf = bufferByComponents(segs, posDist);
if (distance < 0.0) return g.difference(segBuf);
return g.union(segBuf);
}
static List findIntersecting(Collection targetGeoms, Geometry queryGeom) {
List result = new ArrayList();
for (Iterator it = targetGeoms.iterator(); it.hasNext(); ) {
Geometry test = (Geometry) it.next();
if (test.intersects(queryGeom)) {
result.add(test);
}
}
return result;
}
public static List extractElements(Geometry geom, boolean skipEmpty) {
List elem = new ArrayList();
if (geom == null) return elem;
for (int i = 0; i < geom.getNumGeometries(); i++) {
Geometry elemGeom = geom.getGeometryN(i);
if (skipEmpty && elemGeom.isEmpty()) continue;
elem.add(elemGeom);
}
return elem;
}
/**
* Gets the minimum rectangular {@link Polygon} which encloses the input geometry. The rectangle
* has width equal to the minimum diameter, and a longer length. If the convex hull of the input
* is degenerate (a line or point) a {@link LineString} or {@link Point} is returned.
*
* <p>The minimum rectangle can be used as an extremely generalized representation for the given
* geometry.
*
* @return the minimum rectangle enclosing the input (or a line or point if degenerate)
*/
public Geometry getMinimumRectangle() {
computeMinimumDiameter();
// check if minimum rectangle is degenerate (a point or line segment)
if (minWidth == 0.0) {
if (minBaseSeg.p0.equals2D(minBaseSeg.p1)) {
return inputGeom.getFactory().createPoint(minBaseSeg.p0);
}
return minBaseSeg.toGeometry(inputGeom.getFactory());
}
// deltas for the base segment of the minimum diameter
double dx = minBaseSeg.p1.x - minBaseSeg.p0.x;
double dy = minBaseSeg.p1.y - minBaseSeg.p0.y;
/*
double c0 = computeC(dx, dy, minBaseSeg.p0);
double c1 = computeC(dx, dy, minBaseSeg.p1);
*/
double minPara = Double.MAX_VALUE;
double maxPara = -Double.MAX_VALUE;
double minPerp = Double.MAX_VALUE;
double maxPerp = -Double.MAX_VALUE;
// compute maxima and minima of lines parallel and perpendicular to base segment
for (int i = 0; i < convexHullPts.length; i++) {
double paraC = computeC(dx, dy, convexHullPts[i]);
if (paraC > maxPara) maxPara = paraC;
if (paraC < minPara) minPara = paraC;
double perpC = computeC(-dy, dx, convexHullPts[i]);
if (perpC > maxPerp) maxPerp = perpC;
if (perpC < minPerp) minPerp = perpC;
}
// compute lines along edges of minimum rectangle
LineSegment maxPerpLine = computeSegmentForLine(-dx, -dy, maxPerp);
LineSegment minPerpLine = computeSegmentForLine(-dx, -dy, minPerp);
LineSegment maxParaLine = computeSegmentForLine(-dy, dx, maxPara);
LineSegment minParaLine = computeSegmentForLine(-dy, dx, minPara);
// compute vertices of rectangle (where the para/perp max & min lines intersect)
Coordinate p0 = maxParaLine.lineIntersection(maxPerpLine);
Coordinate p1 = minParaLine.lineIntersection(maxPerpLine);
Coordinate p2 = minParaLine.lineIntersection(minPerpLine);
Coordinate p3 = maxParaLine.lineIntersection(minPerpLine);
LinearRing shell =
inputGeom.getFactory().createLinearRing(new Coordinate[] {p0, p1, p2, p3, p0});
return inputGeom.getFactory().createPolygon(shell, null);
}
private void checkExpectedEmpty() {
// can't check areal features
if (input.getDimension() >= 2) return;
// can't check positive distances
if (distance > 0.0) return;
// at this point can expect an empty result
if (!result.isEmpty()) {
isValid = false;
errorMsg = "Result is non-empty";
errorIndicator = result;
}
report("ExpectedEmpty");
}
private void checkArea() {
double inputArea = input.getArea();
double resultArea = result.getArea();
if (distance > 0.0 && inputArea > resultArea) {
isValid = false;
errorMsg = "Area of positive buffer is smaller than input";
errorIndicator = result;
}
if (distance < 0.0 && inputArea < resultArea) {
isValid = false;
errorMsg = "Area of negative buffer is larger than input";
errorIndicator = result;
}
report("Area");
}
public final Geometry edit(Geometry geometry, GeometryFactory factory) {
if (geometry instanceof LinearRing) {
return factory.createLinearRing(edit(geometry.getCoordinates(), geometry));
}
if (geometry instanceof LineString) {
return factory.createLineString(edit(geometry.getCoordinates(), geometry));
}
if (geometry instanceof Point) {
Coordinate[] newCoordinates = edit(geometry.getCoordinates(), geometry);
return factory.createPoint((newCoordinates.length > 0) ? newCoordinates[0] : null);
}
return geometry;
}
private void checkEnvelope() {
if (distance < 0.0) return;
double padding = distance * MAX_ENV_DIFF_FRAC;
if (padding == 0.0) padding = 0.001;
Envelope expectedEnv = new Envelope(input.getEnvelopeInternal());
expectedEnv.expandBy(distance);
Envelope bufEnv = new Envelope(result.getEnvelopeInternal());
bufEnv.expandBy(padding);
if (!bufEnv.contains(expectedEnv)) {
isValid = false;
errorMsg = "Buffer envelope is incorrect";
errorIndicator = input.getFactory().toGeometry(bufEnv);
}
report("Envelope");
}
public Geometry combine(Geometry orig, Geometry geom) {
List origList = extractElements(orig, true);
List geomList = extractElements(geom, true);
origList.addAll(geomList);
if (origList.size() == 0) {
// return a clone of the orig geometry
return (Geometry) orig.clone();
}
// return the "simplest possible" geometry
return geomFactory.buildGeometry(origList);
}
private Geometry editInternal(Geometry geometry, GeometryEditorOperation operation) {
// if client did not supply a GeometryFactory, use the one from the input Geometry
if (factory == null) factory = geometry.getFactory();
if (geometry instanceof GeometryCollection) {
return editGeometryCollection((GeometryCollection) geometry, operation);
}
if (geometry instanceof Polygon) {
return editPolygon((Polygon) geometry, operation);
}
if (geometry instanceof Point) {
return operation.edit(geometry, factory);
}
if (geometry instanceof LineString) {
return operation.edit(geometry, factory);
}
Assert.shouldNeverReachHere("Unsupported Geometry class: " + geometry.getClass().getName());
return null;
}
public static void computeDistance(Geometry geom, Coordinate pt, PointPairDistance ptDist) {
if (geom instanceof LineString) {
computeDistance((LineString) geom, pt, ptDist);
} else if (geom instanceof Polygon) {
computeDistance((Polygon) geom, pt, ptDist);
} else if (geom instanceof GeometryCollection) {
GeometryCollection gc = (GeometryCollection) geom;
for (int i = 0; i < gc.getNumGeometries(); i++) {
Geometry g = gc.getGeometryN(i);
computeDistance(g, pt, ptDist);
}
} else { // assume geom is Point
ptDist.setMinimum(geom.getCoordinate(), pt);
}
}
private void computeWidthConvex(Geometry convexGeom) {
// System.out.println("Input = " + geom);
if (convexGeom instanceof Polygon)
convexHullPts = ((Polygon) convexGeom).getExteriorRing().getCoordinates();
else convexHullPts = convexGeom.getCoordinates();
// special cases for lines or points or degenerate rings
if (convexHullPts.length == 0) {
minWidth = 0.0;
minWidthPt = null;
minBaseSeg = null;
} else if (convexHullPts.length == 1) {
minWidth = 0.0;
minWidthPt = convexHullPts[0];
minBaseSeg.p0 = convexHullPts[0];
minBaseSeg.p1 = convexHullPts[0];
} else if (convexHullPts.length == 2 || convexHullPts.length == 3) {
minWidth = 0.0;
minWidthPt = convexHullPts[0];
minBaseSeg.p0 = convexHullPts[0];
minBaseSeg.p1 = convexHullPts[1];
} else computeConvexRingMinDiameter(convexHullPts);
}
public static Geometry replace(Geometry parent, Geometry original, Geometry replacement) {
List elem = extractElements(parent, false);
Collections.replaceAll(elem, original, replacement);
return parent.getFactory().buildGeometry(elem);
}
public static Geometry normalize(Geometry g) {
Geometry g2 = (Geometry) g.clone();
g2.normalize();
return g2;
}
/**
* Finds all {@link PreparedGeometry}s which might interact with a query {@link Geometry}.
*
* @param g the geometry to query by
* @return a list of candidate PreparedGeometrys
*/
public List query(Geometry g) {
return index.query(g.getEnvelopeInternal());
}
/**
* Inserts a collection of Geometrys into the index.
*
* @param geoms a collection of Geometrys to insert
*/
public void insert(Collection geoms) {
for (Iterator i = geoms.iterator(); i.hasNext(); ) {
Geometry geom = (Geometry) i.next();
index.insert(geom.getEnvelopeInternal(), PreparedGeometryFactory.prepare(geom));
}
}
static Geometry createCircle(Coordinate centre, double radius) {
Geometry centrePt = geomFact.createPoint(centre);
return centrePt.buffer(radius, POLYGON_SIZE);
}
private Coordinate[] createTestPoints(int nPts) {
Point pt = geomFact.createPoint(new Coordinate(baseX, baseY));
Geometry circle = pt.buffer(2 * rectSize, nPts / 4);
return circle.getCoordinates();
}
public static boolean isEqual(Geometry a, Geometry b) {
Geometry a2 = normalize(a);
Geometry b2 = normalize(b);
return a2.equalsExact(b2);
}
/**
* Gets the segment forming the base of the minimum diameter
*
* @return the segment forming the base of the minimum diameter
*/
public LineString getSupportingSegment() {
computeMinimumDiameter();
return inputGeom.getFactory().createLineString(new Coordinate[] {minBaseSeg.p0, minBaseSeg.p1});
}
private void checkValid(Geometry g) {
if (!g.isValid()) {
System.out.println("Snapped geometry is invalid");
}
}
