JtsGeometry.java
/*******************************************************************************
* Copyright (c) 2015 Voyager Search and MITRE
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Apache License, Version 2.0 which
* accompanies this distribution and is available at
* http://www.apache.org/licenses/LICENSE-2.0.txt
******************************************************************************/
package org.locationtech.spatial4j.shape.jts;
import org.locationtech.spatial4j.context.SpatialContext;
import org.locationtech.spatial4j.context.jts.JtsSpatialContext;
import org.locationtech.spatial4j.distance.CartesianDistCalc;
import org.locationtech.spatial4j.exception.InvalidShapeException;
import org.locationtech.spatial4j.shape.*;
import org.locationtech.spatial4j.shape.Point;
import org.locationtech.spatial4j.shape.impl.BBoxCalculator;
import org.locationtech.spatial4j.shape.impl.BufferedLineString;
import org.locationtech.spatial4j.shape.impl.RectangleImpl;
import org.locationtech.jts.geom.*;
import org.locationtech.jts.geom.prep.PreparedGeometry;
import org.locationtech.jts.geom.prep.PreparedGeometryFactory;
import org.locationtech.jts.operation.union.UnaryUnionOp;
import org.locationtech.jts.operation.valid.IsValidOp;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
/**
* Wraps a JTS {@link Geometry} (i.e. may be a polygon or basically anything).
* JTS does a great deal of the hard work, but there is work here in handling
* dateline (aka anti-meridian) wrap.
*/
public class JtsGeometry extends BaseShape<JtsSpatialContext> {
/** System property boolean that can disable auto validation in an assert. */
public static final String SYSPROP_ASSERT_VALIDATE = "spatial4j.JtsGeometry.assertValidate";
private final Geometry geom;//cannot be a direct instance of GeometryCollection as it doesn't support relate()
private final boolean hasArea;
private final Rectangle bbox;
protected PreparedGeometry preparedGeometry;
protected boolean validated = false;
public JtsGeometry(Geometry geom, JtsSpatialContext ctx, boolean dateline180Check, boolean allowMultiOverlap) {
super(ctx);
//GeometryCollection isn't supported in relate()
if (geom.getClass().equals(GeometryCollection.class)) {
geom = narrowCollectionIfPossible((GeometryCollection)geom);
if (geom == null) {
throw new IllegalArgumentException("JtsGeometry does not support GeometryCollection but does support its subclasses.");
}
}
//NOTE: All this logic is fairly expensive. There are some short-circuit checks though.
if (geom.isEmpty()) {
bbox = new RectangleImpl(Double.NaN, Double.NaN, Double.NaN, Double.NaN, this.ctx);
} else if (ctx.isGeo()) {
//Unwraps the geometry across the dateline so it exceeds the standard geo bounds (-180 to +180).
if (dateline180Check)
geom = unwrapDateline(geom);//returns same or new geom
//If given multiple overlapping polygons, fix it by union
if (allowMultiOverlap)
geom = unionGeometryCollection(geom);//returns same or new geom
//Cuts an unwrapped geometry back into overlaid pages in the standard geo bounds.
geom = cutUnwrappedGeomInto360(geom);//returns same or new geom
assert geom.getEnvelopeInternal().getWidth() <= 360;
assert ! geom.getClass().equals(GeometryCollection.class) : "GeometryCollection unsupported";//double check
//Compute bbox
bbox = computeGeoBBox(geom);
} else {//not geo
//If given multiple overlapping polygons, fix it by union
if (allowMultiOverlap)
geom = unionGeometryCollection(geom);//returns same or new geom
Envelope env = geom.getEnvelopeInternal();
bbox = new RectangleImpl(env.getMinX(), env.getMaxX(), env.getMinY(), env.getMaxY(), ctx);
}
geom.getEnvelopeInternal();//ensure envelope is cached internally, which is lazy evaluated. Keeps this thread-safe.
this.geom = geom;
assert assertValidate();//kinda expensive but caches valid state
this.hasArea = !((geom instanceof Lineal) || (geom instanceof Puntal));
}
/**
* Attempts to retype a geometry collection under the following circumstances, returning
* null if the collection can not be retyped.
* <ul>
* <li>Single object collections are collapsed down to the object.</li>
* <li>Homogenous collections are recast as the appropriate subclass.</li>
* </ul>
*
* @see GeometryFactory#buildGeometry(Collection)
*/
private Geometry narrowCollectionIfPossible(GeometryCollection gc) {
List<Geometry> geoms = new ArrayList<>();
for (int i = 0; i < gc.getNumGeometries(); i++) {
geoms.add(gc.getGeometryN(i));
}
Geometry result = gc.getFactory().buildGeometry(geoms);
return !result.getClass().equals(GeometryCollection.class) ? result : null;
}
/** called via assertion */
private boolean assertValidate() {
String assertValidate = System.getProperty(SYSPROP_ASSERT_VALIDATE);
if (assertValidate == null || Boolean.parseBoolean(assertValidate))
validate();
return true;
}
/**
* Validates the shape, throwing a descriptive error if it isn't valid. Note that this
* is usually called automatically by default, but that can be disabled.
*
* @throws InvalidShapeException with descriptive error if the shape isn't valid
*/
public void validate() throws InvalidShapeException {
if (!validated) {
IsValidOp isValidOp = new IsValidOp(geom);
if (!isValidOp.isValid())
throw new InvalidShapeException(isValidOp.getValidationError().toString());
validated = true;
}
}
/**
* Determines if the shape has been indexed.
*/
boolean isIndexed() {
return preparedGeometry != null;
}
/**
* Adds an index to this class internally to compute spatial relations faster. In JTS this
* is called a {@link org.locationtech.jts.geom.prep.PreparedGeometry}. This
* isn't done by default because it takes some time to do the optimization, and it uses more
* memory. Calling this method isn't thread-safe so be careful when this is done. If it was
* already indexed then nothing happens.
*/
public void index() {
if (preparedGeometry == null)
preparedGeometry = PreparedGeometryFactory.prepare(geom);
}
@Override
public boolean isEmpty() {
return bbox.isEmpty(); // fast
}
/** Given {@code geoms} which has already been checked for being in world
* bounds, return the minimal longitude range of the bounding box.
*/
protected Rectangle computeGeoBBox(Geometry geoms) {
final Envelope env = geoms.getEnvelopeInternal();//for minY & maxY (simple)
if (ctx.isGeo() && env.getWidth() > 180 && geoms.getNumGeometries() > 1) {
// This is ShapeCollection's bbox algorithm
BBoxCalculator bboxCalc = new BBoxCalculator(ctx);
for (int i = 0; i < geoms.getNumGeometries(); i++ ) {
Envelope envI = geoms.getGeometryN(i).getEnvelopeInternal();
bboxCalc.expandXRange(envI.getMinX(), envI.getMaxX());
if (bboxCalc.doesXWorldWrap())
break; // can't grow any bigger
}
return new RectangleImpl(bboxCalc.getMinX(), bboxCalc.getMaxX(), env.getMinY(), env.getMaxY(), ctx);
} else {
return new RectangleImpl(env.getMinX(), env.getMaxX(), env.getMinY(), env.getMaxY(), ctx);
}
}
@Override
public JtsGeometry getBuffered(double distance, SpatialContext ctx) {
//TODO doesn't work correctly across the dateline. The buffering needs to happen
// when it's transiently unrolled, prior to being sliced.
return this.ctx.makeShape(geom.buffer(distance), true, true);
}
@Override
public boolean hasArea() {
return hasArea;
}
@Override
public double getArea(SpatialContext ctx) {
double geomArea = geom.getArea();
if (ctx == null || geomArea == 0)
return geomArea;
//Use the area proportional to how filled the bbox is.
double bboxArea = getBoundingBox().getArea(null);//plain 2d area
assert bboxArea >= geomArea;
double filledRatio = geomArea / bboxArea;
return getBoundingBox().getArea(ctx) * filledRatio;
// (Future: if we know we use an equal-area projection then we don't need to
// estimate)
}
@Override
public Rectangle getBoundingBox() {
return bbox;
}
@Override
public JtsPoint getCenter() {
if (isEmpty()) //geom.getCentroid == null
return new JtsPoint(ctx.getGeometryFactory().createPoint((Coordinate)null), ctx);
return new JtsPoint(geom.getCentroid(), ctx);
}
@Override
public SpatialRelation relate(Shape other) {
if (other instanceof Point)
return relate((Point)other);
else if (other instanceof Rectangle)
return relate((Rectangle) other);
else if (other instanceof Circle)
return relate((Circle) other);
else if (other instanceof JtsGeometry)
return relate((JtsGeometry) other);
else if (other instanceof BufferedLineString)
throw new UnsupportedOperationException("Can't use BufferedLineString with JtsGeometry");
return other.relate(this).transpose();
}
public SpatialRelation relate(Point pt) {
if (!getBoundingBox().relate(pt).intersects())
return SpatialRelation.DISJOINT;
Geometry ptGeom;
if (pt instanceof JtsPoint)
ptGeom = ((JtsPoint)pt).getGeom();
else
ptGeom = ctx.getGeometryFactory().createPoint(new Coordinate(pt.getX(), pt.getY()));
return relate(ptGeom);//is point-optimized
}
public SpatialRelation relate(Rectangle rectangle) {
SpatialRelation bboxR = bbox.relate(rectangle);
if (bboxR == SpatialRelation.WITHIN || bboxR == SpatialRelation.DISJOINT)
return bboxR;
// FYI, the right answer could still be DISJOINT or WITHIN, but we don't know yet.
return relate(ctx.getGeometryFrom(rectangle));
}
public SpatialRelation relate(final Circle circle) {
SpatialRelation bboxR = bbox.relate(circle);
if (bboxR == SpatialRelation.WITHIN || bboxR == SpatialRelation.DISJOINT)
return bboxR;
// The result could be anything still.
final SpatialRelation[] result = {null};
// Visit each geometry (this geom might contain others).
geom.apply(new GeometryFilter() {
// We use cartesian math. It's a limitation/assumption when working with JTS. When geo=true (i.e. we're using
// WGS84 instead of a projected coordinate system), the errors here will be pretty terrible east-west. At
// 60 degrees latitude, the circle will work as if it has half the width it should.
// Instead, consider converting the circle to a polygon first (not great but better), or projecting both first.
// Ideally, use Geo3D.
final CartesianDistCalc calcSqd = CartesianDistCalc.INSTANCE_SQUARED;
final double radiusSquared = circle.getRadius() * circle.getRadius();
final Geometry ctrGeom = ctx.getGeometryFrom(circle.getCenter());
@Override
public void filter(Geometry geom) {
if (result[0] == SpatialRelation.INTERSECTS || result[0] == SpatialRelation.CONTAINS) {
// a previous filter(geom) call had a result that won't be changed no matter how this geom relates
return;
}
if (geom instanceof Polygon) {
Polygon polygon = (Polygon) geom;
SpatialRelation rel = relateEnclosedRing((LinearRing) polygon.getExteriorRing());
// if rel == INTERSECTS or WITHIN or DISJOINT; done. But CONTAINS...
if (rel == SpatialRelation.CONTAINS) {
// if the poly outer ring contains the circle, check the holes. Could become DISJOINT or INTERSECTS.
HOLE_LOOP: for (int i = 0; i < polygon.getNumInteriorRing(); i++){
// TODO short-circuit based on the hole's bbox if it's disjoint or within the circle.
switch (relateEnclosedRing((LinearRing) polygon.getInteriorRingN(i))) {
case WITHIN:// fall through
case INTERSECTS:
rel = SpatialRelation.INTERSECTS;
break HOLE_LOOP;
case CONTAINS:
rel = SpatialRelation.DISJOINT;
break HOLE_LOOP;
//case DISJOINT: break; // continue hole loop
}
}
}
result[0] = rel.combine(result[0]);
} else if (geom instanceof LineString) {
LineString lineString = (LineString) geom;
SpatialRelation rel = relateLineString(lineString);
result[0] = rel.combine(result[0]);
} else if (geom instanceof org.locationtech.jts.geom.Point) {
org.locationtech.jts.geom.Point point = (org.locationtech.jts.geom.Point) geom;
SpatialRelation rel =
calcSqd.distance(circle.getCenter(), point.getX(), point.getY()) > radiusSquared
? SpatialRelation.DISJOINT : SpatialRelation.WITHIN;
result[0] = rel.combine(result[0]);
}
// else it's going to be some GeometryCollection and we'll visit the contents.
}
/** As if the ring is the outer ring of a polygon */
SpatialRelation relateEnclosedRing(LinearRing ring) {
SpatialRelation rel = relateLineString(ring);
if (rel == SpatialRelation.DISJOINT
&& ctx.getGeometryFactory().createPolygon(ring, null).contains(ctrGeom)) {
// If it contains the circle center point, then the result is CONTAINS
rel = SpatialRelation.CONTAINS;
}
return rel;
}
SpatialRelation relateLineString(LineString lineString) {
final CoordinateSequence seq = lineString.getCoordinateSequence();
final boolean isRing = lineString instanceof LinearRing;
int numOutside = 0;
// Compare the coordinates:
for (int i = 0, numComparisons = 0; i < seq.size(); i++) {
if (i == 0 && isRing) {
continue;
}
numComparisons++;
boolean outside = calcSqd.distance(circle.getCenter(), seq.getX(i), seq.getY(i)) > radiusSquared;
if (outside) {
numOutside++;
}
// If the comparisons have a mix of outside/inside, then we can short-circuit INTERSECTS.
if (numComparisons != numOutside && numOutside != 0) {
assert numComparisons > 1;
return SpatialRelation.INTERSECTS;
}
}
// Either all vertices are outside or inside, by this stage.
if (numOutside == 0) { // all inside
return SpatialRelation.WITHIN.combine(result[0]);
}
// They are all outside.
// Check the edges (line segments) to see if any are inside.
for (int i = 1; i < seq.size(); i++) {
boolean outside = calcSqd.distanceToLineSegment(
circle.getCenter(), seq.getX(i-1), seq.getY(i-1), seq.getX(i), seq.getY(i))
> radiusSquared;
if (!outside) {
return SpatialRelation.INTERSECTS;
}
}
return SpatialRelation.DISJOINT;
}
});
return result[0] == null ? SpatialRelation.DISJOINT : result[0];
}
public SpatialRelation relate(JtsGeometry jtsGeometry) {
//don't bother checking bbox since geom.relate() does this already
return relate(jtsGeometry.geom);
}
protected SpatialRelation relate(Geometry oGeom) {
//see http://docs.geotools.org/latest/userguide/library/jts/dim9.html#preparedgeometry
if (oGeom instanceof org.locationtech.jts.geom.Point) {
if (preparedGeometry != null)
return preparedGeometry.disjoint(oGeom) ? SpatialRelation.DISJOINT : SpatialRelation.CONTAINS;
return geom.disjoint(oGeom) ? SpatialRelation.DISJOINT : SpatialRelation.CONTAINS;
}
if (preparedGeometry == null)
return intersectionMatrixToSpatialRelation(geom.relate(oGeom));
else if (preparedGeometry.covers(oGeom))
return SpatialRelation.CONTAINS;
else if (preparedGeometry.coveredBy(oGeom))
return SpatialRelation.WITHIN;
else if (preparedGeometry.intersects(oGeom))
return SpatialRelation.INTERSECTS;
return SpatialRelation.DISJOINT;
}
public static SpatialRelation intersectionMatrixToSpatialRelation(IntersectionMatrix matrix) {
//As indicated in SpatialRelation javadocs, Spatial4j CONTAINS & WITHIN are
// OGC's COVERS & COVEREDBY
if (matrix.isCovers())
return SpatialRelation.CONTAINS;
else if (matrix.isCoveredBy())
return SpatialRelation.WITHIN;
else if (matrix.isDisjoint())
return SpatialRelation.DISJOINT;
return SpatialRelation.INTERSECTS;
}
@Override
public String toString() {
return geom.toString();
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
JtsGeometry that = (JtsGeometry) o;
return geom.equalsExact(that.geom);//fast equality for normalized geometries
}
@Override
public int hashCode() {
//FYI if geometry.equalsExact(that.geometry), then their envelopes are the same.
return geom.getEnvelopeInternal().hashCode();
}
public Geometry getGeom() {
return geom;
}
/**
* If <code>geom</code> spans the dateline (aka anti-meridian), then this modifies it to be a
* valid JTS geometry that extends to the right of the standard -180 to +180
* width such that some points are greater than +180 but some remain less.
*
* @return The same geometry or a new one if it was unwrapped
*/
private static Geometry unwrapDateline(Geometry geom) {
if (geom.getEnvelopeInternal().getWidth() < 180)
return geom;//can't possibly cross the dateline
// if a multi-geom: (this is purely an optimization to avoid cloning more than we need to)
if (geom instanceof GeometryCollection) {
if (geom instanceof MultiPoint) {
return geom; // always safe since no point crosses the dateline (on it is okay)
}
GeometryCollection gc = (GeometryCollection) geom;
List<Geometry> list = new ArrayList<>(gc.getNumGeometries());
boolean didUnwrap = false;
for (int n = 0; n < gc.getNumGeometries(); n++) {
Geometry geometryN = gc.getGeometryN(n);
Geometry geometryUnwrapped = unwrapDateline(geometryN); // recursion
list.add(geometryUnwrapped);
didUnwrap |= (geometryUnwrapped != geometryN);
}
return !didUnwrap ? geom : geom.getFactory().buildGeometry(list);
}
// a geom (not multi):
Geometry newGeom = geom.copy(); // clone
final int[] crossings = {0};//an array so that an inner class can modify it.
newGeom.apply(new GeometryFilter() {
@Override
public void filter(Geometry geom) {
int cross;
if (geom instanceof LineString) {//note: LinearRing extends LineString
if (geom.getEnvelopeInternal().getWidth() < 180)
return;//can't possibly cross the dateline
cross = unwrapDateline((LineString) geom);
} else if (geom instanceof Polygon) {
if (geom.getEnvelopeInternal().getWidth() < 180)
return;//can't possibly cross the dateline
cross = unwrapDateline((Polygon) geom);
} else {
// The only other JTS subclass of Geometry is a Point, which can't cross anything.
// If the geom is something custom, we don't know what else to do but return.
return;
}
crossings[0] = Math.max(crossings[0], cross);
}
});//geom.apply()
if (crossings[0] > 0) {
newGeom.geometryChanged();
return newGeom;
} else {
return geom; // original
}
}
/** See {@link #unwrapDateline(Geometry)}. */
private static int unwrapDateline(Polygon poly) {
LineString exteriorRing = poly.getExteriorRing();
int cross = unwrapDateline(exteriorRing);
if (cross > 0) {
//TODO TEST THIS! Maybe bug if doesn't cross but is in another page?
for(int i = 0; i < poly.getNumInteriorRing(); i++) {
LineString innerLineString = poly.getInteriorRingN(i);
unwrapDateline(innerLineString);
for(int shiftCount = 0; ! exteriorRing.contains(innerLineString); shiftCount++) {
if (shiftCount > cross)
throw new IllegalArgumentException("The inner ring doesn't appear to be within the exterior: "
+exteriorRing+" inner: "+innerLineString);
shiftGeomByX(innerLineString, 360);
}
}
}
return cross;
}
/** See {@link #unwrapDateline(Geometry)}. */
private static int unwrapDateline(LineString lineString) {
CoordinateSequence cseq = lineString.getCoordinateSequence();
int size = cseq.size();
if (size <= 1)
return 0;
int shiftX = 0;//invariant: == shiftXPage*360
int shiftXPage = 0;
int shiftXPageMin = 0/* <= 0 */, shiftXPageMax = 0; /* >= 0 */
double prevX = cseq.getX(0);
for(int i = 1; i < size; i++) {
double thisX_orig = cseq.getX(i);
assert thisX_orig >= -180 && thisX_orig <= 180 : "X not in geo bounds";
double thisX = thisX_orig + shiftX;
if (prevX - thisX > 180) {//cross dateline from left to right
thisX += 360;
shiftX += 360;
shiftXPage += 1;
shiftXPageMax = Math.max(shiftXPageMax,shiftXPage);
} else if (thisX - prevX > 180) {//cross dateline from right to left
thisX -= 360;
shiftX -= 360;
shiftXPage -= 1;
shiftXPageMin = Math.min(shiftXPageMin,shiftXPage);
}
if (shiftXPage != 0)
cseq.setOrdinate(i, CoordinateSequence.X, thisX);
prevX = thisX;
}
if (lineString instanceof LinearRing) {
assert cseq.getCoordinate(0).equals(cseq.getCoordinate(size-1));
assert shiftXPage == 0;//starts and ends at 0
}
assert shiftXPageMax >= 0 && shiftXPageMin <= 0;
//Unfortunately we are shifting again; it'd be nice to be smarter and shift once
shiftGeomByX(lineString, shiftXPageMin * -360);
int crossings = shiftXPageMax - shiftXPageMin;
return crossings;
}
private static void shiftGeomByX(Geometry geom, final int xShift) {
if (xShift == 0)
return;
geom.apply(new CoordinateSequenceFilter() {
@Override
public void filter(CoordinateSequence seq, int i) {
seq.setOrdinate(i, CoordinateSequence.X, seq.getX(i) + xShift );
}
@Override public boolean isDone() { return false; }
@Override public boolean isGeometryChanged() { return true; }
});
}
private static Geometry unionGeometryCollection(Geometry geom) {
if (geom instanceof GeometryCollection) {
return geom.union();
}
return geom;
}
/**
* This "pages" through standard geo boundaries offset by multiples of 360
* longitudinally that intersect geom, and the intersecting results of a page
* and the geom are shifted into the standard -180 to +180 and added to a new
* geometry that is returned.
*/
private static Geometry cutUnwrappedGeomInto360(Geometry geom) {
Envelope geomEnv = geom.getEnvelopeInternal();
if (geomEnv.getMinX() >= -180 && geomEnv.getMaxX() <= 180)
return geom;
assert geom.isValid() : "geom";
List<Geometry> geomList = new ArrayList<>();
//page 0 is the standard -180 to 180 range
int startPage = (int) Math.floor((geomEnv.getMinX() + 180) / 360);
for (int page = startPage; true; page++) {
double minX = -180 + page * 360;
if (geomEnv.getMaxX() <= minX)
break;
Geometry rect = geom.getFactory().toGeometry(new Envelope(minX, minX + 360, -90, 90));
assert rect.isValid() : "rect";
Geometry pageGeom = rect.intersection(geom);//JTS is doing some hard work
assert pageGeom.isValid() : "pageGeom";
if (page != 0) {
pageGeom = pageGeom.copy(); // because shiftGeomByX modifies the underlying coordinates shared by geom.
shiftGeomByX(pageGeom, page * -360);
}
geomList.add(pageGeom);
}
return UnaryUnionOp.union(geomList);
}
// private static Geometry removePolyHoles(Geometry geom) {
// //TODO this does a deep copy of geom even if no changes needed; be smarter
// GeometryTransformer gTrans = new GeometryTransformer() {
// @Override
// protected Geometry transformPolygon(Polygon geom, Geometry parent) {
// if (geom.getNumInteriorRing() == 0)
// return geom;
// return factory.createPolygon((LinearRing) geom.getExteriorRing(),null);
// }
// };
// return gTrans.transform(geom);
// }
//
// private static Geometry snapAndClean(Geometry geom) {
// return new GeometrySnapper(geom).snapToSelf(GeometrySnapper.computeOverlaySnapTolerance(geom), true);
// }
}