This moves shape construction from SpatialContext to a new ShapeFactory interface. And it formalizes polygon construction and other shapes without requiring JTS.

Rectangle.relate(Rectangle) reports INTERSECTS in this case when the actual result should be either DISJOINT or preferably whatever the Y dimension reports when it's WITHIN or CONTAINS | :

This fails: assertRelation(WITHIN, ctx.makeRectangle(-180, -180, -10, 10), ctx.makeRectangle(180, 180, -30, 30)); The existing tests normalize rects, and so this wasn't found.

Here is a quick sketch for how to do that. This requires changing the project structure so that we can have multiple .jar files

NOTE: this is not ready to commit -- but want early feedback to see if the direction is OK

Right now the spatial operation code is in the lucene module. This means that libraries require lucene core to know the supported operations. We should have access to the operations from client code

Lets move this to spatial4j

Instead of relying on two separate axis normalization methods, this single convenience method normalizes a Point to fall within world bounds, correctly handling antipodal longitudes when latitude values wrap the poles. Note: randomized testing included

Note that much of this code is copied from https://github.com/spatial4j/spatial4j/blob/185132fae6897f57faacdac91c0a98a92e380bfc/src/main/java/com/spatial4j/core/shape/jts/JtsGeometry.java.

Note that I have (somewhat arbitrarily and regrettably) removed the Date-Line operations from JtsGeometry.

A few modifications have been made:

• Addressed a TODO -- Negative pages are handled by pageGeom() (AKA cutUnwrappedGeomInto360), which allows for the removal of redundant shifting.
• The boundaries of the date-line have been generalized (in order to work with generic projections).
• Rather than unioning paged geometries, they are merely "collected" into a single geometry (for efficiency's sake). This is done by a new method -- collect(). )Perhaps I've missed something here and the use of union is actually crucial in some cases)
• Extended unwrapDateline() to handle coordinates outside of the bounds.
• Fixed a bug inunwrapDateline that invokes Geometry.geometryChanged() for instances of GeometryCollection, which gave rise to another bug in that GeometryCollection.intersects() is an illegal operation, and so...
• These operations have been extended to direct instances of GeometryCollection (i.e. non-subclasses)

Otherwise, some assertions have been removed (sorry), and the style is probably not quite on.

Let me know if you'd like to see some of these changes in with the actual code (as of now, this class is entirely independent, for the purpose of demonstration).

Support should be added for the following WKT syntax. I don't think it's defined in any standard, but several existing GIS libraries/systems already support this syntax (including PostGIS and Geotoolkit).

BOX2D(-180.0 -90.0, 180.0 90.0)

Hi

I have analyzed the source code with a static analyzer and I have removed some code smell

• Missing override
• Removed unused parameters
• Unused assignment
• Boolean literals redundant
• Unused import
• Catches combined
• Return redundant

All the best matteo baccan

Added support for dateline wrapping when converting a circle to a geometry. I implemented it like this;

• support geometries that start at negative pages in JtsGeometry::cutUnwrappedGeomInto360()
• put the geometry of the circle in a JtsGeometry if the circle crosses the dateline

When I do a SpatialPredicate.Intersects between a GeoCircle and Polygon created from the JtsShapeFactory I get an error.

The error is a cast error on line 276 of JtsGeometry.

SpatialRelation rel = relateEnclosedRing((LinearRing) polygon.getExteriorRing());

I have read the comments about this being a tricky areas of the code but dont know what else I should do when I want to test a circle intersects a polygon.

Thanks, Mike

Hi,

I'm using RDF4J which uses your library deeper within. When I wrap everything in a shaded jar in the end I get a signature error.

I think it is because your jar is being signed with the eclipse jar signer plugin.

So far I know that bouncy castle signs their jars to make sure that the crypto content isn't modified.

Is there any such sensitive information in your jar files (eg. crypto implementations)?

Cheers, Håvard

I'm quite confused about distance calculations.

I'm using this website as a reference: https://www.omnicalculator.com/other/latitude-longitude-distance

Then I got an implementation of a distance calculation (haversine) from here: https://tutorialspoint.dev/algorithm/geometric-algorithms/program-distance-two-points-earth

And I want to compare this with various different implementations from Spatial4J.

I'm using these coordinates to test with: Point 1: 40.688939, -74.04455 Point 2: 40.746853, -73.985633

And I'm getting pretty big differences between different ways of calculating the distance between these two points.

First, what mainly concerns me is that the website (omnicalculator) and the implementation from tutorialspoint agree completely on the distance: 8.132 km

But none of my Spatial4J calculations agree with that number. The one that comes closest to it is the CartesianDistCalc implementation at 8.262 km. The tutorialspoint demo code claims to be using haversine but the output of Spatial4J haversine DistCalc implementation is quite a ways off at 7.313 km.

But can somebody explain to me where these differences are coming from and what the "correct" one is?

Below is my experimental code:

import org.junit.jupiter.api.Test;
import org.locationtech.spatial4j.context.SpatialContext;
import org.locationtech.spatial4j.distance.CartesianDistCalc;
import org.locationtech.spatial4j.distance.GeodesicSphereDistCalc;

class GeoDesicCalculationTest {
    @Test
    void testGeoDesicCalculations(){
        SpatialContext ctx = SpatialContext.GEO;

        var startPoint = ctx.getShapeFactory().pointLatLon(40.688939, -74.04455);
        var endPoint = ctx.getShapeFactory().pointLatLon(40.746853, -73.985633);

        System.out.println("GEO spatial context:         " + ctx.calcDistance(startPoint, endPoint) * 100);
        System.out.println("Haversine:                   " + new GeodesicSphereDistCalc.Haversine().distance(startPoint, endPoint) * 100);
        System.out.println("Law of cosine:               " + new GeodesicSphereDistCalc.LawOfCosines().distance(startPoint, endPoint) * 100);
        System.out.println("Vincenty:                    " + new GeodesicSphereDistCalc.Vincenty().distance(startPoint, endPoint) * 100);
        System.out.println("Cartesian:                   " + new CartesianDistCalc().distance(startPoint, endPoint) * 100);
        System.out.println("Tutorials Point (haversine): " + distance(startPoint.getLat(), endPoint.getLat(), startPoint.getLon(), endPoint.getLon()));
    }

    public static double distance(double lat1, double lat2, double lon1, double lon2) {
        // The math module contains a function
        // named toRadians which converts from
        // degrees to radians.
        lon1 = Math.toRadians(lon1);
        lon2 = Math.toRadians(lon2);
        lat1 = Math.toRadians(lat1);
        lat2 = Math.toRadians(lat2);

        // Haversine formula
        double dlon = lon2 - lon1;
        double dlat = lat2 - lat1;
        double a = Math.pow(Math.sin(dlat / 2), 2)
                + Math.cos(lat1) * Math.cos(lat2)
                * Math.pow(Math.sin(dlon / 2),2);

        double c = 2 * Math.asin(Math.sqrt(a));

        // Radius of earth in kilometers. Use 3956
        // for miles
        double r = 6371;

        // calculate the result
        return(c * r);
    }
}

And the output of running it:

GEO spatial context:         7.31307025220976
Haversine:                   7.31307025220976
Law of cosine:               7.313070251733588
Vincenty:                    7.3130702522095286
Cartesian:                   8.261503667613857
Tutorials Point (haversine): 8.131763102409689

I'm multiplying the Spatial4J calculations by 100 which is also confusing to me... it doesn't really make sense that Spatial4J is giving me answers as 1/100th of a kilometer???

I realise I must be doing something wrong or completely misunderstanding some premises here. I would really appreciate some help in understanding what I'm doing wrong.

https://github.com/locationtech/spatial4j/blob/2926812ae302c6e0f24fb5995b1fd24be7fe0b56/src/main/java/org/locationtech/spatial4j/shape/jts/JtsGeometry.java#L492

Why does this check in unwrapDateline() require the exterior ring of a polygon to contains() any interior rings? Doesn't contains() on two LineStrings require one to be a subset of the other? If so, you wouldn't be able to have polygons that contain holes and cross the dateline, which is the problem I'm running into.

It is possible to create invalid shapes through the JtsShapeFactory.MultipolygonBuilder.

You can reproduce by running the following class:

import org.locationtech.spatial4j.context.jts.JtsSpatialContext;
import org.locationtech.spatial4j.context.jts.JtsSpatialContextFactory;
import org.locationtech.spatial4j.exception.InvalidShapeException;
import org.locationtech.spatial4j.shape.jts.JtsShapeFactory;

public class Main {

    public static void main(String[] args) throws Exception {
        JtsSpatialContextFactory ctxFactory = new JtsSpatialContextFactory();
        ctxFactory.geo = false;
        ctxFactory.useJtsLineString = true;
        ctxFactory.useJtsMulti = true;
        ctxFactory.useJtsPoint = true;
        JtsSpatialContext ctx = new JtsSpatialContext(ctxFactory);
        JtsShapeFactory shapeFactory = new JtsShapeFactory(ctx, ctxFactory);

        JtsShapeFactory.PolygonBuilder polygonBuilder = shapeFactory.polygon()
                .pointLatLon(1, 1)
                .pointLatLon(-1, -1)
                .pointLatLon(1, -1)
                .pointLatLon(-1, 1)
                .pointLatLon(1, 1);

        try {
            polygonBuilder.build();
            System.out.println("OK");
        } catch (InvalidShapeException e) {
            System.out.println("KO: " + e.getMessage());
        }
        try {
            shapeFactory.multiPolygon().add(polygonBuilder).build();
            System.out.println("OK");
        } catch (InvalidShapeException e) {
            System.out.println("KO: " + e.getMessage());
        }
    }

}

Output:

KO: Self-intersection at or near point (0.0, 0.0, NaN)
OK

The JtsShapeFactory.MultipolygonBuilder is used in the ShapeDeserializer and GeometryDeserializer classes and can lead jackson to create invalid shapes.

These artifacts have classes in the same package which causes major headaches if one wants to use them together with the module system. Would it be at all possible to separate packages between these two modules?

Hi everyone, I have a small application that I'm using to verify if geojson files are correct. also checked with https://geojsonlint.com/

{ "type": "FeatureCollection", "features": [{ "type": "Feature", "properties": {}, "geometry": { "type": "Polygon", "coordinates": [ [ [170, -9.9], [172.1, -13.2], [177, -5], [-170.1, -5.7], [170, -9], [170, -9.9] ] ] } }] }

` package com.company.jts_test;

import org.locationtech.jts.geom.*; import org.locationtech.jts.util.GeometricShapeFactory; import org.locationtech.spatial4j.context.jts.JtsSpatialContext; import org.locationtech.spatial4j.shape.jts.JtsGeometry; import org.locationtech.spatial4j.shape.jts.JtsShapeFactory;

import java.io.IOException; import java.util.ArrayList; import java.util.Collection; import java.util.List;

public class Main {

/** WGS 84 SRID. */
private static final int SRID = 4326;
/** JTS Floating Precision Model. */
private static final PrecisionModel PRECISION_MODEL = new PrecisionModel(PrecisionModel.FLOATING);

/** The Constant JTS_SPATIAL_CONTEXT. */
private static final JtsSpatialContext JTS_SPATIAL_CONTEXT =  JtsSpatialContext.GEO;

/** The Constant JTS_SHAPE_FACTORY. */
private static final JtsShapeFactory JTS_SHAPE_FACTORY = JTS_SPATIAL_CONTEXT.getShapeFactory();

/** The Constant JTS_GEOMETRY_FACTORY. */
private static final GeometryFactory JTS_GEOMETRY_FACTORY = JTS_SHAPE_FACTORY.getGeometryFactory();

/**
 * JTS Geometry Factory with floating {@link #PRECISION_MODEL} and WGS 85 {@link #SRID}.
 */
public static final GeometryFactory GEOMETRY_FACTORY = new GeometryFactory(PRECISION_MODEL, SRID);

/** The Constant GEOMETRY_SHAPE_FACTORY. */
public static final GeometricShapeFactory GEOMETRY_SHAPE_FACTORY = new GeometricShapeFactory(GEOMETRY_FACTORY);


public static void main(String[] args) {

    try {
        var d =  convert(null);
    } catch (IOException e) {
        e.printStackTrace();
    }
}


public static Collection<Object> convert(byte[] rawData) throws IOException {
    Collection<Object> result = new ArrayList<>();

        Collection<Coordinate2D> p = new ArrayList<>();
        List<List<Double>> coordinates = (List<List<Double>>) List.of(
                List.of(170.0, -9.9),
                List.of(172.1, -13.2),
                List.of(177.0, -5.0),
                List.of(-170.1, -5.7),
                List.of(170.0, -9.0),
                List.of(170.0, -9.9)
        );


    for (List<Double> point : coordinates) {
            p.add(new Coordinate2D(point.get(1), point.get(0)));
        }

        isPolygonValid(p);

    return result;
}

private static JtsWxError isPolygonValid(Collection<Coordinate2D> p) {
    Coordinate[] c = p.stream().map(coordinate -> new Coordinate(coordinate.getLongitude(), coordinate.getLatitude())).toArray(Coordinate[]::new);
    return isPolygonValid(c);
}

public static JtsWxError isPolygonValid(Coordinate[] coordinates) {
    Polygon geometry = JTS_GEOMETRY_FACTORY.createPolygon(coordinates);
    return validateGeometry(geometry);
}

private static JtsWxError validateGeometry(Polygon geometry) {
    if(geometry == null) {
        return new JtsWxError(1,"");
    }
   // try {
        JtsGeometry jtsGeometry = (JtsGeometry) JTS_SHAPE_FACTORY.makeShapeFromGeometry(geometry);
        jtsGeometry.validate();
   // }
    //catch(Exception exception) {
    //    return new JtsWxError(1,exception.getMessage());
   // }
    return new JtsWxError(1,"OK");
}

} `

Exception in thread "main" org.locationtech.jts.geom.TopologyException: found non-noded intersection between LINESTRING ( 172.1 -13.2, 177 -5 ) and LINESTRING ( 180 -7.341708542713568, 170 -9 ) [ (175.11679477586557, -8.151486293449425, NaN) ] at org.locationtech.jts.noding.FastNodingValidator.checkValid(FastNodingValidator.java:139) at org.locationtech.jts.geomgraph.EdgeNodingValidator.checkValid(EdgeNodingValidator.java:80) at org.locationtech.jts.geomgraph.EdgeNodingValidator.checkValid(EdgeNodingValidator.java:45) at org.locationtech.jts.operation.overlay.OverlayOp.computeOverlay(OverlayOp.java:229) at org.locationtech.jts.operation.overlay.OverlayOp.getResultGeometry(OverlayOp.java:181) at org.locationtech.jts.operation.overlay.OverlayOp.overlayOp(OverlayOp.java:84) at org.locationtech.jts.operation.overlay.snap.SnapIfNeededOverlayOp.getResultGeometry(SnapIfNeededOverlayOp.java:75) at org.locationtech.jts.operation.overlay.snap.SnapIfNeededOverlayOp.overlayOp(SnapIfNeededOverlayOp.java:37) at org.locationtech.jts.geom.GeometryOverlay.overlay(GeometryOverlay.java:76) at org.locationtech.jts.geom.GeometryOverlay.intersection(GeometryOverlay.java:119) at org.locationtech.jts.geom.Geometry.intersection(Geometry.java:1330) at org.locationtech.spatial4j.shape.jts.JtsGeometry.cutUnwrappedGeomInto360(JtsGeometry.java:585) at org.locationtech.spatial4j.shape.jts.JtsGeometry.<init>(JtsGeometry.java:67) at org.locationtech.spatial4j.shape.jts.JtsShapeFactory.makeShape(JtsShapeFactory.java:531) at org.locationtech.spatial4j.shape.jts.JtsShapeFactory.makeShape(JtsShapeFactory.java:548) at org.locationtech.spatial4j.shape.jts.JtsShapeFactory.makeShapeFromGeometry(JtsShapeFactory.java:500) at com.company.jts_test.Main.validateGeometry(Main.java:88) at com.company.jts_test.Main.isPolygonValid(Main.java:80) at com.company.jts_test.Main.isPolygonValid(Main.java:75) at com.company.jts_test.Main.convert(Main.java:68) at com.company.jts_test.Main.main(Main.java:43)

Hello,

We are using Lucene and Geotools in our application and tried to update to a newer Geotools version. Now our tests in lucene fail, because of spatial4j dependency. Geotools is now using JTS 18.1 and there is an incompatibility compared to JTS 17.0 in spatial4j. The InStream in org.locationtech.spatial4j.io.jts.JtsBinaryCodec.readJtsGeom(DataInput) has now a return type int instead of void.

This should be an easy fix, I will try to provide a PullRequest for that.