Wrong results for some points

[sytolk]

/** insert this function in Tests.java and add it in main(..){ ..showBugTest(); 
     * test Polygon with Geo coordinates point: north:42.508956 east:27.483328
     */
    public static void showBugTest()
    {   //KML
        /*<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
  <Document>
  <Placemark>
        <name>Plygon</name>
        <LineString>
        <coordinates>
        27.485196,42.499148,1
                27.480000,42.498600,1
                27.474680,42.503800,1
                27.468270,42.510000,1
                27.466904,42.510788,1
                27.465350,42.512116,1
                27.467000,42.512000,1
                27.471027,42.513579,1
                27.472668,42.512938,1
                27.474922,42.511829,1
                27.480124,42.507945,1
                27.482892,42.509082,1
                27.490519,42.536026,1
                27.499703,42.534470,1
                27.485196,42.499148,1
                </coordinates>
                </LineString>
        </Placemark>
        </Document>
</kml>*/

        //you can view kml polygon here: http://display-kml.appspot.com/
        //and here is the point: https://maps.google.bg/?q=42.508956,27.483328

        Polygon polygon = Polygon.Builder()
                .addVertex(new Point(42.499148f, 27.485196f))
                .addVertex(new Point(42.498600f, 27.480000f))
                .addVertex(new Point(42.503800f, 27.474680f))
                .addVertex(new Point(42.510000f, 27.468270f))
                .addVertex(new Point(42.510788f, 27.466904f))
                .addVertex(new Point(42.512116f, 27.465350f))
                .addVertex(new Point(42.512000f, 27.467000f))
                .addVertex(new Point(42.513579f, 27.471027f))
                .addVertex(new Point(42.512938f, 27.472668f))
                .addVertex(new Point(42.511829f, 27.474922f))
                .addVertex(new Point(42.507945f, 27.480124f))
                .addVertex(new Point(42.509082f, 27.482892f))
                .addVertex(new Point(42.536026f, 27.490519f))
                .addVertex(new Point(42.534470f, 27.499703f))
                .addVertex(new Point(42.499148f, 27.485196f))
                .build();

        //I have view on the map that point (42.508956,27.483328) is inside the polygon. But the result of execution show that: The point:(42.51,27.48) is not inside the polygon
        isInside(polygon, new Point(42.508956f, 27.483328f)); //wrong results //function contains(..) -> intersection=0  why?
        isInside(polygon, new Point(42.505f,27.48f)); //but with an other point result is ok..
    }

[mccollumni]

I'm having the same issue. Using coordinates is not yielding the best results.

[VicV]

@mccollumni convert all floats to doubles in these classes.

[ae-mo]

That doesn't fix the problem

[fernandonm]

Here a simple example of coordinates yielding a bad result:

        Polygon p = Polygon.Builder()
                .addVertex(new Point(40.481171f, 6.4107070f)) // NE
                .addVertex(new Point(40.480248f, 6.4101200f)) // SE. This point makes the test fail
                //.addVertex(new Point(40.480248f, 6.411029f)) // SE. But it works with this one
                .addVertex(new Point(40.480237f, 6.4062790f)) // SW
                .addVertex(new Point(40.481161f, 6.4062610f)) // NW
                .build();
        assertTrue(p.contains(new Point(40.480890f, 6.4081030f)));

[tatarize]

The code is flawed for any point hitting a vertex. If the ray drawn strikes a vertex exactly. Then that point counts as outside the polygon while it's inside the polygon.

[sromku]

The main issue was with float. In my tests I didn't use coordinates and took such floating point precision into account. So obviously in this case double must be used. It's fixed.

I have tested and added tests for all failing examples in this issue.

• @sytolk - this is the test: testMapCoordinates1()
• @fernandonm - this is the test: testMapCoordinates2()

You can use latest release 1.0.2 with the fixes - polygon-1.0.2.jar