00_nts_test.markdown

NetTopologySuite(NTS) の演算結果

コード

1. ポリゴンA
2. ポリゴンB
3. ポリゴンA AND B
4. ポリゴンA OR B
5. ポリゴンA XOR B
6. ポリゴンA - B
7. ポリゴン Buffer B

see FOSS4G 開発者の為の、図形演算ライブラリガイド - Qiita [キータ]

注)gist/github で図形演算ができるわけではないので、あしからず

00a_Main.cs

using System;
using GeoAPI.Geometries;
using NetTopologySuite;

namespace TopologyTest
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            var service = NtsGeometryServices.Instance;
            var gf = service.CreateGeometryFactory();

            var polygonA = gf.CreatePolygon(new Coordinate[]
                {
                    new Coordinate(34.0, 136.0),
                    new Coordinate(34.0, 138.0),
                    new Coordinate(37.0, 138.0),
                    new Coordinate(37.0, 136.0),
                    new Coordinate(34.0, 136.0)
                });

            var polygonB = gf.CreatePolygon(new Coordinate[]
                {
                    new Coordinate(36.0, 137.0),
                    new Coordinate(35.0, 137.0),
                    new Coordinate(35.0, 140.0),
                    new Coordinate(36.0, 137.0)
                });

            polygonA.Intersection(polygonB).ToConsole("Intersection");
            polygonA.Union(polygonB).ToConsole("Union");
            polygonA.SymmetricDifference(polygonB).ToConsole("SymmetricDifference");
            polygonA.Difference(polygonB).ToConsole("Difference");
            polygonB.Buffer(0.5).ToConsole("Buffer");
        }

    }

    public static class GeomExtensions
    {
        public static void ToConsole(this IGeometry geom, string tag) {
            Console.WriteLine(tag + " - " + geom.ToString());
        }
    }
}

01_polygonA.geojson

02_polygonB.geojson

{
    "crs": {
        "properties": {
            "name": "urn:ogc:def:crs:OGC:1.3:CRS84"
        }, 
        "type": "name"
    }, 
    "features": [
        {
            "geometry": {
                "coordinates": [
                    [
                        [137.0, 36.0], 
                        [137.0, 35.0], 
                        [140.0, 35.0], 
                        [137.0, 36.0]
                    ]
                ], 
                "type": "Polygon"
            }, 
            "type": "Feature"
        },
        {
            "geometry": {
                "coordinates": [
                    [135.0, 33.0], 
                    [140.0, 33.0], 
                    [140.0, 38.0], 
                    [135.0, 38.0], 
                    [135.0, 33.0]
                ], 
                "type": "LineString"
            }, 
            "type": "Feature"
        }
    ], 
    "type": "FeatureCollection"
}

03_polygonA_intersection_B.geojson

04_polygonA_union_B.geojson

05_polygonA_symmetricdifference_B.geojson

06_polygonA_difference_B.geojson

07_geometryB_buffer.geojson