turf-kinks

Takes a polygon and detects all self-intersections.

Note: This module uses straight line intersections, so giant edges may not be computed correctly, since the curvature of the earth is not accounted for

Experimental: attempts to correct the kinks with reasonable assumptions

<!doctype html>
<html lang="en">
  <head>
    <link rel="stylesheet" href="https://rawcdn.githack.com/openlayers/openlayers.github.io/master/en/v5.3.0/css/ol.css" type="text/css">
    <link rel="stylesheet" href="assets/css/styles.css" type="text/css">
    <script src="//cdn.jsdelivr.net/npm/@turf/turf@5/turf.min.js"></script>
    <script src="https://rawcdn.githack.com/openlayers/openlayers.github.io/master/en/v5.3.0/build/ol.js"></script>
    <title>Turf and OpenLayers 3 - Kinks</title>
  </head>
  <body>
    <div id="map" class="map"></div>
    <script type="text/javascript">

      var polygon = {
        "type": "Feature",
        "properties": {},
        "geometry": {
          "type": "Polygon",
          "coordinates": [
            [
              [1.7578125, 49.38237278700955],
              [-3.779296875, 46.86019101567027],
              [-0.87890625, 43.83452678223682],
              [6.064453125, 42.68243539838623],
              [4.306640625, 44.33956524809713],
              [0.87890625, 42.35854391749705],
              [-1.7578125, 41.11246878918088],
              [-5.44921875, 43.89789239125797],
              [0.087890625, 45.583289756006316],
              [0.615234375, 47.338822694822],
              [-2.28515625, 48.28319289548349],
              [-3.8671874999999996, 49.724479188712984],
              [-0.3515625, 50.736455137010665],
              [1.7578125, 49.38237278700955]
            ]
          ]
        }
      }

      var kinks = turf.kinks(polygon);

      // Declare a source
      var vectorSource = new ol.source.Vector();

      // When reading feature, reproject to EPSG 3857
      var feature = (new ol.format.GeoJSON()).readFeature(polygon, {
        featureProjection: 'EPSG:3857'
      });
      // Add a feature
      vectorSource.addFeature(feature);

      // When reading feature, reproject to EPSG 3857
      var kinks_features = (new ol.format.GeoJSON()).readFeatures(kinks, {
        featureProjection: 'EPSG:3857'
      });
      // Add a feature
      vectorSource.addFeatures(kinks_features);

      // Declare a vector layer with the already
      // created source containing added feature
      var vectorLayer = new ol.layer.Vector({
        source: vectorSource
      });

      // Instanciate a map and add layers
      var map = new ol.Map({
        target: 'map',
        layers: [
          new ol.layer.Tile({
            source: new ol.source.OSM()
          }),
          vectorLayer
        ],
        view: new ol.View({
          center: ol.proj.fromLonLat([4.0297, 45.7598]),
          zoom: 5
        })
      });

    </script>
  </body>
</html>

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