triangulation.html 2.11 KB
<html>
<head>
  <title>Triangulation example</title>
  <link rel="stylesheet" href="http://www.openlayers.org/api/2.11/theme/default/style.css" type="text/css" />
  
  <script src="http://www.openlayers.org/api/2.11/OpenLayers.js"></script>

  <script type="text/javascript" src="https://github.com/bjornharrtell/jsts/raw/master/lib/javascript.util.js"></script>
  <script type="text/javascript" src="https://github.com/bjornharrtell/jsts/raw/master/lib/jsts.js"></script>

<script type="text/javascript">
  function init() {
    var geomFact = new jsts.geom.GeometryFactory();

    var points = new Array(20);
    for (var i=0; i<points.length; i++) {
        points[i] = new jsts.geom.Coordinate((360 * Math.random()) - 180, (180 * Math.random()) - 90);
    }
    var input = new jsts.geom.MultiPoint(points);
    
    var builder = new jsts.triangulate.DelaunayTriangulationBuilder();
    builder.setSites(input);
    var delaunayResult = builder.getTriangles(geomFact);
    
    builder = new jsts.triangulate.VoronoiDiagramBuilder();
    builder.setSites(input);
	var voronoiResult = builder.getDiagram(geomFact);      

    var map = new OpenLayers.Map('map', {
      maxExtent: new OpenLayers.Bounds(-180, -180, 180, 180),
      maxResolution: 100,
      units: 'm',
      controls: [new OpenLayers.Control.MousePosition(), new OpenLayers.Control.Navigation()]
    });
    
    var layer = new OpenLayers.Layer.Vector('test', {
      isBaseLayer: true
    });

    var sites = new OpenLayers.Feature.Vector(input, null);
    var delaunay = new OpenLayers.Feature.Vector(delaunayResult,null,{fillOpacity:0,strokeColor:'#FF0000'});
    var voronoi = new OpenLayers.Feature.Vector(voronoiResult,null,{fillOpacity:0,strokeColor:'#00FF00'});
    layer.addFeatures([delaunay, voronoi, sites]);
    
    map.addLayer(layer);
    map.zoomToExtent(delaunay.geometry.getBounds());
  }
</script>
</head>
<body onload="init()">
En example of delaunay-triangulation (red) and voronoi diagram generation (green) using 20 random points. <br/>
Reloading the page results in a new set of points.
	<div id="map" style="width:500px;height=500px;"></div>
</body>
</html>