Example on how to use JSTS with OpenLayers.
Example showing the integration of JSTS with OpenLayers.
import 'ol/ol.css';
import GeoJSON from 'ol/format/GeoJSON';
import LinearRing from 'ol/geom/LinearRing';
import Map from 'ol/Map';
import OSM from 'ol/source/OSM';
import VectorSource from 'ol/source/Vector';
import View from 'ol/View';
import {
LineString,
MultiLineString,
MultiPoint,
MultiPolygon,
Point,
Polygon,
} from 'ol/geom';
import {Tile as TileLayer, Vector as VectorLayer} from 'ol/layer';
import {fromLonLat} from 'ol/proj';
var source = new VectorSource();
fetch('data/geojson/roads-seoul.geojson')
.then(function (response) {
return response.json();
})
.then(function (json) {
var format = new GeoJSON();
var features = format.readFeatures(json, {
featureProjection: 'EPSG:3857',
});
var parser = new jsts.io.OL3Parser();
parser.inject(
Point,
LineString,
LinearRing,
Polygon,
MultiPoint,
MultiLineString,
MultiPolygon
);
for (var i = 0; i < features.length; i++) {
var feature = features[i];
// convert the OpenLayers geometry to a JSTS geometry
var jstsGeom = parser.read(feature.getGeometry());
// create a buffer of 40 meters around each line
var buffered = jstsGeom.buffer(40);
// convert back from JSTS and replace the geometry on the feature
feature.setGeometry(parser.write(buffered));
}
source.addFeatures(features);
});
var vectorLayer = new VectorLayer({
source: source,
});
var rasterLayer = new TileLayer({
source: new OSM(),
});
var map = new Map({
layers: [rasterLayer, vectorLayer],
target: document.getElementById('map'),
view: new View({
center: fromLonLat([126.979293, 37.528787]),
zoom: 15,
}),
});
<!DOCTYPE html>
<html lang="en">
<head>
<title>JSTS Integration</title>
<!-- Pointer events polyfill for old browsers, see https://caniuse.com/#feat=pointer -->
<script src="https://unpkg.com/elm-pep"></script>
<!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
<script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=fetch,requestAnimationFrame,Element.prototype.classList,URL"></script>
<script src="https://unpkg.com/jsts@2.3.0/dist/jsts.min.js"></script>
<style>
.map {
width: 100%;
height:400px;
}
</style>
</head>
<body>
<div id="map" class="map"></div>
<script src="main.js"></script>
</body>
</html>
{
"name": "jsts",
"dependencies": {
"ol": "6.4.3"
},
"devDependencies": {
"parcel": "1.11.0"
},
"scripts": {
"start": "parcel index.html",
"build": "parcel build --experimental-scope-hoisting --public-url . index.html"
}
}