OpenLayers示例代码：turf.js
OpenLayers示例代码：turf.js
<!DOCTYPE html>
<html>
<head>
<title>turf.js</title>
<link rel="stylesheet" href="https://openlayers.org/en/v4.0.1/css/ol.css" type="text/css">
<!-- 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=requestAnimationFrame,Element.prototype.classList,URL"></script>
<script src="https://openlayers.org/en/v4.0.1/build/ol.js"></script>
<script src="https://api.tiles.mapbox.com/mapbox.js/plugins/turf/v2.0.0/turf.min.js"></script>
</head>
<body>
<div id="map" class="map"></div>
<script>
// this example uses turf.js for which we don't have an externs file.
var source = new ol.source.Vector();
fetch('https://openlayers.org/en/v4.0.1/examples/data/geojson/roads-seoul.geojson').then(function(response) {
return response.json();
}).then(function(json) {
var format = new ol.format.GeoJSON();
var features = format.readFeatures(json);
var street = features[0];
// convert to a turf.js feature
var turfLine = format.writeFeatureObject(street);
// show a marker every 200 meters
var distance = 0.2;
// get the line length in kilometers
var length = turf.lineDistance(turfLine, 'kilometers');
for (var i = 1; i <= length / distance; i++) {
var turfPoint = turf.along(turfLine, i * distance, 'kilometers');
// convert the generated point to a OpenLayers feature
var marker = format.readFeature(turfPoint);
marker.getGeometry().transform('EPSG:4326', 'EPSG:3857');
source.addFeature(marker);
}
street.getGeometry().transform('EPSG:4326', 'EPSG:3857');
source.addFeature(street);
});
var vectorLayer = new ol.layer.Vector({
source: source
});
var rasterLayer = new ol.layer.Tile({
source: new ol.source.OSM()
});
var map = new ol.Map({
layers: [rasterLayer, vectorLayer],
target: document.getElementById('map'),
view: new ol.View({
center: ol.proj.fromLonLat([126.980366, 37.526540]),
zoom: 15
})
});
</script>
</body>
</html>
说明：
OpenLayers示例代码：turf.js
