OpenLayers示例代码：天梭指标
OpenLayers示例代码：天梭指标
<!DOCTYPE html>
<html>
<head>
<title>Tissot Indicatrix</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>
</head>
<body>
<h4>EPSG:4326</h4>
<div id="map4326" class="map"></div>
<h4>EPSG:3857</h4>
<div id="map3857" class="map"></div>
<script>
var vectorLayer4326 = new ol.layer.Vector({
source: new ol.source.Vector()
});
var vectorLayer3857 = new ol.layer.Vector({
source: new ol.source.Vector()
});
var map4326 = new ol.Map({
layers: [
new ol.layer.Tile({
source: new ol.source.TileWMS({
url: 'https://ahocevar.com/geoserver/wms',
params: {
'LAYERS': 'ne:NE1_HR_LC_SR_W_DR'
}
})
}),
vectorLayer4326
],
target: 'map4326',
view: new ol.View({
projection: 'EPSG:4326',
center: [0, 0],
zoom: 2
})
});
var map3857 = new ol.Map({
layers: [
new ol.layer.Tile({
source: new ol.source.TileWMS({
url: 'https://ahocevar.com/geoserver/wms',
params: {
'LAYERS': 'ne:NE1_HR_LC_SR_W_DR'
}
})
}),
vectorLayer3857
],
target: 'map3857',
view: new ol.View({
center: [0, 0],
zoom: 2
})
});
var wgs84Sphere = new ol.Sphere(6378137);
var radius = 800000;
var x, y;
for (x = -180; x < 180; x += 30) {
for (y = -90; y < 90; y += 30) {
var circle4326 = ol.geom.Polygon.circular(wgs84Sphere, [x, y], radius, 64);
var circle3857 = circle4326.clone().transform('EPSG:4326', 'EPSG:3857');
vectorLayer4326.getSource().addFeature(new ol.Feature(circle4326));
vectorLayer3857.getSource().addFeature(new ol.Feature(circle3857));
}
}
</script>
</body>
</html>
说明：
OpenLayers示例代码：天梭指标
