原文链接及内容

原文链接：https://openlayers.org/en/latest/examples/sphere-mollweide.html

运行界面

具有Gaticule层的球体Mollweide贴图的示例。

main.js代码如下：

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import GeoJSON from 'ol/format/GeoJSON.js';
import Graticule from 'ol/layer/Graticule.js';
import Map from 'ol/Map.js';
import Projection from 'ol/proj/Projection.js';
import VectorLayer from 'ol/layer/Vector.js';
import VectorSource from 'ol/source/Vector.js';
import View from 'ol/View.js';
import proj4 from 'proj4';
import {Fill, Style} from 'ol/style.js';
import {register} from 'ol/proj/proj4.js';

proj4.defs(
  'ESRI:53009',
  '+proj=moll +lon_0=0 +x_0=0 +y_0=0 +a=6371000 ' +
    '+b=6371000 +units=m +no_defs'
);
register(proj4);

// Configure the Sphere Mollweide projection object with an extent,
// and a world extent. These are required for the Graticule.
const sphereMollweideProjection = new Projection({
  code: 'ESRI:53009',
  extent: [
    -18019909.21177587, -9009954.605703328, 18019909.21177587,
    9009954.605703328,
  ],
  worldExtent: [-179, -89.99, 179, 89.99],
});

const style = new Style({
  fill: new Fill({
    color: '#eeeeee',
  }),
});

const map = new Map({
  keyboardEventTarget: document,
  layers: [
    new VectorLayer({
      source: new VectorSource({
        url: 'https://openlayers.org/data/vector/ecoregions.json',
        format: new GeoJSON(),
      }),
      style: function (feature) {
        const color = feature.get('COLOR_BIO') || '#eeeeee';
        style.getFill().setColor(color);
        return style;
      },
    }),
    new Graticule(),
  ],
  target: 'map',
  view: new View({
    center: [0, 0],
    projection: sphereMollweideProjection,
    zoom: 2,
  }),
});

界面布局文件index.html代码如下：

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<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Sphere Mollweide</title>
    <link rel="stylesheet" href="node_modules/ol/ol.css">
    <style>
      .map {
        width: 100%;
        height: 400px;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <!-- Pointer events polyfill for old browsers, see https://caniuse.com/#feat=pointer -->
    <script src="https://cdn.jsdelivr.net/npm/elm-pep@1.0.6/dist/elm-pep.js"></script>
    <script type="module" src="main.js"></script>
  </body>
</html>