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Sphere Mollweide

发布于 2022-11-30 23:36:06 字数 3180 浏览 0 评论 0 收藏 0

Example of a Sphere Mollweide map with a Graticule layer.

main.js

import 'ol/ol.css';
import GeoJSON from 'ol/format/GeoJSON';
import Graticule from 'ol/layer/Graticule';
import Map from 'ol/Map';
import Projection from 'ol/proj/Projection';
import VectorLayer from 'ol/layer/Vector';
import VectorSource from 'ol/source/Vector';
import View from 'ol/View';
import proj4 from 'proj4';
import {register} from 'ol/proj/proj4';

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 map = new Map({
  keyboardEventTarget: document,
  layers: [
    new VectorLayer({
      source: new VectorSource({
        url: 'data/geojson/countries-110m.geojson',
        format: new GeoJSON(),
      }),
    }),
    new Graticule(),
  ],
  target: 'map',
  view: new View({
    center: [0, 0],
    projection: sphereMollweideProjection,
    zoom: 1,
  }),
});

index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Sphere Mollweide</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/v3/polyfill.min.js?features=fetch,requestAnimationFrame,Element.prototype.classList,URL,TextDecoder,Number.isInteger"></script>
    <style>
      .map {
        width: 100%;
        height:400px;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <script src="main.js"></script>
  </body>
</html>

package.json

{
  "name": "sphere-mollweide",
  "dependencies": {
    "ol": "7.1.0",
    "proj4": "^2.7.5"
  },
  "devDependencies": {
    "parcel": "^2.0.0-beta.1"
  },
  "scripts": {
    "start": "parcel index.html",
    "build": "parcel build --public-url . index.html"
  }
}

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Sphere Mollweide

main.js

index.html

package.json

如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。