文章来源于网络收集而来，版权归原创者所有，如有侵权请及时联系！

高 DPI WMTS

发布于 2022-11-30 23:36:03 字数 3434 浏览 0 评论 0 收藏 0

本示例演示 HiDPI WMTS 图层。

WMTS 资源对象包含 tilePixelRatio 属性选项。 HiDPI WMTS 资源对象可以提供 512x512 像素的瓦片，但是应用在 256x256 瓦片网格中，需要将 tilePixelRatio 需要设置为 2。

main.js

import 'ol/ol.css';
import Map from 'ol/Map';
import TileLayer from 'ol/layer/Tile';
import View from 'ol/View';
import WMTS, {optionsFromCapabilities} from 'ol/source/WMTS';
import WMTSCapabilities from 'ol/format/WMTSCapabilities';
import {DEVICE_PIXEL_RATIO} from 'ol/has';

const capabilitiesUrl = 'https://basemap.at/wmts/1.0.0/WMTSCapabilities.xml';

// HiDPI support:
// * Use 'bmaphidpi' layer (pixel ratio 2) for device pixel ratio > 1
// * Use 'geolandbasemap' layer (pixel ratio 1) for device pixel ratio == 1
const hiDPI = DEVICE_PIXEL_RATIO > 1;
const layer = hiDPI ? 'bmaphidpi' : 'geolandbasemap';
const tilePixelRatio = hiDPI ? 2 : 1;

const map = new Map({
  target: 'map',
  view: new View({
    center: [1823849, 6143760],
    zoom: 11,
  }),
});

fetch(capabilitiesUrl)
  .then(function (response) {
    return response.text();
  })
  .then(function (text) {
    const result = new WMTSCapabilities().read(text);
    const options = optionsFromCapabilities(result, {
      layer: layer,
      matrixSet: 'google3857',
      style: 'normal',
    });
    options.tilePixelRatio = tilePixelRatio;
    options.attributions =
      'Grundkarte: <a target="_blank" href="https://basemap.at/">basemap.at</a>';
    map.addLayer(
      new TileLayer({
        source: new WMTS(options),
      })
    );
  });

index.html

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

package.json

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

分享到QQ

分享到微博

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

需要登录才能够评论，你可以免费注册一个本站的账号。

列表为空，暂无数据