Custom Canvas Tiles

Renders tiles with TMS coordinates for debugging.

这些黑色网格瓦片是通过 HTML5 canvas 在客户端创建的。这里展示的 TMS 瓦片坐标索引是使用 TMS 自定义模板、矢量瓦片资源的 512 像素瓦片和矢量瓦片 zDirection 设置来生成的。

main.js

import MVT from 'ol/format/MVT.js';
import Map from 'ol/Map.js';
import TileDebug from 'ol/source/TileDebug.js';
import TileLayer from 'ol/layer/Tile.js';
import VectorTileLayer from 'ol/layer/VectorTile.js';
import VectorTileSource from 'ol/source/VectorTile.js';
import View from 'ol/View.js';
import {Fill, Stroke, Style, Text} from 'ol/style.js';

const style = new Style({
  fill: new Fill({
    color: 'rgba(255, 255, 255, 0.6)',
  }),
  stroke: new Stroke({
    color: '#319FD3',
    width: 1,
  }),
  text: new Text({
    font: '12px Calibri,sans-serif',
    fill: new Fill({
      color: '#000',
    }),
    stroke: new Stroke({
      color: '#fff',
      width: 3,
    }),
  }),
});

const vtLayer = new VectorTileLayer({
  declutter: true,
  source: new VectorTileSource({
    maxZoom: 15,
    format: new MVT(),
    url:
      'https://ahocevar.com/geoserver/gwc/service/tms/1.0.0/' +
      'ne:ne_10m_admin_0_countries@EPSG%3A900913@pbf/{z}/{x}/{-y}.pbf',
  }),
  style: function (feature) {
    style.getText().setText(feature.get('name'));
    return style;
  },
});

const debugLayer = new TileLayer({
  source: new TileDebug({
    template: 'z:{z} x:{x} y:{-y}',
    projection: vtLayer.getSource().getProjection(),
    tileGrid: vtLayer.getSource().getTileGrid(),
    zDirection: 1,
  }),
});

const map = new Map({
  layers: [vtLayer, debugLayer],
  target: 'map',
  view: new View({
    center: [0, 6000000],
    zoom: 4,
  }),
});

index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Custom Canvas Tiles</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="./resources/elm-pep.js"></script>
    <script type="module" src="main.js"></script>
  </body>
</html>

package.json

{
  "name": "canvas-tiles-tms",
  "dependencies": {
    "ol": "7.3.0"
  },
  "devDependencies": {
    "vite": "^3.2.3"
  },
  "scripts": {
    "start": "vite",
    "build": "vite build"
  }
}