99 lines
2.4 KiB
JavaScript
99 lines
2.4 KiB
JavaScript
import Map from '../src/ol/Map.js';
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import View from '../src/ol/View.js';
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import GeoJSON from '../src/ol/format/GeoJSON.js';
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import OSM from '../src/ol/source/OSM.js';
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import VectorTileSource from '../src/ol/source/VectorTile.js';
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import {Tile as TileLayer, VectorTile as VectorTileLayer} from '../src/ol/layer.js';
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import Projection from '../src/ol/proj/Projection.js';
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const replacer = function(key, value) {
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if (value.geometry) {
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let type;
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const rawType = value.type;
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let geometry = value.geometry;
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if (rawType === 1) {
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type = 'MultiPoint';
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if (geometry.length == 1) {
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type = 'Point';
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geometry = geometry[0];
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}
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} else if (rawType === 2) {
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type = 'MultiLineString';
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if (geometry.length == 1) {
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type = 'LineString';
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geometry = geometry[0];
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}
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} else if (rawType === 3) {
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type = 'Polygon';
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if (geometry.length > 1) {
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type = 'MultiPolygon';
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geometry = [geometry];
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}
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}
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return {
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'type': 'Feature',
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'geometry': {
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'type': type,
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'coordinates': geometry
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},
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'properties': value.tags
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};
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} else {
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return value;
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}
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};
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const tilePixels = new Projection({
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code: 'TILE_PIXELS',
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units: 'tile-pixels'
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});
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const map = new Map({
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layers: [
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new TileLayer({
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source: new OSM()
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})
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],
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target: 'map',
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view: new View({
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center: [0, 0],
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zoom: 2
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})
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});
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const url = 'data/geojson/countries.geojson';
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fetch(url).then(function(response) {
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return response.json();
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}).then(function(json) {
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const tileIndex = geojsonvt(json, {
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extent: 4096,
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debug: 1
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});
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const vectorSource = new VectorTileSource({
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format: new GeoJSON(),
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tileLoadFunction: function(tile) {
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const format = tile.getFormat();
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const tileCoord = tile.getTileCoord();
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const data = tileIndex.getTile(tileCoord[0], tileCoord[1], tileCoord[2]);
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const features = format.readFeatures(
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JSON.stringify({
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type: 'FeatureCollection',
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features: data ? data.features : []
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}, replacer));
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tile.setLoader(function() {
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tile.setFeatures(features);
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tile.setProjection(tilePixels);
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});
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},
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url: 'data:' // arbitrary url, we don't use it in the tileLoadFunction
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});
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const vectorLayer = new VectorTileLayer({
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source: vectorSource
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});
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map.addLayer(vectorLayer);
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});
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