108 lines
3.1 KiB
JavaScript
108 lines
3.1 KiB
JavaScript
import GeoJSON from '../src/ol/format/GeoJSON.js';
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import Map from '../src/ol/Map.js';
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import VectorSource from '../src/ol/source/Vector.js';
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import View from '../src/ol/View.js';
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import {Fill, Style} from '../src/ol/style.js';
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import {
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Heatmap as HeatmapLayer,
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Vector as VectorLayer,
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} from '../src/ol/layer.js';
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import {asArray} from '../src/ol/color.js';
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const style = new Style({
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fill: new Fill({
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color: '#eeeeee',
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}),
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});
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const map = new Map({
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layers: [
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new VectorLayer({
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source: new VectorSource({
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url: 'https://openlayers.org/data/vector/ecoregions.json',
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format: new GeoJSON(),
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}),
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background: 'white',
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style: function (feature) {
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const color = asArray(feature.get('COLOR_NNH') || '#eeeeee');
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color[3] = 0.75;
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style.getFill().setColor(color);
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return style;
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},
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}),
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new HeatmapLayer({
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source: new VectorSource({
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url: 'data/geojson/world-cities.geojson',
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format: new GeoJSON(),
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}),
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weight: function (feature) {
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return feature.get('population') / 1e7;
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},
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radius: 15,
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blur: 15,
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opacity: 0.75,
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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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document.getElementById('export-png').addEventListener('click', function () {
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map.once('rendercomplete', function () {
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const mapCanvas = document.createElement('canvas');
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const size = map.getSize();
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mapCanvas.width = size[0];
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mapCanvas.height = size[1];
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const mapContext = mapCanvas.getContext('2d');
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Array.prototype.forEach.call(
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map.getViewport().querySelectorAll('.ol-layer canvas, canvas.ol-layer'),
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function (canvas) {
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if (canvas.width > 0) {
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const opacity =
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canvas.parentNode.style.opacity || canvas.style.opacity;
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mapContext.globalAlpha = opacity === '' ? 1 : Number(opacity);
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const backgroundColor = canvas.parentNode.style.backgroundColor;
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if (backgroundColor) {
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mapContext.fillStyle = backgroundColor;
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mapContext.fillRect(0, 0, canvas.width, canvas.height);
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}
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let matrix;
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const transform = canvas.style.transform;
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if (transform) {
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// Get the transform parameters from the style's transform matrix
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matrix = transform
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.match(/^matrix\(([^\(]*)\)$/)[1]
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.split(',')
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.map(Number);
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} else {
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matrix = [
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parseFloat(canvas.style.width) / canvas.width,
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0,
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0,
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parseFloat(canvas.style.height) / canvas.height,
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0,
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0,
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];
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}
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// Apply the transform to the export map context
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CanvasRenderingContext2D.prototype.setTransform.apply(
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mapContext,
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matrix
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);
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mapContext.drawImage(canvas, 0, 0);
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}
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}
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);
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mapContext.globalAlpha = 1;
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const link = document.getElementById('image-download');
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link.href = mapCanvas.toDataURL();
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link.click();
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});
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map.renderSync();
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});
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