Example of a Layer swipe map.
Example of a Layer swipe map.
import ImageTile from 'ol/source/ImageTile.js';
import Map from 'ol/Map.js';
import OSM from 'ol/source/OSM.js';
import TileLayer from 'ol/layer/Tile.js';
import View from 'ol/View.js';
import {getRenderPixel} from 'ol/render.js';
const osm = new TileLayer({
source: new OSM(),
});
const key = 'Get your own API key at https://www.maptiler.com/cloud/';
const attributions =
'<a href="https://www.maptiler.com/copyright/" target="_blank">© MapTiler</a> ' +
'<a href="https://www.openstreetmap.org/copyright" target="_blank">© OpenStreetMap contributors</a>';
const aerial = new TileLayer({
source: new ImageTile({
attributions: attributions,
url: 'https://api.maptiler.com/maps/satellite/{z}/{x}/{y}.jpg?key=' + key,
tileSize: 512,
maxZoom: 20,
}),
});
const map = new Map({
layers: [osm, aerial],
target: 'map',
view: new View({
center: [0, 0],
zoom: 2,
}),
});
const swipe = document.getElementById('swipe');
aerial.on('prerender', function (event) {
const ctx = event.context;
const mapSize = map.getSize();
const width = mapSize[0] * (swipe.value / 100);
const tl = getRenderPixel(event, [width, 0]);
const tr = getRenderPixel(event, [mapSize[0], 0]);
const bl = getRenderPixel(event, [width, mapSize[1]]);
const br = getRenderPixel(event, mapSize);
ctx.save();
ctx.beginPath();
ctx.moveTo(tl[0], tl[1]);
ctx.lineTo(bl[0], bl[1]);
ctx.lineTo(br[0], br[1]);
ctx.lineTo(tr[0], tr[1]);
ctx.closePath();
ctx.clip();
});
aerial.on('postrender', function (event) {
const ctx = event.context;
ctx.restore();
});
swipe.addEventListener('input', function () {
map.render();
});
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Layer Swipe</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>
<input id="swipe" type="range" style="width: 100%">
<script type="module" src="main.js"></script>
</body>
</html>
{
"name": "layer-swipe",
"dependencies": {
"ol": "10.3.1"
},
"devDependencies": {
"vite": "^3.2.3"
},
"scripts": {
"start": "vite",
"build": "vite build"
}
}