Maplibre-GL GeoJSON - Clipped
Chopping up isochrones takes time… but it’s possible!
<!DOCTYPE html>
<html>
<head>
<script src="https://unpkg.com/maplibre-gl@5.14.0/dist/maplibre-gl.js"></script>
<link href="https://unpkg.com/maplibre-gl@5.14.0/dist/maplibre-gl.css" rel="stylesheet">
<script src="https://unpkg.com/@turf/turf@7.2.0/turf.min.js"></script>
<script src="https://releases.targomo.com/core/latest.min.js"></script>
<script src="../_shared/tgm-utils.js"></script>
<style>
body, html {
margin: 0;
width: 100%;
height: 100%;
}
#map {
width: 100%;
height: 100%;
}
</style>
</head>
<body>
<div id="map"></div>
<script>// define a pair of coordinates, where the map should be centered
// and should serve a the source for polygonization
const lnglat = [13.37, 52.51]
const travelTimes = [300, 600, 900, 1200, 1500, 1800]
const timeColors = ['#006837', '#39B54A', '#8CC63F', '#F7931E', '#F15A24', '#C1272D']
// Initialize map and client with TgmExampleUtils (using Berlin preset)
const { client, map } = TgmExampleUtils.initMapLibreMap({
...TgmExampleUtils.PRESETS.berlin,
styleType: 'Dark'
})
// you need to define some options for the polygon service
const options = {
travelType: 'transit',
travelEdgeWeights: travelTimes,
maxEdgeWeight: 1800,
edgeWeight: 'time',
srid: 4326,
simplify: 200,
serializer: 'geojson',
buffer: 0.002
}
const sources = [ { lat: lnglat[1], lng: lnglat[0], id: 1 } ]
// color stop function
function getColorStops(times, colors) {
var colorsConfig = times.map((time, idx) => {
return [times[idx], colors[idx]]
})
return colorsConfig
}
map.on('load', () => {
TgmExampleUtils.createMarker(lnglat, map)
// call the Targomo service
client.polygons.fetch(sources, options).then((geojsonPolygons) => {
const polySort = geojsonPolygons.features.sort((a, b) => {
return b.properties.time - a.properties.time
})
let clippedPolys = []
polySort.forEach((polygon, idx) => {
const isLast = idx == (polySort.length - 1)
const previous = polySort[idx - 1]
if (previous) {
var clip = turf.difference(turf.featureCollection([previous, polygon]))
clippedPolys.push(clip)
} if (isLast) {
clippedPolys.push(polygon)
}
})
var donuts = turf.featureCollection(clippedPolys)
map.addLayer({
id: 'polygons',
type: 'fill',
source: {
type: 'geojson',
data: donuts,
attribution: '<a href="https://www.targomo.com/developers/resources/attribution/" target="_blank">© Targomo</a>'
},
layout: {},
paint: {
'fill-color': {
property: 'time',
stops: getColorStops(travelTimes, timeColors)
},
'fill-outline-color': 'rgba(0,0,0,0)',
'fill-antialias': true,
'fill-opacity': .5
}
}, 'highway_path')
map.flyTo({
center: [lnglat[0], lnglat[1] - .02],
zoom: 10.5, bearing: -60, speed: .5
})
})
})</script>
</body>
</html>
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