Engineer at Mapbox, creator of Leaflet, algorithms geek, open source enthusiast, musician, father of twin girls, Ukrainian. 🇺🇦
Published
Edited
Jun 19, 2020
2 forks
Importers
26 stars
polylabelStretched = (rings, ratio) => {
const polygon = [];
for (const ring of rings) { // stretch the input
const newRing = [];
for (const [x, y] of ring) newRing.push([x / ratio, y]);
polygon.push(newRing);
}
const result = polylabel(polygon, 0.5);
result[0] *= ratio; // stretch the result back
result.distance *= ratio;
return result;
}
getLabelPos = (geometry) => {
let pos;
if (geometry.type === 'MultiPolygon') {
let maxDist = 0; // for multipolygons, pick the polygon with most available space
for (const polygon of geometry.coordinates) {
const p = polylabelStretched(polygon, ratio);
if (p.distance > maxDist) {
pos = p;
maxDist = p.distance;
}
}
} else {
pos = polylabelStretched(geometry.coordinates, ratio);
}
return pos;
}
geojson = topojson.feature(states, states.objects.states)
states = (await fetch('https://cdn.jsdelivr.net/npm/us-atlas@3/states-albers-10m.json')).json()
topojson = require("topojson-client")
d3 = require("d3-geo")
polylabel = require('https://bundle.run/polylabel@1.1.0')
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