@karmicsoft/lc-map

Headless map view model. The math a map island needs — bounds, centre, zoom — with no map library and no DOM. Hand the answer to MapLibre, Leaflet, or whatever you like: swapping the renderer changes nothing here.

npm i @karmicsoft/lc-map

import { view } from '@karmicsoft/lc-map';
import { geoPoints } from '@karmicsoft/lc-record';

const { markers, center, zoom, bounds, empty } = view(geoPoints(record, index), { width: 640, height: 400 });
if (!empty) map.jumpTo({ center: [center.lon, center.lat], zoom });

| | | |---|---| | markers(points) | normalize to {lat, lon, label} — lng/lon both accepted | | bounds(points) | tightest box, or null | | center(points) | box centre, or null | | view(points, opts) | everything at once: {markers, bounds, center, zoom, empty} |

Three decisions. Junk is dropped, not plotted — a point without finite, in-range coordinates would otherwise land off the coast of Africa. The centre is the box centre, not the average, so one outlier can't drag the view. A single point has no box, so it gets pointZoom (default 14) instead of a meaningless fit.

Zoom is standard Web-Mercator tile math (256px tiles), so the number means the same thing to MapLibre and Leaflet.

MIT © KarmicSoft