terriajs/lib/Map/Vector/prettifyProjection.ts

Geospatial data visualization platform.

import proj4 from "proj4";

/**
 * Turns the longitude / latitude in degrees into a human readable pretty UTM zone representation.
 */
export default function prettifyProjection(
  longitude: number,
  latitude: number,
  proj4Projection: string,
  proj4longlat: string,
  projectionUnits: string
) {
  const zone = 1 + Math.floor((longitude + 180) / 6);

  const projection =
    proj4Projection + " +zone=" + zone + (latitude < 0 ? " +south" : "");

  const projPoint = proj4(proj4longlat, projection, [longitude, latitude]);

  return {
    utmZone: zone + (latitude < 0.0 ? "S" : "N"),
    north: projPoint[1].toFixed(2) + projectionUnits,
    east: projPoint[0].toFixed(2) + projectionUnits
  };
}