terriajs/lib/Map/prettifyProjection.js

Geospatial data visualization platform.

'use strict';

import proj4 from 'proj4/lib/index.js';

/**
 * Turns the longitude / latitude in degrees into a human readable pretty UTM zone representation.
 */
function prettifyProjection(longitude, latitude, proj4Projection, proj4longlat, projectionUnits) {
    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
    };
}

module.exports = prettifyProjection;