Function feature2polygons

src/lib/geo_location_utils.js:104–196

(feature)

}

function feature2polygons(feature) {
    var geometry = feature.geometry;
    var coords = geometry.coordinates;
    var loc = feature.id;

    var polygons = [];
    var appendPolygon, j, k, m;

    if (loc === 'RUS' || loc === 'FJI') {
        // Russia and Fiji have landmasses that cross the antimeridian,
        // we need to add +360 to their longitude coordinates, so that
        // polygon 'contains' doesn't get confused when crossing the antimeridian.
        //
        // Note that other countries have polygons on either side of the antimeridian
        // (e.g. some Aleutian island for the USA), but those don't confuse
        // the 'contains' method; these are skipped here.
        appendPolygon = function (_pts) {
            var pts;

            if (doesCrossAntiMeridian(_pts) === null) {
                pts = _pts;
            } else {
                pts = new Array(_pts.length);
                for (m = 0; m < _pts.length; m++) {
                    // do not mutate calcdata[i][j].geojson !!
                    pts[m] = [_pts[m][0] < 0 ? _pts[m][0] + ANTIMERIDIAN_LON_SHIFT : _pts[m][0], _pts[m][1]];
                }
            }

            polygons.push(polygon.tester(pts));
        };
    } else if (loc === 'ATA') {
        // Antarctica has a landmass that wraps around every longitudes which
        // confuses the 'contains' methods.
        appendPolygon = function (pts) {
            var crossAntiMeridianIndex = doesCrossAntiMeridian(pts);

            // polygon that do not cross anti-meridian need no special handling
            if (crossAntiMeridianIndex === null) {
                return polygons.push(polygon.tester(pts));
            }

            // stitch polygon by adding pt over South Pole,
            // so that it covers the projected region covers all latitudes
            //
            // Note that the algorithm below only works for polygons that
            // start and end on longitude -180 (like the ones built by
            // https://github.com/etpinard/sane-topojson).
            var stitch = new Array(pts.length + 1);
            var si = 0;

            for (m = 0; m < pts.length; m++) {
                if (m > crossAntiMeridianIndex) {
                    stitch[si++] = [pts[m][0] + ANTIMERIDIAN_LON_SHIFT, pts[m][1]];
                } else if (m === crossAntiMeridianIndex) {
                    stitch[si++] = pts[m];
                    stitch[si++] = [pts[m][0], -90];
                } else {