geopoint.js

GeoPoint = function(lon, lat) {


    switch (typeof(lon)) {

        case 'number':

            this.lonDeg = this.dec2deg(lon, this.MAX_LON);
            this.lonDec = lon;

            break;

        case 'string':

            if (this.decode(lon)) {
                this.lonDeg = lon;
            }

            this.lonDec = this.deg2dec(lon, this.MAX_LON);

            break;
    }

    switch (typeof(lat)) {

        case 'number':

            this.latDeg = this.dec2deg(lat, this.MAX_LAT);
            this.latDec = lat;

            break;

        case 'string':

            if (this.decode(lat)) {
                this.latDeg = lat;
            }

            this.latDec = this.deg2dec(lat, this.MAX_LAT);

            break;

    }
};

GeoPoint.prototype = {

    CHAR_DEG : "\u00B0",
    CHAR_MIN : "\u0027",
    CHAR_SEC : "\u0022",
    CHAR_SEP : "\u0020",

    MAX_LON: 180,
    MAX_LAT: 90,

    // decimal
    lonDec: NaN,
    latDec: NaN,

    // degrees
    lonDeg: NaN,
    latDeg: NaN,

    dec2deg: function(value, max) {

        var sign = value < 0 ? -1 : 1;

        var abs = Math.abs(Math.round(value * 1000000));

        if (abs > (max * 1000000)) {
            return NaN;
        }

        var dec = abs % 1000000 / 1000000;
        var deg = Math.floor(abs / 1000000) * sign;
        var min = Math.floor(dec * 60);
        var sec = (dec - min / 60) * 3600;

        var result = "";

        result += deg;
        result += this.CHAR_DEG;
        result += this.CHAR_SEP;
        result += min;
        result += this.CHAR_MIN;
        result += this.CHAR_SEP;
        result += sec.toFixed(2);
        result += this.CHAR_SEC;

        return result;

    },

    deg2dec: function(value) {

        var matches = this.decode(value);

        if (!matches) {
            return NaN;
        }

        var deg = parseFloat(matches[1]);
        var min = parseFloat(matches[2]);
        var sec = parseFloat(matches[3]);

        if (isNaN(deg) || isNaN(min) || isNaN(sec)) {
            return NaN;
        }

        return deg + (min / 60.0) + (sec / 3600);
    },

    decode: function(value) {
        var pattern = "";

        // deg
        pattern += "(-?\\d+)";
        pattern += this.CHAR_DEG;
        pattern += "\\s*";

        // min
        pattern += "(\\d+)";
        pattern += this.CHAR_MIN;
        pattern += "\\s*";

        // sec
        pattern += "(\\d+(?:\\.\\d+)?)";
        pattern += this.CHAR_SEC;

        return value.match(new RegExp(pattern));
    },

    getLonDec: function() {
        return this.lonDec;
    },

    getLatDec: function() {
        return this.latDec;
    },

    getLonDeg: function() {
        return this.lonDeg;
    },

    getLatDeg: function() {
        return this.latDeg;
    }

};