polyline decoder

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  <script>
// This is adapted from the implementation in Project-OSRM
// https://github.com/DennisOSRM/Project-OSRM-Web/blob/master/WebContent/routing/OSRM.RoutingGeometry.js

function polyline_decode(str, precision) {
    var index = 0,
        lat = 0,
        lng = 0,
        coordinates = [],
        shift = 0,
        result = 0,
        byte = null,
        latitude_change,
        longitude_change,
        factor = Math.pow(10, precision || 6);

// Coordinates have variable length when encoded, so just keep
    // track of whether we've hit the end of the string. In each
    // loop iteration, a single coordinate is decoded.
    while (index < str.length) {

// Reset shift, result, and byte
        byte = null;
        shift = 0;
        result = 0;

do {
            byte = str.charCodeAt(index++) - 63;
            result |= (byte & 0x1f) << shift;
            shift += 5;
        } while (byte >= 0x20);

latitude_change = ((result & 1) ? ~(result >> 1) : (result >> 1));

shift = result = 0;

do {
            byte = str.charCodeAt(index++) - 63;
            result |= (byte & 0x1f) << shift;
            shift += 5;
        } while (byte >= 0x20);

longitude_change = ((result & 1) ? ~(result >> 1) : (result >> 1));

lat += latitude_change;
        lng += longitude_change;

coordinates.push([lat / factor, lng / factor]);
    }
  	  	var points = JSON.stringify(coordinates);

console.log(points);

return coordinates;
};
    
    
    var input = 'g~iagArdumhFbF`HrVq\\tYm_@jBhClO~RvX~^`\\tc@dEbGlAzAhVp\\jBfCj`@~h@jAxAnDdF`GnIfJhM~HzK`CdDre@so@tJiMtIiLvNqRtZya@bKgN~IkLl@{@vW_^jG]dELvDl@zE|@tExA|ExBzEfDzFfErFbFpGpG`H`HzG~HhWb\\|DbFvHlJze@nh@|JvN|JtOdJtOnIvNfItOdcAzqBrFlKbGlJpGlJhH~HvH~HxHrGfIpGdJrFlJtElJvDdKdDzJzBlKhBzJz@tK^bKLdKMjK_@jKk@dKmAvIkAtI{AhSsF`MuD|IwDtYwMhHwChHyCrFiB~HiCxHyBlIiBtKyBlJ{AtJkAfIm@zK}@baDuNbe@mA~qAaGtJO~HOrKNbK\\dK|@tJz@|JjBzJxBfJfClJfD|IvD~ItEtIdE`]`RhHfDfIvDnHfC`IxBfIzA~HjA~H|@fI\\nI?nI]nIm@dJkA|IkBnJwCfIwCtIuE~HuEhIqGfIqH`HoH~GoJrG}IhGmJvN}TdF_I`GoIjFqGzFsGzFcFbGeFxGsE`HwDvIwDfIwCfIyB|I{AlJkAdK{@bKm@tJ]rbC{K~N_@tO]tNOxb@pHxGjApGzAzKvCzV~HflA~^~Bj@`ClAxBxAtEfDfDvDhCtExBbF`BdFrApGjAbGtEvX~I`{@bA~HrApHzApGjFfX|Jhb@jAbGbBfN\\`GLnIFxW\\ry@^vXF~]TxWNj`@?jAT|_@Vj`@d@`f@D|T?rFFtEt@h`A?fDFxC\\hu@bAlgB^pg@zEfCfqAlt@ld@hWnc@jVrAz@||Ap{@xBz_AFxBkB}@'
    
polyline_decode(input);

</script>
</body>

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