OSRM.RoutingGeometry.js

/*
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU AFFERO General Public License as published by
the Free Software Foundation; either version 3 of the License, or
any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
or see http://www.gnu.org/licenses/agpl.txt.
*/

// OSRM routing geometry
// [renders routing geometry]

var OSRM = {};

OSRM.CONSTANTS = {};

OSRM.CONSTANTS.PRECISION = 6;

OSRM.RoutingGeometry = {

    // show route geometry - if there is a route
    show: function(response) {
	      var geometry = OSRM.RoutingGeometry._decode(response.route_geometry, OSRM.C.PRECISION );

	      OSRM.G.route.showRoute(geometry, OSRM.Route.ROUTE);
    },

    //show route geometry - if there is no route
    showNA: function() {
	      var positions = [];
	      for(var i=0, size=OSRM.G.markers.route.length; i<size; i++)
		        positions.push( OSRM.G.markers.route[i].getPosition() );

	      OSRM.G.route.showRoute(positions, OSRM.Route.NOROUTE);
    },

    //decode compressed route geometry
    _decode: function(encoded, precision) {
	      precision = Math.pow(10, -precision);
	      var len = encoded.length, index=0, lat=0, lng = 0, array = [];
	      while (index < len) {
		        var b, shift = 0, result = 0;
		        do {
			          b = encoded.charCodeAt(index++) - 63;
			          result |= (b & 0x1f) << shift;
			          shift += 5;
		        } while (b >= 0x20);
		        var dlat = ((result & 1) ? ~(result >> 1) : (result >> 1));
		        lat += dlat;
		        shift = 0;
		        result = 0;
		        do {
			          b = encoded.charCodeAt(index++) - 63;
			          result |= (b & 0x1f) << shift;
			          shift += 5;
		        } while (b >= 0x20);
		        var dlng = ((result & 1) ? ~(result >> 1) : (result >> 1));
		        lng += dlng;
		        //array.push( {lat: lat * precision, lng: lng * precision} );
		        array.push( [lat * precision, lng * precision] );
	      }
	      return array;
    }

};

module.exports = OSRM;