Add GraphHopper engine (thanks @karussell!)

diff --git a/app/assets/javascripts/routing_engines/graphhopper_bicycle.js b/app/assets/javascripts/routing_engines/graphhopper_bicycle.js
new file mode 100644 (file)
index 0000000..39c7bca
--- /dev/null
+++ b/app/assets/javascripts/routing_engines/graphhopper_bicycle.js
@@ -0,0 +1,48 @@
+// GraphHopper bicycle engine
+
+OSM.RoutingEngines.list.push({    
+    name: 'Bicycle (GraphHopper)',
+    draggable: true,
+    _hints: {},
+    getRoute: function(final, points) {
+        var url = "http://graphhopper.com/routing/api/route?vehicle=bike&locale=en";
+        for (var i = 0; i < points.length; i++) {
+            var pair = points[i].join(',');
+            url += "&point=" + pair;
+        }
+        if (final)
+            url += "&instructions=true";
+        this.requestJSONP(url + "&type=jsonp&callback=");
+    },
+    gotRoute: function(router, data) {
+        if (!data.info.routeFound) {
+            alert("Couldn't find route between those two places");
+            return false;
+        }
+        // Draw polyline
+        var line = L.PolylineUtil.decode(data.route.coordinates);
+        router.setPolyline(line);
+        // Assemble instructions
+        var steps = [];
+        var instr = data.route.instructions;
+        for (i = 0; i < instr.descriptions.length; i++) {
+            var indi = instr.indications[i];
+            var instrCode = (i==instr.descriptions.length-1) ? 15 : this.GH_INSTR_MAP[indi];
+            var instrText = "<b>" + (i + 1) + ".</b> ";
+            instrText += instr.descriptions[i];
+            var latlng = instr.latLngs[i];
+            var distInMeter = instr.distances[i];            
+            steps.push([{lat: latlng[0], lng: latlng[1]}, instrCode, instrText, distInMeter]);
+        }
+        router.setItinerary({steps: steps});
+    },
+    GH_INSTR_MAP: {
+        "-3": 6, // sharp left
+        "-2": 7, // left       
+        "-1": 8, // slight left                
+        0: 0, // straight
+        1: 1, // slight right
+        2: 2, // right
+        3: 3 // sharp right            
+    }
+});