adds modes of transportation to routing

web/src/lib/util/gpx_util.ts

@@ -29,7 +29,7 @@ export async function gpx2trail(gpxString: string) {
     const totals = gpx.getTotals()
 
     const points = gpx.trk?.at(0)?.trkseg?.at(0)?.trkpt
-    const startPoint = points?.at(0);
+    const startPoint = points?.at(0);    
     if (startPoint) {
         trail.lat = startPoint.$.lat
         trail.lon = startPoint.$.lon

web/src/lib/util/polyline_util.ts

@@ -0,0 +1,80 @@
+function py2_round(value: number) {
+    return Math.floor(Math.abs(value) + 0.5) * (value >= 0 ? 1 : -1);
+}
+
+function encode(current: number, previous: number, factor: number) {
+    current = py2_round(current * factor);
+    previous = py2_round(previous * factor);
+    var coordinate = (current - previous) * 2;
+    if (coordinate < 0) {
+        coordinate = -coordinate - 1
+    }
+    var output = '';
+    while (coordinate >= 0x20) {
+        output += String.fromCharCode((0x20 | (coordinate & 0x1f)) + 63);
+        coordinate /= 32;
+    }
+    output += String.fromCharCode((coordinate | 0) + 63);
+    return output;
+}
+
+
+export function decodePolyline(str: string, precision: number = 6) {
+    var index = 0,
+        lat = 0,
+        lng = 0,
+        coordinates = [],
+        shift = 0,
+        result = 0,
+        byte = null,
+        latitude_change,
+        longitude_change,
+        factor = Math.pow(10, precision);
+
+    while (index < str.length) {
+        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]);
+    }
+
+    return coordinates;
+};
+
+
+export function encodePolyline(coordinates: number[][], precision: number = 6) {
+    if (!coordinates.length) { return ''; }
+
+    var factor = Math.pow(10, precision),
+        output = encode(coordinates[0][0], 0, factor) + encode(coordinates[0][1], 0, factor);
+
+    for (var i = 1; i < coordinates.length; i++) {
+        var a = coordinates[i], b = coordinates[i - 1];
+        output += encode(a[0], b[0], factor);
+        output += encode(a[1], b[1], factor);
+    }
+
+    return output;
+};