Add support for downhill ski routing

src/Itinero/Osm/Vehicles/Ski/Downhill.cs

@@ -0,0 +1,64 @@
+using Itinero.Attributes;
+using Itinero.Profiles;
+
+namespace Itinero.Osm.Vehicles.Ski
+{
+    /// <inheritdoc/>
+    public class Downhill : Itinero.Profiles.Vehicle
+    {
+        /// <summary>
+        /// Creates a new instance of the <see cref="Downhill"/> class. 
+        /// </summary>
+        public Downhill()
+        {
+            base.MetaWhiteList.Add("name");
+
+            base.ProfileWhiteList.Add("piste:type");
+            base.ProfileWhiteList.Add("aerialway");
+
+            Register(new Profile("shortest", ProfileMetric.DistanceInMeters, VehicleTypes, null, this));
+            Register(new Profile(string.Empty, ProfileMetric.TimeInSeconds, VehicleTypes, null, this));
+        }
+
+        /// <inheritdoc/>
+        public override string Name => "downhill";
+
+        /// <inheritdoc/>
+        public override string[] VehicleTypes { get; } = [ "ski", "foot" ];
+
+        /// <inheritdoc/>
+        public override FactorAndSpeed FactorAndSpeed(IAttributeCollection attributes, Whitelist whitelist)
+        {
+            short direction = 0;
+            float speedFactor = 0f, value = 0f;
+
+            if (attributes is null) return Itinero.Profiles.FactorAndSpeed.NoFactor;
+
+            if (attributes.TryGetValue("piste:type", out var piste_type) && piste_type == "downhill") {
+                direction = 1; // always follow piste direction
+                if (attributes.TryGetValue("piste:difficulty", out var piste_difficulty)) {
+                    value = speedFactor = piste_difficulty switch
+                    {
+                        "easy" => 1 / (30f / 3.6f),
+                        "intermediate" => 1 / (50f / 3.6f),
+                        "advanced" => 1 / (30f / 3.6f),
+                        _ => 1 / (20f / 3.6f),
+                    };
+                } else {
+                    value = speedFactor = 1 / (20f / 3.6f);
+                }
+            } else if (attributes.TryGetValue("aerialway", out var aerialway)) {
+                direction = 1; // forward the edge
+                value = speedFactor = 1 / (10f / 3.6f);
+            } else {
+                return Itinero.Profiles.FactorAndSpeed.NoFactor;
+            }
+
+            return new FactorAndSpeed {
+                SpeedFactor = speedFactor,
+                Value = value,
+                Direction = direction
+            };
+        }
+    }
+}

src/Itinero/Osm/Vehicles/Vehicle.cs

@@ -22,6 +22,7 @@
 using Itinero.Profiles.Lua;
 using System.Collections.Generic;
 using System.Linq;
+using Itinero.Osm.Vehicles.Ski;
 
 namespace Itinero.Osm.Vehicles
 {
@@ -70,6 +71,17 @@ public static class Vehicle
         /// </summary>
         public static readonly Profiles.Vehicle Bus = new DynamicVehicle(VehicleExtensions.LoadEmbeddedResource("Itinero.Osm.Vehicles.bus.lua"));
 
+        /// <summary>
+        /// Ski vehicle types.
+        /// </summary>
+        public static class Ski
+        {
+            /// <summary>
+            /// Downhill skiing.
+            /// </summary>
+            public static readonly Profiles.Vehicle Downhill = new Downhill();
+        }
+
         /// <summary>
         /// Registers all default vehicles.
         /// </summary>
@@ -84,6 +96,8 @@ public static void RegisterVehicles()
             SmallTruck.Register();
             BigTruck.Register();
             Bus.Register();
+
+            Ski.Downhill.Register();
         }
 
         private static Dictionary<string, bool?> _accessValues = null;

test/Itinero.Test.Functional/Staging/Download.cs

@@ -37,13 +37,19 @@ public static class Download
         /// <summary>
         /// Downloads the luxembourg data.
         /// </summary>
-        public static void DownloadLuxembourgAll()
+        public static void DownloadLuxembourgAll() => DownloadPBF(Download.LuxembourgPBF, Download.LuxembourgLocal);
+
+        /// <summary>
+        /// Download the given PBF url into a local file.
+        /// </summary>
+        /// <param name="url">URL for the PBF file.</param>
+        /// <param name="localPath">Local path.</param>
+        public static void DownloadPBF(string url, string localPath)
         {
-            if (!File.Exists(Download.LuxembourgLocal))
+            if (!File.Exists(localPath))
             {
-                var client = new WebClient();
-                client.DownloadFile(Download.LuxembourgPBF,
-                    Download.LuxembourgLocal);
+                using var client = new WebClient();
+                client.DownloadFile(url, localPath);
             }
         }
 

test/Itinero.Test.Functional/Tests/RoutingTests.cs

@@ -59,6 +59,8 @@ public static void Run(RouterDb routerDb)
             // one-to-many & many-to-many.
             GetTestOneToManyRoutes(router, profile, 200).TestPerf($"{profile.FullName} one-to-many routes");
             GetTestManyToManyRoutes(router, profile, 20).TestPerf($"{profile.FullName} many-to-many routes");
+
+            RunDownhillSki();
         }
 
         /// <summary>
@@ -358,5 +360,27 @@ public static Func<PerformanceTestResult<Result<Route[][]>>> GetTestManyToManyRo
             return () => new PerformanceTestResult<Result<Route[][]>>(
                 router.TryCalculate(profile, resolvedPoints, resolvedPoints));
         }
+
+        /// <summary>
+        /// Runs ski resort routing tests.
+        /// </summary>
+        public static void RunDownhillSki()
+        {
+            var localPath = Path.Combine(Path.GetTempPath(), "aragon-latest.osm.pbf");
+            Download.DownloadPBF("https://download.geofabrik.de/europe/spain/aragon-latest.osm.pbf", localPath);
+
+            using var stream = new FileInfo(localPath).OpenRead();
+            var routerDb = new RouterDb();
+            routerDb.LoadOsmData(stream, Itinero.Osm.Vehicles.Vehicle.Ski.Downhill, Itinero.Osm.Vehicles.Vehicle.Pedestrian);
+            var router = new Router(routerDb);
+
+            using var routingCancellation = new CancellationTokenSource();
+            routingCancellation.CancelAfter(TimeSpan.FromMinutes(5));
+            var source = new Coordinate(42.58698f, 0.54023f); // El Molino chair lift in Cerler, Spain
+            var target = new Coordinate(42.55933f, 0.56834f); // Ampriu chair lift in Cerler, Spain
+
+            Assert.IsNotNull(router.Calculate(Itinero.Osm.Vehicles.Vehicle.Ski.Downhill.Shortest(),
+                source.Latitude, source.Longitude, target.Latitude, target.Longitude, routingCancellation.Token));
+        }
     }
 }