Implement Ifly737 format.

src/QSP/MathTools/EarthGeometry.cs

@@ -82,6 +82,17 @@ public static Vector3D GetW(Vector3D v, Vector3D v2)
             return v3.Cross(v).Normalize();
         }
 
+        /// <summary>
+        /// Calculates the great circle path from x to y, and returns heading departing x.
+        /// x and y should be unique.
+        /// </summary>
+        /// <exception cref="ArgumentException"></exception>
+        public static double TrueHeading(ICoordinate x, ICoordinate y)
+        {
+            if (x.LatLonEquals(y)) throw new ArgumentException();
+            return TrueHeading(GetW(x.ToVector3D(), y.ToVector3D()), x);
+        }
+
         /// <summary>
         /// Calculates the true heading of the given vector, at the given coordinate.
         /// Return value is larger than 0 and smaller or equal to 360. Note: If v is

src/QSP/RouteFinding/FileExport/Providers/Ifly737Provider.cs

@@ -1,53 +1,57 @@
-using QSP.RouteFinding.Airports;
+using QSP.MathTools;
 using QSP.RouteFinding.Routes;
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using static CommonLibrary.LibraryExtension.Types;
 using static System.Linq.Enumerable;
 
 namespace QSP.RouteFinding.FileExport.Providers
 {
-    // TODO: Add test.
     public static class Ifly737Provider
     {
-        public static string GetExportText(Route route, AirportManager airports)
+        // In the waypoint part, each line contain a waypoint. Let's say the 
+        // waypoint is B, and the previous waypoint is A. The line contains A also
+        // contains a true heading. If you fly a great circle route from A to B, you
+        // will have true heading equal to that value.
+
+        public static string GetExportText(Route route)
         {
             if (route.Count < 2) throw new ArgumentException();
             var linesPart1 = List(
                 route.FirstWaypoint.ID.Substring(0, 4),
-                route.FirstWaypoint.ID.Substring(4),
-                route.LastWaypoint.ID.Substring(0, 4)
+                route.LastWaypoint.ID.Substring(0, 4),
+                route.FirstWaypoint.ID.Substring(4)
             ).Concat(Repeat("", 7))
              .Concat(List("-1", "", "", "", "", "0"));
 
-            var node = route.First.Next;
-            var part2 = List(("DIRECT", node.Value.Waypoint));
-            node = node.Next;
+            var linesPart2 = new List<string>();
+            var prev = route.First;
+            var current = prev.Next;
 
-            while (node != null)
+            while (current != route.Last)
             {
-                var a = node.Previous.Value.Neighbor.Airway;
-                var airway = a == "DCT" ? "DIRECT" : a;
-                part2.Add((a, node.Value.Waypoint));
-                node = node.Next;
+                var airway = prev.Value.Neighbor.Airway;
+                bool isDirect = (prev == route.First) || (airway == "DCT");
+
+                var w = current.Value.Waypoint;
+                var heading = EarthGeometry.TrueHeading(prev.Value.Waypoint, w);
+
+                linesPart2.Add(string.Format(
+                    "{0},{1},0, {2} {3},0,0, {4},0,0,1,-1,0.000,0,-1000,-1000,-1,-1,-1,0,0,000.00000,0,0,,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1000,0",
+                    isDirect ? "DIRECT,3" : $"{airway},2",
+                    w.ID,
+                    w.Lat.ToString("###0.000000"),
+                    w.Lon.ToString("###0.000000"),
+                    heading.ToString("###0.00000")));
+
+                prev = current;
+                current = current.Next;
             }
 
-            var linesPart2 = part2.Select(v =>
-            {
-                var (airway, wpt) = v;
-                var words = List(
-                    airway,
-                    airway == "DIRECT" ? "3" : "2",
-                    wpt.ID,
-                    string.Format("{0} {1}", wpt.Lat, wpt.Lon),
-                    "0",
-                    "0",
-                    "Put heading here"); //TODO: calculate true heading towards next wpt
-                return string.Join(",", words) +
-                       ",0,0,1,-1,0.000,0,-1000,-1000,-1,-1,-1,0,0,000.00000,0,0,,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1000,0";
-            });
+            linesPart2.Add("");
 
             return string.Join(",\n", linesPart1.Concat(linesPart2));
         }
     }
-}
+}

src/Tests/UnitTest/MathTools/EarthGeometryTest.cs

@@ -36,5 +36,11 @@ public void TureHeadingTest()
             Assert.IsTrue(IsZero(TrueHeading(v0, p2)));
             Assert.IsTrue(IsZero(TrueHeading(v1, p3)));
         }
+
+        [Test]
+        public void TureHeadingCoordinateTest()
+        {
+            Assert.AreEqual(90, TrueHeading(new LatLon(0, 20), new LatLon(0, 60)), 1e-7);
+        }
     }
 }

src/Tests/UnitTest/RouteFinding/Common.cs

@@ -13,13 +13,15 @@ namespace UnitTest.RouteFinding
 {
     public static class Common
     {
-        // Format: 
-        // Waypoint1, AirwayToNext, Distance,
-        // Waypoint2, AirwayToNext, Distance,
-        // ...
-        // WaypointN
-        //
-        // Use a negative distance for automatic calculation
+        /// <summary>
+        /// Format: 
+        /// Waypoint1, AirwayToNext, Distance,
+        /// Waypoint2, AirwayToNext, Distance,
+        /// ...
+        /// WaypointN
+        ///
+        /// Use a negative distance for automatic calculation
+        /// </summary>
         public static Route GetRoute(params object[] para)
         {
             if (para.Length % 3 != 1)

src/Tests/UnitTest/RouteFinding/FileExport/Providers/Ifly737ProviderTest.cs

@@ -0,0 +1,58 @@
+using CommonLibrary.LibraryExtension;
+using NUnit.Framework;
+using QSP.RouteFinding.Containers;
+using QSP.RouteFinding.FileExport.Providers;
+
+namespace UnitTest.RouteFinding.FileExport.Providers
+{
+    [TestFixture]
+    public class Ifly737ProviderTest
+    {
+        [Test]
+        public void GetExportTextTest()
+        {
+            var route = Common.GetRoute(
+                new Waypoint("RJBB06L", 0.0, 0.0), "A", -1.0,
+                new Waypoint("WPT0", 0.0, 1.0), "B", -1.0,
+                new Waypoint("WPT1", 0.0, 2.0), "DCT", -1.0,
+                new Waypoint("WPT2", 0.0, 2.5), "C", -1.0,
+                new Waypoint("RJAA18", 0.0, 3.0));
+
+            var text = Ifly737Provider.GetExportText(route);
+
+            var expected =
+@"RJBB,
+RJAA,
+06L,
+,
+,
+,
+,
+,
+,
+,
+-1,
+,
+,
+,
+,
+0,
+DIRECT,3,WPT0,0, 0.000000 1.000000,0,0, 90.00000,0,0,1,-1,0.000,0,-1000,-1000,-1,-1,-1,0,0,000.00000,0,0,,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1000,0,
+B,2,WPT1,0, 0.000000 2.000000,0,0, 90.00000,0,0,1,-1,0.000,0,-1000,-1000,-1,-1,-1,0,0,000.00000,0,0,,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1000,0,
+DIRECT,3,WPT2,0, 0.000000 2.500000,0,0, 90.00000,0,0,1,-1,0.000,0,-1000,-1000,-1,-1,-1,0,0,000.00000,0,0,,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1,-1,-1000,0,-1000,-1000,0,
+";
+
+            Assert.IsTrue(expected.EqualsIgnoreNewlineStyle(text));
+        }
+
+        [Test]
+        public void GetExportTextNoWaypontDoesNotThrow()
+        {
+            var route = Common.GetRoute(
+                new Waypoint("RJBB06L", 0.0, 0.0), "DCT", -1.0,
+                new Waypoint("RJAA18", 0.0, 3.0));
+
+            var text = Ifly737Provider.GetExportText(route);
+        }
+    }
+}

src/Tests/UnitTest/UnitTest.csproj

@@ -102,6 +102,7 @@
     <Compile Include="LibraryExtension\LinkedListsTest.cs" />
     <Compile Include="LibraryExtension\ListsTest.cs" />
     <Compile Include="LibraryExtension\WebRequestsTest.cs" />
+    <Compile Include="MathTools\AnglesTest.cs" />
     <Compile Include="MathTools\EarthGeometryTest.cs" />
     <Compile Include="MathTools\ModuloTest.cs" />
     <Compile Include="MathTools\Tables\Readers\TableReader1DTest.cs" />
@@ -154,6 +155,7 @@
     <Compile Include="RouteFinding\FileExport\ExportCommandTest.cs" />
     <Compile Include="RouteFinding\FileExport\Providers\Fs9ProviderTest.cs" />
     <Compile Include="RouteFinding\FileExport\Providers\FsxProviderTest.cs" />
+    <Compile Include="RouteFinding\FileExport\Providers\Ifly737ProviderTest.cs" />
     <Compile Include="RouteFinding\FileExport\Providers\PmdgProviderTest.cs" />
     <Compile Include="RouteFinding\RandomRoutes\RandomRouteFinderTest.cs" />
     <Compile Include="RouteFinding\RouteAnalyzers\AnalyzerWithCommandsTest.cs" />