From 5334bb4ea630c4ee815ad5acadde3afcde91c504 Mon Sep 17 00:00:00 2001 From: ClemensFischer Date: Thu, 15 Jan 2026 10:58:54 +0100 Subject: [PATCH] Updated map projections --- MapControl/Shared/MapBase.cs | 2 +- MapControl/Shared/MapProjectionFactory.cs | 8 +- .../Shared/PolarStereographicProjection.cs | 75 +++++++------------ MapControl/Shared/WorldMercatorProjection.cs | 4 +- 4 files changed, 35 insertions(+), 54 deletions(-) diff --git a/MapControl/Shared/MapBase.cs b/MapControl/Shared/MapBase.cs index e0afa23d..36c790bd 100644 --- a/MapControl/Shared/MapBase.cs +++ b/MapControl/Shared/MapBase.cs @@ -202,7 +202,7 @@ namespace MapControl /// public Matrix GetMapTransform(Location location) { - var mapScale = GetMapScale(location); + var mapScale = GetMapScale(location.Latitude, location.Longitude); var transform = new Matrix(mapScale.X, 0d, 0d, mapScale.Y, 0d, 0d); transform.Rotate(ViewTransform.Rotation); diff --git a/MapControl/Shared/MapProjectionFactory.cs b/MapControl/Shared/MapProjectionFactory.cs index 7c43093c..5881c620 100644 --- a/MapControl/Shared/MapProjectionFactory.cs +++ b/MapControl/Shared/MapProjectionFactory.cs @@ -24,12 +24,12 @@ namespace MapControl projection = new EquirectangularProjection(crsId); break; - case UpsNorthProjection.DefaultCrsId: - projection = new UpsNorthProjection(); + case Wgs84UpsNorthProjection.DefaultCrsId: + projection = new Wgs84UpsNorthProjection(); break; - case UpsSouthProjection.DefaultCrsId: - projection = new UpsSouthProjection(); + case Wgs84UpsSouthProjection.DefaultCrsId: + projection = new Wgs84UpsSouthProjection(); break; case Wgs84AutoUtmProjection.DefaultCrsId: diff --git a/MapControl/Shared/PolarStereographicProjection.cs b/MapControl/Shared/PolarStereographicProjection.cs index 2b7e06d7..8e35483a 100644 --- a/MapControl/Shared/PolarStereographicProjection.cs +++ b/MapControl/Shared/PolarStereographicProjection.cs @@ -26,70 +26,57 @@ namespace MapControl public double FalseNorthing { get; set; } = 2e6; public Hemisphere Hemisphere { get; set; } - public override Point RelativeScale(double latitude, double longitude) + public static double RelativeScale(Hemisphere hemisphere, double equatorialRadius, double flattening, double scaleFactor, double latitude) { - var phi = latitude * Math.PI / 180d; + var sign = hemisphere == Hemisphere.North ? 1d : -1d; + var phi = sign * latitude * Math.PI / 180d; - if (Hemisphere == Hemisphere.South) - { - phi = -phi; - } - - var e = Math.Sqrt((2d - Flattening) * Flattening); + var e = Math.Sqrt((2d - flattening) * flattening); var eSinPhi = e * Math.Sin(phi); var t = Math.Tan(Math.PI / 4d - phi / 2d) / Math.Pow((1d - eSinPhi) / (1d + eSinPhi), e / 2d); // p.161 (15-9) - var r = 2d * EquatorialRadius * ScaleFactor * t + var r = 2d * equatorialRadius * scaleFactor * t / Math.Sqrt(Math.Pow(1d + e, 1d + e) * Math.Pow(1d - e, 1d - e)); // p.161 (21-33) var m = Math.Cos(phi) / Math.Sqrt(1d - eSinPhi * eSinPhi); // p.160 (14-15) - var k = r / (EquatorialRadius * m); // p.161 (21-32) + + return r / (equatorialRadius * m); // p.161 (21-32) + } + + public override Point RelativeScale(double latitude, double longitude) + { + var k = RelativeScale(Hemisphere, EquatorialRadius, Flattening, ScaleFactor, latitude); return new Point(k, k); } public override Point? LocationToMap(double latitude, double longitude) { - var phi = latitude * Math.PI / 180d; - var lambda = longitude * Math.PI / 180d; - - if (Hemisphere == Hemisphere.South) - { - phi = -phi; - lambda = -lambda; - } + var sign = Hemisphere == Hemisphere.North ? 1d : -1d; + var phi = sign * latitude * Math.PI / 180d; + var lambda = sign * longitude * Math.PI / 180d; var e = Math.Sqrt((2d - Flattening) * Flattening); var eSinPhi = e * Math.Sin(phi); var t = Math.Tan(Math.PI / 4d - phi / 2d) / Math.Pow((1d - eSinPhi) / (1d + eSinPhi), e / 2d); // p.161 (15-9) + var r = 2d * EquatorialRadius * ScaleFactor * t / Math.Sqrt(Math.Pow(1d + e, 1d + e) * Math.Pow(1d - e, 1d - e)); // p.161 (21-33) - var x = r * Math.Sin(lambda); // p.161 (21-30) - var y = -r * Math.Cos(lambda); // p.161 (21-31) - - if (Hemisphere == Hemisphere.South) - { - x = -x; - y = -y; - } + var x = sign * r * Math.Sin(lambda); // p.161 (21-30) + var y = sign * -r * Math.Cos(lambda); // p.161 (21-31) return new Point(x + FalseEasting, y + FalseNorthing); } public override Location MapToLocation(double x, double y) { - x -= FalseEasting; - y -= FalseNorthing; - - if (Hemisphere == Hemisphere.South) - { - x = -x; - y = -y; - } + var sign = Hemisphere == Hemisphere.North ? 1d : -1d; + x = sign * (x - FalseEasting); + y = sign * (y - FalseNorthing); var e = Math.Sqrt((2d - Flattening) * Flattening); var r = Math.Sqrt(x * x + y * y); // p.162 (20-18) @@ -99,29 +86,23 @@ namespace MapControl var phi = WorldMercatorProjection.ApproximateLatitude(e, t); // p.162 (3-5) var lambda = Math.Atan2(x, -y); // p.162 (20-16) - if (Hemisphere == Hemisphere.South) - { - phi = -phi; - lambda = -lambda; - } - - return new Location(phi * 180d / Math.PI, lambda * 180d / Math.PI); + return new Location(sign * phi * 180d / Math.PI, sign * lambda * 180d / Math.PI); } } /// /// Universal Polar Stereographic North Projection - EPSG:32661. /// - public class UpsNorthProjection : PolarStereographicProjection + public class Wgs84UpsNorthProjection : PolarStereographicProjection { public const string DefaultCrsId = "EPSG:32661"; - public UpsNorthProjection() // parameterless constructor for XAML + public Wgs84UpsNorthProjection() // parameterless constructor for XAML : this(DefaultCrsId) { } - public UpsNorthProjection(string crsId) + public Wgs84UpsNorthProjection(string crsId) { CrsId = crsId; Hemisphere = Hemisphere.North; @@ -131,16 +112,16 @@ namespace MapControl /// /// Universal Polar Stereographic South Projection - EPSG:32761. /// - public class UpsSouthProjection : PolarStereographicProjection + public class Wgs84UpsSouthProjection : PolarStereographicProjection { public const string DefaultCrsId = "EPSG:32761"; - public UpsSouthProjection() // parameterless constructor for XAML + public Wgs84UpsSouthProjection() // parameterless constructor for XAML : this(DefaultCrsId) { } - public UpsSouthProjection(string crsId) + public Wgs84UpsSouthProjection(string crsId) { CrsId = crsId; Hemisphere = Hemisphere.South; diff --git a/MapControl/Shared/WorldMercatorProjection.cs b/MapControl/Shared/WorldMercatorProjection.cs index 4f0c245d..b2f1cf2f 100644 --- a/MapControl/Shared/WorldMercatorProjection.cs +++ b/MapControl/Shared/WorldMercatorProjection.cs @@ -30,7 +30,7 @@ namespace MapControl public override Point RelativeScale(double latitude, double longitude) { - var k = ScaleFactor(latitude); + var k = RelativeScale(latitude); return new Point(k, k); } @@ -49,7 +49,7 @@ namespace MapControl x / Wgs84MeterPerDegree); } - public static double ScaleFactor(double latitude) + public static double RelativeScale(double latitude) { var phi = latitude * Math.PI / 180d; var eSinPhi = Wgs84Eccentricity * Math.Sin(phi);