ClemensFischer/XAML-Map-Control
1
0
Fork 0
mirror of https://github.com/ClemensFischer/XAML-Map-Control.git synced 2026-02-06 15:54:14 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity

Updated map projections

Browse source
This commit is contained in:
ClemensFischer 2026-01-29 23:27:39 +01:00
parent d790200cf1
commit 359cbe8908
4 changed files with 84 additions and 52 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
MapControl/Shared/PolarStereographicProjection.cs
View file

@ -69,12 +69,13 @@ namespace MapControl
x = sign * (x - FalseEasting);
y = sign * (y - FalseNorthing);
var e = Math.Sqrt((2d - Flattening) * Flattening);
var e2 = (2d - Flattening) * Flattening;
var e = Math.Sqrt(e2);
var r = Math.Sqrt(x * x + y * y); // p.162 (20-18)
var t = r * Math.Sqrt(Math.Pow(1d + e, 1d + e) * Math.Pow(1d - e, 1d - e))
/ (2d * EquatorialRadius * ScaleFactor); // p.162 (21-39)
var phi = WorldMercatorProjection.ApproximateLatitude(e, t); // p.162 (3-5)
var phi = WorldMercatorProjection.ApproximateLatitude(e2, t); // p.162 (3-5)
var lambda = Math.Atan2(x, -y); // p.162 (20-16)
return new Location(sign * phi * 180d / Math.PI, sign * lambda * 180d / Math.PI);

4
MapControl/Shared/WebMercatorProjection.cs
View file

@ -43,8 +43,8 @@ namespace MapControl
public override Location MapToLocation(double x, double y)
{
return new Location(
YToLatitude(y / EquatorialRadius * 180d / Math.PI),
return new Location(YToLatitude(
y / EquatorialRadius * 180d / Math.PI),
x / EquatorialRadius * 180d / Math.PI);
}

79
MapControl/Shared/WorldMercatorProjection.cs
View file

@ -14,10 +14,10 @@ namespace MapControl
/// </summary>
public class WorldMercatorProjection : MapProjection
{
public static readonly double Wgs84Eccentricity = Math.Sqrt((2d - Wgs84Flattening) * Wgs84Flattening);
public const string DefaultCrsId = "EPSG:3395";
public double Flattening { get; set; } = Wgs84Flattening;
public WorldMercatorProjection() // parameterless constructor for XAML
: this(DefaultCrsId)
{
@ -31,62 +31,51 @@ namespace MapControl
public override Matrix RelativeTransform(double latitude, double longitude)
{
var k = RelativeScale(latitude);
var phi = latitude * Math.PI / 180d;
var e2 = (2d - Flattening) * Flattening;
var sinPhi = Math.Sin(phi);
var k = Math.Sqrt(1d - e2 * sinPhi * sinPhi) / Math.Cos(phi); // p.44 (7-8)
return new Matrix(k, 0d, 0d, k, 0d, 0d);
}
public override Point LocationToMap(double latitude, double longitude)
{
return new Point(
EquatorialRadius * Math.PI / 180d * longitude,
EquatorialRadius * Math.PI / 180d * LatitudeToY(latitude));
var x = EquatorialRadius * longitude * Math.PI / 180d;
double y;
if (latitude <= -90d)
{
y = double.NegativeInfinity;
}
else if (latitude >= 90d)
{
y = double.PositiveInfinity;
}
else
{
var phi = latitude * Math.PI / 180d;
var e = Math.Sqrt((2d - Flattening) * Flattening);
var eSinPhi = e * Math.Sin(phi);
var f = Math.Pow((1d - eSinPhi) / (1d + eSinPhi), e / 2d);
y = EquatorialRadius * Math.Log(Math.Tan(phi / 2d + Math.PI / 4d) * f); // p.44 (7-7)
}
return new Point(x, y);
}
public override Location MapToLocation(double x, double y)
{
return new Location(
YToLatitude(y / EquatorialRadius * 180d / Math.PI),
x / EquatorialRadius * 180d / Math.PI);
var t = Math.Exp(-y / EquatorialRadius); // p.44 (7-10)
var phi = ApproximateLatitude((2d - Flattening) * Flattening, t); // p.45 (3-5)
var lambda = x / EquatorialRadius;
return new Location(phi * 180d / Math.PI, lambda * 180d / Math.PI);
}
public static double RelativeScale(double latitude)
internal static double ApproximateLatitude(double e2, double t)
{
var phi = latitude * Math.PI / 180d;
var eSinPhi = Wgs84Eccentricity * Math.Sin(phi);
return Math.Sqrt(1d - eSinPhi * eSinPhi) / Math.Cos(phi); // p.44 (7-8)
}
public static double LatitudeToY(double latitude)
{
if (latitude <= -90d)
{
return double.NegativeInfinity;
}
if (latitude >= 90d)
{
return double.PositiveInfinity;
}
var phi = latitude * Math.PI / 180d;
var eSinPhi = Wgs84Eccentricity * Math.Sin(phi);
var f = Math.Pow((1d - eSinPhi) / (1d + eSinPhi), Wgs84Eccentricity / 2d);
return Math.Log(Math.Tan(phi / 2d + Math.PI / 4d) * f) * 180d / Math.PI; // p.44 (7-7)
}
public static double YToLatitude(double y)
{
var t = Math.Exp(-y * Math.PI / 180d); // p.44 (7-10)
return ApproximateLatitude(Wgs84Eccentricity, t) * 180d / Math.PI;
}
internal static double ApproximateLatitude(double e, double t)
{
var e2 = e * e;
var e4 = e2 * e2;
var e6 = e2 * e4;
var e8 = e2 * e6;

48
MapProjections/Shared/ProjNetMapProjection.cs
View file

@ -15,7 +15,7 @@ namespace MapControl.Projections
/// </summary>
public class ProjNetMapProjection : MapProjection
{
protected MapProjection FallbackProjection { get; }
protected MapProjection FallbackProjection { get; private set; }
protected ProjNetMapProjection(MapProjection fallbackProjection)
{
@ -49,10 +49,10 @@ namespace MapControl.Projections
field = value ??
throw new ArgumentNullException(nameof(value));
var name = field.Projection?.Name ??
var projection = field.Projection ??
throw new ArgumentException("CoordinateSystem.Projection must not be null.", nameof(value));
IsNormalCylindrical = name.StartsWith("Mercator") || name.Contains("Pseudo-Mercator");
IsNormalCylindrical = projection.Name.StartsWith("Mercator") || projection.Name.Contains("Pseudo-Mercator");
var transformFactory = new CoordinateTransformationFactory();
@ -67,6 +67,48 @@ namespace MapControl.Projections
CrsId = !string.IsNullOrEmpty(field.Authority) && field.AuthorityCode > 0
? $"{field.Authority}:{field.AuthorityCode}"
: string.Empty;
var ellipsoid = field.GeographicCoordinateSystem.HorizontalDatum.Ellipsoid;
if (projection.Name.Contains("Pseudo-Mercator"))
{
FallbackProjection = new MapControl.WebMercatorProjection
{
EquatorialRadius = ellipsoid.SemiMajorAxis
};
}
else if (projection.Name.StartsWith("Mercator"))
{
FallbackProjection = new MapControl.WorldMercatorProjection
{
EquatorialRadius = ellipsoid.SemiMajorAxis,
Flattening = 1d / ellipsoid.InverseFlattening
};
}
else if (projection.Name.StartsWith("Transverse_Mercator"))
{
FallbackProjection = new TransverseMercatorProjection
{
EquatorialRadius = ellipsoid.SemiMajorAxis,
Flattening = 1d / ellipsoid.InverseFlattening,
CentralMeridian = projection.GetParameter("central_meridian").Value,
ScaleFactor = projection.GetParameter("scale_factor").Value,
FalseEasting = projection.GetParameter("false_easting").Value,
FalseNorthing = projection.GetParameter("false_northing").Value
};
}
else if (projection.Name.StartsWith("Polar_Stereographic"))
{
FallbackProjection = new PolarStereographicProjection
{
EquatorialRadius = ellipsoid.SemiMajorAxis,
Flattening = 1d / ellipsoid.InverseFlattening,
ScaleFactor = projection.GetParameter("scale_factor").Value,
FalseEasting = projection.GetParameter("false_easting").Value,
FalseNorthing = projection.GetParameter("false_northing").Value,
Hemisphere = projection.GetParameter("latitude_of_origin").Value >= 0 ? Hemisphere.North : Hemisphere.South
};
}
}
}