ClemensFischer/XAML-Map-Control
1
0
Fork 0
mirror of https://github.com/ClemensFischer/XAML-Map-Control.git synced 2026-04-08 16:05:50 +00:00
Code Issues Projects Releases Packages Wiki Activity

MapProjection.RelativeTransform

Browse source
This commit is contained in:
ClemensFischer 2026-01-27 22:56:09 +01:00
parent a0e82964ef
commit 8d25310b8e
19 changed files with 59 additions and 50 deletions
Download patch file Download diff file Expand all files Collapse all files

29
MapControl/Shared/TransverseMercatorProjection.cs
View file

@ -60,24 +60,21 @@ namespace MapControl
Flattening = Wgs84Flattening;
}
public override Matrix RelativeScale(double latitude, double longitude)
public override Matrix RelativeTransform(double latitude, double longitude)
{
// h = k/k0 for relative scale
var h = 1d;
#if TM_RELATIVE_SCALE // relative scale is usually < 1.001 and hence neglectable
// φ
var phi = latitude * Math.PI / 180d;
var sinPhi = Math.Sin(phi);
// t
var t = Math.Sinh(Atanh(sinPhi) - f2 * Atanh(f2 * sinPhi));
// λ - λ0
var dLambda = (longitude - CentralMeridian) * Math.PI / 180d;
var cosLambda = Math.Cos(dLambda);
// t
var t = Math.Sinh(Atanh(sinPhi) - f2 * Atanh(f2 * sinPhi));
var u = Math.Sqrt(1d + t * t);
// ξ'
var xi_ = Math.Atan2(t, cosLambda);
// η'
var eta_ = Atanh(Math.Sin(dLambda) / Math.Sqrt(1d + t * t));
var eta_ = Atanh(Math.Sin(dLambda) / u);
// σ
var sigma = 1 +
2d * a1 * Math.Cos(2d * xi_) * Math.Cosh(2d * eta_) +
@ -90,10 +87,18 @@ namespace MapControl
6d * a3 * Math.Sin(6d * xi_) * Math.Sinh(6d * eta_);
var n = Flattening / (2d - Flattening);
var u = (1d - n) / (1d + n) * Math.Tan(phi);
h = f1 * Math.Sqrt((1d + u * u) * (sigma * sigma + tau * tau) / (t * t + cosLambda * cosLambda));
#endif
return new Matrix(h, 0d, 0d, h, 0d, 0d);
var m = (1d - n) / (1d + n) * Math.Tan(phi);
// h = k/k0 for relative scale
var h = f1 * Math.Sqrt((1d + m * m) * (sigma * sigma + tau * tau) / (t * t + cosLambda * cosLambda));
var tanLambda = Math.Tan(dLambda);
// γ, meridian convergence angle
var gamma = Math.Atan2(tau * u + sigma * t * tanLambda, sigma * u - tau * t * tanLambda);
var transform = new Matrix(h, 0d, 0d, h, 0d, 0d);
transform.Rotate(-gamma * 180d / Math.PI);
return transform;
}
public override Point? LocationToMap(double latitude, double longitude)