ClemensFischer/XAML-Map-Control
1
0
Fork 0
mirror of https://github.com/ClemensFischer/XAML-Map-Control.git synced 2026-04-08 07:55:13 +00:00
Code Issues Projects Releases Packages Wiki Activity

Abstract MapProjection.RelativeScale

Browse source
This commit is contained in:
ClemensFischer 2026-01-25 18:04:59 +01:00
parent ceb19a9ae4
commit e8e7cacac0
4 changed files with 54 additions and 44 deletions
Download patch file Download diff file Expand all files Collapse all files

10
MapControl/Shared/TransverseMercatorProjectionSnyder.cs
View file

@ -47,8 +47,10 @@ namespace MapControl
public override Matrix RelativeScale(double latitude, double longitude)
{
var k = 1d; // omit k0 for relative scale
// h = k/k0 for relative scale
var h = 1d;
#if TM_RELATIVE_SCALE // relative scale is usually < 1.001 and hence neglectable
if (latitude > -90d && latitude < 90d)
{
var phi = latitude * Math.PI / 180d;
@ -64,12 +66,12 @@ namespace MapControl
var A4 = A2 * A2;
var A6 = A2 * A4;
k *= 1d + (1d + C) * A2 / 2d +
h = 1d + (1d + C) * A2 / 2d +
(5d - 4d * T + 42d * C + 13d * C * C - 28d * e_2) * A4 / 24d +
(61d - 148d * T + 16 * T * T) * A6 / 720d; // (8-11)
}
return new Matrix(k, 0d, 0d, k, 0d, 0d);
#endif
return new Matrix(h, 0d, 0d, h, 0d, 0d);
}
public override Point? LocationToMap(double latitude, double longitude)