mirror of
https://github.com/ClemensFischer/XAML-Map-Control.git
synced 2025-12-06 07:12:04 +01:00
59 lines
2.1 KiB
C#
59 lines
2.1 KiB
C#
// XAML Map Control - https://github.com/ClemensFischer/XAML-Map-Control
|
|
// Copyright © 2024 Clemens Fischer
|
|
// Licensed under the Microsoft Public License (Ms-PL)
|
|
|
|
using System;
|
|
#if WPF
|
|
using System.Windows;
|
|
#elif AVALONIA
|
|
using Avalonia;
|
|
#endif
|
|
|
|
namespace MapControl.Projections
|
|
{
|
|
/// <summary>
|
|
/// Elliptical Mercator Projection implemented by setting the WKT property of a GeoApiProjection.
|
|
/// See "Map Projections - A Working Manual" (https://pubs.usgs.gov/pp/1395/report.pdf), p.44-45.
|
|
/// </summary>
|
|
public class WorldMercatorProjection : GeoApiProjection
|
|
{
|
|
public const int DefaultEpsgCode = 3395;
|
|
|
|
public WorldMercatorProjection()
|
|
{
|
|
CoordinateSystemWkt
|
|
= "PROJCS[\"WGS 84 / World Mercator\","
|
|
+ "GEOGCS[\"WGS 84\","
|
|
+ "DATUM[\"WGS_1984\","
|
|
+ "SPHEROID[\"WGS 84\",6378137,298.257223563,"
|
|
+ "AUTHORITY[\"EPSG\",\"7030\"]],"
|
|
+ "AUTHORITY[\"EPSG\",\"6326\"]],"
|
|
+ "PRIMEM[\"Greenwich\",0,"
|
|
+ "AUTHORITY[\"EPSG\",\"8901\"]],"
|
|
+ "UNIT[\"degree\",0.0174532925199433,"
|
|
+ "AUTHORITY[\"EPSG\",\"9122\"]],"
|
|
+ "AUTHORITY[\"EPSG\",\"4326\"]],"
|
|
+ "PROJECTION[\"Mercator_1SP\"],"
|
|
+ "PARAMETER[\"latitude_of_origin\",0],"
|
|
+ "PARAMETER[\"central_meridian\",0],"
|
|
+ "PARAMETER[\"scale_factor\",1],"
|
|
+ "PARAMETER[\"false_easting\",0],"
|
|
+ "PARAMETER[\"false_northing\",0],"
|
|
+ "UNIT[\"metre\",1,"
|
|
+ "AUTHORITY[\"EPSG\",\"9001\"]],"
|
|
+ "AXIS[\"Easting\",EAST],"
|
|
+ "AXIS[\"Northing\",NORTH],"
|
|
+ "AUTHORITY[\"EPSG\",\"3395\"]]";
|
|
}
|
|
|
|
public override Point GetRelativeScale(Location location)
|
|
{
|
|
var lat = location.Latitude * Math.PI / 180d;
|
|
var eSinLat = Wgs84Eccentricity * Math.Sin(lat);
|
|
var k = Math.Sqrt(1d - eSinLat * eSinLat) / Math.Cos(lat); // p.44 (7-8)
|
|
|
|
return new Point(k, k);
|
|
}
|
|
}
|
|
}
|