ClemensFischer/XAML-Map-Control
1
0
Fork 0
mirror of https://github.com/ClemensFischer/XAML-Map-Control.git synced 2026-04-06 06:55:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

Avoid unnecessary Location and Point allocations

Browse source
This commit is contained in:
ClemensFischer 2025-12-12 21:28:45 +01:00
parent f44d2207e5
commit e268be2948
20 changed files with 205 additions and 172 deletions
Download patch file Download diff file Expand all files Collapse all files

36
MapControl/Shared/PolarStereographicProjection.cs
View file

@ -26,50 +26,50 @@ namespace MapControl
public double FalseNorthing { get; set; } = 2e6;
public bool IsNorth { get; set; }
public override Point GetRelativeScale(Location location)
public override Point GetRelativeScale(double latitude, double longitude)
{
var lat = location.Latitude * Math.PI / 180d;
latitude *= Math.PI / 180d;
if (!IsNorth)
{
lat = -lat;
latitude = -latitude;
}
var e = Math.Sqrt((2d - Flattening) * Flattening);
var eSinLat = e * Math.Sin(lat);
var eSinLat = e * Math.Sin(latitude);
var t = Math.Tan(Math.PI / 4d - lat / 2d)
var t = Math.Tan(Math.PI / 4d - latitude / 2d)
/ Math.Pow((1d - eSinLat) / (1d + eSinLat), 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 m = Math.Cos(lat) / Math.Sqrt(1d - eSinLat * eSinLat); // p.160 (14-15)
var m = Math.Cos(latitude) / Math.Sqrt(1d - eSinLat * eSinLat); // p.160 (14-15)
var k = r / (EquatorialRadius * m); // p.161 (21-32)
return new Point(k, k);
}
public override Point? LocationToMap(Location location)
public override Point? LocationToMap(double latitude, double longitude)
{
var lat = location.Latitude * Math.PI / 180d;
var lon = location.Longitude * Math.PI / 180d;
latitude *= Math.PI / 180d;
longitude *= Math.PI / 180d;
if (!IsNorth)
{
lat = -lat;
lon = -lon;
latitude = -latitude;
longitude = -longitude;
}
var e = Math.Sqrt((2d - Flattening) * Flattening);
var eSinLat = e * Math.Sin(lat);
var eSinLat = e * Math.Sin(latitude);
var t = Math.Tan(Math.PI / 4d - lat / 2d)
var t = Math.Tan(Math.PI / 4d - latitude / 2d)
/ Math.Pow((1d - eSinLat) / (1d + eSinLat), 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(lon); // p.161 (21-30)
var y = -r * Math.Cos(lon); // p.161 (21-31)
var x = r * Math.Sin(longitude); // p.161 (21-30)
var y = -r * Math.Cos(longitude); // p.161 (21-31)
if (!IsNorth)
{
@ -80,10 +80,10 @@ namespace MapControl
return new Point(x + FalseEasting, y + FalseNorthing);
}
public override Location MapToLocation(Point point)
public override Location MapToLocation(double x, double y)
{
var x = point.X - FalseEasting;
var y = point.Y - FalseNorthing;
x -= FalseEasting;
y -= FalseNorthing;
if (!IsNorth)
{