/*
* UTMXYToLatLon
*
* Converts x and y coordinates in the Universal Transverse Mercator
* projection to a latitude/longitude pair.
*
* Inputs:
* x - The easting of the point, in meters.
* y - The northing of the point, in meters.
* zone - The UTM zone in which the point lies.
* southhemi - True if the point is in the southern hemisphere;
* false otherwise.
*
* Outputs:
* latlon - A 2-element array containing the latitude and
* longitude of the point, in degrees.
*/
public static GeoLocation UTMXYToLatLon(GeoLocationXY xy, bool southhemi)
{
if (xy.Zone < 1 || xy.Zone > 60)
{
throw new ArgumentOutOfRangeException(nameof(xy.Zone));
}
var x = xy.X - 500000.0;
x /= UTMScaleFactor;
var y = xy.Y;
/* If in southern hemisphere, adjust y accordingly. */
if (southhemi)
{
y -= 10000000;
}
y /= UTMScaleFactor;
var cmeridian = UTMCentralMeridian(xy.Zone);
var rad = MapXyToLatLon(x, y, cmeridian);
return(new GeoLocation(RadToDeg(rad.Item1), RadToDeg(rad.Item2), xy.Elevation));
}
private double CalculateAngleDeg(GeoLocationXY p1, GeoLocationXY p2)
{
var dx = p2.X - p1.X;
var dy = p2.Y - p1.Y;
var arctg = Math.Atan(dx / dy);
double angle;
if (dx > 0 && dy > 0)
{
angle = arctg;
}
else if (dx > 0 && dy < 0)
{
angle = Math.PI + arctg;
}
else if (dx < 0 && dy > 0)
{
angle = arctg;
}
else
{
angle = Math.PI + arctg;
}
return(angle * 180.0 / Math.PI);
}
public static bool IsInsidePolygon(this GeoLocationXY p, List <GeoLocationXY> poly)
{
// отсюда
// https://stackoverflow.com/questions/4243042/c-sharp-point-in-polygon
bool inside = false;
if (poly.Count < 3)
{
throw new ArgumentException("poly.Count < 3", nameof(poly));
}
var oldPoint = new Point(
poly[poly.Count - 1].X, poly[poly.Count - 1].Y);
for (int i = 0; i < poly.Count; i++)
{
var newPoint = new Point(poly[i].X, poly[i].Y);
Point p2;
Point p1;
if (newPoint.X > oldPoint.X)
{
p1 = oldPoint;
p2 = newPoint;
}
else
{
p1 = newPoint;
p2 = oldPoint;
}
if ((newPoint.X < p.X) == (p.X <= oldPoint.X) &&
(p.Y - (long)p1.Y) * (p2.X - p1.X)
< (p2.Y - (long)p1.Y) * (p.X - p1.X))
{
inside = !inside;
}
oldPoint = newPoint;
}
return(inside);
}
