/// <summary>
/// Converts a grid column to Longitude
/// </summary>
/// <param name="x"></param>
/// <param name="zoom"></param>
/// <returns></returns>
public static double XToLongitudeAtZoom(int x, int zoom)
{
double arc = EarthCircumference / ((1 << zoom) * 256);
double metersX = (x * arc) - HalfEarthCircumference;
double result = GISHelper.RadToDeg(metersX / 6378137);
return(result);
}
/// <summary>
/// Converts a grid row to Latitude
/// </summary>
/// <param name="y"></param>
/// <param name="zoom"></param>
/// <returns></returns>
public static double YToLatitudeAtZoom(int y, int zoom)
{
double arc = EarthCircumference / ((1 << zoom) * 256);
double metersY = HalfEarthCircumference - (y * arc);
double a = Math.Exp(metersY * 2 / 6378137);
double result = GISHelper.RadToDeg(Math.Asin((a - 1) / (a + 1)));
return(result);
}
/// <summary>
/// Converts Globe Point to Lat Long.
/// </summary>
/// <param name="point"></param>
/// <returns></returns>
LatLong PointToLatLong(Point3D point)
{
Point3D pointd = ViewPointToSpherePoint(point);
double d = Math.Asin(pointd.Y);
double radians = Math.Acos(-pointd.X / Math.Cos(d));
d = GISHelper.RadToDeg(d);
radians = GISHelper.RadToDeg(radians);
if (pointd.Z < 0.0)
{
radians = 180.0 + (180.0 - radians);
}
radians = (radians + 270.0) % 360.0;
return(new LatLong(d, radians - 180.0));
}
/// <summary>
///
/// </summary>
/// <returns></returns>
double GetPhiStart()
{
if (double.IsNaN(this.phiStart))
{
double num = 7.1288559127654789;
double num3 = (GISHelper.LatitudeToMercatorY(GISHelper.DegToRad(45.0)) * num) / 2.0;
double num4 = -num3;
double num5 = num3 - num4;
double num6 = ((double)this.Row) / ((double)ZoomManager.ZoomLevelRows(this.ZoomLevel));
double num1 = (this.Row + 1.0) / ((double)ZoomManager.ZoomLevelRows(this.ZoomLevel));
GISHelper.RadToDeg(GISHelper.MercatorYToLatitude(1.0));
ZoomManager.ZoomLevelRows(this.ZoomLevel);
double y = (num6 - 0.5) * num5;
this.phiStart = GISHelper.RadToDeg(GISHelper.MercatorYToLatitude(y)) + 90.0;
}
return(this.phiStart);
}