protected internal override void Unproject(double x, double y, out double latitude, out double longitude)
{
double ros = x * x + (_ro_0 - y) * (_ro_0 - y);
double a = _c_over_n2 - ros * _n_half;
if (Double.IsNaN(a) || Math.Abs(a) > 1 + MathX.Tolerance)
{
throw new ArgumentOutOfRangeException("x, y");
}
latitude = Math.Asin(MathX.Clamp(1, a));
longitude = MathX.Clamp(Math.PI, MathX.Atan2(x, _ro_0 - y, "x, y") * _inv_n);
}
protected internal override void Project(double latitude, double longitude, out double x, out double y)
{
double sin_lat = Math.Sin(latitude);
double cos_lat = Math.Cos(latitude);
double sin_long = Math.Sin(longitude);
double cos_long = Math.Cos(longitude);
double a = _sin_fi_p * sin_lat - _cos_fi_p * cos_lat * sin_long; // sin_fi_p
if (Double.IsNaN(a) || Math.Abs(a) > 1)
{
throw new ArgumentOutOfRangeException("latitude, longitude");
}
x = MathX.Atan2(sin_lat / cos_lat * _cos_fi_p + sin_long * _sin_fi_p, cos_long, "latitude, longitude");
y = MathX.Clamp(MaxY, Math.Log((1 + a) / (1 - a)) / 2); // protect againt +-Infinity
}
protected internal override void Unproject(double x, double y, out double latitude, out double longitude)
{
double sin_x = Math.Sin(x);
double cos_x = Math.Cos(x);
double sinh_y = Math.Sinh(y);
double cosh_y = Math.Cosh(y);
// cosh_y >= 1 by definition
double a = (_sin_fi_p * sinh_y + _cos_fi_p * sin_x) / cosh_y;
if (Math.Abs(a) > 1)
{
throw new ArgumentOutOfRangeException("x, y");
}
latitude = Math.Asin(a);
longitude = MathX.Atan2(_sin_fi_p * sin_x - _cos_fi_p * sinh_y, cos_x, "x, y");
}
protected internal override void Unproject(double x, double y, out double latitude, out double longitude)
{
if (x >= MaxX)
{
latitude = 0;
longitude = Math.PI / 2;
}
else if (x <= -MaxX)
{
latitude = 0;
longitude = -Math.PI / 2;
}
else
{
// 1 <= cosh(x) <= cosh(MaxX)
latitude = Math.Asin(Math.Sin(y) / Math.Cosh(x));
// In case of x=0 and y=+-Pi/2: latitude will be +-90 and longtude will be 0
longitude = MathX.Atan2(Math.Sinh(x), Math.Cos(y));
}
}
