/// <summary>
/// Equality test which is really a proximity.
/// </summary>
public bool Equals(CGeoLatLong Other)
{
bool bLatClose;
bool bLongClose;
if (m_dLat == 0)
{
bLatClose = Other.GetLat() == 0;
}
else
{
bLatClose = Math.Abs((Other.GetLat() - m_dLat) / m_dLat)
< Constants.conEqualityTolerance;
}
if (!bLatClose)
{
return(false); // Get out early if we can.
}
if (m_dLong == 0)
{
bLongClose = Other.GetLong() == 0;
}
else
{
bLongClose = Math.Abs((Other.GetLong() - m_dLong) / m_dLong)
< Constants.conEqualityTolerance;
}
return(bLongClose);
}
/// <summary>
/// Rotation.
/// </summary>
public void Rotate(CGeoLatLong Other)
{
m_dLat += Other.GetLat();
m_dLong += Other.GetLong();
if (m_dLat < -Constants.conHALFPI)
{
m_dLat = Constants.conPI + m_dLat;
}
if (m_dLat > Constants.conHALFPI)
{
m_dLat = -Constants.conPI + m_dLat;
}
if (m_dLong < -Constants.conPI)
{
m_dLong = Constants.conTWOPI + m_dLong;
}
if (m_dLong > Constants.conPI)
{
m_dLong = -Constants.conTWOPI + m_dLong;
}
}
/// <summary>
/// Set using a heading and a range from an origin. Range in metres.
/// </summary>
public void Set(double dHeading, double dRange, CGeoLatLong Origin)
{
// alpha is the angular Distance travelled round the earths surface
double alpha = dRange / Constants.conEARTH_RADIUS_METRES;
double sin_alpha = Math.Sin(alpha);
double cos_alpha = Math.Cos(alpha);
double latO = Origin.GetLat();
double longO = Origin.GetLong();
double sin_Olat = Math.Sin(latO);
double cos_Olat = Math.Cos(latO);
m_dLat = Math.Asin(sin_Olat * cos_alpha + cos_Olat * sin_alpha * Math.Cos(dHeading));
m_dLong = longO + Math.Atan2(Math.Sin(dHeading) * sin_alpha * cos_Olat, cos_alpha - sin_Olat * Math.Sin(m_dLat));
while (m_dLong > Constants.conPI)
{
m_dLong -= Constants.conTWOPI;
}
while (m_dLong < -Constants.conPI)
{
m_dLong += Constants.conTWOPI;
}
}
/// <summary>
/// Project the given lat long to x, y using the input parameters to store the result and retaining
/// the lat long in the class passed.
/// </summary>
public override void Project(CGeoLatLong rLatLong, double dx, double dy)
{
dy = rLatLong.GetLat();
dx = rLatLong.GetLong();
Project(dy, dx);
}
/// <summary>
/// Assigment.
/// </summary>
public CGeoLatLong Set(CGeoLatLong Other)
{
// Simple assignment
m_dLat = Other.GetLat();
m_dLong = Other.GetLong();
// Return reference to this
return(this);
}
/// <summary>
/// Finds the range from one position to another based on sperical earth and
/// great circles. Range is in metres. Error between this and WSG84 slant range is
/// less than 1% at ranges up to 2000km. (Spherical Law of Math.Cosines).
/// </summary>
public double Range(CGeoLatLong Other)
{
double latO = Other.GetLat();
double longO = Other.GetLong();
if (m_dLat == latO && m_dLong == longO)
{
return(0);
}
double A = Math.Sin(m_dLat) * Math.Sin(latO) +
Math.Cos(m_dLat) * Math.Cos(latO) * Math.Cos(m_dLong - longO);
return(Math.Acos(A) * Constants.conEARTH_RADIUS_METRES);
}
/// <summary>
/// Copy constructor.
/// </summary>
public CGeoLatLong(CGeoLatLong Other)
{
// simple assignment
m_dLat = Other.GetLat();
m_dLong = Other.GetLong();
}
/// <summary>
/// Calculates the Range and heading to another location in degrees.
/// </summary>
public void RangeAndHeading(CGeoLatLong Other,
out double dRangeMetres, out double hdng)
{
double latO = Other.GetLat();
double longO = Other.GetLong();
if (m_dLat == latO && m_dLong == longO)
{
dRangeMetres = 0;
hdng = 0;
return;
}
double sin_lat = Math.Sin(m_dLat);
double sin_latO = Math.Sin(latO);
double cos_lat = Math.Cos(m_dLat);
double cos_latO = Math.Cos(latO);
double cos_alpha = sin_latO * sin_lat + cos_latO * cos_lat * Math.Cos(longO - m_dLong);
double alpha = Math.Acos(cos_alpha);
dRangeMetres = alpha * Constants.conEARTH_RADIUS_METRES;
//check to see if they are on the same line of longitude
if (m_dLong == longO)
{
// No need to check if the locations are the same as done already.
if (m_dLat > latO)
{
hdng = Constants.conPI;
return;
}
else
{
hdng = 0; //may as well return 0 as any other
return;
}
}
if ((Math.Abs(m_dLat) == -Constants.conHALFPI) | (Math.Abs(latO) == Constants.conHALFPI))
{
//check to see if the first is at the south pole or the second is at the north pole
if ((m_dLat == -Constants.conHALFPI) | (latO == Constants.conHALFPI))
{
hdng = 0;
return;
}
//check to see if the first is at the north pole or the second is at the south
if ((m_dLat == Constants.conHALFPI) | (latO == -Constants.conHALFPI))
{
hdng = Constants.conPI;
return;
}
}
if (longO > m_dLong)
{
hdng = Math.Acos((sin_latO - sin_lat * cos_alpha) / (cos_lat * Math.Sin(alpha)));
if ((longO - m_dLong) > Constants.conPI)
{
// gone from e.g. e179 to w179
hdng = Constants.conTWOPI - hdng;
}
}
else
{
hdng = Constants.conTWOPI - Math.Acos((sin_latO - sin_lat * cos_alpha) / (cos_lat * Math.Sin(alpha)));
if ((m_dLong - longO) > Constants.conPI)
{
// gone from e.g. w179 to e179
hdng = Constants.conTWOPI - hdng;
}
}
if (hdng == Constants.conTWOPI)
{
hdng = 0;
}
}
/// <summary>
/// Calculates the heading to another location in degrees.
/// </summary>
double Heading(CGeoLatLong Other)
{
double latO = Other.GetLat();
double longO = Other.GetLong();
//check to see if they are on the same line of longitude
if (m_dLong == longO)
{
// first check to see if the locations are the same
if (m_dLat == latO)
{
return(0); //may as well return 0 as any other
}
if (m_dLat > latO)
{
return(180);
}
else
{
return(0);
}
}
if ((Math.Abs(m_dLat) == -Constants.conHALFPI) | (Math.Abs(latO) == Constants.conHALFPI))
{
//check to see if the first is at the south pole or the second is at the north pole
if ((m_dLat == -Constants.conHALFPI) | (latO == Constants.conHALFPI))
{
return(0);
}
//check to see if the first is at the north pole or the second is at the south
if ((m_dLat == Constants.conHALFPI) | (latO == -Constants.conHALFPI))
{
return(180);
}
}
double sin_lat = Math.Sin(m_dLat);
double sin_latO = Math.Sin(latO);
double cos_lat = Math.Cos(m_dLat);
double cos_latO = Math.Cos(latO);
double cos_alpha = sin_latO * sin_lat + cos_latO * cos_lat * Math.Cos(longO - m_dLong);
double alpha = Math.Acos(cos_alpha);
double hdng;
if (longO > m_dLong)
{
hdng = Math.Acos((sin_latO - sin_lat * cos_alpha) / (cos_lat * Math.Sin(alpha)));
if ((longO - m_dLong) > Constants.conPI)
{
// gone from e.g. e179 to w179
hdng = Constants.conTWOPI - hdng;
}
}
else
{
hdng = Constants.conTWOPI - Math.Acos((sin_latO - sin_lat * cos_alpha) / (cos_lat * Math.Sin(alpha)));
if ((m_dLong - longO) > Constants.conPI)
{
// gone from e.g. w179 to e179
hdng = Constants.conTWOPI - hdng;
}
}
if (hdng == Constants.conTWOPI)
{
return(0);
}
return(hdng);
}
/// <summary>
/// Calculates the Range and heading to another location in degrees.
/// </summary>
public void RangeAndHeading(CGeoLatLong Other,
out double dRangeMetres, out double hdng)
{
double latO = Other.GetLat();
double longO = Other.GetLong();
if (m_dLat == latO && m_dLong == longO)
{
dRangeMetres = 0;
hdng = 0;
return;
}
double sin_lat = Math.Sin(m_dLat);
double sin_latO = Math.Sin(latO);
double cos_lat = Math.Cos(m_dLat);
double cos_latO = Math.Cos(latO);
double cos_alpha = sin_latO * sin_lat + cos_latO * cos_lat * Math.Cos(longO - m_dLong);
double alpha = Math.Acos(cos_alpha);
dRangeMetres = alpha * Constants.conEARTH_RADIUS_METRES;
//check to see if they are on the same line of longitude
if(m_dLong == longO)
{
// No need to check if the locations are the same as done already.
if(m_dLat > latO)
{
hdng = Constants.conPI;
return;
}
else
{
hdng = 0;//may as well return 0 as any other
return ;
}
}
if((Math.Abs(m_dLat) == -Constants.conHALFPI) | (Math.Abs(latO) == Constants.conHALFPI))
{
//check to see if the first is at the south pole or the second is at the north pole
if((m_dLat == -Constants.conHALFPI) | (latO == Constants.conHALFPI))
{
hdng = 0;
return;
}
//check to see if the first is at the north pole or the second is at the south
if((m_dLat == Constants.conHALFPI) | (latO ==-Constants.conHALFPI))
{
hdng = Constants.conPI;
return;
}
}
if(longO > m_dLong)
{
hdng = Math.Acos( ( sin_latO - sin_lat * cos_alpha )/( cos_lat * Math.Sin(alpha) ) );
if ( (longO - m_dLong) > Constants.conPI)
{
// gone from e.g. e179 to w179
hdng = Constants.conTWOPI - hdng;
}
}
else
{
hdng = Constants.conTWOPI - Math.Acos( ( sin_latO - sin_lat * cos_alpha )/( cos_lat * Math.Sin(alpha) ) );
if ( (m_dLong - longO) > Constants.conPI)
{
// gone from e.g. w179 to e179
hdng = Constants.conTWOPI - hdng;
}
}
if (hdng == Constants.conTWOPI)
hdng = 0;
}
/// <summary>
/// Equality test which is really a proximity.
/// </summary>
public bool Equals(CGeoLatLong Other)
{
bool bLatClose;
bool bLongClose;
if ( m_dLat == 0 )
bLatClose = Other.GetLat() == 0;
else
bLatClose = Math.Abs(( Other.GetLat() - m_dLat ) / m_dLat )
< Constants.conEqualityTolerance;
if (!bLatClose)
return false; // Get out early if we can.
if ( m_dLong == 0 )
bLongClose = Other.GetLong() == 0;
else
bLongClose = Math.Abs((Other.GetLong() - m_dLong) / m_dLong)
< Constants.conEqualityTolerance;
return (bLongClose);
}
/// <summary>
/// Calculates the heading to another location in degrees.
/// </summary>
double Heading(CGeoLatLong Other)
{
double latO = Other.GetLat();
double longO = Other.GetLong();
//check to see if they are on the same line of longitude
if(m_dLong == longO)
{
// first check to see if the locations are the same
if (m_dLat == latO)
return 0; //may as well return 0 as any other
if(m_dLat > latO)
return 180;
else
return 0;
}
if ((Math.Abs(m_dLat) == -Constants.conHALFPI) | (Math.Abs(latO) == Constants.conHALFPI))
{
//check to see if the first is at the south pole or the second is at the north pole
if((m_dLat == -Constants.conHALFPI) | (latO == Constants.conHALFPI))
return 0;
//check to see if the first is at the north pole or the second is at the south
if((m_dLat == Constants.conHALFPI) | (latO ==-Constants.conHALFPI))
return 180;
}
double sin_lat = Math.Sin(m_dLat);
double sin_latO = Math.Sin(latO);
double cos_lat = Math.Cos(m_dLat);
double cos_latO = Math.Cos(latO);
double cos_alpha = sin_latO * sin_lat + cos_latO * cos_lat * Math.Cos(longO - m_dLong);
double alpha = Math.Acos(cos_alpha);
double hdng;
if(longO > m_dLong)
{
hdng = Math.Acos( ( sin_latO - sin_lat * cos_alpha )/( cos_lat * Math.Sin(alpha) ) );
if ( (longO - m_dLong) > Constants.conPI)
{
// gone from e.g. e179 to w179
hdng = Constants.conTWOPI - hdng;
}
}
else
{
hdng = Constants.conTWOPI - Math.Acos( ( sin_latO - sin_lat * cos_alpha )/( cos_lat * Math.Sin(alpha) ) );
if ( (m_dLong - longO) > Constants.conPI)
{
// gone from e.g. w179 to e179
hdng = Constants.conTWOPI - hdng;
}
}
if (hdng == Constants.conTWOPI)
return 0;
return hdng;
}
/// <summary>
/// Copy constructor.
/// </summary>
public CGeoLatLong(CGeoLatLong Other)
{
// simple assignment
m_dLat = Other.GetLat();
m_dLong = Other.GetLong();
}
/// <summary>
/// Set using a heading and a range from an origin. Range in metres.
/// </summary>
public void Set(double dHeading, double dRange, CGeoLatLong Origin)
{
// alpha is the angular Distance travelled round the earths surface
double alpha = dRange /Constants.conEARTH_RADIUS_METRES;
double sin_alpha = Math.Sin(alpha);
double cos_alpha = Math.Cos(alpha);
double latO = Origin.GetLat();
double longO = Origin.GetLong();
double sin_Olat = Math.Sin(latO);
double cos_Olat = Math.Cos(latO);
m_dLat = Math.Asin( sin_Olat * cos_alpha + cos_Olat * sin_alpha * Math.Cos(dHeading) );
m_dLong = longO + Math.Atan2(Math.Sin(dHeading) * sin_alpha * cos_Olat, cos_alpha - sin_Olat * Math.Sin(m_dLat));
while (m_dLong > Constants.conPI)
m_dLong -= Constants.conTWOPI;
while (m_dLong < -Constants.conPI)
m_dLong += Constants.conTWOPI;
}
/// <summary>
/// Assigment.
/// </summary>
public CGeoLatLong Set(CGeoLatLong Other)
{
// Simple assignment
m_dLat = Other.GetLat();
m_dLong = Other.GetLong();
// Return reference to this
return this;
}
/// <summary>
/// Rotation.
/// </summary>
public void Rotate(CGeoLatLong Other)
{
m_dLat += Other.GetLat();
m_dLong += Other.GetLong();
if (m_dLat < -Constants.conHALFPI)
m_dLat = Constants.conPI + m_dLat;
if (m_dLat > Constants.conHALFPI)
m_dLat = -Constants.conPI + m_dLat;
if (m_dLong < -Constants.conPI)
m_dLong = Constants.conTWOPI + m_dLong;
if (m_dLong > Constants.conPI)
m_dLong = -Constants.conTWOPI + m_dLong;
}
/// <summary>
/// Project the given lat long to x, y using the input parameters to store the result and retaining
/// the lat long in the class passed.
/// </summary>
public override void Project(CGeoLatLong rLatLong, double dx, double dy)
{
dy = rLatLong.GetLat();
dx = rLatLong.GetLong();
Project(dy, dx);
}
/// <summary>
/// Finds the range from one position to another based on sperical earth and
/// great circles. Range is in metres. Error between this and WSG84 slant range is
/// less than 1% at ranges up to 2000km. (Spherical Law of Math.Cosines).
/// </summary>
public double Range(CGeoLatLong Other)
{
double latO = Other.GetLat();
double longO = Other.GetLong();
if (m_dLat == latO && m_dLong == longO) return 0;
double A = Math.Sin(m_dLat) * Math.Sin(latO) +
Math.Cos(m_dLat) * Math.Cos(latO) * Math.Cos(m_dLong - longO);
return Math.Acos(A) * Constants.conEARTH_RADIUS_METRES;
}