public void ClearData()
{
this.latInput = "";
this.longInput = "";
this.latHemi = hemisphereNS.North;
this.longHemi = hemisphereEW.East;
this.latitudeDeg = 0;
this.longitudeDeg = 0;
this.latitudeRad = 0;
this.longitudeRad = 0;
}
/* Coord data must have a latitude and longitude, and both hemispheres
* Once we have these pieces, just set the other values for use later
* Keep the values as degrees and radians for ease of use
*/
public void SetNavCoords(String x, String y, hemisphereNS h1, hemisphereEW h2)
{
this.latInput = x;
this.longInput = y;
this.latHemi = h1;
this.longHemi = h2;
this.latitudeDeg = StringToNumber(latInput);
this.longitudeDeg = StringToNumber(longInput);
this.latitudeRad = DegreesToRadians(latitudeDeg);
this.longitudeRad = DegreesToRadians(longitudeDeg);
}
private void CalculateNav()
{
#region dLongDistance
/*
* This section takes the longitude values, as decimals, as well as their respective hemispheres
* and calculates the distance and which direction to go
*
* If the hemispheres are the same, the distance is simply the difference in the two longitudes
* if they are different, the distance is (usually) the sum
* however at this point if the distance is greater than 180 degrees, it is better to go the opposite direction
* which will be 360 degrees - the previously calculated distance
*/
if (StartCoord.longHemi == EndCoord.longHemi)
{
dLongDistance = Math.Abs(StartCoord.longitudeRad - EndCoord.longitudeRad);
}
else
{
dLongDistance = StartCoord.longitudeRad + EndCoord.longitudeRad;
if (dLongDistance > Math.PI)
{
dLongDistance = (2 * Math.PI) - dLongDistance;
}
}
#endregion
#region dLongDirection
/*
* This function determines if we should be going East or West to get to point B
* 's' is just used as a temporary string
*
* for this function, we need to know the starting/final longitude, the hemispheres, and the distance
* we check first if we are staying in the same hemisphere
* if so, are we in the east or west, then evaluate which is greater or farther, then we know the direction
*/
if (StartCoord.longHemi == EndCoord.longHemi)
{
if (StartCoord.longHemi == hemisphereEW.East)
{
if (StartCoord.longitudeRad < EndCoord.longitudeRad)
{
dLongDirection = hemisphereEW.East;
}
else
{
dLongDirection = hemisphereEW.West;
}
}
else
{
if (StartCoord.longitudeRad > EndCoord.longitudeRad)
{
dLongDirection = hemisphereEW.East;
}
else
{
dLongDirection = hemisphereEW.West;
}
}
}
else
{
if ((StartCoord.longitudeRad + EndCoord.longitudeRad) > Math.PI)
{
if (StartCoord.longHemi == hemisphereEW.East)
{
dLongDirection = hemisphereEW.East;
}
else
{
dLongDirection = hemisphereEW.West;
}
}
else
{
if (StartCoord.longHemi == hemisphereEW.East)
{
dLongDirection = hemisphereEW.West;
}
else
{
dLongDirection = hemisphereEW.East;
}
}
}
#endregion
#region TotalDistance
//If the lattitudes are in the same hemisphere, we add the cos and sin, else we subtract
if (StartCoord.latHemi == EndCoord.latHemi)
{
totalDistance = Math.Round(60 * (180 / Math.PI) * (Math.Acos(Math.Cos(dLongDistance) * Math.Cos(StartCoord.latitudeRad) * Math.Cos(EndCoord.latitudeRad) + Math.Sin(StartCoord.latitudeRad) * Math.Sin(EndCoord.latitudeRad))), 1);
}
else
{
totalDistance = Math.Round(60 * (180 / Math.PI) * (Math.Acos(Math.Cos(dLongDistance) * Math.Cos(StartCoord.latitudeRad) * Math.Cos(EndCoord.latitudeRad) - Math.Sin(StartCoord.latitudeRad) * Math.Sin(EndCoord.latitudeRad))), 1);
}
#endregion
#region InitialCourse
/*
* To calculate the initial course, we need to work out 3 values, known in navigation as A, B, and C values
* The sign of the value is irrelevant, but the 'name' ie North/South is needed
*/
icAValue = Math.Abs(Math.Tan(StartCoord.latitudeRad) / Math.Tan(dLongDistance));
icBValue = Math.Abs(Math.Tan(EndCoord.latitudeRad) / Math.Sin(dLongDistance));
icBDirection = EndCoord.latHemi; //B always same name as latitude
//A is named opposite to lattitude, unless dlong between 90 and 270 degrees
if (dLongDistance > (Math.PI / 2) && dLongDistance < (Math.PI * 1.5))
{
icADirection = StartCoord.latHemi;
}
else
{
if (StartCoord.latHemi == hemisphereNS.North)
{
icADirection = hemisphereNS.South;
}
else
{
icADirection = hemisphereNS.North;
}
}
/*If A and B are same names, C is A + B and same direction
* If different names, ie A is North and B is South, C takes the name of the greater value
* and takes the value of the difference of A and B
*/
if (icADirection == icBDirection)
{
icCValue = icAValue + icBValue;
icCDirection = icADirection;
}
else
{
icCValue = Math.Abs(icAValue - icBValue);
if (icAValue > icBValue)
{
icCDirection = icADirection;
}
else
{
icCDirection = icBDirection;
}
}
/* Tan (Initial Course) = 1 / (C*CosLatA)
* This gives us the initial course as a Quadrantal ie North 30 Degrees East or South 50 Degrees West
* So need to convert to Degrees True based on C direction and our DLong direction
*/
initialCourseQuad = Convert.ToInt32((180 / Math.PI) * (Math.Atan(1 / (icCValue * Math.Cos(StartCoord.latitudeRad)))));
if (icCDirection == hemisphereNS.North)
{
if (dLongDirection == hemisphereEW.East)
{
initialCourseTrue = initialCourseQuad;
}
else
{
initialCourseTrue = 360 - initialCourseQuad;
}
}
else
{
if (dLongDirection == hemisphereEW.East)
{
initialCourseTrue = 180 - initialCourseQuad;
}
else
{
initialCourseTrue = 180 + initialCourseQuad;
}
}
#endregion
#region Vertex
/* To calculate the vertex we need the dLong - distance from Start to Vertex
* We also need to know which hemisphere we are in and direction we are going
*/
dLongAV = Math.Abs(Math.Atan(1 / (Math.Tan((initialCourseQuad / (180 / Math.PI))) * Math.Sin(StartCoord.latitudeRad))));
if (StartCoord.latHemi == icCDirection && dLongDirection == StartCoord.longHemi)
{
Vertex1Coord.SetLongitudeFromRad(StartCoord.longitudeRad + dLongAV);
}
else if (StartCoord.latHemi == icCDirection && dLongDirection != StartCoord.longHemi)
{
Vertex1Coord.SetLongitudeFromRad(StartCoord.longitudeRad - dLongAV);
}
else if (StartCoord.latHemi != icCDirection && dLongDirection == StartCoord.longHemi)
{
Vertex1Coord.SetLongitudeFromRad(StartCoord.longitudeRad - dLongAV);
}
else // if(StartCoord.latHemi == icCDirection && dLongDirection != StartCoord.longHemi)
{
Vertex1Coord.SetLongitudeFromRad(StartCoord.longitudeRad + dLongAV);
}
//Setting an initial hemisphere, can be changed later
Vertex1Coord.longHemi = hemisphereEW.East;
//If the longitude is < 0 or > 180 degrees we change the hemisphere
if (Vertex1Coord.longitudeRad > Math.PI || Vertex1Coord.longitudeRad < 0)
{
Vertex1Coord.longitudeRad = Math.Abs(Vertex1Coord.longitudeRad);
if (Vertex1Coord.longHemi == hemisphereEW.East)
{
Vertex1Coord.longHemi = hemisphereEW.West;
}
else
{
Vertex1Coord.longHemi = hemisphereEW.East;
}
}
Vertex1Coord.latHemi = StartCoord.latHemi;
Vertex1Coord.SetLatitudeFromRad(Math.Acos((Math.Sin(initialCourseQuad / (180 / Math.PI))) * Math.Cos(StartCoord.latitudeRad)));
#endregion
#region Vertex2
/* Set the coordinates for Vertex 2, which are directly opposite the sphere of Vertex 1
* The value for Latitude will remain the same, but hemisphere is swapped
*
* Longitude hemisphere will also be swapped, but the value will be 180 Degrees - Vertex 1
*
*/
Vertex2Coord.SetLatitudeFromRad(Vertex1Coord.latitudeRad);
if (Vertex1Coord.latHemi == hemisphereNS.North)
{
Vertex2Coord.latHemi = hemisphereNS.South;
}
else
{
Vertex2Coord.latHemi = hemisphereNS.North;
}
Vertex2Coord.SetLongitudeFromRad(Math.PI - Vertex1Coord.longitudeRad);
if (Vertex1Coord.longHemi == hemisphereEW.East)
{
Vertex2Coord.longHemi = hemisphereEW.West;
}
else
{
Vertex2Coord.longHemi = hemisphereEW.East;
}
#endregion
}
