public double RectangeDistance(GeomCoordinate coordinate)
{
if (PointContains(coordinate) != IntersectResult.None)
{
return(0);
}
var min = EarthUtilities.GetDistance(new CoordinateRectangle(Left, Top, Right, Top), coordinate);
var res = EarthUtilities.GetDistance(new CoordinateRectangle(Right, Top, Right, Bottom), coordinate);
if (res < min)
{
min = res;
}
res = EarthUtilities.GetDistance(new CoordinateRectangle(Right, Bottom, Left, Bottom), coordinate);
if (res < min)
{
min = res;
}
res = EarthUtilities.GetDistance(new CoordinateRectangle(Left, Bottom, Left, Top), coordinate);
if (res < min)
{
min = res;
}
return(min);
}
public CoordinateRectangle(GeomCoordinate pLeftTop, GeomCoordinate pRightBottom)
{
Left = pLeftTop.Longitude;
Top = pLeftTop.Latitude;
Right = pRightBottom.Longitude;
Bottom = pRightBottom.Latitude;
}
public static GeomCoordinate GetNearestPoint(CoordinateRectangle line, GeomCoordinate pt)
{
const double r2D = 180 / Math.PI; // Constant for converting radians to degrees
var a = GetLength(line.LeftTop, line.RightBottom);
if (a <= 0)
{
return(pt);
}
var b = GetLength(line.LeftTop, pt);
var c = GetLength(line.RightBottom, pt);
var enB = Math.Acos((Math.Pow(a, 2) + Math.Pow(b, 2) - Math.Pow(c, 2)) / (2 * a * b)) * r2D;
if (enB >= 90)
{
return(pt);
}
var enC = Math.Acos((Math.Pow(a, 2) + Math.Pow(c, 2) - Math.Pow(b, 2)) / (2 * a * c)) * r2D;
if (enC >= 90)
{
return(pt);
}
var x = ((line.Right - line.Left) * (line.Bottom - line.Top) * (pt.Latitude - line.Top) +
line.Left * Math.Pow(line.Bottom - line.Top, 2) + pt.Longitude * Math.Pow(line.Right - line.Left, 2)) /
(Math.Pow(line.Bottom - line.Top, 2) + Math.Pow(line.Right - line.Left, 2));
var y = (line.Bottom - line.Top) * (x - line.Left) / (line.Right - line.Left) + line.Top;
return(new GeomCoordinate(x, y));
}
public IntersectResult PointContains(GeomCoordinate point)
{
return((point.Longitude >= Left &&
point.Longitude <= Right &&
point.Latitude <= Top &&
point.Latitude >= Bottom) ? IntersectResult.Contains : IntersectResult.None);
}
/// <summary>
/// Approximate distance from point to line segment
/// Transmitted latitude / longitude in degrees and hundredths
/// </summary>
///
public static double GetDistance(CoordinateRectangle line, GeomCoordinate pt)
{
const double r2D = 180 / Math.PI; // Constant for converting radians to degrees
var a = GetLength(line.LeftTop, line.RightBottom);
var b = GetLength(line.LeftTop, pt);
var c = GetLength(line.RightBottom, pt);
if (a <= 0)
{
return((b + c) / 2);
}
var enB = Math.Acos((Math.Pow(a, 2) + Math.Pow(b, 2) - Math.Pow(c, 2)) / (2 * a * b)) * r2D;
if (enB >= 90)
{
return(b);
}
var enC = Math.Acos((Math.Pow(a, 2) + Math.Pow(c, 2) - Math.Pow(b, 2)) / (2 * a * c)) * r2D;
if (enC >= 90)
{
return(c);
}
var s = (a + b + c) / 2;
var ar = Math.Sqrt(s * (s - a) * (s - b) * (s - c));
return(ar * 2 / a);
}
/// <summary>
/// Approximate distance between two points
/// Transmitted latitude / longitude in degrees and hundredths
/// </summary>
public static double GetLength(GeomCoordinate c1, GeomCoordinate c2)
{
// Constants used to calculate offset and distance
const double d2R = Math.PI / 180; // Constant to convert degrees to radians
const double a = 6378137.0; // Main axis
// const double b = 6356752.314245; // Minor axis
const double e2 = 0.006739496742337; // The square of the eccentricity of the ellipsoid
// Calculate the difference between two longitudes and latitudes and get the average latitude
var fdLambda = (c1.Longitude - c2.Longitude) * d2R; // The difference between the two values of longitude
var fdPhi = (c1.Latitude - c2.Latitude) * d2R; // The difference between the two latitudes
var fPhimean = ((c1.Latitude + c2.Latitude) / 2.0) * d2R; // Mid latitude
// Meridian radius of curvature
var fRho = (a * (1 - e2)) / Math.Pow(1 - e2 * (Math.Pow(Math.Sin(fPhimean), 2)), 1.5);
// Transverse radius of curvature
var fNu = a / (Math.Sqrt(1 - e2 * (Math.Sin(fPhimean) * Math.Sin(fPhimean))));
// Calculate the angular distance from the center of the spheroid
var fz = 2 * Math.Asin(Math.Sqrt(Math.Pow(Math.Sin(fdPhi / 2.0), 2) + Math.Cos(c2.Latitude * d2R) * Math.Cos(c1.Latitude * d2R) * Math.Pow(Math.Sin(fdLambda / 2.0), 2)));
// Calculate the offset
var fAlpha = Math.Asin(Math.Cos(c2.Latitude * d2R) * Math.Sin(fdLambda) * 1 / Math.Sin(fz));
// Calculate the radius of the Earth
var fR = (fRho * fNu) / ((fRho * Math.Pow(Math.Sin(fAlpha), 2)) + (fNu * Math.Pow(Math.Cos(fAlpha), 2)));
// Calculated distance in meters
var distance = fz * fR;
return(distance);
}
public double PoligonDistance(GeomCoordinate coordinate)
{
double res = 0;
for (var i = 0; i < Count; i++)
{
var distance = this[i].LineDistance(coordinate);
if (i == 0 || distance < res)
{
res = distance;
}
}
return(res);
}
public bool Add(GeomCoordinate coordinate)
{
if (Count > 2)
{
var line1 = new CoordinateRectangle(First, coordinate);
var line2 = new CoordinateRectangle(Last, coordinate);
for (var i = 0; i < Count - 1; i++)
{
if (MapUtilities.CheckLinesIntersection(this[i], line1) ||
MapUtilities.CheckLinesIntersection(this[i], line2))
{
return(false);
}
}
}
Coordinates.Add(coordinate);
return(true);
}
public GeomCoordinate GetNearestPoint(GeomCoordinate pt)
{
return(EarthUtilities.GetNearestPoint(this, pt));
}
public double LineDistance(GeomCoordinate coordinate)
{
return(EarthUtilities.GetDistance(this, coordinate));
}
public IntersectResult PointContains(GeomCoordinate coordinate)
{
//to do
return(IntersectResult.None);
}
