using System;
using DevExpress.XtraMap;
namespace CustomProjection {
public class HammerAitoffProjection : ProjectionBase {
const double minLatitude = -90.0;
const double maxLatitude = 90.0;
const double minLongitude = -180.0;
const double maxLongitude = 180.0;
public override double OffsetX { get { return 0.5; } }
public override double OffsetY { get { return 0.5; } }
public override double ScaleX { get { return 0.5; } }
public override double ScaleY { get { return -0.25; } }
bool IsValidPoint(double x, double y) {
if (Math.Pow(x, 2) + Math.Pow(y, 2) > 1)
return false;
else
return true;
}
static double RadianToDegree(double value) {
return value * 180.0 / Math.PI;
}
static double DegreeToRadian(double value) {
return value * Math.PI / 180.0;
}
public override MapUnit GeoPointToMapUnit(GeoPoint geoPoint) {
double lonInRadian = DegreeToRadian(
Math.Min(
maxLongitude,
Math.Max(minLongitude, geoPoint.Longitude)
)
);
double latInRadian = DegreeToRadian(
Math.Min(
maxLatitude,
Math.Max(minLatitude, geoPoint.Latitude)
)
);
double z = Math.Sqrt(1 + Math.Cos(latInRadian) * Math.Cos(lonInRadian / 2));
double x = Math.Cos(latInRadian) * Math.Sin(lonInRadian / 2) / z;
double y = Math.Sin(latInRadian) / z;
return new MapUnit(x * ScaleX + OffsetX, y * ScaleY + OffsetY);
}
public override GeoPoint MapUnitToGeoPoint(MapUnit mapPoint) {
double x = (mapPoint.X - OffsetX) / ScaleX;
double y = Math.Min(1, Math.Max(-1, (mapPoint.Y - OffsetY) / ScaleY));
if (IsValidPoint(x, y)) {
double z = Math.Sqrt(1 - 0.5 * Math.Pow(x, 2) - 0.5 * Math.Pow(y, 2));
double c = Math.Sqrt(2) * z * x / (2 * Math.Pow(z, 2) - 1);
double lon = 2 * Math.Atan(c);
double lat = Math.Asin(Math.Min(Math.Max(Math.Sqrt(2) * z * y, -1), 1));
double latInDegree = lat * 180.0 / Math.PI;
double lonInDegree = lon * 180.0 / Math.PI;
return new GeoPoint(
Math.Min(
maxLatitude,
Math.Max(minLatitude, RadianToDegree(lat))
),
Math.Min(
maxLongitude,
Math.Max(minLongitude, RadianToDegree(lon))
)
);
}
else {
int signX = (x < 0) ? -1 : 1;
int signY = (y < 0) ? -1 : 1;
return new GeoPoint(maxLatitude * signY, maxLongitude * signX);
}
}
public override MapSize GeoToKilometersSize(GeoPoint anchorPoint, MapSize size) {
return new MapSize(
size.Width * LonToKilometersRatio * Math.Cos(DegreeToRadian(anchorPoint.Latitude)),
size.Height * LatToKilometersRatio
);
}
public override MapSize KilometersToGeoSize(GeoPoint anchorPoint, MapSize size) {
return new MapSize(
size.Width / LonToKilometersRatio / Math.Cos(DegreeToRadian(anchorPoint.Latitude)),
size.Height / LatToKilometersRatio
);
}
}
}
Imports System
Imports DevExpress.XtraMap
Namespace CustomProjection
Public Class HammerAitoffProjection
Inherits ProjectionBase
Private Const minLatitude As Double = -90.0
Private Const maxLatitude As Double = 90.0
Private Const minLongitude As Double = -180.0
Private Const maxLongitude As Double = 180.0
Public Overrides Property OffsetX() As Double
Set(value As Double)
End Set
Get
Return 0.5
End Get
End Property
Public Overrides Property OffsetY() As Double
Set(value As Double)
End Set
Get
Return 0.5
End Get
End Property
Public Overrides Property ScaleX() As Double
Set(value As Double)
End Set
Get
Return 0.5
End Get
End Property
Public Overrides Property ScaleY() As Double
Set(value As Double)
End Set
Get
Return -0.25
End Get
End Property
Private Function IsValidPoint(ByVal x As Double, ByVal y As Double) As Boolean
If Math.Pow(x, 2) + Math.Pow(y, 2) > 1 Then
Return False
Else
Return True
End If
End Function
Private Shared Function RadianToDegree(ByVal value As Double) As Double
Return value * 180.0 / Math.PI
End Function
Private Shared Function DegreeToRadian(ByVal value As Double) As Double
Return value * Math.PI / 180.0
End Function
Public Overrides Function GeoPointToMapUnit(ByVal geoPoint As GeoPoint) As MapUnit
Dim lonInRadian As Double = DegreeToRadian(Math.Min(maxLongitude, Math.Max(minLongitude, geoPoint.Longitude)))
Dim latInRadian As Double = DegreeToRadian(Math.Min(maxLatitude, Math.Max(minLatitude, geoPoint.Latitude)))
Dim z As Double = Math.Sqrt(1 + Math.Cos(latInRadian) * Math.Cos(lonInRadian / 2))
Dim x As Double = Math.Cos(latInRadian) * Math.Sin(lonInRadian / 2) / z
Dim y As Double = Math.Sin(latInRadian) / z
Return New MapUnit(x * ScaleX + OffsetX, y * ScaleY + OffsetY)
End Function
Public Overrides Function MapUnitToGeoPoint(ByVal mapPoint As MapUnit) As GeoPoint
Dim x As Double = (mapPoint.X - OffsetX) / ScaleX
Dim y As Double = Math.Min(1, Math.Max(-1, (mapPoint.Y - OffsetY) / ScaleY))
If IsValidPoint(x, y) Then
Dim z As Double = Math.Sqrt(1 - 0.5 * Math.Pow(x, 2) - 0.5 * Math.Pow(y, 2))
Dim c As Double = Math.Sqrt(2) * z * x / (2 * Math.Pow(z, 2) - 1)
Dim lon As Double = 2 * Math.Atan(c)
Dim lat As Double = Math.Asin(Math.Min(Math.Max(Math.Sqrt(2) * z * y, -1), 1))
Dim latInDegree As Double = lat * 180.0 / Math.PI
Dim lonInDegree As Double = lon * 180.0 / Math.PI
Return New GeoPoint(Math.Min(maxLatitude, Math.Max(minLatitude, RadianToDegree(lat))), Math.Min(maxLongitude, Math.Max(minLongitude, RadianToDegree(lon))))
Else
Dim signX As Integer = If(x < 0, -1, 1)
Dim signY As Integer = If(y < 0, -1, 1)
Return New GeoPoint(maxLatitude * signY, maxLongitude * signX)
End If
End Function
Public Overrides Function GeoToKilometersSize(ByVal anchorPoint As GeoPoint, ByVal size As MapSize) As MapSize
Return New MapSize(size.Width * LonToKilometersRatio * Math.Cos(DegreeToRadian(anchorPoint.Latitude)), size.Height * LatToKilometersRatio)
End Function
Public Overrides Function KilometersToGeoSize(ByVal anchorPoint As GeoPoint, ByVal size As MapSize) As MapSize
Return New MapSize(size.Width / LonToKilometersRatio / Math.Cos(DegreeToRadian(anchorPoint.Latitude)), size.Height / LatToKilometersRatio)
End Function
End Class
End Namespace