public static double calcLatlongAreaResolution(GetTerrain.Latlong latlong, double zoom)
{
double pi = 3.14159265358979323846264338327950288419716939937510;
double map_resolution = 156543.04 * Math.Cos(latlong.lati * (pi / 180)) / (Math.Pow(2, zoom));
return(map_resolution);
}
/// <summary>
/// use for bing map
/// </summary>
/// <param name="mapPixel"></param>
/// <param name="zoom"></param>
/// <returns></returns>
public static GetTerrain.Latlong pixelToLatlong(GetTerrain.Mappixel mapPixel, double zoom)
{
mapPixel = clipPixel(mapPixel, zoom);
double pi = 3.14159265358979323846264338327950288419716939937510;
double mapSize = 256.0 * Math.Pow(2.0, zoom);
double x = (mapPixel.x / mapSize) - 0.5;
double y = 0.5 - (mapPixel.y / mapSize);
GetTerrain.Latlong latlong = new GetTerrain.Latlong();
latlong.lati = 90.0 - 360.0 * Math.Atan(Math.Exp(-y * 2.0 * pi)) / pi;
latlong.longti = 360.0 * x;
return(latlong);
}
public static double Distance(GetTerrain.Latlong lt, GetTerrain.Latlong rb)
{
double lat1 = ConvertDegreesToRadians(lt.lati);
double lon1 = ConvertDegreesToRadians(lt.longti);
double lat2 = ConvertDegreesToRadians(rb.lati);
double lon2 = ConvertDegreesToRadians(rb.longti);
double vLon = Math.Abs(lon1 - lon2);
double vLat = Math.Abs(lat1 - lat2);
double h = haverSin(vLat) + Math.Cos(lat1) * Math.Cos(lat2) * haverSin(vLon);
double distance = 2 * EARTH_RADIUS * Math.Asin(Math.Sqrt(h));
return(distance);
}
/// <summary>
/// use for bing map
/// </summary>
/// <param name="latlong"></param>
/// <param name="zoom"></param>
/// <returns></returns>
public static GetTerrain.Mappixel latlongToPixel(GetTerrain.Latlong latlong, double zoom)
{
latlong = clipLatlong(latlong);
double pi = 3.14159265358979323846264338327950288419716939937510;
double x = (latlong.longti + 180.0) / 360.0;
double sinLatitude = Math.Sin(latlong.lati * pi / 180.0);
double y = 0.5 - Math.Log((1.0 + sinLatitude) / (1.0 - sinLatitude)) / (4.0 * pi);
x *= 256.0 * Math.Pow(2.0, zoom);
y *= 256.0 * Math.Pow(2.0, zoom);
GetTerrain.Mappixel mapPixel = new GetTerrain.Mappixel();
mapPixel.x = x;
mapPixel.y = y;
return(mapPixel);
}
public static GetTerrain.Latlong pixelToLatlong(Vector2 offset, GetTerrain.Latlong latlongCenter, double zoom)
{
double pi = 3.14159265358979323846264338327950288419716939937510;
double mapSize = 256.0 * Math.Pow(2.0, zoom);
GetTerrain.Mappixel mapPixelCenter = latlongToPixel(latlongCenter, zoom);
GetTerrain.Mappixel mapPixel = new GetTerrain.Mappixel();
mapPixel.x = mapPixelCenter.x + offset.x;
mapPixel.y = mapPixelCenter.y + offset.y;
double x = (mapPixel.x / mapSize) - 0.5;
double y = 0.5 - (mapPixel.y / mapSize);
GetTerrain.Latlong latlong = new GetTerrain.Latlong();
latlong.lati = 90 - 360 * Math.Atan(Math.Exp(-y * 2 * pi)) / pi;
latlong.longti = 360 * x;
latlong = clipLatlong(latlong);
return(latlong);
}
/// <summary>
/// use for bing map
/// </summary>
/// <param name="latlong"></param>
/// <returns></returns>
public static GetTerrain.Latlong clipLatlong(GetTerrain.Latlong latlong)
{
if (latlong.lati > maxLatitude)
{
latlong.lati -= (maxLatitude * 2);
}
else if (latlong.lati < minLatitude)
{
latlong.lati += (maxLatitude * 2);
}
if (latlong.longti > 180)
{
latlong.longti -= 360;
}
else if (latlong.longti < -180)
{
latlong.longti += 360;
}
return(latlong);
}
