/// <summary>
/// Return list of latitudes in bounding box
/// UTM Longitude: each 6 degrees
/// </summary>
/// <param name="pBoundingBox">
/// </param>
/// <returns>
/// The <see cref="IEnumerable"/>.
/// </returns>
private static IEnumerable<double> CalculateVisibleLongitudeLines(GeographicBoundingBox pBoundingBox)
{
var result = new List<double>();
// first zone intersection inside the southwest corner of the map window
// longitude coordinate is straight-forward...
double x1 = Math.Floor((pBoundingBox.WestBoundLongitude / 6.0) + 1) * 6.0;
result.Add(pBoundingBox.WestBoundLongitude);
if (pBoundingBox.WestBoundLongitude < pBoundingBox.EastBoundLongitude)
{
// normal case
for (double currentLongitude = x1, j = 1;
currentLongitude < pBoundingBox.EastBoundLongitude;
currentLongitude += 6, j++)
{
result.Add(currentLongitude);
}
}
else
{
Debug.Assert(false, "Boundingbox problem with map");
}
result.Add(pBoundingBox.EastBoundLongitude);
return result.Distinct();
}
/// <summary>
/// Return list of latitudes in bounding box
/// UTM Latitude: each 8 degrees
/// </summary>
/// <param name="pBoundingBox">
/// </param>
/// <returns>
/// The <see cref="IEnumerable"/>.
/// </returns>
private static IEnumerable<double> CalculateVisibleLatitudeLines(GeographicBoundingBox pBoundingBox)
{
var result = new List<double>();
result.Add(pBoundingBox.SouthBoundLatitude);
double y1 = (pBoundingBox.SouthBoundLatitude < -80)
? -80
: (Math.Floor((pBoundingBox.SouthBoundLatitude / 8) + 1) * 8.0);
for (var currentLatitude = y1; currentLatitude < pBoundingBox.NorthBoundLatitude; currentLatitude += 8)
{
if (currentLatitude <= 72)
{
result.Add(currentLatitude);
}
else if (currentLatitude <= 80)
{
result.Add(84);
}
}
result.Add(pBoundingBox.NorthBoundLatitude);
return result.Distinct();
}
