public void AddLine(double latitude, double longitude, double?z, double?m)
{
// Transforming from geodetic coordinates to a unit vector.
var endPoint = SpatialUtil.SphericalDegToCartesian(latitude, longitude);
var angle = endPoint.Angle(_startPoint);
if (angle > MinAngle)
{
// _startPoint and endPoint are the unit vectors that correspond to the input
// start and end points. In their 3D space we operate in a local coordinate system
// where _startPoint is the x axis and the xy plane contains endPoint. Every
// point is now generated from the previous one by a fixed rotation in the local
// xy plane, and converted back to geodetic coordinates.
// Construct the local z and y axes.
var zAxis = (_startPoint + endPoint).CrossProduct(_startPoint - endPoint).Unitize();
var yAxis = (_startPoint).CrossProduct(zAxis);
// Calculating how many points we need.
var count = Convert.ToInt32(Math.Ceiling(angle / SpatialUtil.ToRadians(_angle)));
// Scaling the angle so that points are equally placed.
var exactAngle = angle / count;
var cosine = Math.Cos(exactAngle);
var sine = Math.Sin(exactAngle);
// Setting the first x and y points in our local coordinate system.
var x = cosine;
var y = sine;
for (var i = 0; i < count - 1; i++)
{
var newPoint = (_startPoint * x + yAxis * y).Unitize();
// Adding the point.
_sink.AddLine(SpatialUtil.LatitudeDeg(newPoint), SpatialUtil.LongitudeDeg(newPoint), null, null);
// Rotating to get next point.
var r = x * cosine - y * sine;
y = x * sine + y * cosine;
x = r;
}
}
_sink.AddLine(latitude, longitude, z, m);
// Remembering last point we added.
_startPoint = endPoint;
}
public void BeginFigure(double latitude, double longitude, double?z, double?m)
{
// Starting the figure, remembering the vector that corresponds to the first point.
_startPoint = SpatialUtil.SphericalDegToCartesian(latitude, longitude);
_sink.BeginFigure(latitude, longitude, z, m);
}
