/// <summary>
/// convert the 3D sphere to a 2D sphere
/// </summary>
/// <param name="distance">from the user to the screen</param>
/// <returns></returns>
private Sphere2D ToSphere2D(double distance)
{
Point2D center2D = center.Projection(distance);
double temp = (double)Math.Sqrt(center.X * center.X + center.Y * center.Y);
double radius2D = (radius + temp) * distance / (distance - center.Z) - center2D.Magnitude;
Sphere2D sphere2D = new Sphere2D(center2D, radius2D);
return(sphere2D);
}
public void Draw(Graphics gr, Pen pen, double distance)
{
new Line2D(p1.Projection(distance), p2.Projection(distance)).Draw(gr, pen);
endPoints[1].Draw(gr, Color.Red, distance);
}
/// <summary>
/// Draw the line to the screen
/// </summary>
/// <param name="gr"></param>
/// <param name="distance"></param>
public void Draw(Graphics gr, double distance)
{
gr.DrawLine(pen, p1.Projection(distance).PointF, p2.Projection(distance).PointF);
}