/// <summary>
/// Draw the sphere to the graphics output
/// </summary>
/// <param name="gr"></param>
public void Draw(Graphics gr, double distance)
{
Sphere2D sphere2D = ToSphere2D(distance);
sphere2D.Pen = pen;
sphere2D.Draw(gr);
}
/// <summary>
/// Fill the sphere on the graphics output
/// </summary>
/// <param name="gr"></param>
public void Fill(Graphics gr, double distance)
{
Sphere2D sphere2D = ToSphere2D(distance);
sphere2D.Brush = brush;
sphere2D.Fill(gr);
}
/// <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);
}