addline

          
using System;

partial class Examples
{
  public static Rhino.Commands.Result AddLine(Rhino.RhinoDoc doc)
  {
    Rhino.Input.Custom.GetPoint gp = new Rhino.Input.Custom.GetPoint();
    gp.SetCommandPrompt("Start of line");
    gp.Get();
    if (gp.CommandResult() != Rhino.Commands.Result.Success)
      return gp.CommandResult();

    Rhino.Geometry.Point3d pt_start = gp.Point();

    gp.SetCommandPrompt("End of line");
    gp.SetBasePoint(pt_start, false);
    gp.DrawLineFromPoint(pt_start, true);
    gp.Get();
    if (gp.CommandResult() != Rhino.Commands.Result.Success)
      return gp.CommandResult();

    Rhino.Geometry.Point3d pt_end = gp.Point();
    Rhino.Geometry.Vector3d v = pt_end - pt_start;
    if (v.IsTiny(Rhino.RhinoMath.ZeroTolerance))
      return Rhino.Commands.Result.Nothing;

    if (doc.Objects.AddLine(pt_start, pt_end) != Guid.Empty)
    {
      doc.Views.Redraw();
      return Rhino.Commands.Result.Success;
    }
    return Rhino.Commands.Result.Failure;
  }
}