public EllipseShape(Rectangle3d rec)
{
geom = new GraphicsPath();
geom.AddEllipse(ShapeUtil.toRec2D(rec));
}
public ArcShape(Rectangle3d rec, float startAngle, float sweepAngle)
{
geom = new GraphicsPath();
geom.AddArc(ShapeUtil.toRec2D(rec), startAngle, sweepAngle);
}