public void DrawLine(System.Windows.Point start, System.Windows.Point end, double thickness)
{
m_writer.WriteStartElement("line");
m_writer.WriteAttributeString("start", start.ToString(CultureInfo.InvariantCulture));
m_writer.WriteAttributeString("end", end.ToString(CultureInfo.InvariantCulture));
m_writer.WriteAttributeString("thickness", thickness.ToString());
m_writer.WriteEndElement();
}