public void setStartPoint(Vector2 a_startPoint)
{
m_startPosition = new CartesianCoordinate(a_startPoint);
m_endPosition.setParentPositionWithoutMoving(m_startPosition);
m_line.setStartPoint(m_startPosition.getGlobalCartesian());
m_lenght = m_line.getStartPoint().getDistanceTo(m_line.getEndPoint());
m_position = m_startPosition;
}