private void UpdateIsolate()
{
foreach (GridLine2D line2D in m_uGridLines2D)
{
foreach (SegmentLine2D seg in line2D.Segments)
{
System.Drawing.Point startPoint = seg.StartPoint;
// if we get all the U line's start points, we can cover all the conjoints
IsPointIsolate(startPoint);
}
}
}