public void OnMouseDown(int Button, int shift, int X, int Y)
{
if (Button != (int)Keys.LButton) return;
switch (m_etoolPhase)
{
case (ToolPhase.Inactive):
GetFirstPoint();
break;
case (ToolPhase.SecondPoint):
GetSecondPoint();
break;
case (ToolPhase.Intersection):
GetIntersection();
break;
}
}