ElseIf SPXY = 3 Then
            If Y - CurrentNY < 0 Then
               For TOX = StartX To X
                 TOY = -(CurrentNR ^ 2 - (TOX - CurrentNI) ^ 2) ^ 0.5 + CurrentNJ
                   Call DrawLine(CurrentNX, CurrentNY, TOX, TOY)
                 CurrentNX = TOX
                 CurrentNY = TOY
               Next TOX
            Else
               Call PXYTOGraphic(PointX(0), PointY(0), 3, 4, CircleTime)
               Call PXYTOGraphic(PointX(1), PointY(1), 4, 1, CircleTime)
               Call PXYTOGraphic(PointX(2), PointY(2), 1, 2, CircleTime)
               Call PXYTOGraphic(X, Y, 2, 3, CircleTime)
            End If
        ElseIf SPXY = 4 Then
            If Y - CurrentNY > 0 Then
               For TOX = StartX To X
                 TOY = -(CurrentNR ^ 2 - (TOX - CurrentNI) ^ 2) ^ 0.5 + CurrentNJ
                   Call DrawLine(CurrentNX, CurrentNY, TOX, TOY)
                 CurrentNX = TOX
                 CurrentNY = TOY
               Next TOX
            Else
               Call PXYTOGraphic(PointX(1), PointY(1), 4, 1, CircleTime)
               Call PXYTOGraphic(PointX(2), PointY(2), 1, 2, CircleTime)
               Call PXYTOGraphic(PointX(3), PointY(3), 2, 3, CircleTime)
               Call PXYTOGraphic(X, Y, 3, 4, CircleTime)
            End If
        End If
  Else
         If SPXY = 1 Then
            If Y - CurrentNY < 0 Then
               For TOX = StartX To X Step -1
                 TOY = -(CurrentNR ^ 2 - (TOX - CurrentNI) ^ 2) ^ 0.5 + CurrentNJ
                   Call DrawLine(CurrentNX, CurrentNY, TOX, TOY) 数控系统动画仿真软件设计+仿真程序(7):http://www.youerw.com/jixie/lunwen_20570.html