Private Declare Function LineDDA Lib "gdi32" _
    (Byval xStart As Long, _
     Byval yStart As Long, _
     Byval xEnd As Long, _
     Byval yEnd As Long, _
     Byval CProgAdr As Long, _
     Byval lparam As Long) As Long

Public Sub LineCallback (Byval x As Long, Byval y As Long, _
                                         Byval lparam As Long)
 
        ' ....... Anweisungen für die Pointberechnung
End Sub