Private Sub Schraffur(ByVal bmp As Bitmap, versetzung As Integer, _
                       breite As Integer, farbe As Drawing.Color, _
                       Optional ByVal crossed As Boolean = False)
 
     Dim x As Integer
 
     Using g As Graphics = Graphics.FromImage(bmp),
        p As New Pen(farbe, breite)
 
        For x = -Math.Abs(versetzung) To _
           bmp.Width + Math.Abs(versetzung) Step breite * 3
 
           g.DrawLine(p, New Point(x, 0), New Point(x + versetzung, bmp.Height))
        Next x
     End Using
 
     If crossed Then
        Schraffur(bmp, -versetzung, breite, farbe, False)
     End If
 End Sub