I'm glad it worked out. I confess I haven't fully worked through the logic behind your code. I was somewhat shocked it worked when I tried it; I can see the logic in general, but it gets closer than I'd expect to the original pattern considering how indirect the method is. In any case, I had something like the following in mind:

vb.net Code:
  1. Dim m As Integer = 16
  2. Dim w As Integer = Me.ClientSize.Width / (m - 1)
  3. Dim points1() As PointF = Enumerable.Range(1, m - 1).Select(Function(n) New PointF(0, Me.ClientSize.Height - w * n)).ToArray
  4. Dim points2() As PointF = Enumerable.Range(1, m - 1).Select(Function(n) New PointF(w * (m - n), Me.ClientSize.Height)).ToArray
  5. For n As Integer = 0 To m - 2
  6.     e.Graphics.DrawLine(Pens.Black, points1(n), points2(n))
  7. Next

It produces extremely similar output to both your method and your original picture.