Grafik drehen

' gr ... Grafik, die gedreht werden soll
' cx, cy ... Koordinaten
' angle ... Drehwinkel
Private Sub RotateAt(ByVal gr As Graphics, ByVal cx As Integer, ByVal cy As Integer, ByVal angle As Single)
    gr.ResetTransform()
    gr.TranslateTransform(-cx, -cy, Drawing2D.MatrixOrder.Append)
    gr.RotateTransform(angle, Drawing2D.MatrixOrder.Append)
    gr.TranslateTransform(cx, cy, Drawing2D.MatrixOrder.Append)
End Sub