Аффинные преобразования

Public Class Form2
    Private Enum action
        None
        Rotation
        Compression
        Reflection
    End Enum
    Private pnt1, pnt2, pnt3 As Point
    Private act As action
    Private Sub Form2_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        pnt1 = New Point(70, 50)
        pnt2 = New Point(250, 70)
        pnt3 = New Point(110, 130)
        act = action.None
    End Sub
    Private Sub Rotation_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
        act = action.Rotation
        Me.Invalidate()
    End Sub
    Private Sub Compression_Click(sender As System.Object, e As System.EventArgs) Handles Button3.Click
        act = action.Compression
        Me.Invalidate()
    End Sub
    Private Sub Reflection_Click(sender As System.Object, e As System.EventArgs) Handles Button4.Click
        act = action.Reflection
        Me.Invalidate()
    End Sub
    Private Sub Form2_Paint(sender As System.Object, e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
        Dim mt As New Drawing2D.Matrix
        Dim g As Graphics = e.Graphics
        g.DrawPolygon(Pens.Black, {pnt1, pnt2, pnt3})
        Select Case act
            Case action.Rotation
                mt.RotateAt(90, pnt3)
                g.Transform = mt
                g.DrawPolygon(Pens.Red, {pnt1, pnt2, pnt3})
            Case action.Compression
                mt.Translate(pnt1.X, pnt1.Y)
                mt.Scale(0.5, 0.5, Drawing2D.MatrixOrder.Append)
                g.Transform = mt
                g.DrawPolygon(Pens.Red, {pnt1, pnt2, pnt3})
            Case action.Reflection
                Dim yy As Integer = 150
                g.DrawLine(Pens.Blue, New Point(0, yy), New Point(Me.Width - 50, yy))
                mt = New Drawing2D.Matrix(1, 0, 0, -1, 0, yy + yy)
                g.Transform = mt
                g.DrawPolygon(Pens.Red, {pnt1, pnt2, pnt3})
        End Select
    End Sub
End Class