Windows Forms: Display image using Control Paint event

Public Class Form1

    Dim WithEvents t As New Timer

    Dim stp As Integer = 2
    Dim fps As Integer = 25

    Dim ax, ay, bx, by As Integer

    Dim imgpath As String = System.IO.Path.Combine(My.Computer.FileSystem.SpecialDirectories.Desktop, "elephant.png")
    Dim img As Image = Image.FromFile(imgpath)

    Private Sub Form1_Paint(ByVal sender As System.Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
        Dim g As Graphics = e.Graphics
        g.DrawImage(img, ax, ay)
        g.DrawImage(img, bx, by)
    End Sub

    Private Sub PaintNextFrame()
        ax = ax + 2 * stp
        bx = bx + stp
        Me.Invalidate()
    End Sub

    Private Sub tick(ByVal o As Object, ByVal e As EventArgs) Handles t.Tick
        PaintNextFrame()
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        t.Interval = 1000 / fps
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        t.Start()
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        t.Stop()
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        t.Stop()
        ax = 0
        bx = 0
        ay = 0
        by = 0
        Me.Invalidate()
    End Sub
End Class