Скорость отрисовки FillEllipse

Private Sub PicBoxBoard_MouseMove(sender As Object, e As MouseEventArgs) Handles PicBoxBoard.MouseMove
    If e.Button = MouseButtons.Left And ShapeType = "Pensil" Then
       Me.GraphIMGMain.FillEllipse(TextBrush, e.X - ThickCorrect, e.Y - ThickCorrect, ThickPen, ThickPen)
    End If
End Sub

Public Class Form1
    Dim bufferbitmap As New Bitmap(500, 500)
    Dim GraphIimeg As Graphics = Graphics.FromImage(bufferbitmap)
    Dim ColorBrush As New SolidBrush(Color.Blue)
    Dim CentreCorrect As Integer = 5
    Dim ThicknessPen As Integer = 10
    Dim ShapeType As String = "Elips"
    Dim BufferedPicBox As New BufferedPictureBox()
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        BufferedPicBox.Size = New Size(bufferbitmap.Width, bufferbitmap.Height)
        BufferedPicBox.Location = New Point(0, 0)
        Me.Controls.Add(BufferedPicBox)
        AddHandler BufferedPicBox.MouseMove, AddressOf BufferedPicBox_MouseMove
    End Sub
    Private Sub BufferedPicBox_MouseMove(sender As Object, e As MouseEventArgs)
        If e.Button = MouseButtons.Left AndAlso ShapeType = "Elips" Then
            GraphIimeg.FillEllipse(ColorBrush, e.X - CentreCorrect, e.Y - CentreCorrect, ThicknessPen, ThicknessPen)
            BufferedPicBox.Image = bufferbitmap
            BufferedPicBox.Refresh()
        End If
    End Sub
End Class
Public Class BufferedPictureBox
    Inherits PictureBox
    Private _doubleBuffered As Boolean
    Protected Overrides Property DoubleBuffered As Boolean
        Get
            Return True
        End Get
        Set(value As Boolean)
 
        End Set
    End Property
End Class

Imports System.Math
Public Class Form1
    Dim bufferbitmap As New Bitmap(500, 500)
    Dim GraphIimeg As Graphics = Graphics.FromImage(bufferbitmap)
    Dim ColorBrush As New SolidBrush(Color.Blue)
    Dim CentreCorrect As Integer = 5
    Dim ThicknessPen As Integer = 10
    Dim ShapeType As String = "Elips"
    Dim BufferedPicBox As New BufferedPictureBox()
    Private PreviousPoint As Point? = Nothing
   
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        BufferedPicBox.Size = New Size(bufferbitmap.Width, bufferbitmap.Height)
        BufferedPicBox.Location = New Point(0, 0)
        BufferedPicBox.BackColor = Color.Beige
        Me.Controls.Add(BufferedPicBox)
        BufferedPicBox.Image = bufferbitmap
        AddHandler BufferedPicBox.MouseMove, AddressOf BufferedPicBox_MouseMove
    End Sub
 
    Private Sub BufferedPicBox_MouseMove(sender As Object, e As MouseEventArgs)
        If e.Button = MouseButtons.Left AndAlso ShapeType = "Elips" Then
            If PreviousPoint IsNot Nothing Then
                DrawEllipseBetween(PreviousPoint.Value, e.Location)
            End If
            PreviousPoint = e.Location
        End If
    End Sub
 
    Private Sub DrawEllipseBetween(startPoint As Point, endPoint As Point)
        Dim steps As Integer = Max(Abs(endPoint.X - startPoint.X), Abs(endPoint.Y - startPoint.Y))
        For i As Integer = 0 To steps
            Dim t As Double = i / steps
            Dim x As Integer = CInt(startPoint.X + (endPoint.X - startPoint.X) * t)
            Dim y As Integer = CInt(startPoint.Y + (endPoint.Y - startPoint.Y) * t)
            GraphIimeg.FillEllipse(ColorBrush, x - CentreCorrect, y - CentreCorrect, ThicknessPen, ThicknessPen)
        Next
        BufferedPicBox.Image = bufferbitmap
        BufferedPicBox.Refresh()
    End Sub
End Class

    Private Sub PicBoxBoard_MouseMove(sender As Object, e As MouseEventArgs) Handles PicBoxBoard.MouseMove
        If vLoop = 0 Then
            PrevX = e.X : PrevY = e.Y
        End If
 
        If e.Button = MouseButtons.Left And ShapeType = "Pensil" Then
            If vLoop > 0 Then Me.GraphIMGMain.FillEllipse(SolBrush, e.X - CenterCorrect, e.Y - CenterCorrect, ThickPen, ThickPen)
            If Abs(PrevX - e.X) > 5 Or Abs(PrevY - e.Y) > 5 Then Me.GraphIMGMain.DrawLine(SetPen, PrevX, PrevY, e.X, e.Y)
            PrevX = e.X : PrevY = e.Y
            vLoop += 1
            Exit Sub
        End If
    End Sub