Smoothing the Pen

[k3nnt0ter0]

I can't make the Pen smooth. If I adjusted the Size of the pen, it'll produce crack/gap. I don't have any idea to fix it. Check the image.

Here's the code.

Public Class PaintFormDim PenWidth As Single = 1.0F
    Dim PenPoint As Pen

Sub ReloadPen(ByVal PenWd As Single, ByVal CurColor As Color)       PenPoint = New Pen(CurColor, PenWd)


   End Sub

Private Sub PictureBox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseDown
        If e.Button = Windows.Forms.MouseButtons.Left Then
            If drawing = False Then

                startLocation = e.Location

                drawing = True

                If MultiAngleRadioButton.Checked Then

                    If TempLocation.X = -1 Then
                        TempLocation = startLocation
                        TempLocation2 = startLocation
                    End If

                    endLocation = e.Location
                    g.DrawLine(PenPoint, TempLocation, endLocation)
                    TempLocation = endLocation

                ElseIf TriangleRadioButton.Checked Then
                    If TempLocation.X = -1 Then
                        TempLocation = startLocation
                        TempLocation2 = startLocation
                    End If

                    If NumberOfAngle <= 2 Then

                        endLocation = e.Location
                        g.DrawLine(PenPoint, TempLocation, endLocation)
                        TempLocation = endLocation

                        If NumberOfAngle = 2 Then
                            g.DrawLine(PenPoint, TempLocation, TempLocation2)
                            TempLocation = New Point(-1, -1)
                            NumberOfAngle = 0
                        Else
                            NumberOfAngle += 1
                        End If

                    End If

                End If

            End If

        ElseIf e.Button = Windows.Forms.MouseButtons.Right Then

            If MultiAngleRadioButton.Checked Then
                If TempLocation.X <> -1 Then
                    endLocation = e.Location
                    g.DrawLine(PenPoint, TempLocation, TempLocation2)
                    TempLocation = New Point(-1, -1)
                End If

            End If

        End If

    End Sub

Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
        If drawing = True Then
            If LineRadioButton.Checked Then
                g.DrawLine(PenPoint, startLocation.X, startLocation.Y, e.X, e.Y)
                startLocation = e.Location
                UpdateImage()

            ElseIf EraserRadioButton.Checked Then

                Dim p As New Pen(Color.White, PenWidth)

                g.DrawLine(p, startLocation.X, startLocation.Y, e.X, e.Y)
                startLocation = e.Location
                UpdateImage()

            End If

        End If
    End Sub

Private Sub PictureBox1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseUp

        If drawing Then

            If RectangleRadioButton.Checked Then

                endLocation = e.Location

                Dim s As Point

                s.X = endLocation.X - startLocation.X
                If s.X < 0 Then
                    startLocation.X = endLocation.X

                End If

                s.Y = endLocation.Y - startLocation.Y
                If s.Y < 0 Then
                    startLocation.Y = endLocation.Y

                End If

                s.X = Math.Abs(s.X)
                s.Y = Math.Abs(s.Y)
                g.DrawRectangle(PenPoint, New Rectangle(startLocation, s))

            ElseIf GradientRectAngleRadioButton.Checked Then

                endLocation = e.Location

                Dim s As Point

                If s.X < 0 Then
                    startLocation.X = endLocation.X
                ElseIf s.X = 0 Then
                    s.X = 1
                End If

                s.Y = endLocation.Y - startLocation.Y

                If s.Y < 0 Then
                    startLocation.Y = endLocation.Y
                ElseIf s.Y = 0 Then
                    s.Y = 1
                End If

                s.X = Math.Abs(s.X)
                s.Y = Math.Abs(s.Y)

                Dim b As Brush
                b = New Drawing2D.LinearGradientBrush(New Rectangle(startLocation, s), CurrentColor, CurrentColor2, Drawing2D.LinearGradientMode.BackwardDiagonal)
                g.FillRectangle(b, New Rectangle(startLocation, s))

            ElseIf CircleRadioButton.Checked Then

                endLocation = e.Location
                Dim s As Point

                s.X = endLocation.X - startLocation.X

                If s.X < 0 Then
                    startLocation.X = endLocation.X

                End If

                s.Y = endLocation.Y - startLocation.Y

                If s.Y < 0 Then
                    startLocation.Y = endLocation.Y

                End If

                s.X = Math.Abs(s.X)
                s.Y = Math.Abs(s.Y)

                If s.X > s.Y Then
                    s.Y = s.X
                Else
                    s.X = s.Y
                End If

                g.DrawEllipse(PenPoint, New Rectangle(startLocation, s))
            ElseIf ArcRadioButton.Checked Then
                endLocation = e.Location

                Dim s As Point

                s.X = endLocation.X - startLocation.X

                If s.X < 0 Then
                    startLocation.X = endLocation.X

                End If

                s.Y = endLocation.Y - startLocation.Y

                If s.Y < 0 Then
                    startLocation.Y = endLocation.Y

                End If

                s.X = Math.Abs(s.X)
                s.Y = Math.Abs(s.Y)

                If s.X > s.Y Then
                    s.Y = s.X
                Else
                    s.X = s.Y
                End If

                g.DrawArc(PenPoint, New Rectangle(startLocation, s), 0, -180)

            ElseIf ParallelepipedRadioButton.Checked Then

                endLocation = e.Location

                Dim s As Point

                s.X = endLocation.X - startLocation.X

                If s.X < 0 Then
                    Dim tmp As Integer = startLocation.X
                    startLocation.X = endLocation.X
                    endLocation.X = tmp
                End If


                s.Y = endLocation.Y - startLocation.Y


                If s.Y < 0 Then
                    Dim tmp As Integer = startLocation.Y
                    startLocation.Y = endLocation.Y
                    endLocation.Y = tmp
                End If


                s.X = Math.Abs(s.X)
                s.Y = Math.Abs(s.Y)






                Dim p(3) As Point


                p(0) = New Point(startLocation.X + s.X / 5, startLocation.Y)
                p(1) = New Point(startLocation.X + s.X, startLocation.Y)


                p(2) = New Point(endLocation.X - s.X / 5, endLocation.Y)
                p(3) = New Point(endLocation.X - s.X, endLocation.Y)

                g.DrawPolygon(PenPoint, p)


            ElseIf FillRadioButton.Checked Then
                FillRegion(e.X, e.Y, CurrentColor)

            ElseIf TextRadioButton.Checked Then
                Dim txt As String = Me.TextDrawTextBox.Text
                g.DrawString(txt, CurrentFont, New Drawing2D.HatchBrush(Drawing2D.HatchStyle.BackwardDiagonal, CurrentColor), e.X, e.Y)

            End If

        End If

        drawing = False

        UpdateImage()

    End Sub

Private Sub PaintForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        g = Graphics.FromImage(LastImage)
        g.Clear(Color.White)
        UpdateImage()
        ReloadPen(PenWidth, CurrentColor)

    End Sub