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

[dunfiddlin]

I don't know how to improve it either but it's obvious why it's happening as you're not drawing a continuous line but a series of, sometimes very short, straight lines. The wider the stroke the more obvious it becomes that this is effectively a series of rectangles at different angles to each other which means there simply has to be white space between them at one end or the other.

[k3nnt0ter0]

There are a lot of same program that has the same problem. I can't find solution about this.

[.paul.]

try this:

Public Class Form1
    Dim multistartPos As New List(Of Point)
 
    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
            multistartPos.Add(New Point(e.X, e.Y))
        End If
    End Sub
    
    Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
        If multistartPos.Count > 0 Then
            Dim gr As Graphics = Graphics.FromHwnd(PictureBox1.Handle)
            multistartPos.Add(New Point(e.X, e.Y))
            If e.Button = Windows.Forms.MouseButtons.Left Then
                gr.DrawLines(New Pen(Color.Black, 5), multistartPos.ToArray)
            End If
        End If
    End Sub
 
    Private Sub PictureBox1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseUp
        multistartPos.Clear()
    End Sub
 
End Class