Hi ALL, here is a method to produce a SPIRAL. You can specify startRadius, endRadius, direction and distanceBetweenTurnsInPixels as well as the startAngle. Enjoy!!

Question

Hi ALL,

Here is some code you can play around with.  :)

 I thought it was better that you can specify a value for the endRadius so you can limit the spiral.

Please note: For this to work startRadius must be greater than the value for endRadius as the

mathematics involved gradually decreases the radius.I have not added any error checking for this.

Please also note the distanceBetweenTurnsInPixels , so for one full turn make the difference in the startRadius and endRadius

equal to this distance.

E.G: startRadius = 120 , endRadius = 50 , distanceBetweenTurnsInPixels =70

Try different values for these variables.>>

        Dim startRadius As Double = (Me.Height / 2) - 50
        Dim endRadius As Integer = 50
        Dim dir As Direction = Direction.Clockwise
        Dim distanceBetweenTurnsInPixels As Integer = 50
        'Please note the startAngle is from the EAST direction
        ' in the direction specified by the variable 'dir' as Direction.>>
        Dim startAngleInDegrees As Double = 45

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Here is the code in full. Enjoy!!

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>>

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Public Class Form1

    Const PiTimesTwo As Double = Math.PI * 2
    Const DegreesInOneRadian As Double = 180 / Math.PI

    Public Enum Direction
        AntiClockwise = -1
        Clockwise = 1
    End Enum

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        Me.BackColor = Color.Black
        Me.WindowState = FormWindowState.Maximized

    End Sub

    Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint

        Dim startRadius As Double = (Me.Height / 2) - 50
        Dim endRadius As Integer = 50
        Dim dir As Direction = Direction.Clockwise
        Dim distanceBetweenTurnsInPixels As Integer = 50
        'Please note the startAngle is from the EAST direction
        ' in the direction specified by the variable 'dir' as Direction.>>
        Dim startAngleInDegrees As Double = 45

        Dim angle1 As Double = startAngleInDegrees / DegreesInOneRadian
        Dim angle2 As Double = (startAngleInDegrees + 360) / DegreesInOneRadian
        Dim radius As Double = startRadius
        Dim x1, y1 As Double
        Dim myPen As New Pen(Color.White, 1)
        Dim mypoints As New List(Of Point)

        Do
            For index As Double = angle1 To angle2 Step 0.05
                radius = radius - (distanceBetweenTurnsInPixels / (PiTimesTwo / 0.05))
                x1 = radius * Math.Cos(index) + (Me.Width \ 2)
                y1 = dir * radius * Math.Sin(index) + (Me.Height \ 2)
                mypoints.Add(New Point(CInt(Int(x1)), CInt(Int(y1))))
                If radius <= endRadius Then Exit Do
            Next
        Loop

        Me.Text = "Final radius = " & radius.ToString
        e.Graphics.DrawCurve(myPen, mypoints.ToArray)

    End Sub

End Class

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If anyone wants a version to start at a specific angle and spiral outwards

then I can post an altered version of the above code, just say yes please.

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Regards,

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Answer 1

Lol, I tried it, it is intresting. :)

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Ghost,
Call me ghost for short, Thanks
To get the better answer, it should be a better question.

Answer 2

Hi ALL,

Code updated in this thread.>>

http://social.msdn.microsoft.com/Forums/en-US/vbgeneral/thread/94053780-b173-44e6-bb4a-7df08a6bf4b2

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Regards,

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Click this link to see the NEW way of how to insert a picture into a forum post.

Installing VB6 on Windows 7

App Hub for Windows Phone & XBOX 360 developers.

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