How to Draw a Spiral in VB

How to Draw a Spiral in VB

Using a loop and the mathematical formula for a spiral, you can use pset(x,y) to plot the points returned by the formulas. The variables a and b determine the shape of the spiral. Generally, smaller numbers mean a tighter spiral. The following code shows an exponential spiral wherein the distance from the origin increases drastically with each rotation:

Option ExplicitPrivate Const Pi As Double = 3.14159265358979Private Const e As Double = 2.718281828Private Sub cmdDraw_Click()    Dim cX As Long, X As Long    Dim cy As Long, Y As Long    'get the center of the form.    cX = Me.ScaleWidth / 2    cy = Me.ScaleHeight / 2    a = 0.15    b = 0.15        'loop round to plot the points of the spiral.    For i = 0 To 23040        ang = (Pi / 720) * i        X = cX + (a * (Cos(ang)) * (e ^ (b * ang)))        Y = cy - (a * (Sin(ang)) * (e ^ (b * ang)))        Me.PSet (X, Y)    Next i        End SubPrivate Sub Form_Load()    'set the form up.        Me.ScaleMode = vbPixels    Me.AutoRedraw = True    Me.WindowState = vbMaximized    End Sub


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