Glow Bug

[SierraKen]

Ever since I saw B+ and others make these, I've always wanted to try and make something like this myself. So I finally did today, without any help! Well besides Steve's fill-in circles. 
But going back even further to the 80's, I've tried for countless times to make the math of this and never could figure it out, until today!  

Thanks B+ and others for the inspiration! 

Feel free to use the code for anything you want. This is just a glow bug example, to quit press Esc. 

Code: (Select All)

_Title "Glow Bug - by SierraKen"



Screen _NewImage(800, 600, 32)



Randomize Timer

oldx = 400

oldy = 300

Do



    bugs xx, yy, oldx, oldy





Loop Until InKey$ = Chr$(27)





Sub bugs (xx, yy, oldx, oldy)

    Do

        If d1 > d2 Then s = s + .1

        If d2 > d1 Then s = s - .1

        d = d + 1

        If d > t Then

            oldx = oldx + x

            oldy = oldy + y

            morebugs d1, d2, d, t

        End If

        x = Cos(s * _Pi / 180) * d

        y = Sin(s * _Pi / 180) * d

        xx = x + oldx

        yy = y + oldy

        If xx > 750 Then oldx = 50: Cls: morebugs d1, d2, d, t

        If xx < 50 Then oldx = 750: Cls: morebugs d1, d2, d, t

        If yy > 550 Then oldy = 50: Cls: morebugs d1, d2, d, t

        If yy < 50 Then oldy = 550: Cls: morebugs d1, d2, d, t

        fillCircle xx, yy, 10, _RGB32(255, 255, 0)

        _Delay .001

        Line (0, 0)-(800, 600), _RGB32(0, 0, 0, 10), BF

        _Display

    Loop Until InKey$ = Chr$(27)

    End

End Sub



Sub morebugs (d1, d2, d, t)

    d1 = Rnd * 360

    d2 = Rnd * 360

    d = 0

    t = Int(Rnd * 360) + 1

End Sub





'from Steve Gold standard

Sub fillCircle (CX As Integer, CY As Integer, R As Integer, C As _Unsigned Long)

    Dim Radius As Integer, RadiusError As Integer

    Dim X As Integer, Y As Integer

    Radius = Abs(R): RadiusError = -Radius: X = Radius: Y = 0

    If Radius = 0 Then PSet (CX, CY), C: Exit Sub

    Line (CX - X, CY)-(CX + X, CY), C, BF

    While X > Y

        RadiusError = RadiusError + Y * 2 + 1

        If RadiusError >= 0 Then

            If X <> Y + 1 Then

                Line (CX - Y, CY - X)-(CX + Y, CY - X), C, BF

                Line (CX - Y, CY + X)-(CX + Y, CY + X), C, BF

            End If

            X = X - 1

            RadiusError = RadiusError - X * 2

        End If

        Y = Y + 1

        Line (CX - X, CY - Y)-(CX + X, CY - Y), C, BF

        Line (CX - X, CY + Y)-(CX + X, CY + Y), C, BF

    Wend

End Sub