Const pi As Double = 4 * Atn(1)
Dim Shared As Double angulo = 0

Sub giro (grados As Double)
    angulo += grados*pi/180
End Sub

Sub dragon (longitud As Double, division As Integer, d As Double)
    If division = 0 Then
        Line - Step (Cos(angulo)*longitud, Sin(angulo)*longitud), Int(Rnd * 7)
    Else
        giro d*45
        dragon longitud/1.4142136, division-1, 1
        giro -d*90
        dragon longitud/1.4142136, division-1, -1
        giro d*45
    End If
End Sub

'--- Programa Principal ---
Screen 12
Pset (150,180), 0
dragon 400, 12, 1
Bsave "Dragon_curve_FreeBASIC.bmp",0
Sleep