by oigres P (12 Submissions)
Category: Custom Controls/Forms/Menus
Compatability: Visual Basic 3.0
Difficulty: Unknown Difficulty
Date Added: Wed 3rd February 2021
Rating: 
(4 Votes)
Draw fractal star recursively using the algorithm in the book by Robert Sedgewick 'Algorithms in C++'
Inputs
change r to have a denser or lighter pattern . 2..5 okay
Assumes
assume 800x600 screen res
Code Returns
Draws squares using lines 'b' style.
Side Effects
lower values of r increase the time to draw
VBcoders'From the book by Robert Sedgewick 'Algorithms in C++'
'It is a very useful book. Can you find a non recursive way of doing this?
'Recursion makes progs smaller and elegant whilst also making them
'more difficult to understand ( the implicit stack and unwinding of the calls)
Private Sub Form_Load()
Form1.WindowState = 2 'maximum
Form1.ScaleMode = 3 'pixel
Show
Call star(ScaleWidth \ 2, ScaleHeight \ 2, 90)
End Sub
Private Sub star(x As Integer, y As Integer, r As Integer)
If r > 1 Then
Call star(x - r, y + r, r \ 2)
Call star(x + r, y + r, r \ 2)
Call star(x - r, y - r, r \ 2)
Call star(x + r, y - r, r \ 2)
Call box(x, y, r)
End If
End Sub
Private Sub box(x1 As Integer, y1 As Integer, r1 As Integer)
Line (x1 - r1, y1 - r1)-(x1 + r1, y1 + r1), , B
'Form1.Circle (x1 - r1, y1 - r1), r1
'Line (x1 - r1, y1 - r1)-(x1 + r1, y1 - r1), , B
'Line -(x1 - (r1 \ 2), y1 + r1)
'Line -(x1 - r1, y1 - r1)
'trying to draw triangle instead of sqr- not work accurately
End Sub
