L-Systems fractal generator

[lokster]

This script draws fractals based on l-systems. For more info on l-systems read this.

The core is written in FreeBasic - the part wihich calculates the l-system. It can be done in autoit too, but it's very slow, so I made it with FB.

It's a command line application, which can be used separately from the autoit script which draws the gererated system.

The frontend (the GUI) is written in autoit.

The complete fractal generator is here: l_systems.zip - extract it somewhere and run lsystem-fe.au3.

Here are some screenshots:

Here is the autoit script:

and here is the FreeBasic source(this is just for informative purpose, if someone thinks that lsystem.exe is something that will harm his sistem... ):

lsystem.bas

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Function Split(inpstr As String, separator As String, xRes() As String)
    Dim i,n
    Dim a(Len(inpstr))
    i=0
    a(i)=1
    Do
        i+=1
        a(i)=Instr(a(i-1),inpstr,separator)+1
    Loop Until a(i)=1
    a(i)=Len(inpstr)+2
    Redim xres(i+1)
    For n=0 To i-1
        xres(n+1)=Mid$(inpstr,a(n),a(n+1)-a(n)-1)
    Next
    Return i
End Function

Function lsystem (  s() As String, _
    r() As String, _
    Byval axiom As String, _
    Byval level As Integer _
    )   As String
    
    Dim axiom_ As String
    Dim axiom__ As String
    Dim iter As Integer
    Dim i As Integer
    Dim c As String
    Dim i1 As Integer
    
    axiom_ = axiom
    
    For iter = 0 To level-1
        axiom__ = ""
        For i = 1 To Len(axiom_)
            c = Mid(axiom_,i,1)
            For i1 = 0 To Ubound(s)-2
                If (c=s(i1)) Then
                    c=r(i1)
                End If
            Next
            axiom__ += c
        Next
        axiom_ = axiom__
    Next
    Return axiom_
End Function

If Command$(3)="" Then
    Print "L-System calculator by lokster (c)2007"
    Print ""
    Print "Usage: lsystem.exe <axiom> <rules> <level>"
    Print ""
    Print "Example (gererate the ""Dragon"" fractal at level 10):"
    Print ""
    Print " lsystem.exe FX ""F%F&X%X+YF+&Y%-FX-Y"" 10"
    Print ""
    Print "Please note, that the second parameter MUST be surrounded by double-quotes!" 
Else
    Dim a As String
    Dim res() As String
    
    a = Ucase( Command$(2))
    Split(a,"&",res())
    
    Dim s(Ubound(res)) As String
    Dim r(Ubound(res)) As String
    
    For rep = 1 To Ubound(res)-1
        Dim par() As String
        Split(res(rep),"%",par())
        s(rep-1) = par(1)
        r(rep-1) = par(2)
    Next
    Print lsystem(s(),r(),Ucase(Command$(1)),Valint(Command$(3)))
End If

Enjoy!

Edited June 21, 2007 by lokster

[jvanegmond]

Awesome.

Edit: Don't try 25 iterations..

Edited June 21, 2007 by Manadar

[lordofthestrings]

I get an error.. would have loved to see this work..

I checked to solve it myself, but I didn't see the mistake immediately)

probably the space in teh path to lsystems.exe. too busy at work to put too much effort in it at the moment (and I'm sure you'll know what this error is about) :-)

>Running:(3.2.4.9):C:\Program Files\AutoIt3\autoit3.exe "C:\Documents and Settings\gii761\Desktop\Scripting\fractals based on L-system\lsystem-fe.au3"  
C:\Documents and Settings\gii761\Desktop\Scripting\fractals based on L-system\lsystem-fe.au3 (119) : ==> Unable to execute the external program.: 
$pid = Run(@ScriptDir & "\lsystem.exe " & $axiom & " """ & $rules & """ " & $level, @ScriptDir, @SW_HIDE, $STDOUT_CHILD)

[lokster]

Corrected. The problem was that the path contained spaces, and I forgot to surround it with quotes.

[lordofthestrings]

may I also suggest following easy rule for string concatenation: (small tip)

follow kix methodology..

meaning start a string with a single quote.

then if you need to place a double quote simply place one double quote.

in vbscript you can build strings with series of 4 double quotes in a row.. not clean code, you're asking for errors here

hope you get it to work man!

have a nice day!

[RazerM]

This is really nice! Good work.

[gseller]

Very Nice! Thanx...