Simple Julia Fractal

[matthew]

This programme will display a simple Julia Fractal on your Screen.

The best thing is it only takes about a minute.



For some reason the programme isn't very responsive.

If you press the Escape key while the programme is running nothing will happen.

It only responds to the Escape key once it's finished drawing the Fractal.


OPTION Explicit

DIM AppRun : AppRun = TRUE

DIM Sx : Sx = 640
DIM Sy : Sy = 480

DIM XMin : XMin = -2
DIM XMax : XMax =  1.25
DIM YMin : YMin = -1.25
DIM YMax : YMax =  1.25

DIM MaxIter : MaxIter = 512

DIM OldX

DIM Fx, Fy

DIM Ix : Ix = 0.42
DIM Iy : IY = 0.23

DIM M

DIM DX : DX = ( XMax - XMin ) / Sx
DIM Dy : DY = ( YMax - YMin ) / Sy

DIM Px
DIM Py : Py = 0

DIM X1
DIM Y1 : Y1 = YMin

SUB Main()

IF (Graphics.Initialize <> TRUE) THEN EXIT SUB

Graphics.SetTitle "Simple Julia Fractal"

Key.Initialize

Graphics.Clear &h000000

While Py < Sy

Px = 0

X1 = XMin

Py = Py + 1

While Px < Sx

Px = Px + 1

Fx = X1
Fy = Y1

M = 0

Do While (((Fx * Fx + Fy * Fy) < 4) And (M < MaxIter))
 
  OldX = Fx
 
  Fx = Fx * Fx - Fy * FY + Ix
  Fy = 2 * OldX * Fy + Iy
 
  M = M + 1
 
  Loop
 
  Graphics.SetRect Px - 75, Py, 1, 1, ARGB(255, M, M, M)
 
  System.ProcessMessages
 
  X1 = X1 + Dx
 
  Wend
 
  Graphics.Display
 
   Y1 = Y1 + Dy
   
    System.ProcessMessages
 
  Wend

Do While AppRun = TRUE

IF Key.Pressed(1) Or Key.Pressed(0) = TRUE THEN AppRun = FALSE
System.ProcessMessages

Loop

Graphics.Terminate
Key.Terminate

End SUB

CALL Main


[u9]

matthew said:

For some reason the programme isn't very responsive.

If you press the Escape key while the programme is running nothing will happen.

You should check for key 0 and 1 inside the inner most loop as well. Furthermore the loop conditions have to check the AppRun variable as well. E.g.:
Do While (((Fx * Fx + Fy * Fy) < 4) And (M < MaxIter))
becomes:
Do While (((Fx * Fx + Fy * Fy) < 4) And (M < MaxIter)) And AppRun=True
The other loops should also stop when AppRun becomes false.

[u9]

It looks nice btw. I'm in linux atm so I cannot try it out.

[matthew]

^^

Thanx

Btw, Which Linux Distro are you using?

I did have Mandriva 2007 installed but I've gone back to using the 2006 version. ;D

EDIT:

Get the new version of my fractal here.

[u9]

I'm using Ubuntu, simply because it is (well now I must say was) the only disto that worked out-of -the-box on my laptop. I had a brand now laptop at the time. Almost everything worked. But I just updated it tonight through their update system thingy and now the network doesn't work. It's just so typical. And I'm not such a Linux geek that I can figure out what is wrong... oh well, I'll try finding some help on the Internet or just do a re-install. But if I have to do a re-install then it's no better then windows

[matthew]

I've tried about Five different versions of Linux including Ubuntu on my Laptop.

When Mandriva 2007 came out I spent 14 Hours downloading it.

It was a 4.4GB ISO but it didn't work as well as Mandriva 2006, so I went back to using that.

When I first installed Mandriva I had problems with my keyboard and mouse.

I ended up having to edit the config File in order to get my Mouse working correctly.

[u9]

Here's an idea. You should try getting the fractals to appear faster. One thing you could try is just render every other pixel in the first go and then the rest in the next go. So you do two iterations over the image. You could even try 3 or 4 iterations so the user can see the entire fractal sooner, just with a lower detail. Do I make any sense?

[matthew]

Yes, I've got a programme which does exactly that but for a Mandelbrot Fractal.

The only problem is it's written in another version of Basic.

I've tried converting it before but had no luck.