A Simple Mandelbrot Fractal

[matthew]

Okay here is a short Programme that will draw a Fractal on your Screen, the programme isn't perfect by any means.

Currently the only way to Exit the programme is by using the Task Manager. (This is probably because of the way I have set the Code out ).

The Mathematical routine for drawing the Fractal is a bit simplistic and therefore slow (about 5 Minutes to Draw) and the Graphics aren't very colourful.

When you Run it you should get something like this displayed on your Monitor Screen.




OPTION Explicit

DIM AppRun : AppRun = TRUE

DIM X, Y, N, Xh, Yh, Zrh, Zih, Zroh, A

SUB Main()

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

graphics.setTitle "Mandelbrot Fractal - Use Task Manager to Exit"

Graphics.SetViewPort 0, 0, 640, 480

Key.Initialize
Mouse.Initialize

Graphics.Clear &h00000000

For X = 0 TO 639

For Y = 0 TO 479

Xh = -2.0 + X / 163.84
Yh = 1.6 - Y / 153.60
N = 0
Zrh = 0
Zih = 0

Do Until ((Zrh * Zrh) + (Zih * Zih)) > 4 Or N = 16

Zroh = (Zrh * Zrh) - (Zih * Zih) + Xh
Zih = 2 * Zrh * Zih + Yh
Zrh = Zroh
N = N + 1

Loop

A = Sin (N * 9)

Graphics.SetLine X, Y, X+1, Y+1, A

Graphics.Display

Next

Next

Do While AppRun = TRUE

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

Loop

Graphics.Terminate
Mouse.Terminate
Key.Terminate

End SUB

CALL Main


[u9]

if you add a system.processMessages inside the last loop the application becomes much more responsive (when done drawing).

Anyways, nice demo. I like fractals

[matthew]

Thank's for the advice, I tried adding that Command inside the Loop and it worked.

[Guilect]

Good job matthew.
hope you don't mind but I changed the code a bit.
First I added a bunch of statements (system.processmessages) in all of the loops to make the app more responsive.
Next, I added another keypress watch so that the user can easily exit the app.
Thirdly, I changed the the statement from graphics.setline to graphics.setrect which is quicker (although most of the slowness is most likey do to the fact that every pixel on the screen is being drawn to. Need some calculation optimization to improve the speed.).
And lastly I added some grey scaling to image to give it some 'color'.

Still takes a few minutes to complete. Just start it. Let it stay as the top visible app. Go get up from the computer and stretch. Then come back and observe.

Cheers.

OPTION Explicit

DIM AppRun : AppRun = TRUE

DIM X, Y, N, Xh, Yh, Zrh, Zih, Zroh, A

SUB Main()

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

graphics.setTitle "Mandelbrot Fractal"

Key.Initialize

Graphics.Clear &h000000

For X = 0 TO 639

For Y = 0 TO 479

Xh = -2.0 + X / 163.84
Yh = 1.6 - Y / 153.60
N = 0
Zrh = 0
Zih = 0

Do Until ((Zrh * Zrh) + (Zih * Zih)) > 4 Or N = 16

Zroh = (Zrh * Zrh) - (Zih * Zih) + Xh
Zih = 2 * Zrh * Zih + Yh
Zrh = Zroh
N = N + 1
   system.processMessages
Loop

Graphics.SetRect X, Y, 1, 1, ARGB(255,N*15,N*15,N*15)

Graphics.Display

Next
IF Key.Pressed(1) Or Key.Pressed(0) = TRUE THEN
     AppRun = FALSE
     Exit For
end if
system.processMessages
Next

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


[matthew]

Good Re-Write ;D.

When I usually create a Fractal I tend to use a Grey-Scale Palette but as this was the first programme I had created in Brutus2D I didn't know how to.

I've also got the Code for a 'Julia Fractal', when I get around to Re-Writing it in Brutus2D I'll place the Code on the Forum.