Mandelbrot Fractal

[ericfourfour]

Here is a mandelbrot fractal. The algorithm is straight from the mandelbrot fractal page on wikipedia (look at my updateMandelbrot () procedure in the Mandelbrot class). You can set the magnification and the offsets (offsets have not been perfected but it gets the job done). I made it update one pixel at a time so you can add stuff in between (you could even have 2 mandelbrots going at once!). Since this is Turing it will go very slow when the magnification is high.

By the way, a magnification of 1 is very boring. Start at 10 and work your way up.

code:

class Mandelbrot     export create, update     var startX, startY : int     var endX, endY : int     var offsetX, offsetY : int     var pixelX, pixelY : int     var scale : real     var clr : int     proc create (x1, y1, x2, y2 : int, magnification : real)         startX := x1         startY := y1         endX := x2         endY := y2         offsetX := -startX         offsetY := -startY         pixelX := startX         pixelY := startY         scale := 1 / magnification         clr := black     end create     fcn updatePixels () : boolean         if pixelX >= endX and pixelY >= endY then             result false         end if         pixelX += 1         if pixelX > endX then             pixelX := startX             pixelY += 1         end if         result true     end updatePixels     proc updateMandelbrot ()         var x := pixelX * scale         var y := pixelY * scale         var x0 := x         var y0 := y         var x2 := x * x         var y2 := y * y         var iteration := 0         var maxIteration := 1000         loop             exit when x2 + y2 > 4 or iteration >= maxIteration             y := 2 * x * y + y0             x := x2 - y2 + x0             x2 := x * x             y2 := y * y             iteration += 1         end loop         if iteration = maxIteration then             clr := black         end if         clr := (iteration + 1) rem 256     end updateMandelbrot     fcn think () : boolean         if not updatePixels () then             result false         end if         updateMandelbrot ()         result true     end think     proc render ()         Draw.Dot (pixelX + offsetX, pixelY + offsetY, clr)     end render     fcn update () : boolean         if not think () then             result false         end if         render ()         result true     end update end Mandelbrot View.Set ("graphics:max;max") type Data :     record         mag : real         offsetX, offsetY : int     end record fcn getData () : Data     var newData : Data     put "Magnification: " ..     get newData.mag     put "Offset X: " ..     get newData.offsetX     put "Offset Y: " ..     get newData.offsetY     result newData end getData proc mandelbrotLoop (m : ^Mandelbrot)     loop         exit when not m -> update ()     end loop end mandelbrotLoop proc main ()     var data : Data     var highX : int     var lowX : int     var highY : int     var lowY : int     var m : ^Mandelbrot     new Mandelbrot, m     loop         data := getData ()         highX := round (data.mag * 2) + data.offsetX         lowX := -highX         highY := round (data.mag * 2) + data.offsetY         lowY := -highY         m -> create (lowX, lowY, highX, highY, data.mag)         cls         mandelbrotLoop (m)     end loop end main main ()

[ericfourfour]

I updated it and now you can use the mouse with it while it is running.

Controls:
Left Mouse - Centre fractal around mouse coordinates.
Middle Mouse - Clear the screen and refresh the fractal.
Right Mouse - Stop drawing the fractal and go back to the settings.

You can do all of the above commands while it is generating the fractal because I thought it would get boring if you have to wait until it is done before you can move it around to view other parts.

It also now shows the current line (on the y axis) that it is generating so you can have an idea of how long it is going to take.

If you are wondering a bit about the Mandelbrot class here is a few of its procedures it uses (new version):

code:

update ()

Updates the next pixel (calculates colour and draws it). Returns false if there wasn't any pixels left to generate.

code:

refresh ()

Redraws the current state of the fractal.

code:

reload (x, y : int)

Loads the current state of the fractal centred at a new position.

I made it an attachment because the code is around 200 lines now.