Romanesgo

A simple fractal exploration program, named after the "cooler" version of broccoli.

Supported Fractals:

• The Mandelbrot set
• Multibrot sets
• Julia sets
• Multijulia sets
• The Burning Ship fractal
• The "Bird of prey" fractal (the burning ship fractal raised to the power of 3 in lieu of 2)
• Arbitrary power burning ship fractals (multiburningship)
• The Collatz fractal
• The Tricorn set
• Multicorn sets

Contents

• Usage
• Performance
• Example Images

Usage

$ git clone git@github.com:TheTeaCat/romanesgo.git
$ cd romanesgo/
$ go build
$ ./romanesgo 
Do "romanesgo help {Fractal Name}" for further info on a particular fractal function.

Fractals:
	 mandelbrot
	 julia
	 multijulia
	 birdofprey
	 multiburningship
	 multicorn
	 collatz
	 multibrot
	 burningship
	 tricorn

Flags:
  -c value
    	constants
  -cf string
    	coloring function (default "default")
  -ff string
    	fractal (default "none")
  -fn string
    	filename (default "temp.png")
  -h int
    	image height (default 1000)
  -i int
    	maximum iterations (default 128)
  -r int
    	goroutines used (default 4)
  -ss int
    	supersampling factor (default 1)
  -w int
    	image width (default 1000)
  -x float
    	central x coord
  -y float
    	central y coord
  -z float
    	zoom factor (default 1)

Performance

So, here's some usage on an i5-3320m (pretty old lil laptop processor):

$ ./romanesgo -ff=burningship -x=-1.748 -y=0.035 -z=20 -ss=4 -w=25000 -h=25000 -fn=bigship.png

	Fractal (ff):		 burningship 
	Constants (c):		  
	Max Iterations (i):	 128 
	Coloring function (cf): default 
	Centre x Coord (x):	 -1.748 
	Centre y Coord (y):	 0.035 
	Zoom factor (z):	 20 
	Image Width (w):	 25000 
	Image Height (h):	 25000 
	Supersampling (ss):	 4 
	Routines (r):		 4 
	Filename (png) (fn):	 bigship.png 

Routine 2 Done.
Routine 0 Done.
Routine 3 Done.
Routine 1 Done.

Time taken: 14m9.110651581s

What is that, a 625 megapixel image, in 14 minutes? I guess that's alright for an old laptop. 🤷‍♂️

Oh, and that's with supersampling set to 4, so it's making 16 samples per pixel, which basically makes that equivalent to a 10 gigapixel image.

Example images

The Mandelbrot set

-w=2600 -h=2000 -ff=mandelbrot -x=-0.65 -z=0.8 -i=1024 -ss=2

A Julia set

-w=2600 -h=2000 -ff=julia -c=-0.2 -c=0.65 -z=0.9 -i=512 -ss=2

The Burning Ship fractal

-w=2000 -h=2600 -ff=burningship -x=-1.749 -y=0.037 -z=20 -i=256 -ss=2

The Collatz fractal

-ff=collatz -cf=wackyGrayscale -z=0.5 -w=2600 -h=2000 -ss=4 -i=8

A multicorn animation

See samples/multicorn/multicorn-animation.sh

for i in $(seq 1 0.04 5)
do
    ./romanesgo -ff=multicorn -i=256 -z=0.5 -ss=4 -w=400 -h=400 -c=$i -fn="samples/multicorn/frames/${i}.png"
done

A multibrot set

-ff=multibrot -c=4 -w=2600 -h=2000 -z=0.7 -x=-0.2 -ss=2

A multijulia set

-ff=multijulia -c=0.2 -c=0.9 -c=3 -z=0.8 -y=-0.15 -i=256 -ss=2

A smoothed RGB colouring function

-w=2000 -h=2600 -ff=julia -c=0.1 -c=0.7 -z=0.75 -ss=2 -cf=smoothcolor

A stepped RGB colouring function

-w=2000 -h=2600 -ff=julia -c=-0.22 -c=0.65 -z=8 -i=800 -ss=4 -cf=wackyRainbow

A stepped grayscale colouring function

-w=2600 -h=2000 -ff=julia -c=-0.2 -c=0.65 -z=5 -i=512 -ss=2 -cf=wackygrayscale

A smooth grayscale colouring function

-w=2600 -h=2000 -ff=mandelbrot -x=-0.82 -y=-0.1905 -z=50 -i=512 -ss=2 -cf=smoothgrayscale

Another smooth grayscale colouring function

-w=2600 -h=2000 -ff=julia -c=-1 -c=-0.25 -z=1.5 -i=512 -ss=2 -cf=zgrayscale

The Burning Ship Lady

-ff=burningship -z=100 -y=1.015 -cf=wackygrayscale -ss=8 -w=2000 -h=2000