fibonacci_word_fractal.sf

#!/usr/bin/ruby

# A modified Fibonacci word fractal, using Braille graphics.

var(m=14, scale=2) = ARGV.map{.to_i}...

(var world = Hash.new){0}{0} = 1

var loc = 0
var w   = 1
var dir = Quadratic(0, 1, w)

var fib = ['1', '0']
func fib_word(n) {
    fib[n] := (fib_word(n-1) + fib_word(n-2))
}

func step {
    scale.times {
        loc += dir
        world{loc.im}{loc.re} = 1
    }
}

var turns = [
    Quadratic(0, 1, w),
   -Quadratic(0, 1, w),
    Quadratic(1, 0, w),
].shuffle

var n = 1
fib_word(m).each { |c|
    if (c == '0') {
        step()
        dir *= turns[n % 3]
    } else { ++n }
}

func braille_graphics(a) {
    var (xlo, xhi, ylo, yhi) = +([Inf, -Inf]*2)...

    a.each_key { |y|
        ylo.min!(y.to_n)
        yhi.max!(y.to_n)
        a{y}.each_key { |x|
            xlo.min!(x.to_n)
            xhi.max!(x.to_n)
        }
    }

    for y in (ylo .. (yhi, 4)) {
        for x in (xlo .. (xhi, 2)) {
            var cell = 0x2800

            a{y+0}{x+0} && (cell += 1)
            a{y+1}{x+0} && (cell += 2)
            a{y+2}{x+0} && (cell += 4)
            a{y+0}{x+1} && (cell += 8)
            a{y+1}{x+1} && (cell += 16)
            a{y+2}{x+1} && (cell += 32)
            a{y+3}{x+0} && (cell += 64)
            a{y+3}{x+1} && (cell += 128)

            print cell.chr
        }
        print "\n"
    }
}

braille_graphics(world)