Demonstrandum/ascii_mandelbrot.rb

## ascii_mandelbrot.rb
#!/usr/bin/env ruby

height = %x{ tput lines }.to_i - 3 # -3 for PS1
width  = %x{ tput cols  }.to_i

scale = 0.6 * width.to_f / height.to_f
definition = 40

def calculate a, b, c_arr
  ca, cb = c_arr
  left = a * a - b * b
  right = 2 * a * b
  a = left  + ca
  b = right + cb
  [a, b]
end

fractal = String.new
shade = [" ", ".", ":", "-", "~", "^", "•", "=", "&", "£", "$", "#", "@"]
height.times do |y|
  width.times do |x|
    a = ca = (x * 2 * scale / width - scale) - 0.5
    height_scale = 2 * scale * height.to_f / width.to_f # x2 for centering
    b = cb = y * 2 * height_scale / height - height_scale

    snap = 0
    until snap >= definition
      a, b = calculate(a, b, [ca, cb])
      break if a * a + b * b > 16
      snap += 1
    end

    unless snap == definition
      fractal << shade[snap * (shade.size - 1) / definition]
    else
      fractal << shade[-1] # Max iteration is set to black (the inner body part)
    end
  end
  fractal += "\n"
end

print fractal
	#!/usr/bin/env ruby

	height = %x{ tput lines }.to_i - 3 # -3 for PS1
	width = %x{ tput cols }.to_i

	scale = 0.6 * width.to_f / height.to_f
	definition = 40

	def calculate a, b, c_arr
	ca, cb = c_arr
	left = a * a - b * b
	right = 2 * a * b
	a = left + ca
	b = right + cb
	[a, b]
	end

	fractal = String.new
	shade = [" ", ".", ":", "-", "~", "^", "•", "=", "&", "£", "$", "#", "@"]
	height.times do \|y\|
	width.times do \|x\|
	a = ca = (x * 2 * scale / width - scale) - 0.5
	height_scale = 2 * scale * height.to_f / width.to_f # x2 for centering
	b = cb = y * 2 * height_scale / height - height_scale

	snap = 0
	until snap >= definition
	a, b = calculate(a, b, [ca, cb])
	break if a * a + b * b > 16
	snap += 1
	end

	unless snap == definition
	fractal << shade[snap * (shade.size - 1) / definition]
	else
	fractal << shade[-1] # Max iteration is set to black (the inner body part)
	end
	end
	fractal += "\n"
	end

	print fractal