draw circle with Unicode Braille Patterns.

dot.rb

# -*- coding: UTF-8 -*-;

def dot(index)
  index = index & 7 | (index & 112) >> 1 | (index & 8) << 3 | index & 128
  case index
  when 0
    " "
  else
    [0x2800 + index].pack('U*')
  end
end


def circle(x, y, r)
  (x - r) ** 2 + (y - r) ** 2 < r ** 2 ? 1 : 0
end

R = 32

(0...R/2).each do |y|
  (0...R).each do |x|
    print dot (0...8).inject(0){|r, i| r | circle(x * 2 + ((i & 4) >> 2), y * 4 + (i & 3), R) << i}
  end
  puts
end