RGB To Hex Conversion

rgb4hex.rb

def rgb(r, g, b)
  a1, b1 = split_num(r); p a1,b1
  a2, b2 = split_num(g); p a2,b2
  a3, b3 = split_num(b); p a3,b3
  "#{dec_to_hex(a1)}#{dec_to_hex(b1)}#{dec_to_hex(a2)}#{dec_to_hex(b2)}#{dec_to_hex(a3)}#{dec_to_hex(b3)}"
end

def split_num(num)
  if num > 255 then num = 255 end
  if num < 0 then num = 0 end
  a = num / 16.0
  b = a.modulo(1).round(2)
  c = a.floor
  d = (b * 16).round
  [c, d]
end

def dec_to_hex(num) 
  case num
    when 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
      num
    when 10
      'A'
    when 11
      'B'
    when 12
      'C'
    when 13
      'D'
    when 14
      'E'
    when 15
      'F'
    else 
      '0'
  end
end