Module: Colorizer

Extended by:
Colorizer
Included in:
Colorizer
Defined in:
lib/colorizer.rb

Overview

makandracards.com/makandra/24449-hash-any-ruby-object-into-an-rgb-color

Instance Method Summary collapse

Instance Method Details

#colorize(object) ⇒ Object 



5
6
7
8
9
10
11
 
# File 'lib/colorizer.rb', line 5

def colorize(object)
  # Inspired by Jeremy Ruten (http://stackoverflow.com/questions/1698318/ruby-generate-a-random-hex-color)
  hash = object.hash # hash an object, returns a Fixnum
  trimmed_hash = hash & 0xffffff # trim the hash to the size of 6 hex digits (& is bit-wise AND)
  hex_code = "%06x" % trimmed_hash # format as at least 6 hex digits, pad with zeros
  "##{hex_code}"
end

#colorize_similarly(object, saturation, lightness) ⇒ Object 



13
14
15
16
17
18
19
20
21
22
23
24
25
26
 
# File 'lib/colorizer.rb', line 13

def colorize_similarly(object, saturation, lightness)
  # NOTE: We used to default to using XXhash and had it listed as a hard dependency for this gem.
  # In an effort to slim down our dependencies we're making it so that this can work without XXhash.
  # But since changing the way we calculate the seed _also_ changes the color that comes out the
  # other end, we're making it so that people can add `gem "xxhash"` to their `Gemfile` to preserve
  # the colors that were previously being generated.
  seed = if Object.const_defined?(:XXhash)
    XXhash.xxh64(object)
  else
    Digest::MD5.hexdigest(object).to_i(16)
  end
  rnd = ((seed * 7) % 100) * 0.01
  hsl_to_rgb(rnd, saturation, lightness)
end