hashcolor 0.0.3

Microlibrary to get a color given a string

Install

bower install hashcolor
npm install hashcolor

Usage:

> hashcolor.light("foo");
'#fbeaea'
> hashcolor.dark("foo");
'#3a2826'
> hashcolor.val("foo");
7688524
> hashcolor.intToColor(0xF00BA8)
"#F00BA8" 
> hashcolor.strHash "foo"
160415585
> hashcolor.prng 123
1218640798

Literate source code

Globals

Define isNodeJs and runTest in such a way that they will be fully removed by uglifyjs -mc -d isNodeJs=false -d runTest=false

if typeof isNodeJs == "undefined" or typeof runTest == "undefined" then do ->
  root = if typeof global == "undefined" then window else global
  root.isNodeJs = (typeof window == "undefined") if typeof isNodeJs == "undefined"
  root.runTest = isNodeJs and process.argv[2] == "test" if typeof runTest == "undefined"

Actual implementation

hashcolor = {}

hashing based on djb

hashcolor.strHash = (s) ->
  hash = 5381
  i = s.length
  while i
    hash = (hash*31 + s.charCodeAt(--i)) | 0
  hash

pseudorandom number, to make sure hash value uses at least 24 bit, even for single character strings

hashcolor.prng = (n) -> (1664525 * n + 1013904223) |0

convert integer to hexcolor

hashcolor.intToColor = (i) -> "#" + ((i & 0xffffff) + 0x1000000).toString(16).slice(1)

return an integer color base on hash

hashcolor.val = (str) -> hashcolor.prng hashcolor.strHash str

Light and dark version of the color, ready to use in css

hashcolor.light = (str) -> hashcolor.intToColor ((hashcolor.val str) >> 4) | 0xe0e0e0
hashcolor.dark = (str) -> hashcolor.intToColor (hashcolor.val str) & 0x7f7f7f

export

if isNodeJs
  module.exports = hashcolor
else
  window.hashcolor = hashcolor

README.md autogenerated from hashcolor.coffee