Angular.js Shade and Tint color converter.

shadeAndTintColor.cofffee

##*
# UAGE:
#   app = angular.module('yourApp', [])
#   app.factory(require('./shadeAndTintColor'))
#   app.controller('yourCtrl', ['ShadeAndTintColor', (Color) 
#     -> 
#       Color.shade('#f9ea62', 0.1) # '#E0D258'
#       Color.tint('#f9ea62', 0.39) # '#FBF29F'
#   ])
#  
module.exports = 'ShadeAndTintColor', : [
    (

    ) ->

      ##*
      # @param {string} hex cf. '#F12345'
      # @return {Array} [R, G, B]
      toRgb = (hex = null) ->
        result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex)
        if result
          [
            parseInt(result[1], 16)
            parseInt(result[2], 16)
            parseInt(result[3], 16)
          ]
        else
          null

      toHex = (src = [0, 0, 0]) ->
        to = (n) ->
          n = parseInt(n, 10)
          return "00"  if isNaN(n)
          n = Math.max(0, Math.min(n, 255))
          "0123456789ABCDEF".charAt((n - n % 16) / 16) + "0123456789ABCDEF".charAt(n % 16)
        return "##{[to(src[0]), to(src[1]), to(src[2])].join('')}"


      ##*
      # @param {Array} src Mix src [R, G, B]
      # @param {Array} target Mix target [R,G,B]
      # @param {float} m Amount of mix 0 ~ 1.0
      # @return {Array} [R, G, B]
      mix = (src, target, m) ->
        [
          Math.floor(target[0] + (src - target[0]) * m)
          Math.floor(target[1] + (src - target[1]) * m)
          Math.floor(target[2] + (src - target[2]) * m)
        ]

      ##*
      # @param {string} target Mix target HEX
      # @param {float} m Amount of mix 0 ~ 1.0
      # @return {Array} [R, G, B]
      shade = (target, m) -> mix(0, toRgb(target), m)

      ##*
      # @param {string} target Mix target HEX
      # @param {float} m Amount of mix 0 ~ 1.0
      # @return {Array} [R, G, B]
      tint = (target, m) -> mix(255, toRgb(target), m)

      return {
        toRgb: toRgb
        toHex: toHex
        mix: mix
        shade: shade
        tint: tint
      }
  ]