gistfile1.rbx

module Color
  class RGB < Struct.new(:r, :g, :b)
    def to_hsl
      (r,g,b) = *([self.r, self.g, self.b].map { |x| x / 255.0 })
      min = [r,g,b].min
      max = [r,g,b].max

      l = (max + min) / 2.0
      return HSL.new(0, 0, (l * 100).round) if max == min

      s = (max - min) / ((l < 0.5) ? (max + min) : (2.0 - max - min))

      case max
      when r
        h = (g - b) / (max - min)
      when g
        h = 2.0 + (b - r) / (max - min)
      when b
        h = 4.0 + (r - g) / (max - min)
      end

      h *= 60
      h += 360 if h < 0

      HSL.new(h.round, (s * 100).round,(l * 100).round)
    end
  end

  class HSL < Struct.new(:h, :s, :l)
    def to_rgb
      (s, l) = *([self.s / 100.0, self.l / 100.0])
      return RGB.new(*([255, 255, 255].map { |x| (x * l).round })) if s == 0

      q = l < 0.5 ? l * (1.0 + s) : l + s - (l * s)
      p = 2 * l - q
      h = self.h / 360.0
      (tr, tg, tb) = *([h + 1/3.0, h, h - 1/3.0].map { |x|
        next x + 1 if x < 0
        next x - 1 if x > 1
        x
      })
      return RGB.new(*([tr, tg, tb].map { |color|
        if 6.0 * color < 1
          p + (q - p) * 6.0 * color
        elsif 2.0 * color < 1
          q
        elsif 3.0 * color <= 2
          p + (q - p) * ((2.0/3.0) - color) * 6.0
        else
          p
        end
      }.map { |x| (x * 255).round }))
    end
  end
end