Module: Colorable::Converter

Included in:
ColorSpace
Defined in:
lib/colorable/converter.rb

Defined Under Namespace

Classes: NotImplemented

Instance Method Summary collapse

Instance Method Details

#hex2rgb(hex) ⇒ Object 



61
62
63
64
 
# File 'lib/colorable/converter.rb', line 61

def hex2rgb(hex)
  _, *hex = hex.unpack('A1A2A2A2')
  hex.map { |val| val.to_i(16) }
end

#hsb2rgb(hsb) ⇒ Object Also known as: hsv2rgb 



37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
 
# File 'lib/colorable/converter.rb', line 37

def hsb2rgb(hsb)
  hue, sat, bright = hsb
  norm = ->range{ hue.norm(range, 0..255) }
  rgb_h =
    case hue
    when 0..60    then [255, norm[0..60], 0]
    when 60..120  then [255-norm[60..120], 255, 0]
    when 120..180 then [0, 255, norm[120..180]]
    when 180..240 then [0, 255-norm[180..240], 255]
    when 240..300 then [norm[240..300], 0, 255]
    when 300..360 then [255, 0, 255-norm[300..360]]
    end
  rgb_s = rgb_h.map { |val| val + (255-val) * (1-sat/100.0) }
  rgb_s.map { |val| (val * bright/100.0).round }
end

#name2rgb(name) ⇒ Object 



3
4
5
 
# File 'lib/colorable/converter.rb', line 3

def name2rgb(name)
  COLORNAMES.assoc(name).tap{|c, rgb| break rgb if c }
end

#rgb2hex(rgb) ⇒ Object 



54
55
56
57
58
59
 
# File 'lib/colorable/converter.rb', line 54

def rgb2hex(rgb)
  hex = rgb.map do |val|
    val.to_s(16).tap { |h| break "0#{h}" if h.size==1 }
  end
  '#' + hex.join.upcase
end

#rgb2hsb(rgb) ⇒ Object Also known as: rgb2hsv 



12
13
14
15
16
17
18
19
20
21
 
# File 'lib/colorable/converter.rb', line 12

def rgb2hsb(rgb)
  r, g, b = rgb.map(&:to_f)
  hue = Math.atan2(Math.sqrt(3)*(g-b), 2*r-g-b).to_degree

  min, max = [r, g, b].minmax
  sat = [min, max].all?(&:zero?) ? 0.0 : ((max - min) / max * 100)

  bright = max / 2.55
  [hue, sat, bright].map(&:round)
end

#rgb2hsl(rgb) ⇒ Object

Raises:



25
26
27
28
29
30
31
32
33
34
35
 
# File 'lib/colorable/converter.rb', line 25

def rgb2hsl(rgb)
  raise NotImplemented, 'Not Implemented Yet'
  r, g, b = rgb.map(&:to_f)
  hue = Math.atan2(Math.sqrt(3)*(g-b), 2*r-g-b).to_degree

  min, max = [r, g, b].minmax
  sat = [min, max].all?(&:zero?) ? 0.0 : ((max - min) / (1-(max+min-1).abs) * 100)

  lum = 0.298912*r + 0.586611*g + 0.114478*b
  [hue, sat, lum].map(&:round)
end

#rgb2name(rgb) ⇒ Object 



7
8
9
10
 
# File 'lib/colorable/converter.rb', line 7

def rgb2name(rgb)
  COLORNAMES.rassoc(rgb)
            .tap { |c, _| break c if c }
end