Class: Color::HSL

from_fraction(h = 0.0, s = 0.0, l = 0.0)

Creates an HSL colour object from fractional values 0..1.

    # File lib/color/hsl.rb, line 21
21:     def from_fraction(h = 0.0, s = 0.0, l = 0.0)
22:       colour = Color::HSL.new
23:       colour.h = h
24:       colour.s = s
25:       colour.l = l
26:       colour
27:     end

new(h = 0, s = 0, l = 0)

Creates an HSL colour object from the standard values of degrees and percentages (e.g., 145 deg, 30%, 50%).

[Source]

    # File lib/color/hsl.rb, line 47
47:   def initialize(h = 0, s = 0, l = 0)
48:     @h = h / 360.0
49:     @s = s / 100.0
50:     @l = l / 100.0
51:   end

==(other)

Compares the other colour to this one. The other colour will be converted to HSL before comparison, so the comparison between a HSL colour and a non-HSL colour will be approximate and based on the other colour‘s to_hsl conversion. If there is no to_hsl conversion, this will raise an exception. This will report that two HSL values are equivalent if all component values are within Color::COLOR_TOLERANCE of each other.

[Source]

    # File lib/color/hsl.rb, line 37
37:   def ==(other)
38:     other = other.to_hsl
39:     other.kind_of?(Color::HSL) and
40:     ((@h - other.h).abs <= Color::COLOR_TOLERANCE) and
41:     ((@s - other.s).abs <= Color::COLOR_TOLERANCE) and
42:     ((@l - other.l).abs <= Color::COLOR_TOLERANCE)
43:   end

brightness()

Returns the luminosity (l) of the colour.

[Source]

     # File lib/color/hsl.rb, line 137
137:   def brightness
138:     @l
139:   end

css_hsl()

Present the colour as an HSL HTML/CSS colour string (e.g., "hsl(180, 25%, 35%)").

[Source]

    # File lib/color/hsl.rb, line 74
74:   def css_hsl
75:     "hsl(%3.2f, %3.2f%%, %3.2f%%)" % [ hue, saturation, luminosity ]
76:   end

css_hsla()

Present the colour as an HSLA (with alpha) HTML/CSS colour string (e.g., "hsla(180, 25%, 35%, 1)").

[Source]

    # File lib/color/hsl.rb, line 80
80:   def css_hsla
81:     "hsla(%3.2f, %3.2f%%, %3.2f%%, %3.2f)" % [ hue, saturation, luminosity, 1 ]
82:   end

css_rgb()

Present the colour as an RGB HTML/CSS colour string (e.g., "rgb(0%, 50%, 100%)"). Note that this will perform a to_rgb operation using the default conversion formula.

[Source]

    # File lib/color/hsl.rb, line 61
61:   def css_rgb
62:     to_rgb.css_rgb
63:   end

css_rgba()

Present the colour as an RGBA (with alpha) HTML/CSS colour string (e.g., "rgb(0%, 50%, 100%, 1)"). Note that this will perform a to_rgb operation using the default conversion formula.

[Source]

    # File lib/color/hsl.rb, line 68
68:   def css_rgba
69:     to_rgb.css_rgba
70:   end

h()

Returns the hue of the colour in the range 0.0 .. 1.0.

[Source]

     # File lib/color/hsl.rb, line 150
150:   def h
151:     @h
152:   end

h=(hh)

Sets the hue of the colour in the range 0.0 .. 1.0.

[Source]

     # File lib/color/hsl.rb, line 164
164:   def h=(hh)
165:     @h = Color.normalize(hh)
166:   end

html()

Present the colour as an HTML/CSS colour string.

[Source]

    # File lib/color/hsl.rb, line 54
54:   def html
55:     to_rgb.html
56:   end

hue()

Returns the hue of the colour in degrees.

[Source]

     # File lib/color/hsl.rb, line 146
146:   def hue
147:     @h * 360.0
148:   end

hue=(hh)

Sets the hue of the colour in degrees. Colour is perceived as a wheel, so values should be set properly even with negative degree values.

[Source]

     # File lib/color/hsl.rb, line 155
155:   def hue=(hh)
156:     hh = hh / 360.0
157: 
158:     hh += 1.0 if hh < 0.0
159:     hh -= 1.0 if hh > 1.0
160: 
161:     @h = Color.normalize(hh)
162:   end

inspect()

[Source]

     # File lib/color/hsl.rb, line 207
207:   def inspect
208:     "HSL [%.2f deg, %.2f%%, %.2f%%]" % [ hue, saturation, luminosity ]
209:   end

l()

Returns the luminosity of the colour in the range 0.0 .. 1.0.

[Source]

     # File lib/color/hsl.rb, line 190
190:   def l
191:     @l
192:   end

l=(ll)

Sets the luminosity of the colour in the ragne 0.0 .. 1.0.

[Source]

     # File lib/color/hsl.rb, line 199
199:   def l=(ll)
200:     @l = Color.normalize(ll)
201:   end

lightness()

Alias for luminosity

lightness=(ll)

Alias for luminosity=

luminosity()

Returns the percentage of luminosity of the colour.

[Source]

     # File lib/color/hsl.rb, line 185
185:   def luminosity
186:     @l * 100.0
187:   end

luminosity=(ll)

Sets the percentage of luminosity of the colour.

[Source]

     # File lib/color/hsl.rb, line 194
194:   def luminosity=(ll)
195:     @l = Color.normalize(ll / 100.0)
196:   end

mix_with(color, mix_percent = 0.5)

Mix the mask colour (which will be converted to an HSL colour) with the current colour at the stated mix percentage as a decimal value.

NOTE:

This differs from Color::RGB#mix_with.

[Source]

     # File lib/color/hsl.rb, line 215
215:   def mix_with(color, mix_percent = 0.5)
216:     color   = color.to_hsl
217:     _h = ((color.h - self.h) * mix_percent) + self.h
218:     _s = ((color.s - self.s) * mix_percent) + self.s
219:     _l = ((color.l - self.l) * mix_percent) + self.l
220: 
221:     self.class.from_fraction(_h, _s, _l)
222:   end

s()

Returns the saturation of the colour in the range 0.0 .. 1.0.

[Source]

     # File lib/color/hsl.rb, line 172
172:   def s
173:     @s
174:   end

s=(ss)

Sets the saturation of the colour in the ragne 0.0 .. 1.0.

[Source]

     # File lib/color/hsl.rb, line 180
180:   def s=(ss)
181:     @s = Color.normalize(ss)
182:   end

saturation()

Returns the percentage of saturation of the colour.

[Source]

     # File lib/color/hsl.rb, line 168
168:   def saturation
169:     @s * 100.0
170:   end

saturation=(ss)

Sets the percentage of saturation of the colour.

[Source]

     # File lib/color/hsl.rb, line 176
176:   def saturation=(ss)
177:     @s = Color.normalize(ss / 100.0)
178:   end

to_cmyk()

Converts to RGB then CMYK.

[Source]

     # File lib/color/hsl.rb, line 132
132:   def to_cmyk
133:     to_rgb.to_cmyk
134:   end

to_grayscale()

Alias for to_greyscale

to_greyscale()

[Source]

     # File lib/color/hsl.rb, line 140
140:   def to_greyscale
141:     Color::GrayScale.from_fraction(@l)
142:   end

to_hsl()

[Source]

     # File lib/color/hsl.rb, line 203
203:   def to_hsl
204:     self
205:   end

to_rgb(ignored = nil)

Converting to HSL as adapted from Foley and Van-Dam from www.bobpowell.net/RGBHSB.htm.

NOTE:

If the colour‘s luminosity is near zero, the colour is always black.
If the colour‘s luminosity is near one, the colour is always white.
If the colour‘s saturation is near zero, the colour is always a shade of grey and is based only on the luminosity of the colour.

[Source]

     # File lib/color/hsl.rb, line 93
 93:   def to_rgb(ignored = nil)
 94:     return Color::RGB.new if Color.near_zero_or_less?(@l)
 95:     return Color::RGB.new(0xff, 0xff, 0xff) if Color.near_one_or_more?(@l)
 96:     return Color::RGB.from_fraction(@l, @l, @l) if Color.near_zero?(@s)
 97: 
 98:     # Is the value less than 0.5?
 99:     if Color.near_zero_or_less?(@l - 0.5)
100:       tmp2 = @l * (1.0 + @s.to_f)
101:     else
102:       tmp2 = @l + @s - (@l * @s.to_f)
103:     end
104:     tmp1 = 2.0 * @l - tmp2
105: 
106:     tmp3  = [ @h + (1.0 / 3.0), @h, @h - (1.0 / 3.0) ]
107: 
108:     rgb = tmp3.map { |hue|
109:       hue += 1.0 if Color.near_zero_or_less?(hue)
110:       hue -= 1.0 if Color.near_one_or_more?(hue)
111: 
112:       if Color.near_zero_or_less?((6.0 * hue) - 1.0)
113:         tmp1 + ((tmp2 - tmp1) * hue * 6.0)
114:       elsif Color.near_zero_or_less?((2.0 * hue) - 1.0)
115:         tmp2
116:       elsif Color.near_zero_or_less?((3.0 * hue) - 2.0)
117:         tmp1 + (tmp2 - tmp1) * ((2 / 3.0) - hue) * 6.0
118:       else
119:         tmp1
120:       end
121:     }
122: 
123:      Color::RGB.from_fraction(*rgb)
124:   end

to_yiq()

Converts to RGB then YIQ.

[Source]

     # File lib/color/hsl.rb, line 127
127:   def to_yiq
128:     to_rgb.to_yiq
129:   end

Methods

Public Class methods

Public Instance methods