Class: Rubyvis::Color::Hsl

Inherits:
Rubyvis::Color show all
Defined in:
lib/rubyvis/color/color.rb

Overview

Represents a color in HSL space.

Instance Attribute Summary collapse

Attributes inherited from Rubyvis::Color

#color, #opacity

Instance Method Summary collapse

Methods inherited from Rubyvis::Color

#brighter, #darker, names, transparent

Constructor Details

#initialize(h, s, l, a) ⇒ Hsl

Returns a new instance of Hsl.



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# File 'lib/rubyvis/color/color.rb', line 381

def initialize(h,s,l,a)
  c="hsl(#{h},#{s * 100}%,#{l * 100}%)"
  super(c,a)
  @h=h
  @s=s
  @l=l
  @a=a
end

Instance Attribute Details

#a ⇒ Object

The opacity, a float in [0, 1].



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# File 'lib/rubyvis/color/color.rb', line 379

def a
  @a
end

#h ⇒ Object

The hue, an integer in [0, 360].



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# File 'lib/rubyvis/color/color.rb', line 373

def h
  @h
end

#l ⇒ Object

The lightness, a float in [0, 1].



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# File 'lib/rubyvis/color/color.rb', line 377

def l
  @l
end

#s ⇒ Object

The saturation, a float in [0, 1].



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# File 'lib/rubyvis/color/color.rb', line 375

def s
  @s
end

Instance Method Details

#rgb ⇒ Object

Returns the RGB color equivalent to this HSL color.



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# File 'lib/rubyvis/color/color.rb', line 391

def rgb
  h = self.h
  s = self.s
  l = self.l
  
  # Some simple corrections for h, s and l. */
  h = h % 360
  h += 360 if (h < 0)
  s = [0, [s, 1].min].max
  l = [0, [l, 1].min].max
  
  # From FvD 13.37, CSS Color Module Level 3 
  m2 = (l <= 0.5) ? (l * (1 + s)) : (l + s - l * s)
  m1 = 2 * l - m2
  v=lambda {|h1|
    if (h1 > 360)
      h1 -= 360;
    elsif (h1 < 0)
       h1 += 360
    end
    
    
    return m1 + (m2 - m1) * h1 / 60 if (h1 < 60)
    return m2 if (h1 < 180) 
    return m1 + (m2 - m1) * (240 - h1) / 60 if (h1 < 240)
    return m1
  }
  vv=lambda {|h1|
    (v(h1) * 255).round
  }
  
  Rubyvis.rgb(vv.call(h + 120), vv.call(h), vv.call(h - 120), a)
end