Class: ColorMath

Inherits:
Object
  • Object
show all
Defined in:
lib/color_math.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(r, g, b) ⇒ ColorMath

r The red color value (int) g The green color value (int) b The blue color value (int)



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# File 'lib/color_math.rb', line 6

def initialize(r, g, b)
  @r = r
  @g = g
  @b = b
end

Class Method Details

.from_hex(hex) ⇒ Object

creates a color object from hex code



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# File 'lib/color_math.rb', line 27

def self.from_hex(hex)
  r, g, b = hex_to_rgb(hex)
  new(r, g, b)
end

.from_hsl(h, s, l) ⇒ Object

h The hue (int) 0 - 360 s The saturation (int) 0 - 100 l The lightness (int) 0 - 100



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# File 'lib/color_math.rb', line 35

def self.from_hsl(h, s, l)
  r, g, b = hsl_to_rgb(h, s, l)
  new(r, g, b)
end

.hex_to_rgb(hex) ⇒ Object 



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# File 'lib/color_math.rb', line 54

def self.hex_to_rgb(hex)
  hex.gsub!("#", "")
  components = hex.scan(/.{2}/)
  components.collect { |component| component.to_i(16) }
end

.hsl_to_rgb(h, s, l) ⇒ Object

Converts an HSL color value to RGB. Conversion formula adapted from en.wikipedia.org/wiki/HSL_color_space. and

# http://stackoverflow.com/a/9493060/520008

returns r, g, and b in the set [0, 255]. h The hue (int) 0 - 360 s The saturation (int) 0 - 100 l The lightness (int) 0 - 100 returns The RGB representation [r, g, b]



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# File 'lib/color_math.rb', line 107

def self.hsl_to_rgb(h, s, l)
  h = h/360.0
  s = s/100.0
  l = l/100.0

  r = 0.0
  g = 0.0
  b = 0.0
  
  if(s == 0.0)
    r = l.to_f
    g = l.to_f
    b = l.to_f #achromatic
  else
    q = l < 0.5 ? l * (1 + s) : l + s - l * s
    p = 2 * l - q
    r = hue_to_rgb(p, q, h + 1/3.0)
    g = hue_to_rgb(p, q, h)
    b = hue_to_rgb(p, q, h - 1/3.0)
  end

  return [(r * 255).round, (g * 255).round, (b * 255).round]
end

.hue_to_rgb(p, q, t) ⇒ Object 



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# File 'lib/color_math.rb', line 131

def self.hue_to_rgb(p, q, t)
  t += 1                                  if(t < 0) 
  t -= 1                                  if(t > 1)
  return (p + (q - p) * 6 * t)            if(t < 1/6.0) 
  return q                                if(t < 1/2.0) 
  return (p + (q - p) * (2/3.0 - t) * 6)  if(t < 2/3.0) 
  return p
end

.rgb_to_hex(r, g, b) ⇒ Object 



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# File 'lib/color_math.rb', line 40

def self.rgb_to_hex(r, g, b)
  rbg = [r,g,b]
  hex = "#"
  rbg.each do |component|
    _hex = component.to_s(16)
    if component < 16
      hex << "0#{_hex}"
    else
      hex << _hex
    end
  end
  hex.upcase
end

.rgb_to_hsl(r, g, b) ⇒ Object

r The red color value (int) g The green color value (int) b The blue color value (int) The HSL representation [hue, saturation, luminosity]



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# File 'lib/color_math.rb', line 70

def self.rgb_to_hsl(r, g, b)
  r /= 255.0
  g /= 255.0
  b /= 255.0
  max = [r, g, b].max
  min = [r, g, b].min
  h = (max + min) / 2.0
  s = (max + min) / 2.0
  l = (max + min) / 2.0

  if(max == min)
    h = 0
    s = 0 # achromatic
  else
    d = max - min;
    s = l >= 0.5 ? d / (2.0 - max - min) : d / (max + min)
    case max
      when r 
        h = (g - b) / d + (g < b ? 6.0 : 0)
      when g 
        h = (b - r) / d + 2.0
      when b 
        h = (r - g) / d + 4.0
    end
    h /= 6.0
  end
  return [(h*360).round, (s*100).round, (l*100).round]
end

Instance Method Details

#to_hex ⇒ Object 



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# File 'lib/color_math.rb', line 12

def to_hex
  self.class.rgb_to_hex(@r, @g, @b)
end

#to_hsl ⇒ Object 



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# File 'lib/color_math.rb', line 20

def to_hsl
  self.class.rgb_to_hsl(@r, @g, @b)
end

#to_rgb ⇒ Object 



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# File 'lib/color_math.rb', line 16

def to_rgb
  return @r, @g, @b
end