Module: ColorMath::Converters

Defined in:
lib/color_math.rb

Class Method Summary collapse

Class Method Details

.hex_to_rgb(color) ⇒ Object

Adapted from github.com/anilyanduri/color_math

The MIT License (MIT)

Copyright © 2016 Anil Yanduri

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.



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# File 'lib/color_math.rb', line 60

def self.hex_to_rgb(color)
  color = color.gsub(/(.)/, '\1\1') if color.length == 3
  raise new RuntimeError("Hex color must be 6 characters") if color.length != 6
  color.scan(/../).map { |c| c.to_i(16) }
end

.hsl_to_rgb(h, s, l) ⇒ Object 



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# File 'lib/color_math.rb', line 99

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

  [(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 123

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)
  p
end

.rgb_to_hex(rgb) ⇒ Object 



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# File 'lib/color_math.rb', line 66

def self.rgb_to_hex(rgb)
  rgb.map { |c| c.to_s(16).rjust(2, "0") }.join("")
end

.rgb_to_hsl(r, g, b) ⇒ Object 



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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
  [(h * 360).round, (s * 100).round, (l * 100).round]
end