Module: Abachrome::PaletteMixins::StretchLuminance

Defined in:
lib/abachrome/palette_mixins/stretch_luminance.rb

Instance Method Summary collapse

Instance Method Details

#compress_luminance(amount = 0.5) ⇒ Object 



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# File 'lib/abachrome/palette_mixins/stretch_luminance.rb', line 51

def compress_luminance(amount = 0.5)
  amount = AbcDecimal(amount)
  mid_point = AbcDecimal("0.5")
  stretch_luminance(
    new_min: mid_point - (mid_point * amount),
    new_max: mid_point + (mid_point * amount)
  )
end

#compress_luminance!(amount = 0.5) ⇒ Object 



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# File 'lib/abachrome/palette_mixins/stretch_luminance.rb', line 60

def compress_luminance!(amount = 0.5)
  amount = AbcDecimal(amount)
  mid_point = AbcDecimal("0.5")
  stretch_luminance!(
    new_min: mid_point - (mid_point * amount),
    new_max: mid_point + (mid_point * amount)
  )
end

#normalize_luminance ⇒ Object 



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# File 'lib/abachrome/palette_mixins/stretch_luminance.rb', line 43

def normalize_luminance
  stretch_luminance(new_min: 0.0, new_max: 1.0)
end

#normalize_luminance! ⇒ Object 



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# File 'lib/abachrome/palette_mixins/stretch_luminance.rb', line 47

def normalize_luminance!
  stretch_luminance!(new_min: 0.0, new_max: 1.0)
end

#stretch_luminance(new_min: 0.0, new_max: 1.0) ⇒ Object 



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# File 'lib/abachrome/palette_mixins/stretch_luminance.rb', line 6

def stretch_luminance(new_min: 0.0, new_max: 1.0)
  return self if empty?

  new_min = AbcDecimal(new_min)
  new_max = AbcDecimal(new_max)

  oklab_colors = @colors.map(&:to_oklab)
  current_min = oklab_colors.map { |c| c.coordinates[0] }.min
  current_max = oklab_colors.map { |c| c.coordinates[0] }.max

  range = current_max - current_min
  new_range = new_max - new_min

  self.class.new(
    oklab_colors.map do |color|
      l, a, b = color.coordinates
      scaled_l = if range.zero?
                   new_min
                 else
                   new_min + ((l - current_min) * new_range / range)
                 end

      Color.new(
        ColorSpace.find(:oklab),
        [scaled_l, a, b],
        color.alpha
      )
    end
  )
end

#stretch_luminance!(new_min: 0.0, new_max: 1.0) ⇒ Object 



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# File 'lib/abachrome/palette_mixins/stretch_luminance.rb', line 37

def stretch_luminance!(new_min: 0.0, new_max: 1.0)
  stretched = stretch_luminance(new_min: new_min, new_max: new_max)
  @colors = stretched.colors
  self
end