Module: HSV

Defined in:
lib/color/hsv.rb

Overview

Offering functionality related to the HSV color model.

Constant Summary collapse

HUE_MULTIPLIER = 
60
RGB_MAX_VALUE = 
255
ROUND_VALUE = 
3
FULL_CIRCLE_DEG = 
360
MONO_SATURATION = 
0.2
MONO_VALUE = 
0.1

Class Method Summary collapse

Class Method Details

.add_hue_to_hsv(hue_value, hsv_color_to_add) ⇒ Object

Add a value to the hue component of a hsv color Ensures that the hue is still in the range 0..360



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# File 'lib/color/hsv.rb', line 14

def self.add_hue_to_hsv(hue_value, hsv_color_to_add)
  hsv_color_to_add[0] += hue_value
  hsv_color_to_add[0] %= FULL_CIRCLE_DEG
  hsv_color_to_add
end

.calculate_hue(red, green, blue, max_min_diff) ⇒ Object

Method to calculate the hue value of three given rgb colors and the difference of the max - min color.



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# File 'lib/color/hsv.rb', line 43

def self.calculate_hue(red, green, blue, max_min_diff)
  if red > green && red > blue
    HUE_MULTIPLIER * calculate_raw_hue_value(0, green, blue, max_min_diff)
  elsif green > red && green > blue
    HUE_MULTIPLIER * calculate_raw_hue_value(2, blue, red, max_min_diff)
  elsif blue > red && blue > green
    HUE_MULTIPLIER * calculate_raw_hue_value(4, red, green, max_min_diff)
  else
    0
  end
end

.calculate_monochromatic_color(hue_color) ⇒ Object

Calculate the a monochromatic value to a given color



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# File 'lib/color/hsv.rb', line 60

def self.calculate_monochromatic_color(hue_color)
  saturation = hue_color[1]
  value = hue_color[2]
  if saturation > 0.7
    saturation -= MONO_SATURATION
  else
    saturation += MONO_SATURATION
  end
  value -= MONO_VALUE
  [hue_color[0], saturation.round(ROUND_VALUE), value]
end

.calculate_raw_hue_value(offset, first_color, second_color, max_min_diff) ⇒ Object 



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# File 'lib/color/hsv.rb', line 55

def self.calculate_raw_hue_value(offset, first_color, second_color, max_min_diff)
  offset + ((first_color - second_color).to_f / max_min_diff).round(ROUND_VALUE)
end

.calculate_saturation(max_min_diff, max, value) ⇒ Object 



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# File 'lib/color/hsv.rb', line 35

def self.calculate_saturation(max_min_diff, max, value)
  saturation = 0
  saturation = (max_min_diff.to_f / max).round(ROUND_VALUE) if value.positive?
  saturation
end

.hsv_to_rgb(hue, saturation, value) ⇒ Object

rubocop:disable Metrics/AbcSize rubocop:disable Metrics/MethodLength



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# File 'lib/color/hsv.rb', line 74

def self.hsv_to_rgb(hue, saturation, value)
  hue = hue.to_f / FULL_CIRCLE_DEG

  hue_i = (hue * 6).to_i
  f = (hue * 6) - hue_i
  p = value * (1 - saturation)
  q = value * (1 - (f * saturation))
  t = value * (1 - ((1 - f) * saturation))
  if hue_i.zero?
    red = value
    green = t
    blue = p
  end
  if hue_i == 1
    red = q
    green = value
    blue = p
  end
  if hue_i == 2
    red = p
    green = value
    blue = t
  end
  if hue_i == 3
    red = p
    green = q
    blue = value
  end
  if hue_i == 4
    red = t
    green = p
    blue = value
  end
  if hue_i == 5
    red = value
    green = p
    blue = q
  end
  [(red * RGB_MAX_VALUE).round.abs, (green * RGB_MAX_VALUE).round.abs, (blue * RGB_MAX_VALUE).round.abs]
end

.rgb_to_hsv(rgb_color) ⇒ Object

Hex Colors can be represented with three characters, to work



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# File 'lib/color/hsv.rb', line 21

def self.rgb_to_hsv(rgb_color)
  max = rgb_color.max()
  min = rgb_color.min()
  r = rgb_color[0]
  g = rgb_color[1]
  b = rgb_color[2]

  value = (max.to_f / RGB_MAX_VALUE).round(ROUND_VALUE)
  max_min_diff = max - min
  hue = calculate_hue(r, g, b, max_min_diff)
  hue += FULL_CIRCLE_DEG if hue.negative?
  [hue.round, calculate_saturation(max_min_diff, max, value), value]
end