Class: Uniword::Resource::ColorTransformer

Inherits:
Object
  • Object
show all
Defined in:
lib/uniword/resource/color_transformer.rb

Overview

SERVICE for color transformations Pure functions - no state, no side effects

Constant Summary collapse

HUE_SHIFT_RANGE =

Shift ranges (in HSL)

(-15..15)
SATURATION_SHIFT_RANGE = 
(-10..10)
LIGHTNESS_SHIFT_RANGE = 
(-10..10)

Class Method Summary collapse

Class Method Details

.hex_to_rgb(hex) ⇒ Hash

Convert hex color to RGB hash

Parameters:

  • hex (String) —

    Hex color code

Returns:

  • (Hash) —

    RGB hash with :r, :g, :b keys



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# File 'lib/uniword/resource/color_transformer.rb', line 61

def self.hex_to_rgb(hex)
  hex = hex.sub(/^#/, "")
  { r: hex[0..1].to_i(16), g: hex[2..3].to_i(16), b: hex[4..5].to_i(16) }
end

.hsl_to_rgb(hsl) ⇒ Hash

Convert HSL to RGB

Parameters:

  • hsl (Hash) —

    HSL hash with :h (0-360), :s (0-100), :l (0-100)

Returns:

  • (Hash) —

    RGB hash with :r, :g, :b keys (0-255)



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# File 'lib/uniword/resource/color_transformer.rb', line 105

def self.hsl_to_rgb(hsl)
  h = hsl[:h]
  s = hsl[:s] / 100.0
  l = hsl[:l] / 100.0

  if s.zero?
    r = g = b = l
  else
    hue_to_rgb = lambda do |p, q, t|
      t += 1 if t.negative?
      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

    q = l < 0.5 ? l * (1 + s) : l + s - (l * s)
    p = (2 * l) - q
    r = hue_to_rgb.call(p, q, (h / 360.0) + (1 / 3.0))
    g = hue_to_rgb.call(p, q, h / 360.0)
    b = hue_to_rgb.call(p, q, (h / 360.0) - (1 / 3.0))
  end

  { r: (r * 255).round, g: (g * 255).round, b: (b * 255).round }
end

.rgb_to_hex(rgb) ⇒ String

Convert RGB hash to hex color

Parameters:

  • rgb (Hash) —

    RGB hash with :r, :g, :b keys

Returns:

  • (String) —

    Hex color code with # prefix



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# File 'lib/uniword/resource/color_transformer.rb', line 70

def self.rgb_to_hex(rgb)
  format("#%02X%02X%02X", rgb[:r], rgb[:g], rgb[:b])
end

.rgb_to_hsl(rgb) ⇒ Hash

Convert RGB to HSL

Parameters:

  • rgb (Hash) —

    RGB hash with :r, :g, :b keys (0-255)

Returns:

  • (Hash) —

    HSL hash with :h (0-360), :s (0-100), :l (0-100)



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# File 'lib/uniword/resource/color_transformer.rb', line 78

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

  if max == min
    h = s = 0
  else
    d = max - min
    s = l > 0.5 ? d / (2 - max - min) : d / (max + min)
    h = case max
        when r then (((g - b) / d) + (g < b ? 6 : 0)) * 60
        when g then (((b - r) / d) + 2) * 60
        when b then (((r - g) / d) + 4) * 60
        end
  end

  { h: h.round, s: (s * 100).round, l: (l * 100).round }
end

.shift_color(hex_color, hue_shift:, saturation_shift:, lightness_shift:) ⇒ String

Transform a hex color by shifting HSL values

Parameters:

  • hex_color (String) —

    Hex color code (e.g., “#FF0000” or “FF0000”)

  • hue_shift (Integer) —

    Hue shift in degrees (-15..15)

  • saturation_shift (Integer) —

    Saturation shift percent (-10..10)

  • lightness_shift (Integer) —

    Lightness shift percent (-10..10)

Returns:

  • (String) —

    Transformed hex color



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# File 'lib/uniword/resource/color_transformer.rb', line 20

def self.shift_color(hex_color, hue_shift:, saturation_shift:, lightness_shift:)
  return hex_color if hue_shift.zero? && saturation_shift.zero? && lightness_shift.zero?

  rgb = hex_to_rgb(hex_color)
  hsl = rgb_to_hsl(rgb)

  # Apply shifts with clamping
  hsl[:h] = (hsl[:h] + hue_shift) % 360
  hsl[:s] = (hsl[:s] + saturation_shift).clamp(0, 100)
  hsl[:l] = (hsl[:l] + lightness_shift).clamp(0, 100)

  rgb_to_hex(hsl_to_rgb(hsl))
end

.transform_color_scheme(color_scheme, hue_shift:, saturation_shift:, lightness_shift:) ⇒ Themes::ColorScheme

Transform all colors in a color scheme

Parameters:

  • color_scheme (Themes::ColorScheme) —

    Color scheme to transform

  • hue_shift (Integer) —

    Hue shift in degrees

  • saturation_shift (Integer) —

    Saturation shift percent

  • lightness_shift (Integer) —

    Lightness shift percent

Returns:



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# File 'lib/uniword/resource/color_transformer.rb', line 41

def self.transform_color_scheme(color_scheme, hue_shift:, saturation_shift:, lightness_shift:)
  color_scheme.dup.tap do |scheme|
    # Transform each color in the scheme
    scheme.colors&.each_value do |color|
      next unless color.respond_to?(:val) && color.val&.match?(/^[0-9A-Fa-f]{6}$/)

      color.val = shift_color(
        color.val,
        hue_shift:,
        saturation_shift:,
        lightness_shift:
      )
    end
  end
end