Class: Backlogs::Color

Inherits:

Object

• Object
• Backlogs::Color

show all

Defined in:

lib/color.rb

Constant Summary

HEXVAL =

Table for conversion to hex

(('0'..'9').to_a).concat(('A'..'F').to_a).freeze

BRIGHTNESS_DEFAULT =

Default value for #darken, #lighten etc.

0.2

WHITE =

Some constants for general use

Color.new(255,255,255).freeze

BLACK =

Color.new(0,0,0).freeze

Instance Attribute Summary (collapse)

• - (Object) a

  Returns the value of attribute a.

• - (Object) b

  Returns the value of attribute b.

• - (Object) g

  Returns the value of attribute g.

• - (Object) r

  Returns the value of attribute r.

Class Method Summary (collapse)

• + (Object) blend(col1, col2, amt)

  Class-level version for explicit blends of two values, useful with constants.

• + (Object) parse(*args)

  Attempt to read in a string and parse it into values.

Instance Method Summary (collapse)

• - (Object) ==(val)

  Test for equality, accepts string vals as well, eg Color.new('aaa') == '#AAAAAA' => true.

• - (Object) blend(other, amt)

  Blend to a color amt % towards another color value, eg red.blend(blue, 0.5) will be purple, white.blend(black, 0.5) will be gray, etc.

• - (Object) blend!(other, amt)

  In place version of #blend.

• - (Object) darken(amt = BRIGHTNESS_DEFAULT)

  Darken a color towards full black.

• - (Object) darken!(amt = BRIGHTNESS_DEFAULT)

  In place version of #darken.

• - (Object) grayscale

  Convert to grayscale, using perception-based weighting.

• - (Object) grayscale!

  In place version of #grayscale.

• - (Boolean) grayscale?
• - (Color) initialize(*args) constructor

  Constructor.

• - (Object) inspect
• - (Object) lighten(amt = BRIGHTNESS_DEFAULT)

  Lighten color towards white.

• - (Object) lighten!(amt = BRIGHTNESS_DEFAULT)

  In place version of #lighten.

• - (Boolean) opaque?
• - (Object) set(*args)

  All-purpose setter - pass in another Color, '#000000', rgb vals...

• - (Object) to_rgb(add_hash = true)
• - (Object) to_rgba(add_hash = true)
• - (Object) to_s(add_hash = true)
• - (Boolean) trans?

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# File 'lib/color.rb', line 36

def initialize(*args)
  @r = 255
  @g = 255
  @b = 255
  @a = 255
  
  if args.size.between?(3,4)
    self.r = args[0]
    self.g = args[1]
    self.b = args[2]
    self.a = args[3] if args[3]
  else
    set(*args)
  end
end

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

def a
  @a
end

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

def b
  @b
end

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

def g
  @g
end

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

def r
  @r
end

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# File 'lib/color.rb', line 209

def self.blend(col1, col2, amt)
  col1 = Color.parse(col1)
  col2 = Color.parse(col2)
  col1.blend(col2, amt)
end

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# File 'lib/color.rb', line 78

def self.parse(*args)
  case args.size
  
  when 0 then
    return nil
  
  when 1 then
    val = args[0]
  
    # Trivial parse... :-)
    return val if val.is_a?(Color)
  
    # Single value, assume grayscale
    return Color.new(val, val, val) if val.is_a?(Fixnum)
  
    # Assume string
    str = val.to_s.upcase
    str = str[/[0-9A-F]{3,8}/] || ''
    case str.size
    when 3, 4 then
      r, g, b, a = str.scan(/[0-9A-F]/)
    when 6,8 then
      r, g, b, a = str.scan(/[0-9A-F]{2}/)
    else
      return nil
    end
  
    return Color.new(r,g,b,a || 255)
  
  when 3,4 then
    return Color.new(*args)
  
  end
  nil
end

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# File 'lib/color.rb', line 65

def ==(val)
  val = Color.parse(val)
  return false if val.nil?
  return r == val.r && g == val.g && b == val.b && a == val.a
end

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# File 'lib/color.rb', line 191

def blend(other, amt)
  other = Color.parse(other)
  return Color.new(self) if amt <= 0 || other.nil?
  return Color.new(other) if amt >= 1.0
  val = Color.new(self)
  val.r += ((other.r - val.r)*amt).to_i
  val.g += ((other.g - val.g)*amt).to_i
  val.b += ((other.b - val.b)*amt).to_i
  val
end

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# File 'lib/color.rb', line 203

def blend!(other, amt)
  set(blend(other, amt))
  self
end

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# File 'lib/color.rb', line 160

def darken(amt = BRIGHTNESS_DEFAULT)
  return self if amt <= 0
  return BLACK if amt >= 1.0
  val = Color.new(self)
  val.r -= (val.r * amt).to_i
  val.g -= (val.g * amt).to_i
  val.b -= (val.b * amt).to_i
  val
end

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# File 'lib/color.rb', line 171

def darken!(amt = BRIGHTNESS_DEFAULT)
  set(darken(amt))
  self
end

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# File 'lib/color.rb', line 177

def grayscale
  val = Color.new(self)
  val.r = val.g = val.b = (0.2126 * val.r + 0.7152 * val.g + 0.0722 * val.b)
  val
end

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# File 'lib/color.rb', line 184

def grayscale!
  set(grayscale)
  self
end

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# File 'lib/color.rb', line 138

def grayscale?
  @r == @g && @g == @b
end

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# File 'lib/color.rb', line 114

def inspect
  to_s(true)
end

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# File 'lib/color.rb', line 143

def lighten(amt = BRIGHTNESS_DEFAULT)
  return self if amt <= 0
  return WHITE if amt >= 1.0
  val = Color.new(self)
  val.r += ((255-val.r) * amt).to_i
  val.g += ((255-val.g) * amt).to_i
  val.b += ((255-val.b) * amt).to_i
  val
end

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# File 'lib/color.rb', line 154

def lighten!(amt = BRIGHTNESS_DEFAULT)
  set(lighten(amt))
  self
end

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# File 'lib/color.rb', line 130

def opaque?
  @a == 255
end

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# File 'lib/color.rb', line 53

def set(*args)
  val = Color.parse(*args)
  unless val.nil?
    self.r = val.r
    self.g = val.g
    self.b = val.b
    self.a = val.a
  end
  self
end

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# File 'lib/color.rb', line 122

def to_rgb(add_hash = true)
  (add_hash ? '#' : '') + to_hex(r) + to_hex(g) + to_hex(b)
end

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# File 'lib/color.rb', line 126

def to_rgba(add_hash = true)
  to_rgb(add_hash) + to_hex(a)
end

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# File 'lib/color.rb', line 118

def to_s(add_hash = true)
  trans? ? to_rgba(add_hash) : to_rgb(add_hash)
end

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# File 'lib/color.rb', line 134

def trans?
  @a != 255
end