class Cairo::Color::RGB

Attributes

b[RW]
b=[RW]
blue[RW]
g[RW]
g=[RW]
green[RW]
r[RW]
r=[RW]
red[RW]

Public Class Methods

new(r, g, b, a=1.0) click to toggle source
Calls superclass method Cairo::Color::Base::new
# File lib/cairo/color.rb, line 81
def initialize(r, g, b, a=1.0)
  super(a)
  assert_in_range(r, "red")
  assert_in_range(g, "green")
  assert_in_range(b, "blue")
  @red = r
  @green = g
  @blue = b
end

Public Instance Methods

==(other) click to toggle source
# File lib/cairo/color.rb, line 99
def ==(other)
  other.is_a?(self.class) and other.to_s == to_s
end
eql?(other) click to toggle source
# File lib/cairo/color.rb, line 95
def eql?(other)
  self == other
end
hash() click to toggle source
# File lib/cairo/color.rb, line 91
def hash
  to_s.hash
end
to_a() click to toggle source
# File lib/cairo/color.rb, line 103
def to_a
  [@red, @green, @blue, @alpha]
end
Also aliased as: to_ary
to_ary()
Alias for: to_a
to_cmyk() click to toggle source
# File lib/cairo/color.rb, line 116
def to_cmyk
  cmy = [1.0 - @red, 1.0 - @green, 1.0 - @blue]
  key_plate = cmy.min
  if key_plate < 1.0
    one_k = 1.0 - key_plate
    cmyk = cmy.collect {|value| (value - key_plate) / one_k} + [key_plate]
  else
    cmyk = [0, 0, 0, key_plate]
  end
  cmyka = cmyk + [@alpha]
  CMYK.new(*cmyka)
end
to_hsv() click to toggle source
# File lib/cairo/color.rb, line 129
def to_hsv
  max = [@red, @blue, @green].max
  if max > 0
    min = [@red, @blue, @green].min
    max_min = max - min
    case max
    when @red
      numerator = @green - @blue
      angle = 0
    when @green
      numerator = @blue - @red
      angle = 120
    when @blue
      numerator = @red - @green
      angle = 240
    end
    h = max_min > 0 ? 60 * numerator / max_min + angle : 0.0
    s = max_min / max
  else
    h = 0.0
    s = 0.0
  end
  v = max
  HSV.new(h, s, v, @alpha)
end
to_rgb() click to toggle source
# File lib/cairo/color.rb, line 112
def to_rgb
  clone
end
to_s() click to toggle source
# File lib/cairo/color.rb, line 108
def to_s
  "#%02X%02X%02X%02X" % to_a.collect {|v| (v * 255).round(1)}
end