class Hermes::Colour

Generate HTML color values.

Examples¶ ↑

red = Color.new 0xff, 0, 0
black = Color.grey 0
red.to_s                           #=> "#ff0000"
red.to_fract                       #=> [ 1.0, 0.0, 0.0]

(Color.new 0xff, 0, 0).to_hsv      #=> [0.0, 1.0, 1.0]
(Color.new 0, 0xff, 0).to_hsv      #=> [120.0, 1.0, 1.0]
(Color.new 0, 0x7f, 0x7f).to_hsv   #=> [180.0, 1.0, 0.49804]
(Color.new 0, 0x80, 0x80).to_hsv   #=> [180.0, 1.0, 0.50196]
(Color.from_hsv 180, 1, 0.5).to_s  #=> "#007f7f"

Attributes

b[R]

g[R]

r[R]

Public Class Methods

new( r, g, b) → clr click to toggle source

Create a color with red, green and blue values. They are in range 0..255.

# File lib/hermes/color.rb, line 46
def initialize r, *gb
  if gb.any? then
    @r, @g, @b = *[ r, *gb].map { |x| ff x }
  else
    @r = @g = @b = (ff r)
  end
end

Public Instance Methods

==(oth) click to toggle source

# File lib/hermes/color.rb, line 70
def == oth
  case oth
    when Color then to_a == oth.to_a
    when Array then to_a == oth
  end
end

b=(x ;) click to toggle source

# File lib/hermes/color.rb, line 60
def b= x ; @b = ff x ; end

complemetary() → clr click to toggle source

Build the complemetary color.

# File lib/hermes/color.rb, line 240
def complemetary ; Color.new *(tuple.map { |x| 0xff - x }) ; end

edit_hsv() { |h,s,v| ... } → clr click to toggle source

Convert it to an HSV triple, yield that to the block and build a new Color from the blocks result.

# File lib/hermes/color.rb, line 230
def edit_hsv
  hsv = yield *to_hsv
  self.class.from_hsv *hsv
end

from_fract( rf, gf, bf) → clr click to toggle source

Build a Color from three values in range 0..1 where 1.0 means 255.

# File lib/hermes/color.rb, line 132
def from_fract rf, gf, bf
  rgb = [rf, gf, bf].map { |x| 0xff * x }
  new *rgb
end

from_hsv( h, s, v) → clr click to toggle source

Build a Color from HSV parameters.

Ranges are:

h    0...360
s    0.0..1.0
v    0.0..1.0

# File lib/hermes/color.rb, line 201
def from_hsv h, s, v
  if s.nonzero? then
    h /= 60.0
    i = h.to_i % 6
    f = h - i
    rgb = []
    if (i%2).zero? then
      rgb.push v
      rgb.push v * (1.0 - s * (1.0 - f))
    else
      rgb.push v * (1.0 - s * f)
      rgb.push v
    end
    rgb.push v * (1.0 - s)
    rgb.rotate! -(i/2)
    from_fract *rgb
  else
    from_fract v, v, v
  end
end

from_fract( rl, gl, bl) → clr click to toggle source

Build a Color from three values in range 0..0xffff.

# File lib/hermes/color.rb, line 156
def from_long rl, gl, bl
  rgb = [rl, gl, bl].map { |x| x / 0x100 }
  new *rgb
end

from_s( str) → clr click to toggle source

Build a Color from an HTML tags key.

# File lib/hermes/color.rb, line 108
def from_s str
  rgb = str.scan( /[0-9a-f]{2}/i).map do |x| x.to_i 0x10 end
  new *rgb
end

g=(x ;) click to toggle source

# File lib/hermes/color.rb, line 59
def g= x ; @g = ff x ; end

gray( num) → clr click to toggle source

Create a gray color (r=b=g). num is in range 0..255.

# File lib/hermes/color.rb, line 85
def gray i
  new i, i, i
end

inspect() click to toggle source

# File lib/hermes/color.rb, line 99
def inspect ; "#<#{cls}:#{'0x%08x' % (object_id << 1)} #{to_s}>" ; end

r=(x ;) click to toggle source

# File lib/hermes/color.rb, line 58
def r= x ; @r = ff x ; end

to_a() → ary click to toggle source

Return RGB values as an array.

# File lib/hermes/color.rb, line 67
def to_a ; [ @r, @g, @b] ; end

Also aliased as: tuple

to_fract() → ary click to toggle source

Return three values in range 0..1 where 1.0 means 255.

# File lib/hermes/color.rb, line 121
def to_fract
  tuple.map { |x| x / 255.0 }
end

to_hsv() → ary click to toggle source

Convert it to an HSV triple.

# File lib/hermes/color.rb, line 169
def to_hsv
  rgb = [ @r, @g, @b].map { |x| (Integer x) / 255.0 }
  v = rgb.max
  delta = v - rgb.min
  unless delta > 0.0 then
    h = s = 0.0
  else
    s = delta / v
    r, g, b = rgb
    case v
      when r then h =     (g - b) / delta ; h += 6 if h < 0
      when g then h = 2 + (b - r) / delta
      when b then h = 4 + (r - g) / delta
    end
    h *= 60
  end
  [ h, s, v]
end

to_long() → ary click to toggle source

Extend it to a 48-bit color triple.

# File lib/hermes/color.rb, line 145
def to_long
  tuple.map { |x| x * 0x100 + x }
end

to_s() → str click to toggle source

Return color as an HTML tags key.

# File lib/hermes/color.rb, line 97
def to_s ; "#" + tuple.map { |x| "%02x" % x }.join ; end

tuple()

Alias for: to_a

Private Instance Methods

ff(x ;) click to toggle source

# File lib/hermes/color.rb, line 54
def ff x ; (Integer x) & 0xff ; end