Class: Excession::CssRegexHueMod

Inherits:
Object
  • Object
show all
Defined in:
lib/excession/css_regex_hue_mod.rb

Constant Summary collapse

HASHSIX = 
/#([a-f0-9]{2})([a-f0-9]{2})([a-f0-9]{2})(\s|;|})/i
HASHTHREE = 
/#([a-f0-9])([a-f0-9])([a-f0-9])(\s|;|})/i
RGBCALL = 
/rgb\(\s*(-?[0-9]+)\s*,\s*(-?[0-9]+)\s*,\s*(-?[0-9]+)\)/i
RGBPCTCALL = 
/rgb\(\s*(-?[0-9]+)\s*%\s*,\s*(-?[0-9]+)\s*%\s*,\s*(-?[0-9]+)\s*%\s*\)/i

Instance Method Summary collapse

Instance Method Details

#hsl_to_rgb(hsl) ⇒ Object 



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# File 'lib/excession/css_regex_hue_mod.rb', line 54

def hsl_to_rgb(hsl)
  hdeg,s,l = *hsl

  rgb = nil
  if s == 0
    rgb = [l,l,l]
  else
    temp2 =  l < 0.5 ? l*(1+s) : l+s-l*s
    temp1 = 2.0*l-temp2
    h = hdeg/360.0
    temp3 = [h+1.0/3.0, h, h-1.0/3.0].map{|i| i < 0 ? i+1 : (i > 1 ? i-1 : i)}
    rgb = temp3.map do |i|
      if 6.0*i < 1
        temp1 + (temp2-temp1)*6.0*i
      elsif 2*i < 1
        temp2
      elsif 3*i < 2
        temp1 + (temp2-temp1)*((2.0/3.0)-i)*6.0
      else
        temp1
      end
    end
  end
  rgb.map{|i| (i*255).floor}
end

#modify_hsl(hsl, &blk) ⇒ Object 



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# File 'lib/excession/css_regex_hue_mod.rb', line 89

def modify_hsl(hsl, &blk)
  newhsl = blk.call(hsl)
  newhsl[0] %= 360
  newhsl
end

#modify_rgb(rgb, &blk) ⇒ Object 



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# File 'lib/excession/css_regex_hue_mod.rb', line 95

def modify_rgb(rgb, &blk)
  rgb_to_hashsix(hsl_to_rgb(modify_hsl(rgb_to_hsl(rgb), &blk)))
end

#replace_colours(str, &blk) ⇒ Object 



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# File 'lib/excession/css_regex_hue_mod.rb', line 99

def replace_colours(str, &blk)

  str.gsub!(HASHSIX) do
    hexr, hexg, hexb, tend = $1, $2, $3, $4
    modify_rgb([hexr, hexg, hexb].map(&:hex), &blk)+tend
  end

  str.gsub!(HASHTHREE) do 
    hexr, hexg, hexb, tend = $1, $2, $3, $4
    modify_rgb([hexr*2,hexg*2,hexb*2].map(&:hex), &blk)+tend
  end

  str.gsub!(RGBCALL) do
    strr, strg, strb = $1, $2, $3
    modify_rgb([strr, strg, strb].map{|s|Integer(s)}, &blk)
  end
  
  str.gsub!(RGBPCTCALL) do
    strr, strg, strb = $1, $2, $3
    modify_rgb([strr, strg, strb].
               map{|s|Integer(s)}.
               map{|i| (i/100.0) * 255 }, # Don't just multiply by 2.55, it's not accurate
               &blk)
  end
  
  str
end

#rgb_to_hashsix(rgb) ⇒ Object 



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# File 'lib/excession/css_regex_hue_mod.rb', line 80

def rgb_to_hashsix(rgb)
  "#" + rgb.map do |i| 
    str = i.to_s(16)
    raise "Invalid colour (#{rgb.inspect})!" if str.length > 2
    str="0"+str if str.length<2
    str
  end.join
end

#rgb_to_hsl(rgbint) ⇒ Object 



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# File 'lib/excession/css_regex_hue_mod.rb', line 20

def rgb_to_hsl(rgbint)
  rgb = rgbint.map{|i| i/255.0}
  maxcolour = rgb.max
  mincolour = rgb.min

  #puts "maxcolour: #{maxcolour}"
  #puts "mincolour: #{mincolour}"

  cdiff = (maxcolour-mincolour)
  csum = (maxcolour + mincolour)

  #puts "cdiff: #{cdiff}"
  #puts "csum: #{csum}"

  l = csum/2
  #puts "l: #{l}"
  h,s = 0,0
  if maxcolour != mincolour
    s = l < 0.5 ? cdiff/csum : cdiff/(2.0-csum)
    #puts "s: #{s}"
    r,g,b = rgb
    h = if r == maxcolour
          (g-b)/cdiff
        elsif g == maxcolour
          2.0+(b-r)/cdiff
        else
          4.0+(r-g)/cdiff
        end
    #puts "h: #{h}"
  end

  return [(h*360)%360,s,l]
end

#rotate_hue(angle_degrees, str) ⇒ Object

Use this entry point.



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# File 'lib/excession/css_regex_hue_mod.rb', line 11

def rotate_hue(angle_degrees, str)
  replace_colours(str) do |hsl| 
    h,s,l = *hsl
    [h+angle_degrees, s, l]
  end
end