Class: RuCaptcha::Captcha

Inherits:
Object
  • Object
show all
Defined in:
lib/rucaptcha/captcha.rb

Class Method Summary collapse

Class Method Details

.create(code) ⇒ Object

Create Captcha image by code



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# File 'lib/rucaptcha/captcha.rb', line 26

def create(code)
  chars        = code.split('')
  all_left     = 20
  font_size    = RuCaptcha.config.font_size
  full_height  = font_size
  full_width   = font_size * chars.size
  size         = "#{full_width}x#{full_height}"
  half_width   = full_width / 2
  full_height  = full_height
  half_height  = full_height / 2
  text_top     = 0
  text_left    = 0 - (font_size * 0.28).to_i
  stroke_width  = (font_size * 0.08).to_i + 1
  text_width   = font_size + text_left
  label = "=#{' ' * (chars.size - 1)}="

  text_opts = []
  line_opts = []
  chars.each_with_index do |char, i|
    rgb = random_color
    text_color = "rgba(#{rgb.join(',')}, 1)"
    line_color = "rgba(#{rgb.join(',')}, 0.6)"
    text_opts << %(-fill '#{text_color}' -draw 'text #{(text_left + text_width) * i + all_left},#{text_top} "#{char}"')
    left_y = rand_line_top(text_top, font_size)
    right_x = half_width + (half_width * 0.3).to_i
    right_y = rand_line_top(text_top, font_size)
    line_opts << %(-draw 'stroke #{line_color} line #{rand(10)},#{left_y} #{right_x},#{right_y}')
  end

  command = <<-CODE
    convert -size #{size} \
    -strokewidth #{stroke_width} \
    #{line_opts.join(' ')} \
    -pointsize #{font_size} -weight 500 \
    #{text_opts.join(' ')}  \
    -wave #{rand(2) + 3}x#{rand(2) + 1} \
    -rotate #{rand(10) - 5} \
    -gravity NorthWest -sketch 1x10+#{rand(2)} \
    -fill none \
    -implode #{RuCaptcha.config.implode} -trim label:- png:-
  CODE

  if Gem.win_platform?
    png_file_path = Rails.root.join('tmp', 'cache', "#{code}.png")
    command = "convert -size #{size} xc:White -gravity Center -weight 12 -pointsize 20 -annotate 0 \"#{code}\" -trim #{png_file_path}"
    require 'open3'
    _stdout_str, stderr_str = Open3.capture3(command)
    raise "RuCaptcha: #{stderr_str.strip}" if stderr_str != nil && stderr_str.length > 0
    png_file_path
  else
    command.strip!
    pid, stdin, stdout, stderr = POSIX::Spawn.popen4(command)
    Process.waitpid(pid)
    err = stderr.read
    raise "RuCaptcha: #{err.strip}" if err != nil && err.length > 0
    stdout.read
  end
end

.rand_line_top(text_top, font_size) ⇒ Object 



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# File 'lib/rucaptcha/captcha.rb', line 21

def rand_line_top(text_top, font_size)
  text_top + rand(font_size * 0.7).to_i
end

.random_chars ⇒ Object 



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# File 'lib/rucaptcha/captcha.rb', line 15

def random_chars
  chars = SecureRandom.hex(RuCaptcha.config.len / 2).downcase
  chars.gsub!(/[0ol1]/i, (rand(8) + 2).to_s)
  chars
end

.random_color ⇒ Object 



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# File 'lib/rucaptcha/captcha.rb', line 6

def random_color
  if RuCaptcha.config.style == :colorful
    [rand(100).to_s(8), rand(100).to_s(8), rand(100).to_s(8)]
  else
    color_seed = rand(50).to_s(8)
    [color_seed, color_seed, color_seed]
  end
end