Module: RQRCode::Export::PNG

Defined in:
lib/rqrcode/export/png.rb

Instance Method Summary collapse

Instance Method Details

#as_png(options = {}) ⇒ Object

Render the PNG from the Qrcode.

Options: module_px_size - Image size, in pixels. fill - Background ChunkyPNG::Color, defaults to ‘white’ color - Foreground ChunkyPNG::Color, defaults to ‘black’ border - Border thickness, in pixels

It first creates an image where 1px = 1 module, then resizes. Defaults to 90x90 pixels, customizable by option.



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# File 'lib/rqrcode/export/png.rb', line 20

def as_png(options = {})

  default_img_options = {
    :resize_gte_to => false,
    :resize_exactly_to => false,
    :fill => 'white',
    :color => 'black',
    :border_modules => 4,
    :file => false,
    :module_px_size => 6
  }
  options = default_img_options.merge(options) # reverse_merge

  fill   = ChunkyPNG::Color(options[:fill])
  color  = ChunkyPNG::Color(options[:color])
  output_file = options[:file]
  border = options[:border_modules]
  total_border = border * 2
  module_px_size = if options[:resize_gte_to]
    (options[:resize_gte_to].to_f / (self.module_count + total_border).to_f).ceil.to_i
  else
    options[:module_px_size]
  end
  border_px = border *  module_px_size
  total_border_px = border_px * 2
  resize_to = options[:resize_exactly_to]

  img_size = module_px_size * self.module_count
  total_img_size = img_size + total_border_px

  png = ChunkyPNG::Image.new(total_img_size, total_img_size, fill)

  self.modules.each_index do |x|
    self.modules.each_index do |y|
      if self.dark?(x, y)
        (0...module_px_size).each do |i|
          (0...module_px_size).each do |j|
            png[(y * module_px_size) + border_px + j , (x * module_px_size) + border_px + i] = color
          end
        end
      end
    end
  end

  png = png.resize(resize_to, resize_to) if resize_to

  if output_file
    png.save(output_file,{ :color_mode => ChunkyPNG::COLOR_GRAYSCALE, :bit_depth =>1})
  end
  png
end