Class: QrCodeMaker::QRUtil

Inherits:
Object
  • Object
show all
Defined in:
lib/qr_code_maker/encoder.rb

Constant Summary collapse

PATTERN_POSITION_TABLE = 
[
  [],
  [6, 18], [6, 22], [6, 26], [6, 30], [6, 34], [6, 22, 38], [6, 24, 42], [6, 26, 46], [6, 28, 50], [6, 30, 54],
  [6, 32, 58], [6, 34, 62], [6, 26, 46, 66], [6, 26, 48, 70], [6, 26, 50, 74], [6, 30, 54, 78], [6, 30, 56, 82],
  [6, 30, 58, 86], [6, 34, 62, 90], [6, 28, 50, 72, 94], [6, 26, 50, 74, 98], [6, 30, 54, 78, 102],
  [6, 28, 54, 80, 106], [6, 32, 58, 84, 110], [6, 30, 58, 86, 114], [6, 34, 62, 90, 118],
  [6, 26, 50, 74, 98, 122], [6, 30, 54, 78, 102, 126], [6, 26, 52, 78, 104, 130], [6, 30, 56, 82, 108, 134],
  [6, 34, 60, 86, 112, 138], [6, 30, 58, 86, 114, 142], [6, 34, 62, 90, 118, 146], [6, 30, 54, 78, 102, 126, 150],
  [6, 24, 50, 76, 102, 128, 154], [6, 28, 54, 80, 106, 132, 158], [6, 32, 58, 84, 110, 136, 162],
  [6, 26, 54, 82, 110, 138, 166], [6, 30, 58, 86, 114, 142, 170]
].freeze
G15 = 
1 << 10 | 1 << 8 | 1 << 5 | 1 << 4 | 1 << 2 | 1 << 1 | 1 << 0
G18 = 
1 << 12 | 1 << 11 | 1 << 10 | 1 << 9 | 1 << 8 | 1 << 5 | 1 << 2 | 1 << 0
G15_MASK = 
1 << 14 | 1 << 12 | 1 << 10 | 1 << 4 | 1 << 1
DEMERIT_POINTS_1 = 
3
DEMERIT_POINTS_2 = 
3
DEMERIT_POINTS_3 = 
40
DEMERIT_POINTS_4 = 
10
BITS_FOR_MODE = 
{
  QRMODE[:mode_number] => [10, 12, 14],
  QRMODE[:mode_alpha_numk] => [9, 11, 13],
  QRMODE[:mode_8bit_byte] => [8, 16, 16]
}.freeze
ARCH_BITS = 
ENV.fetch("RQRCODE_CORE_ARCH_BITS", nil)&.to_i || 1.size * 8

Class Method Summary collapse

Class Method Details

.demerit_points_1_same_color(modules) ⇒ Object 



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# File 'lib/qr_code_maker/encoder.rb', line 357

def self.demerit_points_1_same_color(modules)
  demerit_points = 0
  module_count = modules.size
  max_index = module_count - 1

  module_count.times do |row|
    modules_row = modules[row]
    module_count.times do |col|
      same_count = 0
      dark = modules_row[col]

      if row > 0
        row_above = modules[row - 1]
        same_count += 1 if col > 0 && dark == row_above[col - 1]
        same_count += 1 if dark == row_above[col]
        same_count += 1 if col < max_index && dark == row_above[col + 1]
      end

      same_count += 1 if col > 0 && dark == modules_row[col - 1]
      same_count += 1 if col < max_index && dark == modules_row[col + 1]

      if row < max_index
        row_below = modules[row + 1]
        same_count += 1 if col > 0 && dark == row_below[col - 1]
        same_count += 1 if dark == row_below[col]
        same_count += 1 if col < max_index && dark == row_below[col + 1]
      end

      demerit_points += (DEMERIT_POINTS_1 + same_count - 5) if same_count > 5
    end
  end
  demerit_points
end

.demerit_points_2_full_blocks(modules) ⇒ Object 



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# File 'lib/qr_code_maker/encoder.rb', line 391

def self.demerit_points_2_full_blocks(modules)
  demerit_points = 0
  module_count = modules.size
  max_row = module_count - 1

  max_row.times do |row|
    row_curr = modules[row]
    row_next = modules[row + 1]

    max_row.times do |col|
      val = row_curr[col]
      if val == row_next[col] && val == row_curr[col + 1] && val == row_next[col + 1]
        demerit_points += DEMERIT_POINTS_2
      end
    end
  end
  demerit_points
end

.demerit_points_3_dangerous_patterns(modules) ⇒ Object 



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# File 'lib/qr_code_maker/encoder.rb', line 410

def self.demerit_points_3_dangerous_patterns(modules)
  demerit_points = 0
  module_count = modules.size
  pattern_len = 7
  max_start = module_count - pattern_len + 1

  modules.each do |row|
    max_start.times do |col|
      if row[col] && !row[col + 1] && row[col + 2] &&
          row[col + 3] && row[col + 4] && !row[col + 5] && row[col + 6]
        demerit_points += DEMERIT_POINTS_3
      end
    end
  end

  module_count.times do |col|
    max_start.times do |row|
      if modules[row][col] && !modules[row + 1][col] && modules[row + 2][col] &&
          modules[row + 3][col] && modules[row + 4][col] && !modules[row + 5][col] && modules[row + 6][col]
        demerit_points += DEMERIT_POINTS_3
      end
    end
  end
  demerit_points
end

.demerit_points_4_dark_ratio(modules) ⇒ Object 



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# File 'lib/qr_code_maker/encoder.rb', line 436

def self.demerit_points_4_dark_ratio(modules)
  dark_count = modules.reduce(0) do |sum, col|
    sum + col.count(true)
  end
  ratio = dark_count.to_f / (modules.size * modules.size)
  ratio_delta = (100 * ratio - 50).abs / 5
  ratio_delta * DEMERIT_POINTS_4
end

.get_bch_digit(data) ⇒ Object 



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# File 'lib/qr_code_maker/encoder.rb', line 307

def self.get_bch_digit(data)
  digit = 0
  while data != 0
    digit += 1
    data = rszf(data, 1)
  end
  digit
end

.get_bch_format_info(data) ⇒ Object 



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# File 'lib/qr_code_maker/encoder.rb', line 287

def self.get_bch_format_info(data)
  d = data << 10
  while get_bch_digit(d) - get_bch_digit(G15) >= 0
    d ^= (G15 << (get_bch_digit(d) - get_bch_digit(G15)))
  end
  ((data << 10) | d) ^ G15_MASK
end

.get_bch_version(data) ⇒ Object 



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# File 'lib/qr_code_maker/encoder.rb', line 299

def self.get_bch_version(data)
  d = data << 12
  while get_bch_digit(d) - get_bch_digit(G18) >= 0
    d ^= (G18 << (get_bch_digit(d) - get_bch_digit(G18)))
  end
  (data << 12) | d
end

.get_error_correct_polynomial(error_correct_length) ⇒ Object 



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# File 'lib/qr_code_maker/encoder.rb', line 325

def self.get_error_correct_polynomial(error_correct_length)
  a = QRPolynomial.new([1], 0)
  (0...error_correct_length).each do |i|
    a = a.multiply(QRPolynomial.new([1, QRMath.gexp(i)], 0))
  end
  a
end

.get_length_in_bits(mode, version) ⇒ Object

Raises:



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# File 'lib/qr_code_maker/encoder.rb', line 333

def self.get_length_in_bits(mode, version)
  raise QRCodeRunTimeError, "Unknown mode: #{mode}" unless QRMODE.value?(mode)
  raise QRCodeRunTimeError, "Unknown version: #{version}" if version > 40

  if version.between?(1, 9)
    macro_version = 0
  elsif version <= 26
    macro_version = 1
  elsif version <= 40
    macro_version = 2
  end

  BITS_FOR_MODE[mode][macro_version]
end

.get_lost_points(modules) ⇒ Object 



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# File 'lib/qr_code_maker/encoder.rb', line 348

def self.get_lost_points(modules)
  demerit_points = 0
  demerit_points += demerit_points_1_same_color(modules)
  demerit_points += demerit_points_2_full_blocks(modules)
  demerit_points += demerit_points_3_dangerous_patterns(modules)
  demerit_points += demerit_points_4_dark_ratio(modules)
  demerit_points
end

.get_mask(mask_pattern, i, j) ⇒ Object

Raises:



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# File 'lib/qr_code_maker/encoder.rb', line 320

def self.get_mask(mask_pattern, i, j)
  raise QRCodeRunTimeError, "bad mask_pattern: #{mask_pattern}" if mask_pattern > QRMASKCOMPUTATIONS.size
  QRMASKCOMPUTATIONS[mask_pattern].call(i, j)
end

.get_pattern_positions(version) ⇒ Object 



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# File 'lib/qr_code_maker/encoder.rb', line 316

def self.get_pattern_positions(version)
  PATTERN_POSITION_TABLE[version - 1]
end

.max_size ⇒ Object 



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# File 'lib/qr_code_maker/encoder.rb', line 283

def self.max_size
  PATTERN_POSITION_TABLE.count
end

.rszf(num, count) ⇒ Object 



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# File 'lib/qr_code_maker/encoder.rb', line 295

def self.rszf(num, count)
  (num >> count) & ((1 << (ARCH_BITS - count)) - 1)
end