Class: RQRCodeCore::QRUtil

Inherits:
Object
  • Object
show all
Defined in:
lib/rqrcode_core/qrcode/qr_util.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]
]
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],
  QRMODE[:mode_kanji] => [8, 10, 12],
}

Class Method Summary collapse

Class Method Details

.demerit_points_1_same_color(modules) ⇒ Object 



151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
 
# File 'lib/rqrcode_core/qrcode/qr_util.rb', line 151

def QRUtil.demerit_points_1_same_color(modules)
  demerit_points = 0
  module_count = modules.size

  # level1
  (0...module_count).each do |row|
    (0...module_count).each do |col|
      same_count = 0
      dark = modules[row][col]

      ( -1..1 ).each do |r|
        next if row + r < 0 || module_count <= row + r

        ( -1..1 ).each do |c|
          next if col + c < 0 || module_count <= col + c
          next if r == 0 && c == 0
          if dark == modules[row + r][col + c]
            same_count += 1
          end
        end
      end

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

  return demerit_points
end

.demerit_points_2_full_blocks(modules) ⇒ Object 



182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
 
# File 'lib/rqrcode_core/qrcode/qr_util.rb', line 182

def QRUtil.demerit_points_2_full_blocks(modules)
  demerit_points = 0
  module_count = modules.size

  # level 2
  (0...(module_count - 1)).each do |row|
    (0...(module_count - 1)).each do |col|
      count = 0
      count += 1 if modules[row][col]
      count += 1 if modules[row + 1][col]
      count += 1 if modules[row][col + 1]
      count += 1 if modules[row + 1][col + 1]
      if (count == 0 || count == 4)
        demerit_points += DEMERIT_POINTS_2
      end
    end
  end

  return demerit_points
end

.demerit_points_3_dangerous_patterns(modules) ⇒ Object 



203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
 
# File 'lib/rqrcode_core/qrcode/qr_util.rb', line 203

def QRUtil.demerit_points_3_dangerous_patterns(modules)
  demerit_points = 0
  module_count = modules.size

  # level 3
  modules.each do |row|
    (module_count - 6).times do |col_idx|
      if row[col_idx] &&
        !row[col_idx + 1] &&
        row[col_idx + 2] &&
        row[col_idx + 3] &&
        row[col_idx + 4] &&
        !row[col_idx + 5] &&
        row[col_idx + 6]
        demerit_points += DEMERIT_POINTS_3
      end
    end
  end

  (0...module_count).each do |col|
    (0...(module_count - 6)).each 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

  return demerit_points
end

.demerit_points_4_dark_ratio(modules) ⇒ Object 



239
240
241
242
243
244
245
246
247
248
249
250
 
# File 'lib/rqrcode_core/qrcode/qr_util.rb', line 239

def QRUtil.demerit_points_4_dark_ratio(modules)
  # level 4
  dark_count = modules.reduce(0) do |sum, col|
    sum + col.count(true)
  end

  ratio = dark_count / (modules.size * modules.size)
  ratio_delta = (100 * ratio - 50).abs / 5

  demerit_points = ratio_delta * DEMERIT_POINTS_4
  return demerit_points
end

.get_bch_digit(data) ⇒ Object 



84
85
86
87
88
89
90
91
92
93
 
# File 'lib/rqrcode_core/qrcode/qr_util.rb', line 84

def QRUtil.get_bch_digit( data )
  digit = 0

  while data != 0
    digit = digit + 1
    data = (data).rszf(1)
  end

  digit
end

.get_bch_format_info(data) ⇒ Object 



68
69
70
71
72
73
74
 
# File 'lib/rqrcode_core/qrcode/qr_util.rb', line 68

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

.get_bch_version(data) ⇒ Object 



76
77
78
79
80
81
82
 
# File 'lib/rqrcode_core/qrcode/qr_util.rb', line 76

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

.get_error_correct_polynomial(error_correct_length) ⇒ Object 



107
108
109
110
111
112
113
114
115
 
# File 'lib/rqrcode_core/qrcode/qr_util.rb', line 107

def QRUtil.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 



117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
 
# File 'lib/rqrcode_core/qrcode/qr_util.rb', line 117

def QRUtil.get_length_in_bits(mode, version)
  if !QRMODE.value?(mode)
      raise QRCodeRunTimeError, "Unknown mode: #{mode}"
  end

  if version > 40
    raise QRCodeRunTimeError, "Unknown version: #{version}"
  end

  if version.between?(1, 9)
    # 1 - 9
    macro_version = 0
  elsif version <= 26
    # 10 - 26
    macro_version = 1
  elsif version <= 40
    # 27 - 40
    macro_version = 2
  end

  return BITS_FOR_MODE[mode][macro_version]
end

.get_lost_points(modules) ⇒ Object 



140
141
142
143
144
145
146
147
148
149
 
# File 'lib/rqrcode_core/qrcode/qr_util.rb', line 140

def QRUtil.get_lost_points(modules)
  demerit_points = 0

  demerit_points += QRUtil.demerit_points_1_same_color(modules)
  demerit_points += QRUtil.demerit_points_2_full_blocks(modules)
  demerit_points += QRUtil.demerit_points_3_dangerous_patterns(modules)
  demerit_points += QRUtil.demerit_points_4_dark_ratio(modules)

  return demerit_points
end

.get_mask(mask_pattern, i, j) ⇒ Object 



99
100
101
102
103
104
105
 
# File 'lib/rqrcode_core/qrcode/qr_util.rb', line 99

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

  return QRMASKCOMPUTATIONS[mask_pattern].call(i, j)
end

.get_pattern_positions(version) ⇒ Object 



95
96
97
 
# File 'lib/rqrcode_core/qrcode/qr_util.rb', line 95

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

.max_size ⇒ Object 



64
65
66
 
# File 'lib/rqrcode_core/qrcode/qr_util.rb', line 64

def QRUtil.max_size
  PATTERN_POSITION_TABLE.count
end