#!/usr/bin/env ruby #-- # Copyright 2004 by Duncan Robertson (duncan@whomwah.com). # All rights reserved. # Permission is granted for use, copying, modification, distribution, # and distribution of modified versions of this work as long as the # above copyright notice is included. #++ module RQRCode #:nodoc: class QRUtil 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], } 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 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 def QRUtil.get_bch_digit( data ) digit = 0 while data != 0 digit = digit + 1 data = (data).rszf(1) end digit end def QRUtil.get_pattern_positions(version) PATTERN_POSITION_TABLE[version - 1] end 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 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 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 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 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 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 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 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 end end