EAN13Reader.cpp Example File

 // -*- mode:c++; tab-width:2; indent-tabs-mode:nil; c-basic-offset:2 -*-
 /*
  *  Copyright 2010 ZXing authors All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "EAN13Reader.h"
 #include <zxing/NotFoundException.h>

 using std::vector;
 using zxing::Ref;
 using zxing::BitArray;
 using zxing::oned::EAN13Reader;

 namespace {
   const int FIRST_DIGIT_ENCODINGS[10] = {
     0x00, 0x0B, 0x0D, 0xE, 0x13, 0x19, 0x1C, 0x15, 0x16, 0x1A
   };
 }

 EAN13Reader::EAN13Reader() : decodeMiddleCounters(4, 0) { }

 int EAN13Reader::decodeMiddle(Ref<BitArray> row,
                               Range const& startRange,
                               std::string& resultString) {
   vector<int>& counters (decodeMiddleCounters);
   counters.clear();
   counters.resize(4);
   int end = row->getSize();
   int rowOffset = startRange[1];

   int lgPatternFound = 0;

   for (int x = 0; x < 6 && rowOffset < end; x++) {
     int bestMatch = decodeDigit(row, counters, rowOffset, L_AND_G_PATTERNS);
     resultString.append(1, (byte) ('0' + bestMatch % 10));
     for (int i = 0, end = counters.size(); i <end; i++) {
       rowOffset += counters[i];
     }
     if (bestMatch >= 10) {
       lgPatternFound |= 1 << (5 - x);
     }
   }

   determineFirstDigit(resultString, lgPatternFound);

   Range middleRange = findGuardPattern(row, rowOffset, true, MIDDLE_PATTERN) ;
   rowOffset = middleRange[1];

   for (int x = 0; x < 6 && rowOffset < end; x++) {
     int bestMatch =
       decodeDigit(row, counters, rowOffset, L_PATTERNS);
     resultString.append(1, (byte) ('0' + bestMatch));
     for (int i = 0, end = counters.size(); i < end; i++) {
       rowOffset += counters[i];
     }
   }
   return rowOffset;
 }

 void EAN13Reader::determineFirstDigit(std::string& resultString, int lgPatternFound) {
   // std::cerr << "K " << resultString << " " << lgPatternFound << " " <<FIRST_DIGIT_ENCODINGS << std::endl;
   for (int d = 0; d < 10; d++) {
     if (lgPatternFound == FIRST_DIGIT_ENCODINGS[d]) {
       resultString.insert((size_t)0, (size_t)1, (byte) ('0' + d));
       return;
     }
   }
   throw NotFoundException();
 }

 zxing::BarcodeFormat EAN13Reader::getBarcodeFormat(){
   return BarcodeFormat::EAN_13;
 }