cpp/core/src/zxing/oned/EAN13Reader.cpp

   1 /*
   2  *  EAN13Reader.cpp
   3  *  ZXing
   4  *
   5  *  Created by Lukasz Warchol on 10-01-22.
   6  *  Copyright 2010 ZXing authors All rights reserved.
   7  *
   8  * Licensed under the Apache License, Version 2.0 (the "License");
   9  * you may not use this file except in compliance with the License.
  10  * You may obtain a copy of the License at
  11  *
  12  *      http://www.apache.org/licenses/LICENSE-2.0
  13  *
  14  * Unless required by applicable law or agreed to in writing, software
  15  * distributed under the License is distributed on an "AS IS" BASIS,
  16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  17  * See the License for the specific language governing permissions and
  18  * limitations under the License.
  19  */
  20
  21 #include "EAN13Reader.h"
  22 #include <zxing/ReaderException.h>
  23
  24 namespace zxing {
  25         namespace oned {
  26
  27                 static const int FIRST_DIGIT_ENCODINGS[10] = {0x00, 0x0B, 0x0D, 0xE, 0x13, 0x19, 0x1C, 0x15, 0x16, 0x1A};
  28
  29
  30                 EAN13Reader::EAN13Reader(){
  31                         decodeMiddleCounters = new int[4];
  32                         for (int i=0; i<4; i++) {
  33                                 decodeMiddleCounters[i] = 0;
  34                         }
  35                 }
  36
  37                 int EAN13Reader::decodeMiddle(Ref<BitArray> row, int startRange[], int startRangeLen, std::string& resultString){
  38                         int countersLen = 4;
  39                         int* counters = decodeMiddleCounters;
  40                         counters[0] = 0;
  41                         counters[1] = 0;
  42                         counters[2] = 0;
  43                         counters[3] = 0;
  44
  45
  46                         int end = row->getSize();
  47                         int rowOffset = startRange[1];
  48
  49                         int lgPatternFound = 0;
  50
  51                         for (int x = 0; x < 6 && rowOffset < end; x++) {
  52                                 int bestMatch = decodeDigit(row, counters, countersLen, rowOffset, UPC_EAN_PATTERNS_L_AND_G_PATTERNS);
  53                                 resultString.append(1, (char) ('0' + bestMatch % 10));
  54                                 for (int i = 0; i < countersLen; i++) {
  55                                         rowOffset += counters[i];
  56                                 }
  57                                 if (bestMatch >= 10) {
  58                                         lgPatternFound |= 1 << (5 - x);
  59                                 }
  60                         }
  61
  62                         determineFirstDigit(resultString, lgPatternFound);
  63
  64                         int* middleRange = findGuardPattern(row, rowOffset, true, (int*)getMIDDLE_PATTERN(), getMIDDLE_PATTERN_LEN());
  65                         rowOffset = middleRange[1];
  66
  67                         for (int x = 0; x < 6 && rowOffset < end; x++) {
  68                                 int bestMatch = decodeDigit(row, counters, countersLen, rowOffset, UPC_EAN_PATTERNS_L_PATTERNS);
  69                                 resultString.append(1, (char) ('0' + bestMatch));
  70                                 for (int i = 0; i < countersLen; i++) {
  71                                         rowOffset += counters[i];
  72                                 }
  73                         }
  74
  75                         return rowOffset;
  76                 }
  77
  78                 void EAN13Reader::determineFirstDigit(std::string& resultString, int lgPatternFound){
  79                         for (int d = 0; d < 10; d++) {
  80                                 if (lgPatternFound == FIRST_DIGIT_ENCODINGS[d]) {
  81                                         resultString.insert(0, 1, (char) ('0' + d));
  82                                         return;
  83                                 }
  84                         }
  85                         throw ReaderException("determineFirstDigit");
  86                 }
  87
  88                 BarcodeFormat EAN13Reader::getBarcodeFormat(){
  89                         return BarcodeFormat_EAN_13;
  90                 }
  91                 EAN13Reader::~EAN13Reader(){
  92                         delete [] decodeMiddleCounters;
  93                 }
  94         }
  95 }