qzxing/source/zxing/oned/EAN13Reader.cpp

// -*- 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/ReaderException.h>
#include <qglobal.h>

namespace zxing {
namespace oned {

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

EAN13Reader::EAN13Reader() { }

int EAN13Reader::decodeMiddle(Ref<BitArray> row, int startGuardBegin, int startGuardEnd,
                              std::string& resultString) {
    (void)startGuardBegin;
    const int countersLen = 4;
    int counters[countersLen] = { 0, 0, 0, 0 };

    int end = row->getSize();
    int rowOffset = startGuardEnd;
    int lgPatternFound = 0;

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

    if (!determineFirstDigit(resultString, lgPatternFound)) {
        return -1;
    }

    int middleRangeStart;
    int middleRangeEnd;
    if (findGuardPattern(row, rowOffset, true, (int*)getMIDDLE_PATTERN(),
                         getMIDDLE_PATTERN_LEN(), &middleRangeStart, &middleRangeEnd)) {
        rowOffset = middleRangeEnd;
        for (int x = 0; x < 6 && rowOffset < end; x++) {
            int bestMatch = decodeDigit(row, counters, countersLen, rowOffset,
                                        UPC_EAN_PATTERNS_L_PATTERNS);
            if (bestMatch < 0) {
                return -1;
            }
            resultString.append(1, (char) ('0' + bestMatch));
            for (int i = 0; i < countersLen; i++) {
                rowOffset += counters[i];
            }
        }
        return rowOffset;
    }
    return -1;
}

bool EAN13Reader::determineFirstDigit(std::string& resultString, int lgPatternFound) {
    for (int d = 0; d < 10; d++) {
        if (lgPatternFound == FIRST_DIGIT_ENCODINGS[d]) {
#if defined(Q_OS_SYMBIAN)
            resultString.insert((char*)0, 1, (char) ('0' + d));
#else
            resultString.insert(/*(char*)*/0, 1, (char) ('0' + d));
#endif
            return true;
        }
    }
    return false;
}

BarcodeFormat EAN13Reader::getBarcodeFormat(){
    return BarcodeFormat_EAN_13;
}
}
}