qzxing/source/zxing/oned/UPCEReader.cpp

148 lines
4.6 KiB
C++

// -*- 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 "UPCEReader.h"
#include <zxing/ReaderException.h>
#include <qglobal.h>
namespace zxing {
namespace oned {
/**
* The pattern that marks the middle, and end, of a UPC-E pattern.
* There is no "second half" to a UPC-E barcode.
*/
static const int MIDDLE_END_PATTERN[6] = {1, 1, 1, 1, 1, 1};
/**
* See {@link #L_AND_G_PATTERNS}; these values similarly represent patterns of
* even-odd parity encodings of digits that imply both the number system (0 or 1)
* used, and the check digit.
*/
static const int NUMSYS_AND_CHECK_DIGIT_PATTERNS[2][10] = {
{0x38, 0x34, 0x32, 0x31, 0x2C, 0x26, 0x23, 0x2A, 0x29, 0x25},
{0x07, 0x0B, 0x0D, 0x0E, 0x13, 0x19, 0x1C, 0x15, 0x16, 0x1A}
};
UPCEReader::UPCEReader() {
}
int UPCEReader::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 (!determineNumSysAndCheckDigit(resultString, lgPatternFound)) {
return -1;
}
return rowOffset;
}
bool UPCEReader::decodeEnd(Ref<BitArray> row, int endStart, int* endGuardBegin,
int* endGuardEnd) {
return findGuardPattern(row, endStart, true, MIDDLE_END_PATTERN,
sizeof(MIDDLE_END_PATTERN) / sizeof(int), endGuardBegin, endGuardEnd);
}
bool UPCEReader::checkChecksum(std::string s){
return UPCEANReader::checkChecksum(convertUPCEtoUPCA(s));
}
bool UPCEReader::determineNumSysAndCheckDigit(std::string& resultString, int lgPatternFound) {
for (int numSys = 0; numSys <= 1; numSys++) {
for (int d = 0; d < 10; d++) {
if (lgPatternFound == NUMSYS_AND_CHECK_DIGIT_PATTERNS[numSys][d]) {
#if defined(Q_OS_SYMBIAN)
resultString.insert((char*)0, 1, (char) ((int)'0' + numSys));
#else
resultString.insert(/*(char*)*/0, 1, (char) ((int)'0' + numSys));
#endif
resultString.append(1, (char) ('0' + d));
return true;
}
}
}
return false;
}
/**
* Expands a UPC-E value back into its full, equivalent UPC-A code value.
*
* @param upce UPC-E code as string of digits
* @return equivalent UPC-A code as string of digits
*/
std::string UPCEReader::convertUPCEtoUPCA(std::string upce) {
std::string result;
result.append(1, upce[0]);
char lastChar = upce[6];
switch (lastChar) {
case '0':
case '1':
case '2':
result.append(upce.substr(1,2));
result.append(1, lastChar);
result.append("0000");
result.append(upce.substr(3,3));
break;
case '3':
result.append(upce.substr(1,3));
result.append("00000");
result.append(upce.substr(4,2));
break;
case '4':
result.append(upce.substr(1,4));
result.append("00000");
result.append(1, upce[5]);
break;
default:
result.append(upce.substr(1,5));
result.append("0000");
result.append(1, lastChar);
break;
}
result.append(1, upce[7]);
return result;
}
BarcodeFormat UPCEReader::getBarcodeFormat() {
return BarcodeFormat_UPC_E;
}
}
}