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- /*
- * Copyright 2012 ZXing authors
- *
- * 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.
- */
-
- #import "ZXBitArray.h"
- #import "ZXCode93Reader.h"
- #import "ZXErrors.h"
- #import "ZXIntArray.h"
- #import "ZXResult.h"
- #import "ZXResultPoint.h"
-
- NSString *ZX_CODE93_ALPHABET_STRING = nil;
- const unichar ZX_CODE93_ALPHABET[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
- 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
- 'X', 'Y', 'Z', '-', '.', ' ', '$', '/', '+', '%', 'a', 'b', 'c', 'd', '*'};
-
- /**
- * These represent the encodings of characters, as patterns of wide and narrow bars.
- * The 9 least-significant bits of each int correspond to the pattern of wide and narrow.
- */
- const int ZX_CODE93_CHARACTER_ENCODINGS[] = {
- 0x114, 0x148, 0x144, 0x142, 0x128, 0x124, 0x122, 0x150, 0x112, 0x10A, // 0-9
- 0x1A8, 0x1A4, 0x1A2, 0x194, 0x192, 0x18A, 0x168, 0x164, 0x162, 0x134, // A-J
- 0x11A, 0x158, 0x14C, 0x146, 0x12C, 0x116, 0x1B4, 0x1B2, 0x1AC, 0x1A6, // K-T
- 0x196, 0x19A, 0x16C, 0x166, 0x136, 0x13A, // U-Z
- 0x12E, 0x1D4, 0x1D2, 0x1CA, 0x16E, 0x176, 0x1AE, // - - %
- 0x126, 0x1DA, 0x1D6, 0x132, 0x15E, // Control chars? $-*
- };
-
- const int ZX_CODE93_ASTERISK_ENCODING = 0x15E;
-
- @interface ZXCode93Reader ()
-
- @property (nonatomic, strong, readonly) ZXIntArray *counters;
-
- @end
-
- @implementation ZXCode93Reader
-
- + (void)initialize {
- if ([self class] != [ZXCode93Reader class]) return;
-
- ZX_CODE93_ALPHABET_STRING = [[NSString alloc] initWithCharacters:ZX_CODE93_ALPHABET
- length:sizeof(ZX_CODE93_ALPHABET) / sizeof(unichar)];
- }
-
- - (id)init {
- if (self = [super init]) {
- _counters = [[ZXIntArray alloc] initWithLength:6];
- }
-
- return self;
- }
-
- - (ZXResult *)decodeRow:(int)rowNumber row:(ZXBitArray *)row hints:(ZXDecodeHints *)hints error:(NSError **)error {
- ZXIntArray *start = [self findAsteriskPattern:row];
- if (!start) {
- if (error) *error = ZXNotFoundErrorInstance();
- return nil;
- }
- // Read off white space
- int nextStart = [row nextSet:start.array[1]];
- int end = row.size;
-
- ZXIntArray *theCounters = self.counters;
- memset(theCounters.array, 0, theCounters.length * sizeof(int32_t));
- NSMutableString *result = [NSMutableString string];
-
- unichar decodedChar;
- int lastStart;
- do {
- if (![ZXOneDReader recordPattern:row start:nextStart counters:theCounters]) {
- if (error) *error = ZXNotFoundErrorInstance();
- return nil;
- }
- int pattern = [self toPattern:theCounters];
- if (pattern < 0) {
- if (error) *error = ZXNotFoundErrorInstance();
- return nil;
- }
- decodedChar = [self patternToChar:pattern];
- if (decodedChar == 0) {
- if (error) *error = ZXNotFoundErrorInstance();
- return nil;
- }
- [result appendFormat:@"%C", decodedChar];
- lastStart = nextStart;
- for (int i = 0; i < theCounters.length; i++) {
- nextStart += theCounters.array[i];
- }
- // Read off white space
- nextStart = [row nextSet:nextStart];
- } while (decodedChar != '*');
- [result deleteCharactersInRange:NSMakeRange([result length] - 1, 1)]; // remove asterisk
-
- int lastPatternSize = [theCounters sum];
-
- // Should be at least one more black module
- if (nextStart == end || ![row get:nextStart]) {
- if (error) *error = ZXNotFoundErrorInstance();
- return nil;
- }
-
- if ([result length] < 2) {
- // false positive -- need at least 2 checksum digits
- if (error) *error = ZXNotFoundErrorInstance();
- return nil;
- }
-
- if (![self checkChecksums:result error:error]) {
- return nil;
- }
- [result deleteCharactersInRange:NSMakeRange([result length] - 2, 2)];
-
- NSString *resultString = [self decodeExtended:result];
- if (!resultString) {
- if (error) *error = ZXFormatErrorInstance();
- return nil;
- }
-
- float left = (float) (start.array[1] + start.array[0]) / 2.0f;
- float right = lastStart + lastPatternSize / 2.0f;
- return [ZXResult resultWithText:resultString
- rawBytes:nil
- resultPoints:@[[[ZXResultPoint alloc] initWithX:left y:(float)rowNumber],
- [[ZXResultPoint alloc] initWithX:right y:(float)rowNumber]]
- format:kBarcodeFormatCode93];
- }
-
- - (ZXIntArray *)findAsteriskPattern:(ZXBitArray *)row {
- int width = row.size;
- int rowOffset = [row nextSet:0];
-
- [self.counters clear];
- ZXIntArray *theCounters = self.counters;
- int patternStart = rowOffset;
- BOOL isWhite = NO;
- int patternLength = theCounters.length;
-
- int counterPosition = 0;
- for (int i = rowOffset; i < width; i++) {
- if ([row get:i] ^ isWhite) {
- theCounters.array[counterPosition]++;
- } else {
- if (counterPosition == patternLength - 1) {
- if ([self toPattern:theCounters] == ZX_CODE93_ASTERISK_ENCODING) {
- return [[ZXIntArray alloc] initWithInts:patternStart, i, -1];
- }
- patternStart += theCounters.array[0] + theCounters.array[1];
- for (int y = 2; y < patternLength; y++) {
- theCounters.array[y - 2] = theCounters.array[y];
- }
- theCounters.array[patternLength - 2] = 0;
- theCounters.array[patternLength - 1] = 0;
- counterPosition--;
- } else {
- counterPosition++;
- }
- theCounters.array[counterPosition] = 1;
- isWhite = !isWhite;
- }
- }
-
- return nil;
- }
-
- - (int)toPattern:(ZXIntArray *)counters {
- int max = counters.length;
- int sum = [counters sum];
- int32_t *array = counters.array;
- int pattern = 0;
- for (int i = 0; i < max; i++) {
- int scaled = round(array[i] * 9.0f / sum);
- if (scaled < 1 || scaled > 4) {
- return -1;
- }
- if ((i & 0x01) == 0) {
- for (int j = 0; j < scaled; j++) {
- pattern = (pattern << 1) | 0x01;
- }
- } else {
- pattern <<= scaled;
- }
- }
- return pattern;
- }
-
- - (unichar)patternToChar:(int)pattern {
- for (int i = 0; i < sizeof(ZX_CODE93_CHARACTER_ENCODINGS) / sizeof(int); i++) {
- if (ZX_CODE93_CHARACTER_ENCODINGS[i] == pattern) {
- return ZX_CODE93_ALPHABET[i];
- }
- }
-
- return -1;
- }
-
- - (NSString *)decodeExtended:(NSMutableString *)encoded {
- NSUInteger length = [encoded length];
- NSMutableString *decoded = [NSMutableString stringWithCapacity:length];
- for (int i = 0; i < length; i++) {
- unichar c = [encoded characterAtIndex:i];
- if (c >= 'a' && c <= 'd') {
- if (i >= length - 1) {
- return nil;
- }
- unichar next = [encoded characterAtIndex:i + 1];
- unichar decodedChar = '\0';
- switch (c) {
- case 'd':
- if (next >= 'A' && next <= 'Z') {
- decodedChar = (unichar)(next + 32);
- } else {
- return nil;
- }
- break;
- case 'a':
- if (next >= 'A' && next <= 'Z') {
- decodedChar = (unichar)(next - 64);
- } else {
- return nil;
- }
- break;
- case 'b':
- if (next >= 'A' && next <= 'E') {
- decodedChar = (unichar)(next - 38);
- } else if (next >= 'F' && next <= 'W') {
- decodedChar = (unichar)(next - 11);
- } else {
- return nil;
- }
- break;
- case 'c':
- if (next >= 'A' && next <= 'O') {
- decodedChar = (unichar)(next - 32);
- } else if (next == 'Z') {
- decodedChar = ':';
- } else {
- return nil;
- }
- break;
- }
- [decoded appendFormat:@"%C", decodedChar];
- i++;
- } else {
- [decoded appendFormat:@"%C", c];
- }
- }
-
- return decoded;
- }
-
- - (BOOL)checkChecksums:(NSMutableString *)result error:(NSError **)error {
- NSUInteger length = [result length];
- if (![self checkOneChecksum:result checkPosition:(int)length - 2 weightMax:20 error:error]) {
- return NO;
- }
- return [self checkOneChecksum:result checkPosition:(int)length - 1 weightMax:15 error:error];
- }
-
- - (BOOL)checkOneChecksum:(NSMutableString *)result checkPosition:(int)checkPosition weightMax:(int)weightMax error:(NSError **)error {
- int weight = 1;
- int total = 0;
-
- for (int i = checkPosition - 1; i >= 0; i--) {
- total += weight * [ZX_CODE93_ALPHABET_STRING rangeOfString:[NSString stringWithFormat:@"%C", [result characterAtIndex:i]]].location;
- if (++weight > weightMax) {
- weight = 1;
- }
- }
-
- if ([result characterAtIndex:checkPosition] != ZX_CODE93_ALPHABET[total % 47]) {
- if (error) *error = ZXChecksumErrorInstance();
- return NO;
- }
- return YES;
- }
-
- @end
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