/* * Copyright 2008 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. */ use rxing_one_d_proc_derive::{EANReader, OneDReader}; use super::UPCEANReader; use super::upc_ean_reader; use super::OneDReader; use crate::common::Result; use crate::BarcodeFormat; use crate::Exceptions; /** *

Implements decoding of the EAN-13 format.

* * @author dswitkin@google.com (Daniel Switkin) * @author Sean Owen * @author alasdair@google.com (Alasdair Mackintosh) */ #[derive(OneDReader, EANReader, Default)] pub struct EAN13Reader; impl UPCEANReader for EAN13Reader { fn getBarcodeFormat(&self) -> crate::BarcodeFormat { BarcodeFormat::EAN_13 } fn decodeMiddle( &self, row: &crate::common::BitArray, startRange: &[usize; 2], resultString: &mut String, ) -> Result { let mut counters = [0_u32; 4]; //decodeMiddleCounters; // counters[0] = 0; // counters[1] = 0; // counters[2] = 0; // counters[3] = 0; let end = row.getSize(); let mut rowOffset = startRange[1]; let mut lgPatternFound = 0; let mut x = 0; while x < 6 && rowOffset < end { // for (int x = 0; x < 6 && rowOffset < end; x++) { let bestMatch = self.decodeDigit( row, &mut counters, rowOffset, &upc_ean_reader::L_AND_G_PATTERNS, )?; resultString .push(char::from_u32('0' as u32 + bestMatch as u32 % 10).ok_or(Exceptions::parse)?); rowOffset += counters.iter().sum::() as usize; if bestMatch >= 10 { lgPatternFound |= 1 << (5 - x); } x += 1; } Self::determineFirstDigit(resultString, lgPatternFound)?; let middleRange = self.findGuardPattern(row, rowOffset, true, &upc_ean_reader::MIDDLE_PATTERN)?; rowOffset = middleRange[1]; let mut x = 0; while x < 6 && rowOffset < end { let bestMatch = self.decodeDigit(row, &mut counters, rowOffset, &upc_ean_reader::L_PATTERNS)?; resultString .push(char::from_u32('0' as u32 + bestMatch as u32).ok_or(Exceptions::parse)?); rowOffset += counters.iter().sum::() as usize; x += 1; } Ok(rowOffset) } } impl EAN13Reader { // For an EAN-13 barcode, the first digit is represented by the parities used // to encode the next six digits, according to the table below. For example, // if the barcode is 5 123456 789012 then the value of the first digit is // signified by using odd for '1', even for '2', even for '3', odd for '4', // odd for '5', and even for '6'. See http://en.wikipedia.org/wiki/EAN-13 // // Parity of next 6 digits // Digit 0 1 2 3 4 5 // 0 Odd Odd Odd Odd Odd Odd // 1 Odd Odd Even Odd Even Even // 2 Odd Odd Even Even Odd Even // 3 Odd Odd Even Even Even Odd // 4 Odd Even Odd Odd Even Even // 5 Odd Even Even Odd Odd Even // 6 Odd Even Even Even Odd Odd // 7 Odd Even Odd Even Odd Even // 8 Odd Even Odd Even Even Odd // 9 Odd Even Even Odd Even Odd // // Note that the encoding for '0' uses the same parity as a UPC barcode. Hence // a UPC barcode can be converted to an EAN-13 barcode by prepending a 0. // // The encoding is represented by the following array, which is a bit pattern // using Odd = 0 and Even = 1. For example, 5 is represented by: // // Odd Even Even Odd Odd Even // in binary: // 0 1 1 0 0 1 == 0x19 // pub const FIRST_DIGIT_ENCODINGS: [usize; 10] = [0x00, 0x0B, 0x0D, 0xE, 0x13, 0x19, 0x1C, 0x15, 0x16, 0x1A]; /** * Based on pattern of odd-even ('L' and 'G') patterns used to encoded the explicitly-encoded * digits in a barcode, determines the implicitly encoded first digit and adds it to the * result string. * * @param resultString string to insert decoded first digit into * @param lgPatternFound int whose bits indicates the pattern of odd/even L/G patterns used to * encode digits * @throws NotFoundException if first digit cannot be determined */ fn determineFirstDigit(resultString: &mut String, lgPatternFound: usize) -> Result<()> { for d in 0..10 { // for (int d = 0; d < 10; d++) { if lgPatternFound == Self::FIRST_DIGIT_ENCODINGS[d] { resultString.insert( 0, char::from_u32('0' as u32 + d as u32).ok_or(Exceptions::parse)?, ); return Ok(()); } } Err(Exceptions::notFound) } }