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/*
* Copyright 2007 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 crate::{
common::{BitMatrix, Result},
Exceptions,
};
use super::{DataMask, FormatInformation, Version, VersionRef};
/**
* @author Sean Owen
*/
pub struct BitMatrixParser {
bitMatrix: BitMatrix,
parsedVersion: Option<VersionRef>,
parsedFormatInfo: Option<FormatInformation>,
mirror: bool,
}
impl BitMatrixParser {
/**
* @param bitMatrix {@link BitMatrix} to parse
* @throws FormatException if dimension is not >= 21 and 1 mod 4
*/
pub fn new(bit_matrix: BitMatrix) -> Result<Self> {
let dimension = bit_matrix.getHeight();
if dimension < 21 || (dimension & 0x03) != 1 {
Err(Exceptions::format_with(format!(
"{dimension} < 21 || ({dimension} % 0x03) != 1"
)))
} else {
Ok(Self {
bitMatrix: bit_matrix,
parsedVersion: None,
parsedFormatInfo: None,
mirror: false,
})
}
}
/**
* <p>Reads format information from one of its two locations within the QR Code.</p>
*
* @return {@link FormatInformation} encapsulating the QR Code's format info
* @throws FormatException if both format information locations cannot be parsed as
* the valid encoding of format information
*/
pub fn readFormatInformation(&mut self) -> Result<&FormatInformation> {
if self.parsedFormatInfo.is_some() {
return self.parsedFormatInfo.as_ref().ok_or(Exceptions::PARSE);
}
// Read top-left format info bits
let mut formatInfoBits1 = 0;
for i in 0..6 {
formatInfoBits1 = self.copyBit(i, 8, formatInfoBits1);
}
// .. and skip a bit in the timing pattern ...
formatInfoBits1 = self.copyBit(7, 8, formatInfoBits1);
formatInfoBits1 = self.copyBit(8, 8, formatInfoBits1);
formatInfoBits1 = self.copyBit(8, 7, formatInfoBits1);
// .. and skip a bit in the timing pattern ...
for j in (0..=5).rev() {
formatInfoBits1 = self.copyBit(8, j, formatInfoBits1);
}
// Read the top-right/bottom-left pattern too
let dimension = self.bitMatrix.getHeight();
let mut formatInfoBits2 = 0;
let jMin = dimension - 7;
for j in (jMin..=dimension - 1).rev() {
formatInfoBits2 = self.copyBit(8, j, formatInfoBits2);
}
for i in (dimension - 8)..dimension {
formatInfoBits2 = self.copyBit(i, 8, formatInfoBits2);
}
self.parsedFormatInfo =
FormatInformation::decodeFormatInformation(formatInfoBits1, formatInfoBits2);
self.parsedFormatInfo.as_ref().ok_or(Exceptions::FORMAT)
}
/**
* <p>Reads version information from one of its two locations within the QR Code.</p>
*
* @return {@link Version} encapsulating the QR Code's version
* @throws FormatException if both version information locations cannot be parsed as
* the valid encoding of version information
*/
pub fn readVersion(&mut self) -> Result<VersionRef> {
if let Some(pv) = self.parsedVersion {
return Ok(pv);
}
let dimension = self.bitMatrix.getHeight();
let provisionalVersion = (dimension - 17) / 4;
if provisionalVersion <= 6 {
return Version::getVersionForNumber(provisionalVersion);
}
// Read top-right version info: 3 wide by 6 tall
let mut versionBits = 0;
let ijMin = dimension - 11;
for j in (0..=5).rev() {
for i in (ijMin..(dimension - 8)).rev() {
versionBits = self.copyBit(i, j, versionBits);
}
}
if let Ok(theParsedVersion) = Version::decodeVersionInformation(versionBits) {
if theParsedVersion.getDimensionForVersion() == dimension {
self.parsedVersion = Some(theParsedVersion);
return Ok(theParsedVersion);
}
}
// Hmm, failed. Try bottom left: 6 wide by 3 tall
versionBits = 0;
for i in (0..=5).rev() {
for j in (ijMin..(dimension - 5)).rev() {
versionBits = self.copyBit(i, j, versionBits);
}
}
if let Ok(theParsedVersion) = Version::decodeVersionInformation(versionBits) {
if theParsedVersion.getDimensionForVersion() == dimension {
self.parsedVersion = Some(theParsedVersion);
return Ok(theParsedVersion);
}
}
Err(Exceptions::FORMAT)
}
fn copyBit(&self, i: u32, j: u32, versionBits: u32) -> u32 {
let bit = if self.mirror {
self.bitMatrix.get(j, i)
} else {
self.bitMatrix.get(i, j)
};
if bit {
(versionBits << 1) | 0x1
} else {
versionBits << 1
}
}
/**
* <p>Reads the bits in the {@link BitMatrix} representing the finder pattern in the
* correct order in order to reconstruct the codewords bytes contained within the
* QR Code.</p>
*
* @return bytes encoded within the QR Code
* @throws FormatException if the exact number of bytes expected is not read
*/
pub fn readCodewords(&mut self) -> Result<Vec<u8>> {
let version = self.readVersion()?;
// Get the data mask for the format used in this QR Code. This will exclude
// some bits from reading as we wind through the bit matrix.
let dataMask: DataMask = self.readFormatInformation()?.getDataMask().try_into()?;
let dimension = self.bitMatrix.getHeight();
dataMask.unmaskBitMatrix(&mut self.bitMatrix, dimension);
let functionPattern = version.buildFunctionPattern()?;
let mut readingUp = true;
let mut result = vec![0u8; version.getTotalCodewords() as usize];
let mut resultOffset = 0;
let mut currentByte = 0;
let mut bitsRead = 0;
// Read columns in pairs, from right to left
let mut j = dimension as i32 - 1;
while j > 0 {
if j == 6 {
// Skip whole column with vertical alignment pattern;
// saves time and makes the other code proceed more cleanly
j -= 1;
}
// Read alternatingly from bottom to top then top to bottom
for count in 0..dimension {
let i = if readingUp {
dimension - 1 - count
} else {
count
};
for col in 0..2 {
// Ignore bits covered by the function pattern
if !functionPattern.get(j as u32 - col, i) {
// Read a bit
bitsRead += 1;
currentByte <<= 1;
if self.bitMatrix.get(j as u32 - col, i) {
currentByte |= 1;
}
// If we've made a whole byte, save it off
if bitsRead == 8 {
result[resultOffset] = currentByte;
resultOffset += 1;
bitsRead = 0;
currentByte = 0;
}
}
}
}
readingUp ^= true; // readingUp = !readingUp; // switch directions
j -= 2;
}
if resultOffset != version.getTotalCodewords() as usize {
return Err(Exceptions::FORMAT);
}
Ok(result)
}
/**
* Revert the mask removal done while reading the code words. The bit matrix should revert to its original state.
*/
pub fn remask(&mut self) -> Result<()> {
if let Some(pfi) = &self.parsedFormatInfo {
let dataMask: DataMask = pfi.getDataMask().try_into()?;
let dimension = self.bitMatrix.getHeight();
dataMask.unmaskBitMatrix(&mut self.bitMatrix, dimension);
} else {
// We have no format information, and have no data mask
}
Ok(())
}
/**
* Prepare the parser for a mirrored operation.
* This flag has effect only on the {@link #readFormatInformation()} and the
* {@link #readVersion()}. Before proceeding with {@link #readCodewords()} the
* {@link #mirror()} method should be called.
*
* @param mirror Whether to read version and format information mirrored.
*/
pub fn setMirror(&mut self, mirror: bool) {
self.parsedVersion = None;
self.parsedFormatInfo = None;
self.mirror = mirror;
}
/** Mirror the bit matrix in order to attempt a second reading. */
pub fn mirror(&mut self) {
for x in 0..self.bitMatrix.getWidth() {
for y in (x + 1)..self.bitMatrix.getHeight() {
if self.bitMatrix.get(x, y) != self.bitMatrix.get(y, x) {
self.bitMatrix.flip_coords(y, x);
self.bitMatrix.flip_coords(x, y);
}
}
}
}
}