<?php
/*
* 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.
*/
namespace Zxing\Qrcode\Decoder;
/**
* <p>Encapsulates a block of data within a QR Code. QR Codes may split their data into
* multiple blocks, each of which is a unit of data and error-correction codewords. Each
* is represented by an instance of this class.</p>
*
* @author Sean Owen
*/
final class DataBlock
{
//byte[]
private function __construct(private $numDataCodewords, private $codewords)
{
}
/**
* <p>When QR Codes use multiple data blocks, they are actually interleaved.
* That is, the first byte of data block 1 to n is written, then the second bytes, and so on. This
* method will separate the data into original blocks.</p>
*
* @param array $rawCodewords as read directly from the QR Code
* @param Version $version of the QR Code
* @param ErrorCorrectionLevel $ecLevel error-correction level of the QR Code
*
* @return \Zxing\Qrcode\Decoder\DataBlock[] DataBlocks containing original bytes, "de-interleaved" from representation in the
QR Code
*/
public static function getDataBlocks(
$rawCodewords,
Version $version,
ErrorCorrectionLevel $ecLevel
): array {
if ((is_countable($rawCodewords) ? count($rawCodewords) : 0) != $version->getTotalCodewords()) {
throw new \InvalidArgumentException();
}
// Figure out the number and size of data blocks used by this version and
// error correction level
$ecBlocks = $version->getECBlocksForLevel($ecLevel);
// First count the total number of data blocks
$totalBlocks = 0;
$ecBlockArray = $ecBlocks->getECBlocks();
foreach ($ecBlockArray as $ecBlock) {
$totalBlocks += $ecBlock->getCount();
}
// Now establish DataBlocks of the appropriate size and number of data codewords
$result = []; //new DataBlock[$totalBlocks];
$numResultBlocks = 0;
foreach ($ecBlockArray as $ecBlock) {
$ecBlockCount = $ecBlock->getCount();
for ($i = 0; $i < $ecBlockCount; $i++) {
$numDataCodewords = $ecBlock->getDataCodewords();
$numBlockCodewords = $ecBlocks->getECCodewordsPerBlock() + $numDataCodewords;
$result[$numResultBlocks++] = new DataBlock($numDataCodewords, fill_array(0, $numBlockCodewords, 0));
}
}
// All blocks have the same amount of data, except that the last n
// (where n may be 0) have 1 more byte. Figure out where these start.
$shorterBlocksTotalCodewords = is_countable($result[0]->codewords) ? count($result[0]->codewords) : 0;
$longerBlocksStartAt = count($result) - 1;
while ($longerBlocksStartAt >= 0) {
$numCodewords = is_countable($result[$longerBlocksStartAt]->codewords) ? count($result[$longerBlocksStartAt]->codewords) : 0;
if ($numCodewords == $shorterBlocksTotalCodewords) {
break;
}
$longerBlocksStartAt--;
}
$longerBlocksStartAt++;
$shorterBlocksNumDataCodewords = $shorterBlocksTotalCodewords - $ecBlocks->getECCodewordsPerBlock();
// The last elements of result may be 1 element longer;
// first fill out as many elements as all of them have
$rawCodewordsOffset = 0;
for ($i = 0; $i < $shorterBlocksNumDataCodewords; $i++) {
for ($j = 0; $j < $numResultBlocks; $j++) {
$result[$j]->codewords[$i] = $rawCodewords[$rawCodewordsOffset++];
}
}
// Fill out the last data block in the longer ones
for ($j = $longerBlocksStartAt; $j < $numResultBlocks; $j++) {
$result[$j]->codewords[$shorterBlocksNumDataCodewords] = $rawCodewords[$rawCodewordsOffset++];
}
// Now add in error correction blocks
$max = is_countable($result[0]->codewords) ? count($result[0]->codewords) : 0;
for ($i = $shorterBlocksNumDataCodewords; $i < $max; $i++) {
for ($j = 0; $j < $numResultBlocks; $j++) {
$iOffset = $j < $longerBlocksStartAt ? $i : $i + 1;
$result[$j]->codewords[$iOffset] = $rawCodewords[$rawCodewordsOffset++];
}
}
return $result;
}
public function getNumDataCodewords()
{
return $this->numDataCodewords;
}
public function getCodewords()
{
return $this->codewords;
}
}