653 Zeilen
21 KiB
PHP
653 Zeilen
21 KiB
PHP
<?php
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declare(strict_types = 1);
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namespace BaconQrCode\Encoder;
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use BaconQrCode\Common\BitArray;
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use BaconQrCode\Common\CharacterSetEci;
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use BaconQrCode\Common\ErrorCorrectionLevel;
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use BaconQrCode\Common\Mode;
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use BaconQrCode\Common\ReedSolomonCodec;
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use BaconQrCode\Common\Version;
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use BaconQrCode\Exception\WriterException;
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use SplFixedArray;
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/**
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* Encoder.
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*/
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final class Encoder
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{
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/**
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* Default byte encoding.
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*/
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public const DEFAULT_BYTE_MODE_ECODING = 'ISO-8859-1';
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/**
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* The original table is defined in the table 5 of JISX0510:2004 (p.19).
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*/
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private const ALPHANUMERIC_TABLE = [
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x00-0x0f
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x10-0x1f
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36, -1, -1, -1, 37, 38, -1, -1, -1, -1, 39, 40, -1, 41, 42, 43, // 0x20-0x2f
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0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 44, -1, -1, -1, -1, -1, // 0x30-0x3f
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-1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, // 0x40-0x4f
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25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, -1, -1, -1, -1, -1, // 0x50-0x5f
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];
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/**
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* Codec cache.
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*
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* @var array
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*/
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private static $codecs = [];
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/**
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* Encodes "content" with the error correction level "ecLevel".
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*/
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public static function encode(
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string $content,
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ErrorCorrectionLevel $ecLevel,
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string $encoding = self::DEFAULT_BYTE_MODE_ECODING
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) : QrCode {
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// Pick an encoding mode appropriate for the content. Note that this
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// will not attempt to use multiple modes / segments even if that were
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// more efficient. Would be nice.
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$mode = self::chooseMode($content, $encoding);
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// This will store the header information, like mode and length, as well
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// as "header" segments like an ECI segment.
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$headerBits = new BitArray();
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// Append ECI segment if applicable
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if (Mode::BYTE() === $mode && self::DEFAULT_BYTE_MODE_ECODING !== $encoding) {
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$eci = CharacterSetEci::getCharacterSetEciByName($encoding);
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if (null !== $eci) {
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self::appendEci($eci, $headerBits);
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}
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}
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// (With ECI in place,) Write the mode marker
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self::appendModeInfo($mode, $headerBits);
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// Collect data within the main segment, separately, to count its size
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// if needed. Don't add it to main payload yet.
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$dataBits = new BitArray();
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self::appendBytes($content, $mode, $dataBits, $encoding);
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// Hard part: need to know version to know how many bits length takes.
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// But need to know how many bits it takes to know version. First we
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// take a guess at version by assuming version will be the minimum, 1:
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$provisionalBitsNeeded = $headerBits->getSize()
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+ $mode->getCharacterCountBits(Version::getVersionForNumber(1))
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+ $dataBits->getSize();
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$provisionalVersion = self::chooseVersion($provisionalBitsNeeded, $ecLevel);
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// Use that guess to calculate the right version. I am still not sure
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// this works in 100% of cases.
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$bitsNeeded = $headerBits->getSize()
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+ $mode->getCharacterCountBits($provisionalVersion)
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+ $dataBits->getSize();
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$version = self::chooseVersion($bitsNeeded, $ecLevel);
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$headerAndDataBits = new BitArray();
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$headerAndDataBits->appendBitArray($headerBits);
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// Find "length" of main segment and write it.
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$numLetters = (Mode::BYTE() === $mode ? $dataBits->getSizeInBytes() : strlen($content));
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self::appendLengthInfo($numLetters, $version, $mode, $headerAndDataBits);
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// Put data together into the overall payload.
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$headerAndDataBits->appendBitArray($dataBits);
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$ecBlocks = $version->getEcBlocksForLevel($ecLevel);
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$numDataBytes = $version->getTotalCodewords() - $ecBlocks->getTotalEcCodewords();
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// Terminate the bits properly.
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self::terminateBits($numDataBytes, $headerAndDataBits);
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// Interleave data bits with error correction code.
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$finalBits = self::interleaveWithEcBytes(
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$headerAndDataBits,
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$version->getTotalCodewords(),
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$numDataBytes,
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$ecBlocks->getNumBlocks()
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);
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// Choose the mask pattern.
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$dimension = $version->getDimensionForVersion();
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$matrix = new ByteMatrix($dimension, $dimension);
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$maskPattern = self::chooseMaskPattern($finalBits, $ecLevel, $version, $matrix);
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// Build the matrix.
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MatrixUtil::buildMatrix($finalBits, $ecLevel, $version, $maskPattern, $matrix);
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return new QrCode($mode, $ecLevel, $version, $maskPattern, $matrix);
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}
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/**
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* Gets the alphanumeric code for a byte.
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*/
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private static function getAlphanumericCode(int $code) : int
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{
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if (isset(self::ALPHANUMERIC_TABLE[$code])) {
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return self::ALPHANUMERIC_TABLE[$code];
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}
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return -1;
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}
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/**
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* Chooses the best mode for a given content.
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*/
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private static function chooseMode(string $content, string $encoding = null) : Mode
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{
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if (null !== $encoding && 0 === strcasecmp($encoding, 'SHIFT-JIS')) {
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return self::isOnlyDoubleByteKanji($content) ? Mode::KANJI() : Mode::BYTE();
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}
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$hasNumeric = false;
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$hasAlphanumeric = false;
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$contentLength = strlen($content);
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for ($i = 0; $i < $contentLength; ++$i) {
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$char = $content[$i];
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if (ctype_digit($char)) {
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$hasNumeric = true;
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} elseif (-1 !== self::getAlphanumericCode(ord($char))) {
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$hasAlphanumeric = true;
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} else {
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return Mode::BYTE();
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}
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}
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if ($hasAlphanumeric) {
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return Mode::ALPHANUMERIC();
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} elseif ($hasNumeric) {
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return Mode::NUMERIC();
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}
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return Mode::BYTE();
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}
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/**
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* Calculates the mask penalty for a matrix.
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*/
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private static function calculateMaskPenalty(ByteMatrix $matrix) : int
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{
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return (
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MaskUtil::applyMaskPenaltyRule1($matrix)
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+ MaskUtil::applyMaskPenaltyRule2($matrix)
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+ MaskUtil::applyMaskPenaltyRule3($matrix)
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+ MaskUtil::applyMaskPenaltyRule4($matrix)
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);
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}
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/**
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* Checks if content only consists of double-byte kanji characters.
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*/
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private static function isOnlyDoubleByteKanji(string $content) : bool
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{
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$bytes = @iconv('utf-8', 'SHIFT-JIS', $content);
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if (false === $bytes) {
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return false;
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}
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$length = strlen($bytes);
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if (0 !== $length % 2) {
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return false;
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}
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for ($i = 0; $i < $length; $i += 2) {
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$byte = $bytes[$i] & 0xff;
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if (($byte < 0x81 || $byte > 0x9f) && $byte < 0xe0 || $byte > 0xeb) {
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return false;
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}
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}
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return true;
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}
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/**
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* Chooses the best mask pattern for a matrix.
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*/
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private static function chooseMaskPattern(
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BitArray $bits,
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ErrorCorrectionLevel $ecLevel,
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Version $version,
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ByteMatrix $matrix
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) : int {
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$minPenalty = PHP_INT_MAX;
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$bestMaskPattern = -1;
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for ($maskPattern = 0; $maskPattern < QrCode::NUM_MASK_PATTERNS; ++$maskPattern) {
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MatrixUtil::buildMatrix($bits, $ecLevel, $version, $maskPattern, $matrix);
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$penalty = self::calculateMaskPenalty($matrix);
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if ($penalty < $minPenalty) {
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$minPenalty = $penalty;
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$bestMaskPattern = $maskPattern;
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}
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}
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return $bestMaskPattern;
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}
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/**
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* Chooses the best version for the input.
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*
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* @throws WriterException if data is too big
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*/
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private static function chooseVersion(int $numInputBits, ErrorCorrectionLevel $ecLevel) : Version
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{
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for ($versionNum = 1; $versionNum <= 40; ++$versionNum) {
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$version = Version::getVersionForNumber($versionNum);
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$numBytes = $version->getTotalCodewords();
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$ecBlocks = $version->getEcBlocksForLevel($ecLevel);
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$numEcBytes = $ecBlocks->getTotalEcCodewords();
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$numDataBytes = $numBytes - $numEcBytes;
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$totalInputBytes = intdiv($numInputBits + 8, 8);
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if ($numDataBytes >= $totalInputBytes) {
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return $version;
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}
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}
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throw new WriterException('Data too big');
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}
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/**
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* Terminates the bits in a bit array.
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*
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* @throws WriterException if data bits cannot fit in the QR code
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* @throws WriterException if bits size does not equal the capacity
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*/
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private static function terminateBits(int $numDataBytes, BitArray $bits) : void
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{
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$capacity = $numDataBytes << 3;
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if ($bits->getSize() > $capacity) {
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throw new WriterException('Data bits cannot fit in the QR code');
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}
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for ($i = 0; $i < 4 && $bits->getSize() < $capacity; ++$i) {
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$bits->appendBit(false);
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}
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$numBitsInLastByte = $bits->getSize() & 0x7;
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if ($numBitsInLastByte > 0) {
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for ($i = $numBitsInLastByte; $i < 8; ++$i) {
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$bits->appendBit(false);
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}
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}
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$numPaddingBytes = $numDataBytes - $bits->getSizeInBytes();
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for ($i = 0; $i < $numPaddingBytes; ++$i) {
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$bits->appendBits(0 === ($i & 0x1) ? 0xec : 0x11, 8);
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}
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if ($bits->getSize() !== $capacity) {
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throw new WriterException('Bits size does not equal capacity');
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}
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}
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/**
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* Gets number of data- and EC bytes for a block ID.
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*
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* @return int[]
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* @throws WriterException if block ID is too large
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* @throws WriterException if EC bytes mismatch
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* @throws WriterException if RS blocks mismatch
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* @throws WriterException if total bytes mismatch
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*/
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private static function getNumDataBytesAndNumEcBytesForBlockId(
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int $numTotalBytes,
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int $numDataBytes,
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int $numRsBlocks,
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int $blockId
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) : array {
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if ($blockId >= $numRsBlocks) {
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throw new WriterException('Block ID too large');
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}
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$numRsBlocksInGroup2 = $numTotalBytes % $numRsBlocks;
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$numRsBlocksInGroup1 = $numRsBlocks - $numRsBlocksInGroup2;
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$numTotalBytesInGroup1 = intdiv($numTotalBytes, $numRsBlocks);
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$numTotalBytesInGroup2 = $numTotalBytesInGroup1 + 1;
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$numDataBytesInGroup1 = intdiv($numDataBytes, $numRsBlocks);
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$numDataBytesInGroup2 = $numDataBytesInGroup1 + 1;
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$numEcBytesInGroup1 = $numTotalBytesInGroup1 - $numDataBytesInGroup1;
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$numEcBytesInGroup2 = $numTotalBytesInGroup2 - $numDataBytesInGroup2;
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if ($numEcBytesInGroup1 !== $numEcBytesInGroup2) {
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throw new WriterException('EC bytes mismatch');
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}
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if ($numRsBlocks !== $numRsBlocksInGroup1 + $numRsBlocksInGroup2) {
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throw new WriterException('RS blocks mismatch');
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}
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if ($numTotalBytes !==
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(($numDataBytesInGroup1 + $numEcBytesInGroup1) * $numRsBlocksInGroup1)
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+ (($numDataBytesInGroup2 + $numEcBytesInGroup2) * $numRsBlocksInGroup2)
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) {
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throw new WriterException('Total bytes mismatch');
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}
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if ($blockId < $numRsBlocksInGroup1) {
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return [$numDataBytesInGroup1, $numEcBytesInGroup1];
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} else {
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return [$numDataBytesInGroup2, $numEcBytesInGroup2];
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}
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}
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/**
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* Interleaves data with EC bytes.
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*
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* @throws WriterException if number of bits and data bytes does not match
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* @throws WriterException if data bytes does not match offset
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* @throws WriterException if an interleaving error occurs
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*/
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private static function interleaveWithEcBytes(
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BitArray $bits,
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int $numTotalBytes,
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int $numDataBytes,
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int $numRsBlocks
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) : BitArray {
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if ($bits->getSizeInBytes() !== $numDataBytes) {
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throw new WriterException('Number of bits and data bytes does not match');
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}
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$dataBytesOffset = 0;
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$maxNumDataBytes = 0;
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$maxNumEcBytes = 0;
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$blocks = new SplFixedArray($numRsBlocks);
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for ($i = 0; $i < $numRsBlocks; ++$i) {
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list($numDataBytesInBlock, $numEcBytesInBlock) = self::getNumDataBytesAndNumEcBytesForBlockId(
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$numTotalBytes,
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$numDataBytes,
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$numRsBlocks,
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$i
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);
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$size = $numDataBytesInBlock;
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$dataBytes = $bits->toBytes(8 * $dataBytesOffset, $size);
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$ecBytes = self::generateEcBytes($dataBytes, $numEcBytesInBlock);
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$blocks[$i] = new BlockPair($dataBytes, $ecBytes);
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$maxNumDataBytes = max($maxNumDataBytes, $size);
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$maxNumEcBytes = max($maxNumEcBytes, count($ecBytes));
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$dataBytesOffset += $numDataBytesInBlock;
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}
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if ($numDataBytes !== $dataBytesOffset) {
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throw new WriterException('Data bytes does not match offset');
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}
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$result = new BitArray();
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for ($i = 0; $i < $maxNumDataBytes; ++$i) {
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foreach ($blocks as $block) {
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$dataBytes = $block->getDataBytes();
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if ($i < count($dataBytes)) {
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$result->appendBits($dataBytes[$i], 8);
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}
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}
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}
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for ($i = 0; $i < $maxNumEcBytes; ++$i) {
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foreach ($blocks as $block) {
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$ecBytes = $block->getErrorCorrectionBytes();
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if ($i < count($ecBytes)) {
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$result->appendBits($ecBytes[$i], 8);
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}
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}
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}
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if ($numTotalBytes !== $result->getSizeInBytes()) {
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throw new WriterException(
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'Interleaving error: ' . $numTotalBytes . ' and ' . $result->getSizeInBytes() . ' differ'
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);
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}
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return $result;
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}
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/**
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* Generates EC bytes for given data.
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*
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* @param SplFixedArray<int> $dataBytes
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* @return SplFixedArray<int>
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*/
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private static function generateEcBytes(SplFixedArray $dataBytes, int $numEcBytesInBlock) : SplFixedArray
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{
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$numDataBytes = count($dataBytes);
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$toEncode = new SplFixedArray($numDataBytes + $numEcBytesInBlock);
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for ($i = 0; $i < $numDataBytes; $i++) {
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$toEncode[$i] = $dataBytes[$i] & 0xff;
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}
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$ecBytes = new SplFixedArray($numEcBytesInBlock);
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$codec = self::getCodec($numDataBytes, $numEcBytesInBlock);
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$codec->encode($toEncode, $ecBytes);
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return $ecBytes;
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}
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/**
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* Gets an RS codec and caches it.
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*/
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private static function getCodec(int $numDataBytes, int $numEcBytesInBlock) : ReedSolomonCodec
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{
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$cacheId = $numDataBytes . '-' . $numEcBytesInBlock;
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if (isset(self::$codecs[$cacheId])) {
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return self::$codecs[$cacheId];
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}
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return self::$codecs[$cacheId] = new ReedSolomonCodec(
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8,
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0x11d,
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0,
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1,
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$numEcBytesInBlock,
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255 - $numDataBytes - $numEcBytesInBlock
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);
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}
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/**
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* Appends mode information to a bit array.
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*/
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private static function appendModeInfo(Mode $mode, BitArray $bits) : void
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{
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$bits->appendBits($mode->getBits(), 4);
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}
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/**
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* Appends length information to a bit array.
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*
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* @throws WriterException if num letters is bigger than expected
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*/
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private static function appendLengthInfo(int $numLetters, Version $version, Mode $mode, BitArray $bits) : void
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{
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$numBits = $mode->getCharacterCountBits($version);
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if ($numLetters >= (1 << $numBits)) {
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throw new WriterException($numLetters . ' is bigger than ' . ((1 << $numBits) - 1));
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}
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$bits->appendBits($numLetters, $numBits);
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}
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/**
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* Appends bytes to a bit array in a specific mode.
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*
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* @throws WriterException if an invalid mode was supplied
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*/
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private static function appendBytes(string $content, Mode $mode, BitArray $bits, string $encoding) : void
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{
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switch ($mode) {
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case Mode::NUMERIC():
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self::appendNumericBytes($content, $bits);
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break;
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case Mode::ALPHANUMERIC():
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self::appendAlphanumericBytes($content, $bits);
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break;
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case Mode::BYTE():
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self::append8BitBytes($content, $bits, $encoding);
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break;
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case Mode::KANJI():
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self::appendKanjiBytes($content, $bits);
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break;
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default:
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throw new WriterException('Invalid mode: ' . $mode);
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}
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}
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/**
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* Appends numeric bytes to a bit array.
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*/
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private static function appendNumericBytes(string $content, BitArray $bits) : void
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|
{
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$length = strlen($content);
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$i = 0;
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|
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while ($i < $length) {
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$num1 = (int) $content[$i];
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|
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if ($i + 2 < $length) {
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// Encode three numeric letters in ten bits.
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$num2 = (int) $content[$i + 1];
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$num3 = (int) $content[$i + 2];
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$bits->appendBits($num1 * 100 + $num2 * 10 + $num3, 10);
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|
$i += 3;
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|
} elseif ($i + 1 < $length) {
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|
// Encode two numeric letters in seven bits.
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|
$num2 = (int) $content[$i + 1];
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|
$bits->appendBits($num1 * 10 + $num2, 7);
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$i += 2;
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} else {
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|
// Encode one numeric letter in four bits.
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|
$bits->appendBits($num1, 4);
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|
++$i;
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|
}
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|
}
|
|
}
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|
|
|
/**
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|
* Appends alpha-numeric bytes to a bit array.
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|
*
|
|
* @throws WriterException if an invalid alphanumeric code was found
|
|
*/
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|
private static function appendAlphanumericBytes(string $content, BitArray $bits) : void
|
|
{
|
|
$length = strlen($content);
|
|
$i = 0;
|
|
|
|
while ($i < $length) {
|
|
$code1 = self::getAlphanumericCode(ord($content[$i]));
|
|
|
|
if (-1 === $code1) {
|
|
throw new WriterException('Invalid alphanumeric code');
|
|
}
|
|
|
|
if ($i + 1 < $length) {
|
|
$code2 = self::getAlphanumericCode(ord($content[$i + 1]));
|
|
|
|
if (-1 === $code2) {
|
|
throw new WriterException('Invalid alphanumeric code');
|
|
}
|
|
|
|
// Encode two alphanumeric letters in 11 bits.
|
|
$bits->appendBits($code1 * 45 + $code2, 11);
|
|
$i += 2;
|
|
} else {
|
|
// Encode one alphanumeric letter in six bits.
|
|
$bits->appendBits($code1, 6);
|
|
++$i;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Appends regular 8-bit bytes to a bit array.
|
|
*
|
|
* @throws WriterException if content cannot be encoded to target encoding
|
|
*/
|
|
private static function append8BitBytes(string $content, BitArray $bits, string $encoding) : void
|
|
{
|
|
$bytes = @iconv('utf-8', $encoding, $content);
|
|
|
|
if (false === $bytes) {
|
|
throw new WriterException('Could not encode content to ' . $encoding);
|
|
}
|
|
|
|
$length = strlen($bytes);
|
|
|
|
for ($i = 0; $i < $length; $i++) {
|
|
$bits->appendBits(ord($bytes[$i]), 8);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Appends KANJI bytes to a bit array.
|
|
*
|
|
* @throws WriterException if content does not seem to be encoded in SHIFT-JIS
|
|
* @throws WriterException if an invalid byte sequence occurs
|
|
*/
|
|
private static function appendKanjiBytes(string $content, BitArray $bits) : void
|
|
{
|
|
if (strlen($content) % 2 > 0) {
|
|
// We just do a simple length check here. The for loop will check
|
|
// individual characters.
|
|
throw new WriterException('Content does not seem to be encoded in SHIFT-JIS');
|
|
}
|
|
|
|
$length = strlen($content);
|
|
|
|
for ($i = 0; $i < $length; $i += 2) {
|
|
$byte1 = ord($content[$i]) & 0xff;
|
|
$byte2 = ord($content[$i + 1]) & 0xff;
|
|
$code = ($byte1 << 8) | $byte2;
|
|
|
|
if ($code >= 0x8140 && $code <= 0x9ffc) {
|
|
$subtracted = $code - 0x8140;
|
|
} elseif ($code >= 0xe040 && $code <= 0xebbf) {
|
|
$subtracted = $code - 0xc140;
|
|
} else {
|
|
throw new WriterException('Invalid byte sequence');
|
|
}
|
|
|
|
$encoded = (($subtracted >> 8) * 0xc0) + ($subtracted & 0xff);
|
|
|
|
$bits->appendBits($encoded, 13);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Appends ECI information to a bit array.
|
|
*/
|
|
private static function appendEci(CharacterSetEci $eci, BitArray $bits) : void
|
|
{
|
|
$mode = Mode::ECI();
|
|
$bits->appendBits($mode->getBits(), 4);
|
|
$bits->appendBits($eci->getValue(), 8);
|
|
}
|
|
}
|