/**
* Read in code lengths for symbols first to last in the given table.
* The code lengths are stored in their own special LZX way.
*
* @param BitReader $reader The reader that provides the data.
* @param int $first
* @param int $last
*/
public function readLengthTable(BitReader $reader, $first, $last)
{
$preTree = new self(6, static::PRETREE_NUM_ELEMENTS);
for ($i = 0; $i < $preTree->maxSymbol; ++$i) {
$preTree->lens[$i] = $reader->readLE(4);
}
$preTree->makeSymbolTable();
for ($pos = $first; $pos < $last;) {
$symbol = $preTree->readHuffmanSymbol($reader);
switch ($symbol) {
case 0x11:
$pos2 = $pos + $reader->readLE(4) + 4;
while ($pos < $pos2) {
$this->lens[$pos++] = 0;
}
break;
case 0x12:
$pos2 = $pos + $reader->readLE(5) + 20;
while ($pos < $pos2) {
$this->lens[$pos++] = 0;
}
break;
case 0x13:
$pos2 = $pos + $reader->readLE(1) + 4;
$symbol = $this->lens[$pos] - $preTree->readHuffmanSymbol($reader);
if ($symbol < 0) {
$symbol += 0x11;
}
while ($pos < $pos2) {
$this->lens[$pos++] = $symbol;
}
break;
default:
$symbol = $this->lens[$pos] - $symbol;
if ($symbol < 0) {
$symbol += 0x11;
}
$this->lens[$pos++] = $symbol;
break;
}
}
}
