PocketMine-MP/src/network/mcpe/serializer/ChunkSerializer.php
2021-11-30 19:17:26 +00:00

172 lines
6.1 KiB
PHP

<?php
/*
*
* ____ _ _ __ __ _ __ __ ____
* | _ \ ___ ___| | _____| |_| \/ (_)_ __ ___ | \/ | _ \
* | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
* | __/ (_) | (__| < __/ |_| | | | | | | | __/_____| | | | __/
* |_| \___/ \___|_|\_\___|\__|_| |_|_|_| |_|\___| |_| |_|_|
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* @author PocketMine Team
* @link http://www.pocketmine.net/
*
*
*/
declare(strict_types=1);
namespace pocketmine\network\mcpe\serializer;
use pocketmine\block\tile\Spawnable;
use pocketmine\data\bedrock\BiomeIds;
use pocketmine\data\bedrock\LegacyBiomeIdToStringIdMap;
use pocketmine\nbt\TreeRoot;
use pocketmine\network\mcpe\convert\RuntimeBlockMapping;
use pocketmine\network\mcpe\protocol\serializer\NetworkNbtSerializer;
use pocketmine\network\mcpe\protocol\serializer\PacketSerializer;
use pocketmine\network\mcpe\protocol\serializer\PacketSerializerContext;
use pocketmine\utils\Binary;
use pocketmine\utils\BinaryStream;
use pocketmine\world\format\Chunk;
use pocketmine\world\format\PalettedBlockArray;
use pocketmine\world\format\SubChunk;
use function chr;
use function count;
use function str_repeat;
final class ChunkSerializer{
public const LOWER_PADDING_SIZE = 4;
private function __construct(){
//NOOP
}
/**
* Returns the number of subchunks that will be sent from the given chunk.
* Chunks are sent in a stack, so every chunk below the top non-empty one must be sent.
*/
public static function getSubChunkCount(Chunk $chunk) : int{
for($y = Chunk::MAX_SUBCHUNK_INDEX, $count = count($chunk->getSubChunks()); $y >= Chunk::MIN_SUBCHUNK_INDEX; --$y, --$count){
if($chunk->getSubChunk($y)->isEmptyFast()){
continue;
}
return $count;
}
return 0;
}
public static function serializeFullChunk(Chunk $chunk, RuntimeBlockMapping $blockMapper, PacketSerializerContext $encoderContext, ?string $tiles = null) : string{
$stream = PacketSerializer::encoder($encoderContext);
//TODO: HACK! fill in fake subchunks to make up for the new negative space client-side
for($y = 0; $y < self::LOWER_PADDING_SIZE; $y++){
$stream->putByte(8); //subchunk version 8
$stream->putByte(0); //0 layers - client will treat this as all-air
}
$subChunkCount = self::getSubChunkCount($chunk);
for($y = Chunk::MIN_SUBCHUNK_INDEX, $writtenCount = 0; $writtenCount < $subChunkCount; ++$y, ++$writtenCount){
self::serializeSubChunk($chunk->getSubChunk($y), $blockMapper, $stream, false);
}
//TODO: right now we don't support 3D natively, so we just 3Dify our 2D biomes so they fill the column
$encodedBiomePalette = self::serializeBiomesAsPalette($chunk);
$stream->put(str_repeat($encodedBiomePalette, 25));
$stream->putByte(0); //border block array count
//Border block entry format: 1 byte (4 bits X, 4 bits Z). These are however useless since they crash the regular client.
if($tiles !== null){
$stream->put($tiles);
}else{
$stream->put(self::serializeTiles($chunk));
}
return $stream->getBuffer();
}
public static function serializeSubChunk(SubChunk $subChunk, RuntimeBlockMapping $blockMapper, PacketSerializer $stream, bool $persistentBlockStates) : void{
$layers = $subChunk->getBlockLayers();
$stream->putByte(8); //version
$stream->putByte(count($layers));
foreach($layers as $blocks){
$bitsPerBlock = $blocks->getBitsPerBlock();
$words = $blocks->getWordArray();
$stream->putByte(($bitsPerBlock << 1) | ($persistentBlockStates ? 0 : 1));
$stream->put($words);
$palette = $blocks->getPalette();
if($bitsPerBlock !== 0){
//these LSHIFT by 1 uvarints are optimizations: the client expects zigzag varints here
//but since we know they are always unsigned, we can avoid the extra fcall overhead of
//zigzag and just shift directly.
$stream->putUnsignedVarInt(count($palette) << 1); //yes, this is intentionally zigzag
}
if($persistentBlockStates){
$nbtSerializer = new NetworkNbtSerializer();
foreach($palette as $p){
$stream->put($nbtSerializer->write(new TreeRoot($blockMapper->getBedrockKnownStates()[$blockMapper->toRuntimeId($p)])));
}
}else{
foreach($palette as $p){
$stream->put(Binary::writeUnsignedVarInt($blockMapper->toRuntimeId($p) << 1));
}
}
}
}
public static function serializeTiles(Chunk $chunk) : string{
$stream = new BinaryStream();
foreach($chunk->getTiles() as $tile){
if($tile instanceof Spawnable){
$stream->put($tile->getSerializedSpawnCompound()->getEncodedNbt());
}
}
return $stream->getBuffer();
}
private static function serializeBiomesAsPalette(Chunk $chunk) : string{
$biomeIdMap = LegacyBiomeIdToStringIdMap::getInstance();
$biomePalette = new PalettedBlockArray($chunk->getBiomeId(0, 0));
for($x = 0; $x < 16; ++$x){
for($z = 0; $z < 16; ++$z){
$biomeId = $chunk->getBiomeId($x, $z);
if($biomeIdMap->legacyToString($biomeId) === null){
//make sure we aren't sending bogus biomes - the 1.18.0 client crashes if we do this
$biomeId = BiomeIds::OCEAN;
}
for($y = 0; $y < 16; ++$y){
$biomePalette->set($x, $y, $z, $biomeId);
}
}
}
$biomePaletteBitsPerBlock = $biomePalette->getBitsPerBlock();
$encodedBiomePalette =
chr(($biomePaletteBitsPerBlock << 1) | 1) . //the last bit is non-persistence (like for blocks), though it has no effect on biomes since they always use integer IDs
$biomePalette->getWordArray();
//these LSHIFT by 1 uvarints are optimizations: the client expects zigzag varints here
//but since we know they are always unsigned, we can avoid the extra fcall overhead of
//zigzag and just shift directly.
$biomePaletteArray = $biomePalette->getPalette();
if($biomePaletteBitsPerBlock !== 0){
$encodedBiomePalette .= Binary::writeUnsignedVarInt(count($biomePaletteArray) << 1);
}
foreach($biomePaletteArray as $p){
$encodedBiomePalette .= Binary::writeUnsignedVarInt($p << 1);
}
return $encodedBiomePalette;
}
}