Further refactors to prepare for y=-64 lower limit

changelogs/4.0-snapshot.md

@@ -867,6 +867,7 @@ This version features substantial changes to the network system, improving coher
   - `World->populateChunk()` has been split into `World->requestChunkPopulation()` and `World->orderChunkPopulation()`.
 - The following API methods have changed behaviour:
   - `World->getChunk()` no longer tries to load chunks from disk. If the chunk is not already in memory, null is returned. (This behaviour now properly matches other `ChunkManager` implementations.)
+  - `World->getHighestBlockAt()` now returns `null` instead of `-1` if the target X/Z column contains no blocks.
   - The following methods now throw `WorldException` when targeting ungenerated terrain:
     - `World->getSafeSpawn()` (previously it just silently returned the input position)
     - `World->getHighestBlockAt()` (previously it returned -1)

src/item/ChorusFruit.php

@@ -49,7 +49,7 @@ class ChorusFruit extends Food{
 
 		$origin = $consumer->getPosition();
 		$minX = $origin->getFloorX() - 8;
-		$minY = min($origin->getFloorY(), $consumer->getWorld()->getWorldHeight()) - 8;
+		$minY = min($origin->getFloorY(), $consumer->getWorld()->getMaxY()) - 8;
 		$minZ = $origin->getFloorZ() - 8;
 
 		$maxX = $minX + 16;

src/world/ChunkManager.php

@@ -45,9 +45,14 @@ interface ChunkManager{
 	public function setChunk(int $chunkX, int $chunkZ, Chunk $chunk) : void;
 
 	/**
-	 * Returns the height of the world
+	 * Returns the lowest buildable Y coordinate of the world
 	 */
-	public function getWorldHeight() : int;
+	public function getMinY() : int;
+
+	/**
+	 * Returns the highest buildable Y coordinate of the world
+	 */
+	public function getMaxY() : int;
 
 	/**
 	 * Returns whether the specified coordinates are within the valid world boundaries, taking world format limitations

src/world/SimpleChunkManager.php

@@ -35,13 +35,13 @@ class SimpleChunkManager implements ChunkManager{
 	protected $chunks = [];
 
 	/** @var int */
-	protected $worldHeight;
+	private $minY;
+	/** @var int */
+	private $maxY;
 
-	/**
-	 * SimpleChunkManager constructor.
-	 */
-	public function __construct(int $worldHeight = World::Y_MAX){
-		$this->worldHeight = $worldHeight;
+	public function __construct(int $minY, int $maxY){
+		$this->minY = $minY;
+		$this->maxY = $maxY;
 	}
 
 	public function getBlockAt(int $x, int $y, int $z) : Block{
@@ -71,14 +71,18 @@ class SimpleChunkManager implements ChunkManager{
 		$this->chunks = [];
 	}
 
-	public function getWorldHeight() : int{
-		return $this->worldHeight;
+	public function getMinY() : int{
+		return $this->minY;
+	}
+
+	public function getMaxY() : int{
+		return $this->maxY;
 	}
 
 	public function isInWorld(int $x, int $y, int $z) : bool{
 		return (
 			$x <= Limits::INT32_MAX and $x >= Limits::INT32_MIN and
-			$y < $this->worldHeight and $y >= 0 and
+			$y < $this->maxY and $y >= $this->minY and
 			$z <= Limits::INT32_MAX and $z >= Limits::INT32_MIN
 		);
 	}

src/world/World.php

@@ -174,7 +174,9 @@ class World implements ChunkManager{
 	private $providerGarbageCollectionTicker = 0;
 
 	/** @var int */
-	private $worldHeight;
+	private $minY;
+	/** @var int */
+	private $maxY;
 
 	/** @var ChunkLoader[] */
 	private $loaders = [];
@@ -383,7 +385,8 @@ class World implements ChunkManager{
 		$this->displayName = $this->provider->getWorldData()->getName();
 		$this->logger = new \PrefixedLogger($server->getLogger(), "World: $this->displayName");
 
-		$this->worldHeight = $this->provider->getWorldHeight();
+		$this->minY = $this->provider->getWorldMinY();
+		$this->maxY = $this->provider->getWorldMaxY();
 
 		$this->server->getLogger()->info($this->server->getLanguage()->translateString("pocketmine.level.preparing", [$this->displayName]));
 		$this->generator = GeneratorManager::getInstance()->getGenerator($this->provider->getWorldData()->getGenerator(), true);
@@ -1335,7 +1338,7 @@ class World implements ChunkManager{
 	public function isInWorld(int $x, int $y, int $z) : bool{
 		return (
 			$x <= Limits::INT32_MAX and $x >= Limits::INT32_MIN and
-			$y < $this->worldHeight and $y >= 0 and
+			$y < $this->maxY and $y >= $this->minY and
 			$z <= Limits::INT32_MAX and $z >= Limits::INT32_MIN
 		);
 	}
@@ -2089,10 +2092,10 @@ class World implements ChunkManager{
 	/**
 	 * Gets the highest block Y value at a specific $x and $z
 	 *
-	 * @return int 0-255, or -1 if the column is empty
+	 * @return int|null 0-255, or null if the column is empty
 	 * @throws WorldException if the terrain is not generated
 	 */
-	public function getHighestBlockAt(int $x, int $z) : int{
+	public function getHighestBlockAt(int $x, int $z) : ?int{
 		if(($chunk = $this->loadChunk($x >> 4, $z >> 4)) !== null){
 			return $chunk->getHighestBlockAt($x & 0x0f, $z & 0x0f);
 		}
@@ -2481,7 +2484,7 @@ class World implements ChunkManager{
 			$spawn = $this->getSpawnLocation();
 		}
 
-		$max = $this->worldHeight;
+		$max = $this->maxY;
 		$v = $spawn->floor();
 		$chunk = $this->getOrLoadChunkAtPosition($v);
 		if($chunk === null){
@@ -2491,7 +2494,7 @@ class World implements ChunkManager{
 		$z = (int) $v->z;
 		$y = (int) min($max - 2, $v->y);
 		$wasAir = $this->getBlockAt($x, $y - 1, $z)->getId() === BlockLegacyIds::AIR; //TODO: bad hack, clean up
-		for(; $y > 0; --$y){
+		for(; $y > $this->minY; --$y){
 			if($this->getBlockAt($x, $y, $z)->isFullCube()){
 				if($wasAir){
 					$y++;
@@ -2502,7 +2505,7 @@ class World implements ChunkManager{
 			}
 		}
 
-		for(; $y >= 0 and $y < $max; ++$y){
+		for(; $y >= $this->minY and $y < $max; ++$y){
 			if(!$this->getBlockAt($x, $y + 1, $z)->isFullCube()){
 				if(!$this->getBlockAt($x, $y, $z)->isFullCube()){
 					return new Position($spawn->x, $y === (int) $spawn->y ? $spawn->y : $y, $spawn->z, $this);
@@ -2575,8 +2578,12 @@ class World implements ChunkManager{
 		return $this->provider->getWorldData()->getSeed();
 	}
 
-	public function getWorldHeight() : int{
-		return $this->worldHeight;
+	public function getMinY() : int{
+		return $this->minY;
+	}
+
+	public function getMaxY() : int{
+		return $this->maxY;
 	}
 
 	public function getDifficulty() : int{

src/world/format/Chunk.php

@@ -131,17 +131,17 @@ class Chunk{
 	 * @param int $x 0-15
 	 * @param int $z 0-15
 	 *
-	 * @return int 0-255, or -1 if there are no blocks in the column
+	 * @return int|null 0-255, or null if there are no blocks in the column
 	 */
-	public function getHighestBlockAt(int $x, int $z) : int{
+	public function getHighestBlockAt(int $x, int $z) : ?int{
 		for($y = $this->subChunks->count() - 1; $y >= 0; --$y){
-			$height = $this->getSubChunk($y)->getHighestBlockAt($x, $z) | ($y << 4);
-			if($height !== -1){
-				return $height;
+			$height = $this->getSubChunk($y)->getHighestBlockAt($x, $z);
+			if($height !== null){
+				return $height | ($y << 4);
 			}
 		}
 
-		return -1;
+		return null;
 	}
 
 	/**

src/world/format/SubChunk.php

@@ -96,9 +96,9 @@ class SubChunk{
 		return $this->blockLayers;
 	}
 
-	public function getHighestBlockAt(int $x, int $z) : int{
+	public function getHighestBlockAt(int $x, int $z) : ?int{
 		if(count($this->blockLayers) === 0){
-			return -1;
+			return null;
 		}
 		for($y = 15; $y >= 0; --$y){
 			if($this->blockLayers[0]->get($x, $y, $z) !== $this->emptyBlockId){
@@ -106,7 +106,7 @@ class SubChunk{
 			}
 		}
 
-		return -1; //highest block not in this subchunk
+		return null; //highest block not in this subchunk
 	}
 
 	public function getBlockSkyLightArray() : LightArray{

src/world/format/io/WorldProvider.php

@@ -36,10 +36,15 @@ interface WorldProvider{
 	 */
 	public function __construct(string $path);
 
+	/**
+	 * Returns the lowest buildable Y coordinate of this world
+	 */
+	public function getWorldMinY() : int;
+
 	/**
 	 * Gets the build height limit of this world
 	 */
-	public function getWorldHeight() : int;
+	public function getWorldMaxY() : int;
 
 	public function getPath() : string;
 

src/world/format/io/leveldb/LevelDB.php

@@ -132,7 +132,11 @@ class LevelDB extends BaseWorldProvider implements WritableWorldProvider{
 		return new BedrockWorldData($this->getPath() . DIRECTORY_SEPARATOR . "level.dat");
 	}
 
-	public function getWorldHeight() : int{
+	public function getWorldMinY() : int{
+		return 0;
+	}
+
+	public function getWorldMaxY() : int{
 		return 256;
 	}
 

src/world/format/io/region/Anvil.php

@@ -51,7 +51,11 @@ class Anvil extends RegionWorldProvider{
 		return 19133;
 	}
 
-	public function getWorldHeight() : int{
+	public function getWorldMinY() : int{
+		return 0;
+	}
+
+	public function getWorldMaxY() : int{
 		//TODO: add world height options
 		return 256;
 	}

src/world/format/io/region/McRegion.php

@@ -106,7 +106,11 @@ class McRegion extends RegionWorldProvider{
 		return 19132;
 	}
 
-	public function getWorldHeight() : int{
+	public function getWorldMinY() : int{
+		return 0;
+	}
+
+	public function getWorldMaxY() : int{
 		//TODO: add world height options
 		return 128;
 	}

src/world/format/io/region/PMAnvil.php

@@ -50,7 +50,11 @@ class PMAnvil extends RegionWorldProvider{
 		return -1; //Not a PC format, only PocketMine-MP
 	}
 
-	public function getWorldHeight() : int{
+	public function getWorldMinY() : int{
+		return 0;
+	}
+
+	public function getWorldMaxY() : int{
 		return 256;
 	}
 }

src/world/generator/GeneratorRegisterTask.php

@@ -42,7 +42,9 @@ class GeneratorRegisterTask extends AsyncTask{
 	/** @var int */
 	public $worldId;
 	/** @var int */
-	public $worldHeight = World::Y_MAX;
+	public $worldMinY;
+	/** @var int */
+	public $worldMaxY;
 
 	/**
 	 * @param mixed[] $generatorSettings
@@ -54,7 +56,8 @@ class GeneratorRegisterTask extends AsyncTask{
 		$this->settings = igbinary_serialize($generatorSettings);
 		$this->seed = $world->getSeed();
 		$this->worldId = $world->getId();
-		$this->worldHeight = $world->getWorldHeight();
+		$this->worldMinY = $world->getMinY();
+		$this->worldMaxY = $world->getMaxY();
 	}
 
 	public function onRun() : void{
@@ -63,6 +66,6 @@ class GeneratorRegisterTask extends AsyncTask{
 		 * @see Generator::__construct()
 		 */
 		$generator = new $this->generatorClass($this->seed, igbinary_unserialize($this->settings));
-		ThreadLocalGeneratorContext::register(new ThreadLocalGeneratorContext($generator, $this->worldHeight), $this->worldId);
+		ThreadLocalGeneratorContext::register(new ThreadLocalGeneratorContext($generator, $this->worldMinY, $this->worldMaxY), $this->worldId);
 	}
 }

src/world/generator/PopulationTask.php

@@ -83,7 +83,7 @@ class PopulationTask extends AsyncTask{
 			throw new AssumptionFailedError("Generator context should have been initialized before any PopulationTask execution");
 		}
 		$generator = $context->getGenerator();
-		$manager = new SimpleChunkManager($context->getWorldHeight());
+		$manager = new SimpleChunkManager($context->getWorldMinY(), $context->getWorldMaxY());
 
 		/** @var Chunk[] $chunks */
 		$chunks = [];

src/world/generator/ThreadLocalGeneratorContext.php

@@ -47,15 +47,21 @@ final class ThreadLocalGeneratorContext{
 
 	/** @var Generator */
 	private $generator;
-	/** @var int */
-	private $worldHeight;
 
-	public function __construct(Generator $generator, int $worldHeight){
+	/** @var int */
+	private $worldMinY;
+	/** @var int */
+	private $worldMaxY;
+
+	public function __construct(Generator $generator, int $worldMinY, int $worldMaxY){
 		$this->generator = $generator;
-		$this->worldHeight = $worldHeight;
+		$this->worldMinY = $worldMinY;
+		$this->worldMaxY = $worldMaxY;
 	}
 
 	public function getGenerator() : Generator{ return $this->generator; }
 
-	public function getWorldHeight() : int{ return $this->worldHeight; }
+	public function getWorldMinY() : int{ return $this->worldMinY; }
+
+	public function getWorldMaxY() : int{ return $this->worldMaxY; }
 }

src/world/light/LightPopulationTask.php

@@ -62,7 +62,7 @@ class LightPopulationTask extends AsyncTask{
 	public function onRun() : void{
 		$chunk = FastChunkSerializer::deserialize($this->chunk);
 
-		$manager = new SimpleChunkManager();
+		$manager = new SimpleChunkManager(World::Y_MIN, World::Y_MAX);
 		$manager->setChunk($this->chunkX, $this->chunkZ, $chunk);
 
 		$blockFactory = BlockFactory::getInstance();

src/world/light/SkyLightUpdate.php

@@ -178,7 +178,7 @@ class SkyLightUpdate extends LightUpdate{
 				break;
 			}
 		}
-		$result = HeightArray::fill(0);
+		$result = HeightArray::fill(World::Y_MIN);
 		if($maxSubChunkY === -1){ //whole column is definitely empty
 			return $result;
 		}
@@ -188,16 +188,16 @@ class SkyLightUpdate extends LightUpdate{
 				$y = null;
 				for($subChunkY = $maxSubChunkY; $subChunkY >= 0; $subChunkY--){
 					$subHighestBlockY = $chunk->getSubChunk($subChunkY)->getHighestBlockAt($x, $z);
-					if($subHighestBlockY !== -1){
+					if($subHighestBlockY !== null){
 						$y = ($subChunkY * 16) + $subHighestBlockY;
 						break;
 					}
 				}
 
 				if($y === null){ //no blocks in the column
-					$result->set($x, $z, 0);
+					$result->set($x, $z, World::Y_MIN);
 				}else{
-					for(; $y >= 0; --$y){
+					for(; $y >= World::Y_MIN; --$y){
 						if($directSkyLightBlockers[$chunk->getFullBlock($x, $y, $z)]){
 							$result->set($x, $z, $y + 1);
 							break;
@@ -221,7 +221,10 @@ class SkyLightUpdate extends LightUpdate{
 	 */
 	private static function recalculateHeightMapColumn(Chunk $chunk, int $x, int $z, \SplFixedArray $directSkyLightBlockers) : int{
 		$y = $chunk->getHighestBlockAt($x, $z);
-		for(; $y >= 0; --$y){
+		if($y === null){
+			return World::Y_MIN;
+		}
+		for(; $y >= World::Y_MIN; --$y){
 			if($directSkyLightBlockers[$chunk->getFullBlock($x, $y, $z)]){
 				break;
 			}