From 30c5487f9402a68c23c1996d1340acadab4d8bb1 Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Sat, 8 Jul 2017 17:13:22 +0100
Subject: [PATCH] Drastically improved performance of basic chunk sky-light
 population back 2 commits: 53ms per chunk back 1 commit: 27ms per chunk this
 commit: 3ms per chunk

(on my machine, of course)
---
 src/pocketmine/level/format/Chunk.php         | 37 +++++++++++++++++--
 src/pocketmine/level/format/EmptySubChunk.php |  8 ++++
 src/pocketmine/level/format/SubChunk.php      | 12 +++++-
 .../level/format/SubChunkInterface.php        | 10 +++++
 4 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/src/pocketmine/level/format/Chunk.php b/src/pocketmine/level/format/Chunk.php
index 985d96d31..1ae0f5532 100644
--- a/src/pocketmine/level/format/Chunk.php
+++ b/src/pocketmine/level/format/Chunk.php
@@ -313,6 +313,17 @@ class Chunk{
 		}
 	}
 
+	/**
+	 * @param int $level
+	 */
+	public function setAllBlockSkyLight(int $level){
+		$char = chr(($level & 0x0f) | ($level << 4));
+		$data = str_repeat($char, 2048);
+		for($y = $this->getHighestSubChunkIndex(); $y >= 0; --$y){
+			$this->getSubChunk($y, true)->setBlockSkyLightArray($data);
+		}
+	}
+
 	/**
 	 * Returns the block light level at the specified chunk block coordinates
 	 *
@@ -340,6 +351,17 @@ class Chunk{
 		}
 	}
 
+	/**
+	 * @param int $level
+	 */
+	public function setAllBlockLight(int $level){
+		$char = chr(($level & 0x0f) | ($level << 4));
+		$data = str_repeat($char, 2048);
+		for($y = $this->getHighestSubChunkIndex(); $y >= 0; --$y){
+			$this->getSubChunk($y, true)->setBlockLightArray($data);
+		}
+	}
+
 	/**
 	 * Returns the Y coordinate of the highest non-air block at the specified X/Z chunk block coordinates
 	 *
@@ -366,6 +388,10 @@ class Chunk{
 		return -1;
 	}
 
+	public function getMaxY() : int{
+		return ($this->getHighestSubChunkIndex() << 4) | 0x0f;
+	}
+
 	/**
 	 * Returns the heightmap value at the specified X/Z chunk block coordinates
 	 *
@@ -427,7 +453,10 @@ class Chunk{
 	 * TODO: fast adjacent light spread
 	 */
 	public function populateSkyLight(){
-		$maxY = ($this->getHighestSubChunkIndex() + 1) << 4;
+		$maxY = $this->getMaxY();
+
+		$this->setAllBlockSkyLight(0);
+
 		for($x = 0; $x < 16; ++$x){
 			for($z = 0; $z < 16; ++$z){
 				$heightMap = $this->getHeightMap($x, $z);
@@ -437,11 +466,11 @@ class Chunk{
 				}
 
 				$light = 15;
-				for(; $y > 0; --$y){
+				for(; $y >= 0; --$y){
 					if($light > 0){
 						$light -= Block::$lightFilter[$this->getBlockId($x, $y, $z)];
-						if($light < 0){
-							$light = 0;
+						if($light <= 0){
+							break;
 						}
 					}
 					$this->setBlockSkyLight($x, $y, $z, $light);
diff --git a/src/pocketmine/level/format/EmptySubChunk.php b/src/pocketmine/level/format/EmptySubChunk.php
index f946d4083..88d002429 100644
--- a/src/pocketmine/level/format/EmptySubChunk.php
+++ b/src/pocketmine/level/format/EmptySubChunk.php
@@ -101,10 +101,18 @@ class EmptySubChunk implements SubChunkInterface{
 		return str_repeat("\x00", 2048);
 	}
 
+	public function setBlockLightArray(string $data){
+
+	}
+
 	public function getBlockSkyLightArray() : string{
 		return str_repeat("\xff", 2048);
 	}
 
+	public function setBlockSkyLightArray(string $data){
+
+	}
+
 	public function networkSerialize() : string{
 		return "\x00" . str_repeat("\x00", 10240);
 	}
diff --git a/src/pocketmine/level/format/SubChunk.php b/src/pocketmine/level/format/SubChunk.php
index 56db712f1..d69fbf0a3 100644
--- a/src/pocketmine/level/format/SubChunk.php
+++ b/src/pocketmine/level/format/SubChunk.php
@@ -30,7 +30,7 @@ class SubChunk implements SubChunkInterface{
 	protected $blockLight;
 	protected $skyLight;
 
-	private static function assignData(&$target, $data, $length, $value = "\x00"){
+	private static function assignData(&$target, string $data, int $length, string $value = "\x00"){
 		if(strlen($data) !== $length){
 			assert($data === "", "Invalid non-zero length given, expected $length, got " . strlen($data));
 			$target = str_repeat($value, $length);
@@ -203,11 +203,21 @@ class SubChunk implements SubChunkInterface{
 		return $this->skyLight;
 	}
 
+	public function setBlockSkyLightArray(string $data){
+		assert(strlen($data) === 2048, "Wrong length of skylight array, expecting 2048 bytes, got " . strlen($data));
+		$this->skyLight = $data;
+	}
+
 	public function getBlockLightArray() : string{
 		assert(strlen($this->blockLight) === 2048, "Wrong length of light array, expecting 2048 bytes, got " . strlen($this->blockLight));
 		return $this->blockLight;
 	}
 
+	public function setBlockLightArray(string $data){
+		assert(strlen($data) === 2048, "Wrong length of light array, expecting 2048 bytes, got " . strlen($data));
+		$this->blockLight = $data;
+	}
+
 	public function networkSerialize() : string{
 		// storage version, ids, data, skylight, blocklight
 		return "\x00" . $this->ids . $this->data . $this->skyLight . $this->blockLight;
diff --git a/src/pocketmine/level/format/SubChunkInterface.php b/src/pocketmine/level/format/SubChunkInterface.php
index a0001b12f..182c06e43 100644
--- a/src/pocketmine/level/format/SubChunkInterface.php
+++ b/src/pocketmine/level/format/SubChunkInterface.php
@@ -182,11 +182,21 @@ interface SubChunkInterface{
 	 */
 	public function getBlockSkyLightArray() : string;
 
+	/**
+	 * @param string $data
+	 */
+	public function setBlockSkyLightArray(string $data);
+
 	/**
 	 * @return string
 	 */
 	public function getBlockLightArray() : string;
 
+	/**
+	 * @param string $data
+	 */
+	public function setBlockLightArray(string $data);
+
 	/**
 	 * @return string
 	 */