From ae9f57ac285e3fb588a95e649f5113676b70a8d4 Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Sun, 10 Mar 2019 19:46:23 +0000
Subject: [PATCH] Revert "Remove hacks for triggering adjacent light refill"

This reverts commit 1dca9074d5f087d15f8d30d2941150fe51617489.
This change introduced performance issues with transparent blocks.
---
 src/pocketmine/level/Level.php             |  8 +++++---
 src/pocketmine/level/light/LightUpdate.php | 14 +++++++-------
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/src/pocketmine/level/Level.php b/src/pocketmine/level/Level.php
index f5c51f9c1..b20e4b9d1 100644
--- a/src/pocketmine/level/Level.php
+++ b/src/pocketmine/level/Level.php
@@ -1492,8 +1492,8 @@ class Level implements ChunkManager, Metadatable{
 			for($i = $y; $i >= $newHeightMap; --$i){
 				$this->skyLightUpdate->setAndUpdateLight($x, $i, $z, 15);
 			}
-		}else{ //No heightmap change, block changed "underground" - trigger recalculation from surroundings
-			$this->skyLightUpdate->setAndUpdateLight($x, $y, $z, 0);
+		}else{ //No heightmap change, block changed "underground"
+			$this->skyLightUpdate->setAndUpdateLight($x, $y, $z, max(0, $this->getHighestAdjacentBlockSkyLight($x, $y, $z) - BlockFactory::$lightFilter[($source->getId() << 4) | $source->getMeta()]));
 		}
 
 		$this->timings->doBlockSkyLightUpdates->stopTiming();
@@ -1523,10 +1523,12 @@ class Level implements ChunkManager, Metadatable{
 		$this->timings->doBlockLightUpdates->startTiming();
 
 		$block = $this->getBlockAt($x, $y, $z);
+		$newLevel = max($block->getLightLevel(), $this->getHighestAdjacentBlockLight($x, $y, $z) - BlockFactory::$lightFilter[($block->getId() << 4) | $block->getMeta()]);
+
 		if($this->blockLightUpdate === null){
 			$this->blockLightUpdate = new BlockLightUpdate($this);
 		}
-		$this->blockLightUpdate->setAndUpdateLight($x, $y, $z, $block->getLightLevel());
+		$this->blockLightUpdate->setAndUpdateLight($x, $y, $z, $newLevel);
 
 		$this->timings->doBlockLightUpdates->stopTiming();
 	}
diff --git a/src/pocketmine/level/light/LightUpdate.php b/src/pocketmine/level/light/LightUpdate.php
index cf360acab..c141b2ee3 100644
--- a/src/pocketmine/level/light/LightUpdate.php
+++ b/src/pocketmine/level/light/LightUpdate.php
@@ -72,13 +72,13 @@ abstract class LightUpdate{
 
 				if($oldLevel !== $newLevel){
 					$this->setLight($x, $y, $z, $newLevel);
-				}
-				if($newLevel > $oldLevel){ //light increased
-					$this->spreadVisited[$blockHash] = true;
-					$this->spreadQueue->enqueue([$x, $y, $z]);
-				}elseif($newLevel < 15){ //light removed or stayed the same, force recheck nearby environment
-					$this->removalVisited[$blockHash] = true;
-					$this->removalQueue->enqueue([$x, $y, $z, $oldLevel]);
+					if($oldLevel < $newLevel){ //light increased
+						$this->spreadVisited[$blockHash] = true;
+						$this->spreadQueue->enqueue([$x, $y, $z]);
+					}else{ //light removed
+						$this->removalVisited[$blockHash] = true;
+						$this->removalQueue->enqueue([$x, $y, $z, $oldLevel]);
+					}
 				}
 			}
 		}