From 4eb59aeeb2f2b535f4eb2a1608189bb03098454e Mon Sep 17 00:00:00 2001
From: Loic Blot <loic.blot@unix-experience.fr>
Date: Wed, 26 Jul 2017 23:50:53 +0200
Subject: [PATCH] MapBlock::actuallyUpdateDayNightDiff(): little performance
 optimization

don't check isLightDayNightEq if checked on previous node
---
 src/mapblock.cpp | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/mapblock.cpp b/src/mapblock.cpp
index f52a5ee3f..d94955a3b 100644
--- a/src/mapblock.cpp
+++ b/src/mapblock.cpp
@@ -366,12 +366,19 @@ void MapBlock::actuallyUpdateDayNightDiff()
 	/*
 		Check if any lighting value differs
 	*/
+
+	MapNode previous_n;
 	for (u32 i = 0; i < nodecount; i++) {
-		MapNode &n = data[i];
+		MapNode n = data[i];
+
+		// If node is identical to previous node, don't verify if it differs
+		if (n == previous_n)
+			continue;
 
 		differs = !n.isLightDayNightEq(nodemgr);
 		if (differs)
 			break;
+		previous_n = n;
 	}
 
 	/*
-- 
2.25.1