1 files changed, 53 insertions, 0 deletions
diff --git a/patches/server/0802-Always-parse-protochunk-light-sources-unless-it-is-m.patch b/patches/server/0802-Always-parse-protochunk-light-sources-unless-it-is-m.patch
new file mode 100644
index 0000000000..a1b655d7c1
--- /dev/null
+++ b/patches/server/0802-Always-parse-protochunk-light-sources-unless-it-is-m.patch
@@ -0,0 +1,53 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Spottedleaf <[email protected]>
+Date: Mon, 23 Aug 2021 04:50:05 -0700
+Subject: [PATCH] Always parse protochunk light sources unless it is marked as
+ non-lit
+
+Chunks not marked as lit will always go through the light engine,
+so they should always have their block sources parsed.
+
+diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/ChunkSerializer.java b/src/main/java/net/minecraft/world/level/chunk/storage/ChunkSerializer.java
+index 54ade15cdab222e9818f2635a8a12418e78e1ce6..887b3bc6370d23d2ff38e8fdbe286d678b035cc7 100644
+--- a/src/main/java/net/minecraft/world/level/chunk/storage/ChunkSerializer.java
++++ b/src/main/java/net/minecraft/world/level/chunk/storage/ChunkSerializer.java
+@@ -312,16 +312,33 @@ public class ChunkSerializer {
+             BelowZeroRetrogen belowzeroretrogen = protochunk.getBelowZeroRetrogen();
+             boolean flag2 = chunkstatus.isOrAfter(ChunkStatus.LIGHT) || belowzeroretrogen != null && belowzeroretrogen.targetStatus().isOrAfter(ChunkStatus.LIGHT);
+ 
+-            if (!flag && flag2) {
+-                Iterator iterator = BlockPos.betweenClosed(chunkPos.getMinBlockX(), world.getMinBuildHeight(), chunkPos.getMinBlockZ(), chunkPos.getMaxBlockX(), world.getMaxBuildHeight() - 1, chunkPos.getMaxBlockZ()).iterator();
++            if (!flag) { // Paper - fix incorrect parsing of blocks that emit light - it should always parse it, unless the chunk is marked as lit
++                // Paper start - let's make sure the implementation isn't as slow as possible
++                int offX = chunkPos.x << 4;
++                int offZ = chunkPos.z << 4;
++
++                int minChunkSection = io.papermc.paper.util.WorldUtil.getMinSection(world);
++                int maxChunkSection = io.papermc.paper.util.WorldUtil.getMaxSection(world);
++
++                LevelChunkSection[] sections = achunksection;
++                for (int sectionY = minChunkSection; sectionY <= maxChunkSection; ++sectionY) {
++                    LevelChunkSection section = sections[sectionY - minChunkSection];
++                    if (section == null || section.hasOnlyAir()) {
++                        // no sources in empty sections
++                        continue;
++                    }
++                    int offY = sectionY << 4;
+ 
+-                while (iterator.hasNext()) {
+-                    BlockPos blockposition = (BlockPos) iterator.next();
++                    for (int index = 0; index < (16 * 16 * 16); ++index) {
++                        if (section.states.get(index).getLightEmission() <= 0) {
++                            continue;
++                        }
+ 
+-                    if (((ChunkAccess) object).getBlockState(blockposition).getLightEmission() != 0) {
+-                        protochunk.addLight(blockposition);
++                        // index = x | (z << 4) | (y << 8)
++                        protochunk.addLight(new BlockPos(offX | (index & 15), offY | (index >>> 8), offZ | ((index >>> 4) & 15)));
+                     }
+                 }
++                // Paper end
+             }
+         }
+