From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 14 Jan 2018 17:36:02 -0500
Subject: [PATCH] PlayerNaturallySpawnCreaturesEvent

This event can be used for when you want to exclude a certain player
from triggering monster spawns on a server.

Also a highly more effecient way to blanket block spawns in a world

diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
index e580df88baadfd943756b1e440c7253a287fa0e9..ea520b828378c268d05425096c6493ca1c7ad385 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -701,7 +701,9 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         chunkRange = (chunkRange > this.level.spigotConfig.viewDistance) ? (byte) this.level.spigotConfig.viewDistance : chunkRange;
         chunkRange = (chunkRange > 8) ? 8 : chunkRange;
 
-        double blockRange = (reducedRange) ? Math.pow(chunkRange << 4, 2) : 16384.0D;
+        final int finalChunkRange = chunkRange; // Paper for lambda below
+        //double blockRange = (reducedRange) ? Math.pow(chunkRange << 4, 2) : 16384.0D; // Paper - use from event
+        double blockRange = 16384.0D; // Paper
         // Spigot end
         if (!this.distanceManager.hasPlayersNearby(chunkcoordintpair.toLong())) {
             return false;
@@ -716,6 +718,15 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
                 }
 
                 entityplayer = (ServerPlayer) iterator.next();
+                // Paper start - add PlayerNaturallySpawnCreaturesEvent
+                com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent event;
+                blockRange = 16384.0D;
+                if (reducedRange) {
+                    event = entityplayer.playerNaturallySpawnedEvent;
+                    if (event == null || event.isCancelled()) return false;
+                    blockRange = (double) ((event.getSpawnRadius() << 4) * (event.getSpawnRadius() << 4));
+                }
+                // Paper end
             } while (!this.playerIsCloseEnoughForSpawning(entityplayer, chunkcoordintpair, blockRange)); // Spigot
 
             return true;
diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
index b4d36ff6b6ba72693c269929b84c5481949f13fd..058b4e79ac861e772e828b92aacffba7efe4bb7e 100644
--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
@@ -557,6 +557,15 @@ public class ServerChunkCache extends ChunkSource {
                 boolean flag = this.level.getGameRules().getBoolean(GameRules.RULE_DOMOBSPAWNING) && !this.level.players().isEmpty(); // CraftBukkit
 
                 Util.shuffle(list, this.level.random);
+                // Paper start - call player naturally spawn event
+                int chunkRange = level.spigotConfig.mobSpawnRange;
+                chunkRange = (chunkRange > level.spigotConfig.viewDistance) ? (byte) level.spigotConfig.viewDistance : chunkRange;
+                chunkRange = Math.min(chunkRange, 8);
+                for (ServerPlayer entityPlayer : this.level.players()) {
+                    entityPlayer.playerNaturallySpawnedEvent = new com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent(entityPlayer.getBukkitEntity(), (byte) chunkRange);
+                    entityPlayer.playerNaturallySpawnedEvent.callEvent();
+                }
+                // Paper end
                 int l = this.level.getGameRules().getInt(GameRules.RULE_RANDOMTICKING);
                 boolean flag1 = this.level.ticksPerSpawnCategory.getLong(org.bukkit.entity.SpawnCategory.ANIMAL) != 0L && this.level.getLevelData().getGameTime() % this.level.ticksPerSpawnCategory.getLong(org.bukkit.entity.SpawnCategory.ANIMAL) == 0L; // CraftBukkit
                 Iterator iterator1 = list.iterator();
diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
index 75d2213aadcbd1d0a49fd4c8cef2d4d51669c73d..1b56d6b05fee0aa430dab666f50c5b886c3910d0 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
@@ -265,6 +265,7 @@ public class ServerPlayer extends Player {
     // CraftBukkit end
     public boolean isRealPlayer; // Paper
     public final com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> cachedSingleHashSet; // Paper
+    public com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent playerNaturallySpawnedEvent; // Paper
 
     // Paper start - replace player chunk loader
     private final java.util.concurrent.atomic.AtomicReference<io.papermc.paper.chunk.system.RegionizedPlayerChunkLoader.ViewDistances> viewDistances = new java.util.concurrent.atomic.AtomicReference<>(new io.papermc.paper.chunk.system.RegionizedPlayerChunkLoader.ViewDistances(-1, -1, -1));