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 97bb0fc7e890273f2f975f137ec1194a1a83fde7..2a0e81a3ec0774ad98e2d74ac7672c167e28f38e 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -1203,7 +1203,9 @@ 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;
@@ -1218,6 +1220,15 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
                 }
 
                 entityplayer = (ServerPlayer) iterator.next();
+                // Paper start - 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 - PlayerNaturallySpawnCreaturesEvent
             } 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 e0ae7274da59ff043cd423d282ed8db0382561d4..369e4bf5ff52cb774f1acaf760b8bd276a0745f5 100644
--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
@@ -568,6 +568,15 @@ 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 - PlayerNaturallySpawnCreaturesEvent
+                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 - PlayerNaturallySpawnCreaturesEvent
                 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 54f343a1979794781757b221514f70aa0f7a5dec..98d229fb8f342775482f2ed199265bda3f043a96 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 - PlayerNaturallySpawnCreaturesEvent
 
     public ServerPlayer(MinecraftServer server, ServerLevel world, GameProfile profile, ClientInformation clientOptions) {
         super(world, world.getSharedSpawnPos(), world.getSharedSpawnAngle(), profile);