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 261943f1f188643793a72bd239dfc5fe604e3b99..985ba48a5ac027d3c3dcd9b710b53748508966fb 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -1098,7 +1098,9 @@ 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
         Iterator iterator = this.playerMap.getAllPlayers().iterator();
 
@@ -1110,6 +1112,15 @@ 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 2e2976efcf99de269f67dec2c87cb910ff280562..5749698b0c9647295e0be6f7d532d39c18432539 100644
--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
@@ -501,6 +501,15 @@ public class ServerChunkCache extends ChunkSource {
         List list1;
 
         if (flag && (this.spawnEnemies || this.spawnFriendlies)) {
+            // 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
             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
 
             list1 = NaturalSpawner.getFilteredSpawningCategories(spawnercreature_d, this.spawnFriendlies, this.spawnEnemies, flag1, this.level); // CraftBukkit
diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
index b99bd43bf5185bed21fad7dac31baf1a30bdd1fe..98aeafcc51e23a7534c8d57e4db0eb58abb3f30b 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
@@ -314,6 +314,7 @@ public class ServerPlayer extends net.minecraft.world.entity.player.Player {
     public String kickLeaveMessage = null; // SPIGOT-3034: Forward leave message to PlayerQuitEvent
     // CraftBukkit end
     public boolean isRealPlayer; // 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);