From cc85d73644b4dcfeae066be7202558d876062be0 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/SpawnerCreature.java b/src/main/java/net/minecraft/server/SpawnerCreature.java
index b57616960..e62616552 100644
--- a/src/main/java/net/minecraft/server/SpawnerCreature.java
+++ b/src/main/java/net/minecraft/server/SpawnerCreature.java
@@ -47,6 +47,15 @@ public final class SpawnerCreature {
                     byte b0 = worldserver.spigotConfig.mobSpawnRange;
                     b0 = ( b0 > entityhuman.getViewDistance() ) ? (byte) entityhuman.getViewDistance() : b0; // Paper - Use player view distance API
                     b0 = ( b0 > 8 ) ? 8 : b0;
+                    // Paper start
+                    com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent event;
+                    event = new com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent(
+                            (org.bukkit.entity.Player) entityhuman.getBukkitEntity(), b0);
+                    if (!event.callEvent()) {
+                        continue;
+                    }
+                    b0 = event.getSpawnRadius();
+                    // Paperr end
 
                     for (int i1 = -b0; i1 <= b0; ++i1) {
                         for (k = -b0; k <= b0; ++k) {
-- 
2.21.0