From dfc5fc7e7c89633a50c3673a29e2ea274e28c8be Mon Sep 17 00:00:00 2001
From: md_5 <md_5@live.com.au>
Date: Fri, 21 Jun 2013 17:29:54 +1000
Subject: [PATCH] Fix Mob Spawning Relative to View Distance

Changes the mob spawning algorithm to properly account for view distance and the range around players.

Needs better documentation.

diff --git a/src/main/java/net/minecraft/server/PlayerChunkMap.java b/src/main/java/net/minecraft/server/PlayerChunkMap.java
index aa263166d..5ee9aad6e 100644
--- a/src/main/java/net/minecraft/server/PlayerChunkMap.java
+++ b/src/main/java/net/minecraft/server/PlayerChunkMap.java
@@ -654,8 +654,16 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
     }
 
     boolean d(ChunkCoordIntPair chunkcoordintpair) {
+        // Spigot Start
+        int chunkRange = world.spigotConfig.mobSpawnRange;
+        chunkRange = (chunkRange > world.spigotConfig.viewDistance) ? (byte) world.spigotConfig.viewDistance : chunkRange;
+        chunkRange = (chunkRange > 8) ? 8 : chunkRange;
+
+        double blockRange = Math.pow(chunkRange << 4, 2);
+        // Spigot end
+
         return this.y.a(chunkcoordintpair.pair()).noneMatch((entityplayer) -> {
-            return !entityplayer.isSpectator() && a(chunkcoordintpair, (Entity) entityplayer) < 16384.0D;
+            return !entityplayer.isSpectator() && a(chunkcoordintpair, (Entity) entityplayer) < blockRange; // Spigot
         });
     }
 
diff --git a/src/main/java/org/spigotmc/SpigotWorldConfig.java b/src/main/java/org/spigotmc/SpigotWorldConfig.java
index 0dd4b2d37..bcf5d1653 100644
--- a/src/main/java/org/spigotmc/SpigotWorldConfig.java
+++ b/src/main/java/org/spigotmc/SpigotWorldConfig.java
@@ -132,4 +132,11 @@ public class SpigotWorldConfig
         viewDistance = getInt( "view-distance", Bukkit.getViewDistance() );
         log( "View Distance: " + viewDistance );
     }
+
+    public byte mobSpawnRange;
+    private void mobSpawnRange()
+    {
+        mobSpawnRange = (byte) getInt( "mob-spawn-range", 6 );
+        log( "Mob Spawn Range: " + mobSpawnRange );
+    }
 }
-- 
2.20.1