From 549694c3d8f321a18137eeaea66417c6a54e723b 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/SpawnerCreature.java b/src/main/java/net/minecraft/server/SpawnerCreature.java
index 5f262bc53..6ca0e19cb 100644
--- a/src/main/java/net/minecraft/server/SpawnerCreature.java
+++ b/src/main/java/net/minecraft/server/SpawnerCreature.java
@@ -42,10 +42,15 @@ public final class SpawnerCreature {
 
                     j = MathHelper.floor(entityhuman.locZ / 16.0D);
                     boolean flag3 = true;
-
-                    for (int i1 = -8; i1 <= 8; ++i1) {
-                        for (k = -8; k <= 8; ++k) {
-                            boolean flag4 = i1 == -8 || i1 == 8 || k == -8 || k == 8;
+                    // Spigot Start
+                    byte b0 = worldserver.spigotConfig.mobSpawnRange;
+                    b0 = ( b0 > worldserver.spigotConfig.viewDistance ) ? (byte) worldserver.spigotConfig.viewDistance : b0;
+                    b0 = ( b0 > 8 ) ? 8 : b0;
+
+                    for (int i1 = -b0; i1 <= b0; ++i1) {
+                        for (k = -b0; k <= b0; ++k) {
+                            boolean flag4 = i1 == -b0 || i1 == b0 || k == -b0 || k == b0;
+                            // Spigot End
                             ChunkCoordIntPair chunkcoordintpair = new ChunkCoordIntPair(i1 + l, k + j);
 
                             // CraftBukkit start - use LongHash and LongHashSet
diff --git a/src/main/java/org/spigotmc/SpigotWorldConfig.java b/src/main/java/org/spigotmc/SpigotWorldConfig.java
index f5096e3a4..5aa21d910 100644
--- a/src/main/java/org/spigotmc/SpigotWorldConfig.java
+++ b/src/main/java/org/spigotmc/SpigotWorldConfig.java
@@ -126,4 +126,11 @@ 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 );
+    }
 }
-- 
2.19.1