Paper/CraftBukkit-Patches/0020-Fix-Mob-Spawning-Relative-to-View-Distance.patch

From d1a43b7d46685cdaa095ef806f9300db709c5d84 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


diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
index 7416edc..e8d30c5 100644
--- a/src/main/java/net/minecraft/server/Chunk.java
+++ b/src/main/java/net/minecraft/server/Chunk.java
@@ -33,6 +33,7 @@ public class Chunk {
     public int p;
     private int u;
     boolean q;
+    protected gnu.trove.map.hash.TObjectIntHashMap<Class> entityCount = new gnu.trove.map.hash.TObjectIntHashMap<Class>(); // Spigot
 
     public Chunk(World world, int i, int j) {
         this.sections = new ChunkSection[16];
@@ -560,6 +561,15 @@ public class Chunk {
         entity.ak = k;
         entity.al = this.z;
         this.entitySlices[k].add(entity);
+        // Spigot start - increment creature type count
+        for ( EnumCreatureType creatureType : EnumCreatureType.values() )
+        {
+            if ( creatureType.a().isAssignableFrom( entity.getClass() ) )
+            {
+                this.entityCount.adjustOrPutValue( creatureType.a(), 1, 1 );
+            }
+        }
+        // Spigot end
     }
 
     public void b(Entity entity) {
@@ -576,6 +586,15 @@ public class Chunk {
         }
 
         this.entitySlices[i].remove(entity);
+        // Spigot start - decrement creature type count
+        for ( EnumCreatureType creatureType : EnumCreatureType.values() )
+        {
+            if ( creatureType.a().isAssignableFrom( entity.getClass() ) )
+            {
+                this.entityCount.adjustValue( creatureType.a(), -1 );
+            }
+        }
+        // Spigot end
     }
 
     public boolean d(int i, int j, int k) {
diff --git a/src/main/java/net/minecraft/server/SpawnerCreature.java b/src/main/java/net/minecraft/server/SpawnerCreature.java
index 056100f..bec0d91 100644
--- a/src/main/java/net/minecraft/server/SpawnerCreature.java
+++ b/src/main/java/net/minecraft/server/SpawnerCreature.java
@@ -26,6 +26,23 @@ public final class SpawnerCreature {
         return new ChunkPosition(k, i1, l);
     }
 
+    // Spigot start - get entity count only from chunks being processed in b
+    private static int getEntityCount(WorldServer server, Class oClass)
+    {
+        int i = 0;
+        for ( Long coord : b.keySet() )
+        {
+            int x = LongHash.msw( coord );
+            int z = LongHash.lsw( coord );
+            if ( !server.chunkProviderServer.unloadQueue.contains( coord ) && server.isChunkLoaded( x, z ) )
+            {
+                i += server.getChunkAt( x, z ).entityCount.get( oClass );
+            }
+        }
+        return i;
+    }
+    // Spigot end
+
     public static final int spawnEntities(WorldServer worldserver, boolean flag, boolean flag1, boolean flag2) {
         if (!flag && !flag1) {
             return 0;
@@ -41,6 +58,11 @@ public final class SpawnerCreature {
 
                 j = MathHelper.floor(entityhuman.locZ / 16.0D);
                 byte b0 = 8;
+                // Spigot Start
+                b0 = worldserver.spigotConfig.mobSpawnRange;
+                b0 = ( b0 > worldserver.spigotConfig.viewDistance ) ? (byte) worldserver.spigotConfig.viewDistance : b0;
+                b0 = ( b0 > 8 ) ? 8 : b0;
+                // Spigot End
 
                 for (int l = -b0; l <= b0; ++l) {
                     for (int i1 = -b0; i1 <= b0; ++i1) {
@@ -88,13 +110,15 @@ public final class SpawnerCreature {
                 if (limit == 0) {
                     continue;
                 }
+                int mobcnt = 0;
                 // CraftBukkit end
 
-                if ((!enumcreaturetype.d() || flag1) && (enumcreaturetype.d() || flag) && (!enumcreaturetype.e() || flag2) && worldserver.a(enumcreaturetype.a()) <= limit * b.size() / 256) { // CraftBukkit - use per-world limits
+                if ((!enumcreaturetype.d() || flag1) && (enumcreaturetype.d() || flag) && (!enumcreaturetype.e() || flag2) && (mobcnt = getEntityCount(worldserver, enumcreaturetype.a())) <= limit * b.size() / 256) { // Spigot - use per-world limits and use all loaded chunks
                     Iterator iterator = b.keySet().iterator();
 
+                    int moblimit = (limit * b.size() / 256) - mobcnt + 1; // Spigot - up to 1 more than limit
                     label110:
-                    while (iterator.hasNext()) {
+                    while (iterator.hasNext() && (moblimit > 0)) { // Spigot - while more allowed
                         // CraftBukkit start
                         long key = ((Long) iterator.next()).longValue();
 
@@ -158,6 +182,13 @@ public final class SpawnerCreature {
                                                                 a(entityliving, worldserver, f, f1, f2);
                                                                 worldserver.addEntity(entityliving, SpawnReason.NATURAL);
                                                                 // CraftBukkit end
+                                                                // Spigot start
+                                                                if ( --moblimit <= 0 )
+                                                                {
+                                                                    // If we're past limit, stop spawn
+                                                                    continue label110;
+                                                                }
+                                                                // Spigot end
                                                                 if (j2 >= entityliving.by()) {
                                                                     continue label110;
                                                                 }
diff --git a/src/main/java/org/spigotmc/SpigotWorldConfig.java b/src/main/java/org/spigotmc/SpigotWorldConfig.java
index 0a304e8..6c2a430 100644
--- a/src/main/java/org/spigotmc/SpigotWorldConfig.java
+++ b/src/main/java/org/spigotmc/SpigotWorldConfig.java
@@ -145,4 +145,11 @@ public class SpigotWorldConfig
         
         antiXrayInstance = new AntiXray( this );
     }
+
+    public byte mobSpawnRange;
+    private void mobSpawnRange()
+    {
+        mobSpawnRange = (byte) getInt( "mob-spawn-range", 4 );
+        log( "Mob Spawn Range: " + mobSpawnRange );
+    }
 }
-- 
1.8.1.2