spigot/CraftBukkit-Patches/0009-Fix-Mob-Spawning-Relative-to-View-Distance.patch

From ec5715b7ffc31b515617c49215d3b215f5cb831c Mon Sep 17 00:00:00 2001
From: md_5 <git@md-5.net>
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/level/ChunkProviderServer.java b/src/main/java/net/minecraft/server/level/ChunkProviderServer.java
index 196e383e6..248027280 100644
--- a/src/main/java/net/minecraft/server/level/ChunkProviderServer.java
+++ b/src/main/java/net/minecraft/server/level/ChunkProviderServer.java
@@ -483,7 +483,7 @@ public class ChunkProviderServer extends IChunkProvider {
         }
 
         if (!list.isEmpty()) {
-            if (this.level.canSpawnEntitiesInChunk(chunkcoordintpair)) {
+            if (this.level.canSpawnEntitiesInChunk(chunkcoordintpair) && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkcoordintpair, true)) { // Spigot
                 SpawnerCreature.spawnForChunk(this.level, chunk, spawnercreature_d, list);
             }
 
diff --git a/src/main/java/net/minecraft/server/level/PlayerChunkMap.java b/src/main/java/net/minecraft/server/level/PlayerChunkMap.java
index 8d197013e..8487d9861 100644
--- a/src/main/java/net/minecraft/server/level/PlayerChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/PlayerChunkMap.java
@@ -1060,14 +1060,31 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.b, Gener
     }
 
     boolean anyPlayerCloseEnoughForSpawning(ChunkCoordIntPair chunkcoordintpair) {
+        // Spigot start
+        return anyPlayerCloseEnoughForSpawning(chunkcoordintpair, false);
+    }
+
+    boolean anyPlayerCloseEnoughForSpawning(ChunkCoordIntPair chunkcoordintpair, boolean reducedRange) {
+        // Spigot end
         TriState tristate = this.distanceManager.hasPlayersNearby(chunkcoordintpair.toLong());
 
-        return tristate == TriState.DEFAULT ? this.anyPlayerCloseEnoughForSpawningInternal(chunkcoordintpair) : tristate.toBoolean(true);
+        return tristate == TriState.DEFAULT ? this.anyPlayerCloseEnoughForSpawningInternal(chunkcoordintpair, reducedRange) : tristate.toBoolean(true); // Spigot
     }
 
     private boolean anyPlayerCloseEnoughForSpawningInternal(ChunkCoordIntPair chunkcoordintpair) {
+        // Spigot start
+        return anyPlayerCloseEnoughForSpawningInternal(chunkcoordintpair, false);
+    }
+
+    private boolean anyPlayerCloseEnoughForSpawningInternal(ChunkCoordIntPair chunkcoordintpair, boolean reducedRange) {
+        int chunkRange = level.spigotConfig.mobSpawnRange;
+        chunkRange = (chunkRange > level.spigotConfig.viewDistance) ? (byte) level.spigotConfig.viewDistance : chunkRange;
+        chunkRange = (chunkRange > 8) ? 8 : chunkRange;
+
+        double blockRange = (reducedRange) ? Math.pow(chunkRange << 4, 2) : 16384.0D;
+        // Spigot end
         for (EntityPlayer entityplayer : this.playerMap.getAllPlayers()) {
-            if (this.playerIsCloseEnoughForSpawning(entityplayer, chunkcoordintpair)) {
+            if (this.playerIsCloseEnoughForSpawning(entityplayer, chunkcoordintpair, blockRange)) { // Spigot
                 return true;
             }
         }
@@ -1084,7 +1101,7 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.b, Gener
             ImmutableList.Builder<EntityPlayer> immutablelist_builder = ImmutableList.builder();
 
             for (EntityPlayer entityplayer : this.playerMap.getAllPlayers()) {
-                if (this.playerIsCloseEnoughForSpawning(entityplayer, chunkcoordintpair)) {
+                if (this.playerIsCloseEnoughForSpawning(entityplayer, chunkcoordintpair, 16384.0D)) { // Spigot
                     immutablelist_builder.add(entityplayer);
                 }
             }
@@ -1093,13 +1110,13 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.b, Gener
         }
     }
 
-    private boolean playerIsCloseEnoughForSpawning(EntityPlayer entityplayer, ChunkCoordIntPair chunkcoordintpair) {
+    private boolean playerIsCloseEnoughForSpawning(EntityPlayer entityplayer, ChunkCoordIntPair chunkcoordintpair, double range) { // Spigot
         if (entityplayer.isSpectator()) {
             return false;
         } else {
             double d0 = euclideanDistanceSquared(chunkcoordintpair, entityplayer.position());
 
-            return d0 < 16384.0D;
+            return d0 < range; // Spigot
         }
     }
 
diff --git a/src/main/java/org/spigotmc/SpigotWorldConfig.java b/src/main/java/org/spigotmc/SpigotWorldConfig.java
index acaf90301..0c0c29efe 100644
--- a/src/main/java/org/spigotmc/SpigotWorldConfig.java
+++ b/src/main/java/org/spigotmc/SpigotWorldConfig.java
@@ -180,4 +180,11 @@ public class SpigotWorldConfig
 
         log( "Simulation Distance: " + simulationDistance );
     }
+
+    public byte mobSpawnRange;
+    private void mobSpawnRange()
+    {
+        mobSpawnRange = (byte) getInt( "mob-spawn-range", 6 );
+        log( "Mob Spawn Range: " + mobSpawnRange );
+    }
 }
-- 
2.49.0