Fix lag caused by water mobs across the board - Fixes #1462

This update introduces Entity Activation Range for water mobs.

Activation Range has been one of my biggest performance improvements
I ever added to Minecraft, however "Entity is in Water" is an immunity
case that keeps an entity active.

This update ignores the water check for known water based mobs, allowing
them to actually go inactive.

In addition to that, a new config option was added to spigot.yml to go with
the rest of the entity-activation-range options to let you configure
aquatic mobs like fish, squid and dolphins separately.

This should overall fix all lag caused by water mobs.

Spigot-Server-Patches/0161-Activation-Range-Improvements.patch

@@ -1,10 +1,12 @@
-From 41be89ac350a161565254c71c675b9b3f06d6021 Mon Sep 17 00:00:00 2001
+From 5c8d5740834de57a88322d4bdb1a0fb33831dc29 Mon Sep 17 00:00:00 2001
 From: Aikar <aikar@aikar.co>
 Date: Tue, 27 Dec 2016 22:38:06 -0500
 Subject: [PATCH] Activation Range Improvements
 
 Fixes and adds new Immunities to improve gameplay behavior
 
+Adds water Mobs to activation range config and nerfs fish
+
 diff --git a/src/main/java/net/minecraft/server/BlockPosition.java b/src/main/java/net/minecraft/server/BlockPosition.java
 index f4ed98d2d9..1dfd71df0a 100644
 --- a/src/main/java/net/minecraft/server/BlockPosition.java
@@ -110,18 +112,105 @@ index 9a75cb63ba..cf10605aaa 100644
                          }
                      }
 diff --git a/src/main/java/org/spigotmc/ActivationRange.java b/src/main/java/org/spigotmc/ActivationRange.java
-index f9bb19fed6..03ca577b4c 100644
+index f9bb19fed6..d176008f44 100644
 --- a/src/main/java/org/spigotmc/ActivationRange.java
 +++ b/src/main/java/org/spigotmc/ActivationRange.java
-@@ -20,6 +20,7 @@ import net.minecraft.server.EntityFireball;
+@@ -13,13 +13,16 @@ import net.minecraft.server.EntityArrow;
+ import net.minecraft.server.EntityComplexPart;
+ import net.minecraft.server.EntityCreature;
+ import net.minecraft.server.EntityCreeper;
++import net.minecraft.server.EntityDrowned;
+ import net.minecraft.server.EntityEnderCrystal;
+ import net.minecraft.server.EntityEnderDragon;
+ import net.minecraft.server.EntityFallingBlock;
+ import net.minecraft.server.EntityFireball;
  import net.minecraft.server.EntityFireworks;
++import net.minecraft.server.EntityFish;
  import net.minecraft.server.EntityHuman;
  import net.minecraft.server.EntityLiving;
 +import net.minecraft.server.EntityLlama;
  import net.minecraft.server.EntityMonster;
  import net.minecraft.server.EntityProjectile;
  import net.minecraft.server.EntitySheep;
-@@ -212,18 +213,29 @@ public class ActivationRange
+@@ -27,6 +30,7 @@ import net.minecraft.server.EntitySlime;
+ import net.minecraft.server.EntityTNTPrimed;
+ import net.minecraft.server.EntityThrownTrident;
+ import net.minecraft.server.EntityVillager;
++import net.minecraft.server.EntityWaterAnimal;
+ import net.minecraft.server.EntityWeather;
+ import net.minecraft.server.EntityWither;
+ import net.minecraft.server.MCUtil;
+@@ -40,6 +44,7 @@ public class ActivationRange
+     static AxisAlignedBB maxBB = new AxisAlignedBB( 0, 0, 0, 0, 0, 0 );
+     static AxisAlignedBB miscBB = new AxisAlignedBB( 0, 0, 0, 0, 0, 0 );
+     static AxisAlignedBB animalBB = new AxisAlignedBB( 0, 0, 0, 0, 0, 0 );
++    static AxisAlignedBB waterBB = new AxisAlignedBB( 0, 0, 0, 0, 0, 0 ); // Paper
+     static AxisAlignedBB monsterBB = new AxisAlignedBB( 0, 0, 0, 0, 0, 0 );
+ 
+     /**
+@@ -51,6 +56,7 @@ public class ActivationRange
+      */
+     public static byte initializeEntityActivationType(Entity entity)
+     {
++        if (entity instanceof EntityWaterAnimal) { return 4; } // Paper
+         if ( entity instanceof EntityMonster || entity instanceof EntitySlime )
+         {
+             return 1; // Monster
+@@ -75,6 +81,7 @@ public class ActivationRange
+         if ( ( entity.activationType == 3 && config.miscActivationRange == 0 )
+                 || ( entity.activationType == 2 && config.animalActivationRange == 0 )
+                 || ( entity.activationType == 1 && config.monsterActivationRange == 0 )
++                || ( entity.activationType == 4 && config.waterActivationRange == 0 ) // Paper
+                 || entity instanceof EntityHuman
+                 || entity instanceof EntityProjectile
+                 || entity instanceof EntityEnderDragon
+@@ -106,6 +113,7 @@ public class ActivationRange
+         final int miscActivationRange = world.spigotConfig.miscActivationRange;
+         final int animalActivationRange = world.spigotConfig.animalActivationRange;
+         final int monsterActivationRange = world.spigotConfig.monsterActivationRange;
++        final int waterActivationRange = world.spigotConfig.waterActivationRange; // Paper
+ 
+         int maxRange = Math.max( monsterActivationRange, animalActivationRange );
+         maxRange = Math.max( maxRange, miscActivationRange );
+@@ -119,6 +127,7 @@ public class ActivationRange
+             maxBB = player.getBoundingBox().grow( playerMaxRange, 256, playerMaxRange ); // Paper - Use player view distance API
+             miscBB = player.getBoundingBox().grow( miscActivationRange, 256, miscActivationRange );
+             animalBB = player.getBoundingBox().grow( animalActivationRange, 256, animalActivationRange );
++            waterBB = player.getBoundingBox().grow( waterActivationRange, 256, waterActivationRange ); // Paper
+             monsterBB = player.getBoundingBox().grow( monsterActivationRange, 256, monsterActivationRange );
+ 
+             int i = MathHelper.floor( maxBB.a / 16.0D );
+@@ -172,6 +181,14 @@ public class ActivationRange
+                                 entity.activatedTick = MinecraftServer.currentTick;
+                             }
+                             break;
++                            // Paper start
++                        case 4:
++                            if ( waterBB.c( entity.getBoundingBox() ) )
++                            {
++                                entity.activatedTick = MinecraftServer.currentTick;
++                            }
++                            break;
++                            // Paper end
+                         case 3:
+                         default:
+                             if ( miscBB.c( entity.getBoundingBox() ) )
+@@ -193,8 +210,13 @@ public class ActivationRange
+      */
+     public static boolean checkEntityImmunities(Entity entity)
+     {
++        // Paper start - optimize Water cases
++        if (entity instanceof EntityFish) {
++            return false;
++        }
+         // quick checks.
+-        if ( entity.inWater || entity.fireTicks > 0 )
++        if ( (entity.inWater && (!(entity instanceof EntityWaterAnimal || entity instanceof EntityDrowned))) || entity.fireTicks > 0 )
++        // Paper end
+         {
+             return true;
+         }
+@@ -212,18 +234,29 @@ public class ActivationRange
          if ( entity instanceof EntityLiving )
          {
              EntityLiving living = (EntityLiving) entity;
@@ -154,7 +243,7 @@ index f9bb19fed6..03ca577b4c 100644
              if ( entity instanceof EntityAnimal )
              {
                  EntityAnimal animal = (EntityAnimal) entity;
-@@ -276,10 +288,10 @@ public class ActivationRange
+@@ -276,10 +309,10 @@ public class ActivationRange
          {
              isActive = false;
          }
@@ -168,6 +257,25 @@ index f9bb19fed6..03ca577b4c 100644
          if ( isActive && !( chunk != null && chunk.areNeighborsLoaded( 1 ) ) )
          {
              isActive = false;
+diff --git a/src/main/java/org/spigotmc/SpigotWorldConfig.java b/src/main/java/org/spigotmc/SpigotWorldConfig.java
+index 87bc8e2d9c..06d84a0b66 100644
+--- a/src/main/java/org/spigotmc/SpigotWorldConfig.java
++++ b/src/main/java/org/spigotmc/SpigotWorldConfig.java
+@@ -144,12 +144,14 @@ public class SpigotWorldConfig
+     public int animalActivationRange = 32;
+     public int monsterActivationRange = 32;
+     public int miscActivationRange = 16;
++    public int waterActivationRange = 16; // Paper
+     public boolean tickInactiveVillagers = true;
+     private void activationRange()
+     {
+         animalActivationRange = getInt( "entity-activation-range.animals", animalActivationRange );
+         monsterActivationRange = getInt( "entity-activation-range.monsters", monsterActivationRange );
+         miscActivationRange = getInt( "entity-activation-range.misc", miscActivationRange );
++        waterActivationRange = getInt( "entity-activation-range.water", waterActivationRange ); // Paper
+         tickInactiveVillagers = getBoolean( "entity-activation-range.tick-inactive-villagers", tickInactiveVillagers );
+         log( "Entity Activation Range: An " + animalActivationRange + " / Mo " + monsterActivationRange + " / Mi " + miscActivationRange + " / Tiv " + tickInactiveVillagers );
+     }
 -- 
 2.19.0