Possible fix and optimisation for PlayerEntitySenses

src/main/java/net/citizensnpcs/npc/entity/EntityHumanNPC.java

@@ -56,6 +56,7 @@ public class EntityHumanNPC extends EntityPlayer implements NPCHolder {
     private final CitizensNPC npc;
     private final Location packetLocationCache = new Location(null, 0, 0, 0);
     private int packetUpdateCount;
+    private int sensesUpdateCount = 0;
     private int useListName = -1;
 
     public EntityHumanNPC(MinecraftServer minecraftServer, World world, String string,
@@ -136,8 +137,8 @@ public class EntityHumanNPC extends EntityPlayer implements NPCHolder {
             // swallow
         }
 
-        Y = 1F; // stepHeight - must not stay as the default 0 (breaks steps).
-                // Check the EntityPlayer constructor for the new name.
+        NMS.setStepHeight(this, 1);// stepHeight - must not stay as the default
+                                   // 0 (breaks steps).
 
         try {
             socket.close();
@@ -234,7 +235,10 @@ public class EntityHumanNPC extends EntityPlayer implements NPCHolder {
     }
 
     public void updateAI() {
-        entitySenses.a();
+        if (++sensesUpdateCount == 5) {
+            sensesUpdateCount = 0;
+            entitySenses.a();
+        }
         controllerMove.c();
         controllerLook.a();
         controllerJump.b();
@@ -320,6 +324,5 @@ public class EntityHumanNPC extends EntityPlayer implements NPCHolder {
     }
 
     private static final float EPSILON = 0.005F;
-
     private static final Location LOADED_LOCATION = new Location(null, 0, 0, 0);
 }

src/main/java/net/citizensnpcs/npc/entity/HorseController.java

@@ -70,6 +70,7 @@ public class HorseController extends MobEntityController {
             if (npc == null) {
                 super.c();
             } else {
+                NMS.setStepHeight(this, 1);
                 updateAIWithMovement();
                 npc.update();
             }

src/main/java/net/citizensnpcs/util/NMS.java

@@ -319,6 +319,10 @@ public class NMS {
         }
     }
 
+    public static void setStepHeight(EntityLiving entity, float height) {
+        entity.Y = height;
+    }
+
     public static boolean shouldJump(net.minecraft.server.v1_6_R2.Entity entity) {
         if (JUMP_FIELD == null || !(entity instanceof EntityLiving))
             return false;
@@ -432,15 +436,13 @@ public class NMS {
     }
 
     private static final float DEFAULT_SPEED = 1F;
-
     private static Map<Class<?>, Integer> ENTITY_CLASS_TO_INT;
-
     private static final Map<Class<?>, Constructor<?>> ENTITY_CONSTRUCTOR_CACHE = new WeakHashMap<Class<?>, Constructor<?>>();
     private static Map<Integer, Class<?>> ENTITY_INT_TO_CLASS;
-    private static Map<Class<?>, Integer> MC_ENTITY_CLASS_TO_INT = null;
-    private static Map<Integer, Class<?>> MC_ENTITY_INT_TO_CLASS = null;
     private static Field GOAL_FIELD = getField(PathfinderGoalSelector.class, "a");
     private static final Field JUMP_FIELD = getField(EntityLiving.class, "bd");
+    private static Map<Class<?>, Integer> MC_ENTITY_CLASS_TO_INT = null;
+    private static Map<Integer, Class<?>> MC_ENTITY_INT_TO_CLASS = null;
     private static Field NAVIGATION_WORLD_FIELD = getField(Navigation.class, "b");
     private static final Location PACKET_CACHE_LOCATION = new Location(null, 0, 0, 0);
     private static Field PATHFINDING_RANGE = getField(Navigation.class, "e");

src/main/java/net/citizensnpcs/util/nms/PlayerEntitySenses.java

@@ -1,15 +1,15 @@
 package net.citizensnpcs.util.nms;
 
-import java.util.ArrayList;
-import java.util.List;
+import java.util.HashSet;
+import java.util.Set;
 
 import net.minecraft.server.v1_6_R2.Entity;
 import net.minecraft.server.v1_6_R2.EntityLiving;
 
 public class PlayerEntitySenses {
-    EntityLiving entity;
-    List<Entity> seenEntities = new ArrayList<Entity>();
-    List<Entity> unseenEntities = new ArrayList<Entity>();
+    private final EntityLiving entity;
+    private final Set<Entity> seenEntities = new HashSet<Entity>();
+    private final Set<Entity> unseenEntities = new HashSet<Entity>();
 
     public PlayerEntitySenses(EntityLiving entityinsentient) {
         this.entity = entityinsentient;