Reduce number of collision checks for living entities.

CraftBukkit-Patches/0023-Reduce-number-of-LivingEntity-collision-checks.patch

@@ -0,0 +1,37 @@
+From 2e2b7c86482c38d4c37f1df77509bca28655cb63 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Fri, 18 Jan 2013 19:31:14 -0500
+Subject: [PATCH] Reduce number of LivingEntity collision checks.
+
+---
+ src/main/java/net/minecraft/server/EntityLiving.java | 8 ++++++++
+ 1 file changed, 8 insertions(+)
+
+diff --git a/src/main/java/net/minecraft/server/EntityLiving.java b/src/main/java/net/minecraft/server/EntityLiving.java
+index b2481aa..e476393 100644
+--- a/src/main/java/net/minecraft/server/EntityLiving.java
++++ b/src/main/java/net/minecraft/server/EntityLiving.java
+@@ -1402,12 +1402,20 @@ public abstract class EntityLiving extends Entity {
+     }
+ 
+     protected void bd() {
++        // Spigot start
++        boolean skip = false;
++        if (!(this instanceof EntityPlayer) && this.ticksLived % 2 != 0) {
++            skip = true;
++        }
++        // Spigot end
++
+         List list = this.world.getEntities(this, this.boundingBox.grow(0.20000000298023224D, 0.0D, 0.20000000298023224D));
+ 
+         if (list != null && !list.isEmpty()) {
+             for (int i = 0; i < list.size(); ++i) {
+                 Entity entity = (Entity) list.get(i);
+ 
++                if (!(entity instanceof EntityMinecart) && skip) { continue; } // Spigot
+                 if (entity.M()) {
+                     this.o(entity);
+                 }
+-- 
+1.8.1-rc2
+