From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Simon Gardling <titaniumtown@gmail.com>
Date: Fri, 14 Jan 2022 12:00:42 -0500
Subject: [PATCH] some entity micro opts

Original code by Titaniumtown, licensed under GNU General Public License v3.0
You can find the original code on https://gitlab.com/Titaniumtown/JettPack

diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index a189fdcafda1e52ee8bf52361b1aae5cfff7614b..6bc313aa05d572236f05d0960fde0f27b9f93d50 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -1866,12 +1866,18 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource {
         }
     }
 
+    // JettPack start - allow passing BlockPos to getLightLevelDependentMagicValue
     /** @deprecated */
     @Deprecated
     public float getLightLevelDependentMagicValue() {
-        return this.level.hasChunkAt(this.getBlockX(), this.getBlockZ()) ? this.level.getLightLevelDependentMagicValue(new BlockPos(this.getX(), this.getEyeY(), this.getZ())) : 0.0F;
+        return this.level.getLightLevelDependentMagicValue(new BlockPos(this.getX(), this.getEyeY(), this.getZ()));
     }
 
+    public float getLightLevelDependentMagicValue(BlockPos pos) {
+        return this.level.hasChunkAt(this.getBlockX(), this.getBlockZ()) ? this.level.getLightLevelDependentMagicValue(pos) : 0.0F;
+    }
+    // JettPack end
+
     public void absMoveTo(double x, double y, double z, float yaw, float pitch) {
         this.absMoveTo(x, y, z);
         this.setYRot(yaw % 360.0F);
@@ -4309,6 +4315,12 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource {
     }
     // Paper end - block invalid positions
 
+    // JettPack start
+    public final int getPositionHashCode() {
+        return this.position.hashCode();
+    }
+    // JettPack end
+
     public final void setPosRaw(double x, double y, double z) {
         // Paper start
         this.setPosRaw(x, y, z, false);
diff --git a/src/main/java/net/minecraft/world/entity/Mob.java b/src/main/java/net/minecraft/world/entity/Mob.java
index 9980df9128dfc51f2afbca8f4aa2031e3728796a..a60cca663da4200d482c19d0b41a9514825a1e9b 100644
--- a/src/main/java/net/minecraft/world/entity/Mob.java
+++ b/src/main/java/net/minecraft/world/entity/Mob.java
@@ -1641,15 +1641,31 @@ public abstract class Mob extends LivingEntity {
 
     }
 
+    // JettPack start - cache eye blockpos
+    private BlockPos cached_eye_blockpos;
+    private int cached_position_hashcode;
+    // JettPack end
     public boolean isSunBurnTick() {
         if (this.level.isDay() && !this.level.isClientSide) {
-            float f = this.getLightLevelDependentMagicValue();
-            BlockPos blockposition = new BlockPos(this.getX(), this.getEyeY(), this.getZ());
+            // JettPack start - optimizations and cache eye blockpos
+            int positionHashCode = this.getPositionHashCode();
+            if (this.cached_position_hashcode != positionHashCode) {
+                this.cached_eye_blockpos = new BlockPos(this.getX(), this.getEyeY(), this.getZ());
+                this.cached_position_hashcode = positionHashCode;
+            }
+
+            float f = this.getLightLevelDependentMagicValue(cached_eye_blockpos); // Pass BlockPos to getBrightness
+
+            // Check brightness first
+            if (f <= 0.5F) return false;
+            if (this.random.nextFloat() * 30.0F >= (f - 0.4F) * 2.0F) return false;
+
             boolean flag = this.isInWaterRainOrBubble() || this.isInPowderSnow || this.wasInPowderSnow;
 
-            if (f > 0.5F && this.random.nextFloat() * 30.0F < (f - 0.4F) * 2.0F && !flag && this.level.canSeeSky(blockposition)) {
+            if (!flag && this.level.canSeeSky(this.cached_eye_blockpos)) { // JettPack - move brightness checks up
                 return true;
             }
+            // JettPack end
         }
 
         return false;