From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Andrew Steinborn <git@steinborn.me>
Date: Mon, 18 Jan 2021 20:45:25 -0500
Subject: [PATCH] Inline shift direction fields

Removes a layer of indirection for EnumDirection.getAdjacent(X|Y|Z)(), which is in the
critical section for much of the server, including the lighting engine.

diff --git a/src/main/java/net/minecraft/core/Direction.java b/src/main/java/net/minecraft/core/Direction.java
index 14b57310811bb930b40396a02b263cdbccb1076b..75694cfd7d8adde6b9246518c20fe75774297a57 100644
--- a/src/main/java/net/minecraft/core/Direction.java
+++ b/src/main/java/net/minecraft/core/Direction.java
@@ -48,6 +48,12 @@ public enum Direction implements StringRepresentable {
         .sorted(Comparator.comparingInt(direction -> direction.data2d))
         .toArray(Direction[]::new);
 
+    // Paper start - Perf: Inline shift direction fields
+    private final int adjX;
+    private final int adjY;
+    private final int adjZ;
+    // Paper end - Perf: Inline shift direction fields
+
     private Direction(int id, int idOpposite, int idHorizontal, String name, Direction.AxisDirection direction, Direction.Axis axis, Vec3i vector) {
         this.data3d = id;
         this.data2d = idHorizontal;
@@ -56,6 +62,11 @@ public enum Direction implements StringRepresentable {
         this.axis = axis;
         this.axisDirection = direction;
         this.normal = vector;
+        // Paper start - Perf: Inline shift direction fields
+        this.adjX = vector.getX();
+        this.adjY = vector.getY();
+        this.adjZ = vector.getZ();
+        // Paper end - Perf: Inline shift direction fields
     }
 
     public static Direction[] orderedByNearest(Entity entity) {
@@ -219,15 +230,15 @@ public enum Direction implements StringRepresentable {
     }
 
     public int getStepX() {
-        return this.normal.getX();
+        return this.adjX; // Paper - Perf: Inline shift direction fields
     }
 
     public int getStepY() {
-        return this.normal.getY();
+        return this.adjY; // Paper - Perf: Inline shift direction fields
     }
 
     public int getStepZ() {
-        return this.normal.getZ();
+        return this.adjZ; // Paper - Perf: Inline shift direction fields
     }
 
     public Vector3f step() {