From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Newwind <support@newwindserver.com>
Date: Wed, 7 Aug 2024 13:25:55 +0200
Subject: [PATCH] Configuration for horizontal-only item merging

Most of the visual artifacts that result from having item merge radius above vanilla levels is from items merging vertically,
which realistically, only happens when a player is dropping items, or items are dropping from breaking a block.

Most of the scenarios where item merging makes sense involves the two item entities being on the same Y level. i.e on the ground next to each other.
This is even more apparent since paper fixed items being able to merge through blocks.

This patch allows us to configure items to only merge horizontally, which is what vanilla does.
This allows us to have both the reduced number of item entities a high item-merge radius provides,
without most of the visual artifacts caused by items merging vertically.

diff --git a/src/main/java/net/minecraft/world/entity/item/ItemEntity.java b/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
index e83a705f54063a17fc69a22683333aacad5a43ce..246b5649883e4f305afa5a887b9df0f3735f7593 100644
--- a/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
+++ b/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
@@ -285,7 +285,7 @@ public class ItemEntity extends Entity implements TraceableEntity {
         if (this.isMergable()) {
             // Spigot start
             double radius = this.level().spigotConfig.itemMerge;
-            List<ItemEntity> list = this.level().getEntitiesOfClass(ItemEntity.class, this.getBoundingBox().inflate(radius, radius - 0.5D, radius), (entityitem) -> {
+            List<ItemEntity> list = this.level().getEntitiesOfClass(ItemEntity.class, this.getBoundingBox().inflate(radius, this.level().paperConfig().entities.behavior.onlyMergeItemsHorizontally ? 0 : radius - 0.5D, radius), (entityitem) -> { // Paper - configuration to only merge items horizontally
                 // Spigot end
                 return entityitem != this && entityitem.isMergable();
             });