From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: mrhua269 <mrhua269@gmail.com>
Date: Sat, 23 Aug 2025 19:49:51 +0800
Subject: [PATCH] Pufferfish: Reduce projectile chunk loading

A part of Pufferfish(https://github.com/Pufferfish-gg/Pufferfish)
Co-authored-by: Paul Sauve <paul@technove.co>
Original patch: https://github.com/pufferfish-gg/Pufferfish/blob/ver/1.21/pufferfish-server/minecraft-patches/features/0006-Reduce-projectile-chunk-loading.patch
Original license(GPL-3.0): https://github.com/pufferfish-gg/Pufferfish/blob/ver/1.21/PATCH-LICENSE

diff --git a/net/minecraft/world/entity/projectile/Projectile.java b/net/minecraft/world/entity/projectile/Projectile.java
index 2d5ba788d48ea2cb7f78c3119013c2d73c90f106..c8f098b7c1c1889e46f8cbb462c78fd991d58f9f 100644
--- a/net/minecraft/world/entity/projectile/Projectile.java
+++ b/net/minecraft/world/entity/projectile/Projectile.java
@@ -50,6 +50,36 @@ public abstract class Projectile extends Entity implements TraceableEntity {
         super(entityType, level);
     }
 
+    // Pufferfish start
+    private static final ThreadLocal<Long> loadedThisTick = ThreadLocal.withInitial(() -> 0L);
+    private static final ThreadLocal<Long> loadedTick = ThreadLocal.withInitial(() -> 0L);
+
+    private int loadedLifetime = 0;
+    @Override
+    public void setPos(double x, double y, double z) {
+        long currentTick = io.papermc.paper.threadedregions.TickRegionScheduler.getCurrentRegion().getData().getCurrentTick();
+        if (loadedTick.get() != currentTick) {
+            loadedTick.set(currentTick);
+            loadedThisTick.set(0L);
+        }
+        int previousX = Mth.floor(this.getX()) >> 4, previousZ = Mth.floor(this.getZ()) >> 4;
+        int newX = Mth.floor(x) >> 4, newZ = Mth.floor(z) >> 4;
+        if (previousX != newX || previousZ != newZ) {
+            boolean isLoaded = ((net.minecraft.server.level.ServerChunkCache) this.level().getChunkSource()).getChunkAtIfLoadedImmediately(newX, newZ) != null;
+            if (!isLoaded) {
+                if (Projectile.loadedThisTick.get() > me.earthme.luminol.config.modules.optimizations.ProjectileChunkReduceConfig.maxProjectileLoadsPerTick) {
+                    if (++this.loadedLifetime > me.earthme.luminol.config.modules.optimizations.ProjectileChunkReduceConfig.maxProjectileLoadsPerProjectile) {
+                        this.discard();
+                    }
+                    return;
+                }
+                Projectile.loadedThisTick.set(Projectile.loadedThisTick.get() + 1);
+            }
+        }
+        super.setPos(x, y, z);
+    }
+    // Pufferfish end
+
     protected void setOwner(@Nullable EntityReference<Entity> owner) {
         this.owner = owner;
     }