Scissors/patches/server/0015-Limit-amount-of-vehicle-collision-checks-to-3-and-di.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Telesphoreo <me@telesphoreo.me>
Date: Wed, 8 May 2024 13:00:39 -0500
Subject: [PATCH] Limit amount of vehicle collision checks to 3 and discard
 vehicles if they collide with more than 15 other entities


diff --git a/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecart.java b/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecart.java
index 4d7454e5a64fc18e63793a221daa94617f17c666..0ebc9b469d684251ba73989b3f7483522faf48d7 100644
--- a/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecart.java
+++ b/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecart.java
@@ -8,6 +8,7 @@ import com.mojang.datafixers.util.Pair;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.TimeUnit;
 import javax.annotation.Nullable;
 import net.minecraft.BlockUtil;
 import net.minecraft.Util;
@@ -101,6 +102,7 @@ public abstract class AbstractMinecart extends VehicleEntity {
     private double flyingX = 0.95;
     private double flyingY = 0.95;
     private double flyingZ = 0.95;
+    private long lastLargeCollision = 0L; // Scissors - Add a collision debounce
     public double maxSpeed = 0.4D;
     // CraftBukkit end
 
@@ -381,8 +383,8 @@ public abstract class AbstractMinecart extends VehicleEntity {
             if (this.getMinecartType() == AbstractMinecart.Type.RIDEABLE && this.getDeltaMovement().horizontalDistanceSqr() > 0.01D) {
                 List<Entity> list = this.level().getEntities((Entity) this, this.getBoundingBox().inflate(0.20000000298023224D, 0.0D, 0.20000000298023224D), EntitySelector.pushableBy(this));
 
-                if (!list.isEmpty()) {
-                    Iterator iterator = list.iterator();
+                if (!list.isEmpty() && (System.currentTimeMillis() - lastLargeCollision) >= TimeUnit.SECONDS.toMillis(5)) { // Scissors - add collision debounce, using TimeUnit for better code readability
+                    Iterator iterator = list.size() <= 15 ? list.iterator() : list.subList(0, 15).iterator(); // Scissors
 
                     while (iterator.hasNext()) {
                         Entity entity = (Entity) iterator.next();
@@ -411,6 +413,13 @@ public abstract class AbstractMinecart extends VehicleEntity {
                             entity.push(this);
                         }
                     }
+                    // Scissors start - Add a collision debounce
+                    if (list.size() > 15) {
+                        this.discard(null);
+                    } else if (list.size() > 3) {
+                        lastLargeCollision = System.currentTimeMillis();
+                    }
+                    // Scissors end
                 }
             } else {
                 Iterator iterator1 = this.level().getEntities(this, this.getBoundingBox().inflate(0.20000000298023224D, 0.0D, 0.20000000298023224D)).iterator();
diff --git a/src/main/java/net/minecraft/world/entity/vehicle/Boat.java b/src/main/java/net/minecraft/world/entity/vehicle/Boat.java
index b068cff9b5aa457d65b679529956e8210296d799..8274154f2ce4a752ea49790c6526ecb353934a04 100644
--- a/src/main/java/net/minecraft/world/entity/vehicle/Boat.java
+++ b/src/main/java/net/minecraft/world/entity/vehicle/Boat.java
@@ -4,6 +4,7 @@ import com.google.common.collect.Lists;
 import com.google.common.collect.UnmodifiableIterator;
 import java.util.Iterator;
 import java.util.List;
+import java.util.concurrent.TimeUnit;
 import java.util.function.IntFunction;
 import javax.annotation.Nullable;
 import net.minecraft.BlockUtil;
@@ -107,6 +108,8 @@ public class Boat extends VehicleEntity implements VariantHolder<Boat.Type> {
     public boolean landBoats = false;
     // CraftBukkit end
 
+    private long lastLargeCollision = 0L; // Scissors - Add a collision debounce
+
     public Boat(EntityType<? extends Boat> type, Level world) {
         super(type, world);
         this.paddlePositions = new float[2];
@@ -401,9 +404,9 @@ public class Boat extends VehicleEntity implements VariantHolder<Boat.Type> {
         this.checkInsideBlocks();
         List<Entity> list = this.level().getEntities((Entity) this, this.getBoundingBox().inflate(0.20000000298023224D, -0.009999999776482582D, 0.20000000298023224D), EntitySelector.pushableBy(this));
 
-        if (!list.isEmpty()) {
+        if (!list.isEmpty() && (System.currentTimeMillis() - lastLargeCollision) >= TimeUnit.SECONDS.toMillis(5)) { // Scissors - add collision debounce, using TimeUnit for better code readability
             boolean flag = !this.level().isClientSide && !(this.getControllingPassenger() instanceof Player);
-            Iterator iterator = list.iterator();
+            Iterator iterator = list.size() <= 15 ? list.iterator() : list.subList(0, 15).iterator(); // Scissors
 
             while (iterator.hasNext()) {
                 Entity entity = (Entity) iterator.next();
@@ -416,6 +419,13 @@ public class Boat extends VehicleEntity implements VariantHolder<Boat.Type> {
                     }
                 }
             }
+            // Scissors start - Add collision debounce
+            if (list.size() > 15) {
+                this.discard(null);
+            } else if (list.size() > 3) {
+                lastLargeCollision = System.currentTimeMillis();
+            }
+            // Scissors end
         }
 
     }