Scissors/patches/unapplied/server/0021-Limit-amount-of-vehicle-collision-checks-to-3-and-di.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Allink <arclicious@vivaldi.net>
Date: Thu, 21 Apr 2022 13:52:32 +0100
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 44a6118d3bd67a95180f750c17967561946e2e87..8aece67eba8d6b558bc2441b8b8e599f86e12e4f 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; // Scissors
 import javax.annotation.Nullable;
 import net.minecraft.BlockUtil;
 import net.minecraft.Util;
@@ -111,6 +112,7 @@ public abstract class AbstractMinecart extends Entity {
     private double flyingX = 0.949999988079071D; // Paper - restore vanilla precision
     private double flyingY = 0.949999988079071D; // Paper - restore vanilla precision
     private double flyingZ = 0.949999988079071D; // Paper - restore vanilla precision
+    private long lastLargeCollision = 0L; // Scissors - Add a collision debounce
     public double maxSpeed = 0.4D;
     // CraftBukkit end
 
@@ -432,8 +434,8 @@ public abstract class AbstractMinecart extends Entity {
             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();
@@ -462,6 +464,14 @@ public abstract class AbstractMinecart extends Entity {
                             entity.push(this);
                         }
                     }
+
+                    // Scissors start - Add a collision debounce
+                    if (list.size() > 15) {
+                        this.discard();
+                    } 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 5c07da62c82bc70138f6cb5007629d6974be69ac..301a72dffd4ac58333d987e85d22136498d2d82a 100644
--- a/src/main/java/net/minecraft/world/entity/vehicle/Boat.java
+++ b/src/main/java/net/minecraft/world/entity/vehicle/Boat.java
@@ -5,6 +5,7 @@ import com.google.common.collect.UnmodifiableIterator;
 import java.util.Iterator;
 import java.util.List;
 import java.util.function.IntFunction;
+import java.util.concurrent.TimeUnit; // Scissors
 import javax.annotation.Nullable;
 import net.minecraft.BlockUtil;
 import net.minecraft.core.BlockPos;
@@ -112,6 +113,7 @@ public class Boat extends Entity implements VariantHolder<Boat.Type> {
     public double unoccupiedDeceleration = -1;
     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);
@@ -465,9 +467,9 @@ public class Boat extends Entity 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();
@@ -480,6 +482,14 @@ public class Boat extends Entity implements VariantHolder<Boat.Type> {
                     }
                 }
             }
+
+            // Scissors start - Add collision debounce
+            if (list.size() > 15) {
+                this.discard();
+            } else if (list.size() > 3) {
+                lastLargeCollision = System.currentTimeMillis();
+            }
+            // Scissors end
         }
 
     }