Scissors/patches/server/0026-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: Sun, 1 May 2022 14:23:35 -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 3f31a3c17ecca6e93b794478129b95ecff4e1a9c..1db184c47880a3527e6c83666c90b7d9a9bd3ad7 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;
@@ -106,6 +107,7 @@ 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
 
@@ -424,8 +426,10 @@ 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()) {
-                    for (int l = 0; l < list.size(); ++l) {
+                // Scissors - Add a collision debounce
+                if (!list.isEmpty() && (System.currentTimeMillis() - lastLargeCollision) >= TimeUnit.SECONDS.toMillis(5)) { // Using TimeUnit for better code readability
+                    // Scissors - Limit amount of vehicle collision checks to 3 maximum
+                    for (int l = 0; l < Math.min(3, list.size()); ++l) {
                         Entity entity = (Entity) list.get(l);
 
                         if (!(entity instanceof Player) && !(entity instanceof IronGolem) && !(entity instanceof AbstractMinecart) && !this.isVehicle() && !entity.isPassenger()) {
@@ -452,6 +456,16 @@ public abstract class AbstractMinecart extends Entity {
                             entity.push(this);
                         }
                     }
+
+                    // Scissors - Add a collision debounce
+                    if (list.size() > 3) {
+                        lastLargeCollision = System.currentTimeMillis();
+                    }
+
+                    // Scissors - Delete entity if the collision amount is over 15
+                    if (list.size() > 15) {
+                        this.discard();
+                    }
                 }
             } else {
                 Iterator iterator = 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 eb753323f67badb1bed28405c07b03078e322b44..8e1855ae99ce0a1c098a67c7e0fead87c061eb4f 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 javax.annotation.Nullable;
 import net.minecraft.BlockUtil;
 import net.minecraft.core.BlockPos;
@@ -106,6 +107,7 @@ public class Boat extends Entity {
     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);
@@ -403,10 +405,12 @@ public class Boat extends Entity {
         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()) {
+        // Scissors - Add collision debounce
+        if (!list.isEmpty() && (System.currentTimeMillis() - lastLargeCollision) >= TimeUnit.SECONDS.toMillis(5)) { // Using TimeUnit for better code readability
             boolean flag = !this.level.isClientSide && !(this.getControllingPassenger() instanceof Player);
 
-            for (int j = 0; j < list.size(); ++j) {
+            // Scissors - Limit amount of vehicle collision checks to 3 maximum
+            for (int j = 0; j < Math.min(3, list.size()); ++j) {
                 Entity entity = (Entity) list.get(j);
 
                 if (!entity.hasPassenger((Entity) this)) {
@@ -417,6 +421,16 @@ public class Boat extends Entity {
                     }
                 }
             }
+
+            // Scissors - Add collision debounce
+            if (list.size() > 3) {
+                lastLargeCollision = System.currentTimeMillis();
+            }
+
+            // Scissors - Delete entity if the collision amount is over 15
+            if (list.size() > 15) {
+                this.discard();
+            }
         }
 
     }