From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <spottedleaf@spottedleaf.dev>
Date: Mon, 2 Aug 2021 10:10:40 +0200
Subject: [PATCH] Improve boat collision performance


diff --git a/src/main/java/net/minecraft/Util.java b/src/main/java/net/minecraft/Util.java
index 81f4f26a6b83079d36acd1fd86dede0eb1116c01..59437f04911662f06596ef61b91017caa6427eec 100644
--- a/src/main/java/net/minecraft/Util.java
+++ b/src/main/java/net/minecraft/Util.java
@@ -75,6 +75,7 @@ public class Util {
     }).findFirst().orElseThrow(() -> {
         return new IllegalStateException("No jar file system provider found");
     });
+    public static final double COLLISION_EPSILON = 1.0E-7; // Paper
     static final Logger LOGGER = LogManager.getLogger();
 
     public static <K, V> Collector<Entry<? extends K, ? extends V>, ?, Map<K, V>> toMap() {
diff --git a/src/main/java/net/minecraft/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java
index 24c629d5f26bc5aadebcf39a63930b3448525242..2b7eeb5659b1083ef550eb9feb0b7ba8a92a92e3 100644
--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
+++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
@@ -1321,7 +1321,7 @@ public abstract class LivingEntity extends Entity {
                 if (!source.isProjectile()) {
                     Entity entity = source.getDirectEntity();
 
-                    if (entity instanceof LivingEntity) {
+                    if (entity instanceof LivingEntity && entity.distanceToSqr(this) <= (200.0D * 200.0D)) { // Paper
                         this.blockUsingShield((LivingEntity) entity);
                     }
                 }
@@ -1430,11 +1430,12 @@ public abstract class LivingEntity extends Entity {
                 }
 
                 if (entity1 != null) {
-                    double d0 = entity1.getX() - this.getX();
+                    final boolean far = entity1.distanceToSqr(this) > (200.0 * 200.0); // Paper
+                    double d0 = far ? (Math.random() - Math.random()) : entity1.getX() - this.getX(); // Paper
 
                     double d1;
 
-                    for (d1 = entity1.getZ() - this.getZ(); d0 * d0 + d1 * d1 < 1.0E-4D; d1 = (Math.random() - Math.random()) * 0.01D) {
+                    for (d1 = far ? Math.random() - Math.random() : entity1.getZ() - this.getZ(); d0 * d0 + d1 * d1 < 1.0E-4D; d1 = (Math.random() - Math.random()) * 0.01D) { // Paper
                         d0 = (Math.random() - Math.random()) * 0.01D;
                     }
 
@@ -2086,7 +2087,7 @@ public abstract class LivingEntity extends Entity {
                 this.hurtCurrentlyUsedShield((float) -event.getDamage(DamageModifier.BLOCKING));
                 Entity entity = damagesource.getDirectEntity();
 
-                if (entity instanceof LivingEntity) {
+                if (entity instanceof LivingEntity && entity.distanceToSqr(this) <= (200.0D * 200.0D)) { // Paper
                     this.blockUsingShield((LivingEntity) entity);
                 }
             }
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 aa7c022c4faade23bd9061311d4152cf845d3331..95ccf785fd8a4fb4903807840c2fe41d58658354 100644
--- a/src/main/java/net/minecraft/world/entity/vehicle/Boat.java
+++ b/src/main/java/net/minecraft/world/entity/vehicle/Boat.java
@@ -689,7 +689,7 @@ public class Boat extends Entity {
         if (this.oldStatus == Boat.Status.IN_AIR && this.status != Boat.Status.IN_AIR && this.status != Boat.Status.ON_LAND) {
             this.waterLevel = this.getY(1.0D);
             this.setPos(this.getX(), (double) (this.getWaterLevelAbove() - this.getBbHeight()) + 0.101D, this.getZ());
-            this.setDeltaMovement(this.getDeltaMovement().multiply(1.0D, 0.0D, 1.0D));
+            this.setDeltaMovement(this.getDeltaMovement().multiply(1.0D, 0.0D, 1.0D).add(0.0, ((double) (this.getWaterLevelAbove() - this.getBbHeight()) + 0.101D) - this.getY(), 0.0)); // Paper
             this.lastYd = 0.0D;
             this.status = Boat.Status.IN_WATER;
         } else {
diff --git a/src/main/java/net/minecraft/world/item/BoatItem.java b/src/main/java/net/minecraft/world/item/BoatItem.java
index c0864c833fd313e6ba9339ecc7f9e2359954bda3..87e0faaab1ec98123fd735112d15da332a830554 100644
--- a/src/main/java/net/minecraft/world/item/BoatItem.java
+++ b/src/main/java/net/minecraft/world/item/BoatItem.java
@@ -67,7 +67,7 @@ public class BoatItem extends Item {
 
                 entityboat.setType(this.type);
                 entityboat.setYRot(user.getYRot());
-                if (!world.noCollision(entityboat, entityboat.getBoundingBox().inflate(-0.1D))) {
+                if (!world.noCollision(entityboat, entityboat.getBoundingBox().inflate(net.minecraft.Util.COLLISION_EPSILON))) {
                     return InteractionResultHolder.fail(itemstack);
                 } else {
                     if (!world.isClientSide) {