0035-Optimise-Entity-Collisions.patch

From 149e3f34e143cfcdedbe683f4b926894a5024dcb Mon Sep 17 00:00:00 2001
From: "kfian294ma4@gmail.com" <kfian294ma4@gmail.com>
Date: Sun, 21 Feb 2021 22:36:38 +0000
Subject: [PATCH] Optimise Entity Collisions


diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
index a3693edc8..82f4e2240 100644
--- a/src/main/java/net/minecraft/server/Chunk.java
+++ b/src/main/java/net/minecraft/server/Chunk.java
@@ -964,6 +964,57 @@ public class Chunk {
     public void e() {
         this.q = true;
     }
+    // IonSpigot start - Optimise Entity Collisions
+    public boolean collectEntitiesByAmount(Entity source, AxisAlignedBB axisalignedbb, List<Entity> entities,
+                                           Predicate<? super Entity> by, int amount) {
+        int i = MathHelper.floor((axisalignedbb.b - 2.0D) / 16.0D);
+        int j = MathHelper.floor((axisalignedbb.e + 2.0D) / 16.0D);
+
+        i = MathHelper.clamp(i, 0, this.entitySlices.length - 1);
+        j = MathHelper.clamp(j, 0, this.entitySlices.length - 1);
+
+        for (int k = i; k <= j; ++k) {
+            if (!this.entitySlices[k].isEmpty()) {
+                if (collectEntities(source, axisalignedbb, this.entitySlices[k], entities, by, amount)) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+    private boolean collectEntities(Entity source, AxisAlignedBB axisalignedbb, List<Entity> slice,
+                                    List<Entity> entities, Predicate<? super Entity> by, int amount) {
+        for (int i = 0; i < slice.size(); ++i) {
+            int next = world.random.nextInt(slice.size());
+            Entity entity = slice.get(next);
+
+            if (entity.getBoundingBox().b(axisalignedbb) && entity != source && !entities.contains(entity)) {
+                if (by == null || by.apply(entity)) {
+                    entities.add(entity);
+                }
+
+                Entity[] passengers = entity.aB();
+
+                if (passengers != null) {
+                    for (Entity value : passengers) {
+                        if (value != source && value.getBoundingBox().b(axisalignedbb) && (by == null
+                            || by.apply(value)) && !entities.contains(entity)) {
+                            entities.add(value);
+                        }
+                    }
+                }
+
+                if (entities.size() >= amount) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+    // IonSpigot end
 
     public void a(Entity entity, AxisAlignedBB axisalignedbb, List<Entity> list, Predicate<? super Entity> predicate) {
         int i = MathHelper.floor((axisalignedbb.b - 2.0D) / 16.0D);
diff --git a/src/main/java/net/minecraft/server/EntityLiving.java b/src/main/java/net/minecraft/server/EntityLiving.java
index 1b87740dd..808e38690 100644
--- a/src/main/java/net/minecraft/server/EntityLiving.java
+++ b/src/main/java/net/minecraft/server/EntityLiving.java
@@ -28,6 +28,8 @@ import co.aikar.timings.SpigotTimings; // Spigot
 // PaperSpigot start
 import org.bukkit.Bukkit;
 import org.spigotmc.event.entity.EntityDismountEvent;
+
+import javax.annotation.Nullable;
 // PaperSpigot end
 
 public abstract class EntityLiving extends Entity {
@@ -1736,15 +1738,10 @@ public abstract class EntityLiving extends Entity {
             return;
         }
         // IonSpigot end
-        List list = this.world.a((Entity) this, this.getBoundingBox().grow(0.20000000298023224D, 0.0D, 0.20000000298023224D), Predicates.and(IEntitySelector.d, new Predicate() {
-            public boolean a(Entity entity) {
-                return entity.ae();
-            }
-
-            public boolean apply(Object object) {
-                return this.a((Entity) object);
-            }
-        }));
+        // IonSpigot start - Optimise Entity Collisions
+        List list = this.world.getEntitiesByAmount(this, this.getBoundingBox().grow(0.20000000298023224D, 0.0D, 0.20000000298023224D),
+                input -> IEntitySelector.d.apply(input) && input != null && input.ae(), world.spigotConfig.maxCollisionsPerEntity);
+        // IonSpigot end
 
         if (this.ad() && !list.isEmpty()) { // Spigot: Add this.ad() condition
             numCollisions -= world.spigotConfig.maxCollisionsPerEntity; // Spigot
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 06923705f..fa1ff0797 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -2657,6 +2657,28 @@ public abstract class World implements IBlockAccess {
         return null;
     }
 
+    // IonSpigot start - Optimise Entity Collisions
+    public List<Entity> getEntitiesByAmount(Entity entity, AxisAlignedBB axisalignedbb, Predicate<? super Entity> by, int amount) {
+        List<Entity> entities = new io.papermc.paper.util.maplist.ObjectMapList<>();
+
+        int i = MathHelper.floor((axisalignedbb.a - 2.0D) / 16.0D);
+        int j = MathHelper.floor((axisalignedbb.d + 2.0D) / 16.0D);
+        int k = MathHelper.floor((axisalignedbb.c - 2.0D) / 16.0D);
+        int l = MathHelper.floor((axisalignedbb.f + 2.0D) / 16.0D);
+
+        for (int i1 = i; i1 <= j; ++i1) {
+            for (int j1 = k; j1 <= l; ++j1) {
+                if (this.isChunkLoaded(i1, j1, true)) {
+                    if (this.getChunkAt(i1, j1).collectEntitiesByAmount(entity, axisalignedbb, entities, by, amount)) {
+                        return entities;
+                    }
+                }
+            }
+        }
+
+        return entities;
+    }
+    // IonSpigot end
     public List<Entity> getEntities(Entity entity, AxisAlignedBB axisalignedbb) {
         return this.a(entity, axisalignedbb, IEntitySelector.d);
     }
-- 
2.29.2.windows.2