PaperMC/Spigot-Server-Patches/0403-Optimize-Small-Entity-Movement.patch

From ce3b80309494df7c3a3f9c288d3cfe5d07fd8fb3 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Thu, 1 Nov 2018 19:45:51 -0400
Subject: [PATCH] Optimize Small Entity Movement

Optimizes small movements by entities by merging the movement
into the entities next larger movement, until enough movement
velocity has been hit.

This reduces collision detection and able to reduce movement
cpu cost by 5-7%.

The default option of 0.75 seems to provide all the gains without
any noticable behavior change to entity movement.

We have to exclude slimes due to weird jumping animation bugs.

diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index eabb2c1bad..f6d4c476bc 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -569,4 +569,10 @@ public class PaperWorldConfig {
     private void preventMovingIntoUnloadedChunks() {
         preventMovingIntoUnloadedChunks = getBoolean("prevent-moving-into-unloaded-chunks", false);
     }
+
+    public double mergeEntityMovement = 0.075D;
+    private void mergeEntityMovement() {
+        mergeEntityMovement = getDouble("merge-entity-movement", mergeEntityMovement);
+    }
+
 }
diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index 32b90f30d9..5031e4737d 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -558,6 +558,15 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
 
     }
 
+    // Paper start
+    protected double pendingX = 0D;
+    protected double pendingY = 0D;
+    protected double pendingZ = 0D;
+    public boolean shouldMergeMovement(double mergeMin, double d0, double d1, double d2) {
+        return d0 * d0 < mergeMin && d1 * d1 < mergeMin && d2 * d2 < mergeMin;
+    }
+    // Paper end
+
     public void extinguish() {
         this.fireTicks = 0;
     }
@@ -580,6 +589,23 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
             this.a(this.getBoundingBox().d(d0, d1, d2));
             this.recalcPosition();
         } else {
+            // Paper start
+            final double mergeMin = this.world.paperConfig.mergeEntityMovement;
+            if (mergeMin > 0 && enummovetype == EnumMoveType.SELF) {
+                if (pendingX != 0D) {
+                    d0 += pendingX;
+                    pendingX = 0D;
+                }
+                if (pendingY != 0D) {
+                    d1 += pendingY;
+                    pendingY = 0D;
+                }
+                if (pendingZ != 0D) {
+                    d2 += pendingZ;
+                    pendingZ = 0D;
+                }
+            }
+            // Paper end
             if (enummovetype == EnumMoveType.PISTON) {
                 this.activatedTick = MinecraftServer.currentTick + 20; // Paper
                 long i = this.world.getTime();
@@ -683,6 +709,17 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
                 }
             }
 
+            // Paper start
+            if (mergeMin > 0 && enummovetype == EnumMoveType.SELF && shouldMergeMovement(mergeMin, d0, d1, d2)) {
+                pendingX = d0;
+                pendingY = d1;
+                pendingZ = d2;
+                d0 = d7 = 0;
+                d1 = d8 = 0;
+                d2 = d9 = 0;
+            }
+            // Paper end
+
             AxisAlignedBB axisalignedbb = this.getBoundingBox();
 
             if (d0 != 0.0D || d1 != 0.0D || d2 != 0.0D) {
diff --git a/src/main/java/net/minecraft/server/EntityOcelot.java b/src/main/java/net/minecraft/server/EntityOcelot.java
index 90a7e00a05..630e2407b3 100644
--- a/src/main/java/net/minecraft/server/EntityOcelot.java
+++ b/src/main/java/net/minecraft/server/EntityOcelot.java
@@ -64,6 +64,14 @@ public class EntityOcelot extends EntityTameableAnimal {
         return !this.isTamed() && !this.hasCustomName() && !this.isLeashed() /*&& this.ticksLived > 2400*/; // CraftBukkit - Paper (honor name and leash)
     }
 
+    // Paper start
+    @Override
+    public boolean shouldMergeMovement(double mergeMin, double d0, double d1, double d2) {
+        // Cats have weird movement bugs when a move is skipped, ideally we can fix this and fix that state
+        return false;
+    }
+    // Paper end
+
     protected void initAttributes() {
         super.initAttributes();
         this.getAttributeInstance(GenericAttributes.maxHealth).setValue(10.0D);
diff --git a/src/main/java/net/minecraft/server/EntityParrot.java b/src/main/java/net/minecraft/server/EntityParrot.java
index 86488e9709..e6348a2931 100644
--- a/src/main/java/net/minecraft/server/EntityParrot.java
+++ b/src/main/java/net/minecraft/server/EntityParrot.java
@@ -91,6 +91,14 @@ public class EntityParrot extends EntityPerchable implements EntityBird {
         this.goalSelector.a(3, new PathfinderGoalFollowEntity(this, 1.0D, 3.0F, 7.0F));
     }
 
+    // Paper start
+    @Override
+    public boolean shouldMergeMovement(double mergeMin, double d0, double d1, double d2) {
+        // Parrots have weird movement bugs when a move is skipped, ideally we can fix this and fix that state
+        return false;
+    }
+    // Paper end
+
     protected void initAttributes() {
         super.initAttributes();
         this.getAttributeMap().b(GenericAttributes.e);
diff --git a/src/main/java/net/minecraft/server/EntitySlime.java b/src/main/java/net/minecraft/server/EntitySlime.java
index e63f4afa9b..f1266c0ce1 100644
--- a/src/main/java/net/minecraft/server/EntitySlime.java
+++ b/src/main/java/net/minecraft/server/EntitySlime.java
@@ -495,6 +495,12 @@ public class EntitySlime extends EntityInsentient implements IMonster {
     }
 
     // Paper start
+    @Override
+    public boolean shouldMergeMovement(double mergeMin, double d0, double d1, double d2) {
+        // Slimes have weird movement bugs when a move is skipped, ideally we can fix this and fix that state
+        return false;
+    }
+
     private boolean canWander = true;
     public boolean canWander() {
         return canWander;
diff --git a/src/main/java/net/minecraft/server/EntityWolf.java b/src/main/java/net/minecraft/server/EntityWolf.java
index 68db6af622..8ba3438f77 100644
--- a/src/main/java/net/minecraft/server/EntityWolf.java
+++ b/src/main/java/net/minecraft/server/EntityWolf.java
@@ -342,6 +342,14 @@ public class EntityWolf extends EntityTameableAnimal {
         this.datawatcher.set(EntityWolf.bI, Integer.valueOf(enumcolor.getColorIndex()));
     }
 
+    // Paper start
+    @Override
+    public boolean shouldMergeMovement(double mergeMin, double d0, double d1, double d2) {
+        // Wolf have weird movement bugs when a move is skipped, ideally we can fix this and fix that state
+        return false;
+    }
+    // Paper end
+
     public EntityWolf b(EntityAgeable entityageable) {
         EntityWolf entitywolf = EntityTypes.WOLF.create(world); // Paper
         UUID uuid = this.getOwnerUUID();
-- 
2.19.1