Extracted position sending from Entity#tick and improved checks, also removed duplicate code from Player#update

src/main/java/net/minestom/server/entity/Entity.java

@@ -138,6 +138,8 @@ public class Entity implements Viewable, Tickable, EventHandler, DataContainer,
      */
     private final Object entityTypeLock = new Object();
 
+    private final boolean isNettyClient;
+
     public Entity(@NotNull EntityType entityType, @NotNull UUID uuid) {
         this.id = generateId();
         this.entityType = entityType;
@@ -152,6 +154,8 @@ public class Entity implements Viewable, Tickable, EventHandler, DataContainer,
 
         setAutoViewable(true);
 
+        isNettyClient = PlayerUtils.isNettyClient(this);
+
         Entity.ENTITY_BY_ID.put(id, this);
         Entity.ENTITY_BY_UUID.put(uuid, this);
     }
@@ -493,47 +497,7 @@ public class Entity implements Viewable, Tickable, EventHandler, DataContainer,
             }
         }
 
-        final boolean isNettyClient = PlayerUtils.isNettyClient(this);
+        sendPositionUpdate();
-
-        // Synchronization with updated fields in #getPosition()
-        {
-            final boolean positionChange = !position.isSimilar(lastSyncedPosition);
-            final boolean viewChange = !position.hasSimilarView(lastSyncedPosition);
-            final double distance = positionChange ? position.getDistance(lastSyncedPosition) : 0;
-
-            if (distance >= 8 || (positionChange && isNettyClient)) {
-                // Teleport has the priority over everything else
-                teleport(position);
-            } else if (positionChange && viewChange) {
-                EntityPositionAndRotationPacket positionAndRotationPacket =
-                        EntityPositionAndRotationPacket.getPacket(getEntityId(),
-                                position, lastSyncedPosition, isOnGround());
-
-                sendPacketToViewersAndSelf(positionAndRotationPacket);
-
-                refreshPosition(position.clone());
-
-                // Fix head rotation
-                EntityHeadLookPacket entityHeadLookPacket = new EntityHeadLookPacket();
-                entityHeadLookPacket.entityId = getEntityId();
-                entityHeadLookPacket.yaw = position.getYaw();
-
-                sendPacketToViewersAndSelf(entityHeadLookPacket);
-
-            } else if (positionChange) {
-                EntityPositionPacket entityPositionPacket = EntityPositionPacket.getPacket(getEntityId(),
-                        position, lastSyncedPosition, isOnGround());
-
-                sendPacketToViewersAndSelf(entityPositionPacket);
-
-                refreshPosition(position.clone());
-
-            } else if (viewChange) {
-                // Yaw/Pitch
-                setView(position);
-            }
-
-        }
 
         // Entity tick
         {
@@ -713,6 +677,70 @@ public class Entity implements Viewable, Tickable, EventHandler, DataContainer,
         }
     }
 
+    /**
+     * Sends the correct packets to update the entity's position, should be called
+     * every tick. The movement is checked inside the method!
+     * <p>
+     *     The following packets are sent to viewers (check are performed in this order):
+     *     <ol>
+     *         <li>{@link EntityTeleportPacket} if <pre>distanceX > 8 || distanceY > 8 || distanceZ > 8</pre>
+     *          <i>(performed using {@link #synchronizePosition()})</i></li>
+     *         <li>{@link EntityPositionAndRotationPacket} if <pre>positionChange && viewChange</pre></li>
+     *         <li>{@link EntityPositionPacket} if <pre>positionChange</pre></li>
+     *         <li>{@link EntityRotationPacket} if <pre>viewChange</pre>
+     *          <i>(performed using {@link #setView(float, float)})</i></li>
+     *     </ol>
+     *     In case of a player's position and/or view change an additional {@link PlayerPositionAndLookPacket}
+     *     is sent to self.
+     */
+    protected void sendPositionUpdate() {
+        final boolean viewChange = !position.hasSimilarView(lastSyncedPosition);
+        final double distanceX = Math.abs(position.getX()-lastSyncedPosition.getX());
+        final double distanceY = Math.abs(position.getY()-lastSyncedPosition.getY());
+        final double distanceZ = Math.abs(position.getZ()-lastSyncedPosition.getZ());
+        final boolean positionChange = (distanceX+distanceY+distanceZ) > 0;
+
+        if (distanceX > 8 || distanceY > 8 || distanceZ > 8) {
+            synchronizePosition();
+            // #synchronizePosition sets sync fields, it's safe to return
+            return;
+        } else if (positionChange && viewChange) {
+            EntityPositionAndRotationPacket positionAndRotationPacket = EntityPositionAndRotationPacket
+                    .getPacket(getEntityId(), position, lastSyncedPosition, isOnGround());
+            sendPacketToViewers(positionAndRotationPacket);
+
+            // Fix head rotation
+            EntityHeadLookPacket entityHeadLookPacket = new EntityHeadLookPacket();
+            entityHeadLookPacket.entityId = getEntityId();
+            entityHeadLookPacket.yaw = position.getYaw();
+            sendPacketToViewersAndSelf(entityHeadLookPacket);
+        } else if (positionChange) {
+            final EntityPositionPacket entityPositionPacket = EntityPositionPacket
+                    .getPacket(getEntityId(), position, lastSyncedPosition, onGround);
+            sendPacketToViewers(entityPositionPacket);
+        } else if (viewChange) {
+            setView(position.getYaw(), position.getPitch());
+            /*
+            #setView indirectly sets last sync field and it appears that EntityRotation packet
+            can be used for players as well, so it's safe to return
+             */
+            return;
+        } else {
+            // Nothing changed, return
+            return;
+        }
+
+        if (isNettyClient) {
+            final PlayerPositionAndLookPacket playerPositionAndLookPacket = new PlayerPositionAndLookPacket();
+            playerPositionAndLookPacket.flags = 0b111;
+            playerPositionAndLookPacket.position = position.clone().subtract(lastSyncedPosition.getX(), lastSyncedPosition.getY(), lastSyncedPosition.getZ());
+            playerPositionAndLookPacket.teleportId = ((Player)this).getNextTeleportId();
+            ((Player) this).getPlayerConnection().sendPacket(playerPositionAndLookPacket);
+        }
+
+        lastSyncedPosition.set(position);
+    }
+
     /**
      * Gets the number of ticks this entity has been active for.
      *

src/main/java/net/minestom/server/entity/Player.java

@@ -148,9 +148,6 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
     // Only used if multi player breaking is disabled, contains only this player
     private final Set<Player> targetBreakers = Collections.singleton(this);
 
-    // Position synchronization with viewers
-    private final Position lastSyncedPlayerPosition;
-
     // Experience orb pickup
     protected Cooldown experiencePickupCooldown = new Cooldown(new UpdateOption(10, TimeUnit.TICK));
 
@@ -187,7 +184,6 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
         setBoundingBox(0.6f, 1.8f, 0.6f);
 
         setRespawnPoint(new Position(0, 0, 0));
-        this.lastSyncedPlayerPosition = new Position();
 
         this.settings = new PlayerSettings();
         this.inventory = new PlayerInventory(this);
@@ -421,50 +417,6 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
 
         // Tick event
         callEvent(PlayerTickEvent.class, playerTickEvent);
-
-        // Multiplayer sync
-        if (!viewers.isEmpty()) {
-            final boolean positionChanged = !position.isSimilar(lastSyncedPlayerPosition);
-            final boolean viewChanged = !position.hasSimilarView(lastSyncedPlayerPosition);
-
-            if (positionChanged || viewChanged) {
-                // Player moved since last time
-
-                ServerPacket updatePacket;
-                ServerPacket optionalUpdatePacket = null;
-                if (positionChanged && viewChanged) {
-                    updatePacket = EntityPositionAndRotationPacket.getPacket(getEntityId(),
-                            position, lastSyncedPlayerPosition, onGround);
-                } else if (positionChanged) {
-                    updatePacket = EntityPositionPacket.getPacket(getEntityId(),
-                            position, lastSyncedPlayerPosition, onGround);
-                } else {
-                    // View changed
-                    updatePacket = EntityRotationPacket.getPacket(getEntityId(),
-                            position.getYaw(), position.getPitch(), onGround);
-                }
-
-                if (viewChanged) {
-                    // Yaw from the rotation packet seems to be ignored, which is why this is required
-                    EntityHeadLookPacket entityHeadLookPacket = new EntityHeadLookPacket();
-                    entityHeadLookPacket.entityId = getEntityId();
-                    entityHeadLookPacket.yaw = position.getYaw();
-                    optionalUpdatePacket = entityHeadLookPacket;
-                }
-
-                // Send the update packet
-                if (optionalUpdatePacket != null) {
-                    sendPacketsToViewers(updatePacket, optionalUpdatePacket);
-                } else {
-                    sendPacketToViewers(updatePacket);
-                }
-
-            }
-
-            // Update sync data
-            lastSyncedPlayerPosition.set(position);
-        }
-
     }
 
     @Override
@@ -2007,6 +1959,10 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
         playerConnection.sendPacket(updateViewPositionPacket);
     }
 
+    public int getNextTeleportId() {
+        return teleportId.getAndIncrement();
+    }
+
     public int getLastSentTeleportId() {
         return teleportId.get();
     }