Despawn throwable entities in the void

core/src/main/java/org/geysermc/geyser/entity/type/FireballEntity.java

@@ -72,6 +72,9 @@ public class FireballEntity extends ThrowableEntity {
 
     @Override
     public void tick() {
+        if (removedInVoid()) {
+            return;
+        }
         moveAbsoluteImmediate(tickMovement(position), getYaw(), getPitch(), getHeadYaw(), false, false);
     }
 }

core/src/main/java/org/geysermc/geyser/entity/type/FishingHookEntity.java

@@ -133,6 +133,9 @@ public class FishingHookEntity extends ThrowableEntity {
 
     @Override
     public void tick() {
+        if (removedInVoid()) {
+            return;
+        }
         if (hooked || !isInAir() && !isInWater() || isOnGround()) {
             motion = Vector3f.ZERO;
             return;

core/src/main/java/org/geysermc/geyser/entity/type/ItemEntity.java

@@ -74,7 +74,7 @@ public class ItemEntity extends ThrowableEntity {
 
     @Override
     public void tick() {
-        if (isInWater()) {
+        if (removedInVoid() || isInWater()) {
             return;
         }
         if (!isOnGround() || (motion.getX() * motion.getX() + motion.getZ() * motion.getZ()) > 0.00001) {

core/src/main/java/org/geysermc/geyser/entity/type/ThrowableEntity.java

@@ -55,6 +55,9 @@ public class ThrowableEntity extends Entity implements Tickable {
      */
     @Override
     public void tick() {
+        if (removedInVoid()) {
+            return;
+        }
         moveAbsoluteImmediate(position.add(motion), getYaw(), getPitch(), getHeadYaw(), isOnGround(), false);
         float drag = getDrag();
         float gravity = getGravity();
@@ -191,4 +194,17 @@ public class ThrowableEntity extends Entity implements Tickable {
         moveAbsoluteImmediate(position, yaw, pitch, headYaw, isOnGround, teleported);
         lastJavaPosition = position;
     }
+
+    /**
+     * Removes the entity if it is 64 blocks below the world.
+     *
+     * @return true if the entity was removed
+     */
+    public boolean removedInVoid() {
+        if (position.getY() < session.getDimensionType().minY() - 64) {
+            session.getEntityCache().removeEntity(this);
+            return true;
+        }
+        return false;
+    }
 }