From 2a44874458fba950e9156aad479f604a9a4ba19a Mon Sep 17 00:00:00 2001
From: rosiecube <53262103+rosiecube@users.noreply.github.com>
Date: Thu, 10 Dec 2020 05:09:14 +0900
Subject: [PATCH] Fix Bedrock ItemEntity Y position bug (#1636)

Setting motion while on the ground causes visual issues. Additionally, there is an offset difference in the movement of an item entity.
---
 .../geysermc/connector/entity/ItemEntity.java   | 17 +++++++++++++++--
 .../connector/entity/type/EntityType.java       |  2 +-
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/connector/src/main/java/org/geysermc/connector/entity/ItemEntity.java b/connector/src/main/java/org/geysermc/connector/entity/ItemEntity.java
index 41308a0de..4a69c834b 100644
--- a/connector/src/main/java/org/geysermc/connector/entity/ItemEntity.java
+++ b/connector/src/main/java/org/geysermc/connector/entity/ItemEntity.java
@@ -36,7 +36,20 @@ import org.geysermc.connector.network.translators.item.ItemTranslator;
 public class ItemEntity extends Entity {
 
     public ItemEntity(long entityId, long geyserId, EntityType entityType, Vector3f position, Vector3f motion, Vector3f rotation) {
-        super(entityId, geyserId, entityType, position, motion, rotation);
+        super(entityId, geyserId, entityType, position.add(0d, entityType.getOffset(), 0d), motion, rotation);
+    }
+
+    @Override
+    public void setMotion(Vector3f motion) {
+        if (isOnGround())
+            motion = Vector3f.from(motion.getX(), 0, motion.getZ());
+
+        super.setMotion(motion);
+    }
+
+    @Override
+    public void moveAbsolute(GeyserSession session, Vector3f position, Vector3f rotation, boolean isOnGround, boolean teleported) {
+        super.moveAbsolute(session, position.add(0d, this.entityType.getOffset(), 0d), rotation, isOnGround, teleported);
     }
 
     @Override
@@ -44,7 +57,7 @@ public class ItemEntity extends Entity {
         if (entityMetadata.getId() == 7) {
             AddItemEntityPacket itemPacket = new AddItemEntityPacket();
             itemPacket.setRuntimeEntityId(geyserId);
-            itemPacket.setPosition(position);
+            itemPacket.setPosition(position.add(0d, this.entityType.getOffset(), 0d));
             itemPacket.setMotion(motion);
             itemPacket.setUniqueEntityId(geyserId);
             itemPacket.setFromFishing(false);
diff --git a/connector/src/main/java/org/geysermc/connector/entity/type/EntityType.java b/connector/src/main/java/org/geysermc/connector/entity/type/EntityType.java
index a77d3504c..3e6b6c72d 100644
--- a/connector/src/main/java/org/geysermc/connector/entity/type/EntityType.java
+++ b/connector/src/main/java/org/geysermc/connector/entity/type/EntityType.java
@@ -100,7 +100,7 @@ public enum EntityType {
     ARMOR_STAND(ArmorStandEntity.class, 61, 1.975f, 0.5f),
     TRIPOD_CAMERA(Entity.class, 62, 0f),
     PLAYER(PlayerEntity.class, 63, 1.8f, 0.6f, 0.6f, 1.62f),
-    ITEM(ItemEntity.class, 64, 0.25f, 0.25f),
+    ITEM(ItemEntity.class, 64, 0.25f, 0.25f, 0.25f, 0.125f),
     PRIMED_TNT(TNTEntity.class, 65, 0.98f, 0.98f, 0.98f, 0f, "minecraft:tnt"),
     FALLING_BLOCK(FallingBlockEntity.class, 66, 0.98f, 0.98f),
     MOVING_BLOCK(Entity.class, 67, 0f),