Merge pull request #1798 from socksprox/fix/mob-combat-poses

🤖 Agent: thank you! Merged after the contribution gate (checked against vanilla 26.3; one integration branch of main + its batch: clippy -D warnings, tests, the affected parity harnesses (111/112, all pass), in game on the server thread and in-frame, lan_e2e in both host modes) and this head's verify.

crates/horizon-client/src/game/lan.rs

@@ -162,6 +162,13 @@ fn mob_meta(
             meta.push((3, serializer::BOOLEAN, Value::Bool(true)));
         }
     }
+    // LivingEntity.DATA_LIVING_ENTITY_FLAGS: using an item 1, in the off
+    // hand 2 (a skeleton draws its bow, a witch raises her potion).
+    let using = i8::from(m.extra.using_item > 0) | i8::from(m.extra.using_off_hand) << 1;
+    if using != 0 {
+        meta.push((8, serializer::BYTE, Value::Byte(using)));
+    }
+    defaults.push((8, serializer::BYTE, Value::Byte(0)));
     // LivingEntity.DATA_HEALTH_ID: defined as 1, then set to the max health.
     let health = m.health.max(0.0);
     if health != 1.0 {
@@ -293,6 +300,21 @@ fn mob_meta(
                 meta.push((18, serializer::BOOLEAN, Value::Bool(true)));
             }
         }
+        // Pillager.IS_CHARGING_CROSSBOW: the charge pose and the held
+        // item's loading animation.
+        "minecraft:pillager" => {
+            if e.flag {
+                meta.push((17, serializer::BOOLEAN, Value::Bool(true)));
+            }
+            defaults.push((17, serializer::BOOLEAN, Value::Bool(false)));
+        }
+        // SpellcasterIllager.DATA_SPELL_CASTING_ID: the casting pose.
+        "minecraft:evoker" | "minecraft:illusioner" => {
+            if e.variant2 != 0 {
+                meta.push((17, serializer::BYTE, Value::Byte(e.variant2 as i8)));
+            }
+            defaults.push((17, serializer::BYTE, Value::Byte(0)));
+        }
         // Enderman.DATA_CARRY_STATE.
         "minecraft:enderman" => {
             if let Some(state) = e.carried {

crates/horizon-client/src/game/mob_blocks.rs

@@ -259,7 +259,7 @@ impl Game<'_> {
         // ItemInHandLayer submits with OverlayTexture.NO_OVERLAY: no hurt tint.
         for (item, off_hand) in [(&mob.extra.main_hand, false), (&mob.extra.off_hand, true)] {
             let Some(item) = item else { continue };
-            let left = off_hand != mob.extra.main_hand_left;
+            let left = off_hand != mob.main_arm_left();
             let Some(t) =
                 render::held_item_transform(mob, alpha as f32, camera, self.res.mob_data(), left)
             else {
@@ -305,7 +305,7 @@ impl Game<'_> {
                     .player_model
                     .as_ref()
                     .is_some_and(|p| std::ptr::eq(p, mob));
-            owner.main_arm_left = mob.extra.main_hand_left;
+            owner.main_arm_left = mob.main_arm_left();
             if off_hand == mob.extra.using_off_hand && mob.extra.using_item > 0 {
                 owner.using_this_item = true;
                 owner.use_duration = 72_000;

crates/horizon-client/src/game/remote.rs

@@ -1904,25 +1904,12 @@ impl Game<'_> {
                         }
                     }
                 }
-                // LivingEntity.onSyncedDataUpdated(DATA_LIVING_ENTITY_FLAGS):
-                // another player starts using the item in a hand (eating, a
-                // bow drawn, a shield up), or stops.
+                // LivingEntity.DATA_LIVING_ENTITY_FLAGS: for another player
+                // too, remote_mob_data's apply reads index 8 above.
                 let other = self
                     .remote
                     .as_ref()
                     .is_some_and(|r| r.level_players.contains_key(&p.id) && r.entity_id != p.id);
-                if other && let Some(m) = self.mobs.iter_mut().find(|m| m.id == p.id as u32) {
-                    for (index, _, value) in &p.values {
-                        if let (8, Value::Byte(flags)) = (index, value) {
-                            m.extra.using_off_hand = flags & 2 != 0;
-                            if flags & 1 == 0 {
-                                m.extra.using_item = 0;
-                            } else if m.extra.using_item == 0 {
-                                m.extra.using_item = 1;
-                            }
-                        }
-                    }
-                }
                 // LivingEntity.onSyncedDataUpdated(SLEEPING_POS_ID): another
                 // player lies down in their bed (drawn lying in it), or gets up.
                 if other {
@@ -3406,25 +3393,28 @@ impl Game<'_> {
                 m.head_yaw += wrap_degrees(*yaw - m.head_yaw) / *steps as f32;
                 *steps -= 1;
             }
-            // LivingEntity.updatingUsingItem for another player: the ticks the
-            // item has been used before this one.
-            if player && m.extra.using_item > 0 {
-                let item = if m.extra.using_off_hand {
-                    m.extra.off_hand.clone()
-                } else {
-                    m.extra.main_hand.clone()
-                };
-                if let Some(item) = item {
-                    let eye = if m.extra.crouching { 1.27 } else { 1.62 };
-                    let at = [m.position.x, m.position.y, m.position.z];
-                    using.push((
-                        item,
-                        m.extra.using_item as u32 - 1,
-                        at,
-                        eye,
-                        m.head_pitch,
-                        m.yaw,
-                    ));
+            // LivingEntity.updatingUsingItem: the ticks the item has been
+            // used before this one. Another player's use particles; a mob's
+            // drawn bow only needs the count (its pull follows it).
+            if m.extra.using_item > 0 {
+                if player {
+                    let item = if m.extra.using_off_hand {
+                        m.extra.off_hand.clone()
+                    } else {
+                        m.extra.main_hand.clone()
+                    };
+                    if let Some(item) = item {
+                        let eye = if m.extra.crouching { 1.27 } else { 1.62 };
+                        let at = [m.position.x, m.position.y, m.position.z];
+                        using.push((
+                            item,
+                            m.extra.using_item as u32 - 1,
+                            at,
+                            eye,
+                            m.head_pitch,
+                            m.yaw,
+                        ));
+                    }
                 }
                 m.extra.using_item += 1;
             }

crates/horizon-client/src/game/remote_mob_data.rs

@@ -20,6 +20,17 @@ fn apply(m: &mut Mob, values: &[(u8, i32, Value)], builtin: &Builtin) {
             // client, which draws the flames. A client doesn't count the
             // fire down: the flag goes off when the server's fire is out.
             (0, Value::Byte(flags)) => m.fire_ticks = i32::from(flags & 1),
+            // LivingEntity.DATA_LIVING_ENTITY_FLAGS: using an item 1, in the
+            // off hand 2. The flag starts and stops the use; the client ticks
+            // the count itself (a bow's pull follows it).
+            (8, Value::Byte(flags)) => {
+                m.extra.using_off_hand = flags & 2 != 0;
+                if flags & 1 == 0 {
+                    m.extra.using_item = 0;
+                } else if m.extra.using_item == 0 {
+                    m.extra.using_item = 1;
+                }
+            }
             // LivingEntity.DATA_HEALTH_ID: the boss bars and the death
             // animation follow it.
             (9, Value::Float(health)) => m.health = *health,
@@ -53,6 +64,13 @@ fn apply(m: &mut Mob, values: &[(u8, i32, Value)], builtin: &Builtin) {
             (Species::Slime | Species::MagmaCube, 18, Value::Int(size)) => {
                 m.extra.size = (*size).clamp(1, 127);
             }
+            // Pillager.IS_CHARGING_CROSSBOW: the charge pose (Raider's
+            // IS_CELEBRATING takes 16).
+            (Species::Pillager, 17, Value::Bool(charging)) => m.extra.flag = *charging,
+            // SpellcasterIllager.DATA_SPELL_CASTING_ID: the casting pose.
+            (Species::Evoker | Species::Illusioner, 17, Value::Byte(spell)) => {
+                m.extra.variant2 = (*spell).max(0) as u8;
+            }
             // Villager.DATA_VILLAGER_DATA and ZombieVillager's (after
             // Zombie's three): what VillagerProfessionLayer draws.
             (Species::Villager, 19, Value::Ids(data))
@@ -239,4 +257,42 @@ mod tests {
         );
         assert_eq!(name(&z), ("desert", "farmer", 3));
     }
+
+    #[test]
+    fn the_mob_flags_drive_the_aggressive_poses() {
+        let Some(mut m) = mob("minecraft:skeleton") else {
+            return;
+        };
+        apply(&mut m, &[(15, s::BYTE, Value::Byte(2 | 4))]);
+        assert!(m.ai.aggressive && m.extra.left_handed && !m.no_ai);
+        apply(&mut m, &[(15, s::BYTE, Value::Byte(0))]);
+        assert!(!m.ai.aggressive && !m.extra.left_handed);
+    }
+
+    #[test]
+    fn the_living_flags_start_and_stop_a_mob_using_an_item() {
+        let Some(mut m) = mob("minecraft:skeleton") else {
+            return;
+        };
+        apply(&mut m, &[(8, s::BYTE, Value::Byte(1))]);
+        assert_eq!(m.extra.using_item, 1);
+        assert!(!m.extra.using_off_hand);
+        // Using in the off hand.
+        apply(&mut m, &[(8, s::BYTE, Value::Byte(3))]);
+        assert!(m.extra.using_off_hand);
+        apply(&mut m, &[(8, s::BYTE, Value::Byte(0))]);
+        assert_eq!(m.extra.using_item, 0);
+    }
+
+    #[test]
+    fn a_pillager_charges_and_a_spellcaster_casts() {
+        let Some(mut p) = mob("minecraft:pillager") else {
+            return;
+        };
+        apply(&mut p, &[(17, s::BOOLEAN, Value::Bool(true))]);
+        assert!(p.extra.flag);
+        let mut e = mob("minecraft:evoker").unwrap();
+        apply(&mut e, &[(17, s::BYTE, Value::Byte(2))]);
+        assert_eq!(e.extra.variant2, 2);
+    }
 }

crates/horizon-client/src/mobs.rs

@@ -1646,6 +1646,11 @@ impl Mob {
     pub fn species(&self) -> Species {
         self.kind.species
     }
+    /// `Mob.getMainArm`: the left arm when the mob is left-handed, a player's
+    /// `mainHand` option for a player mob.
+    pub fn main_arm_left(&self) -> bool {
+        self.extra.main_hand_left || self.extra.left_handed
+    }
     /// The player hit this mob (melee): LivingEntity.hurt with knockback.
     pub fn hurt(
         &mut self,

crates/horizon-client/src/mobs/anim.rs

@@ -642,7 +642,7 @@ pub fn setup(
             } else {
                 ArmPose::Empty
             };
-            let mut h = if m.extra.main_hand_left {
+            let mut h = if m.main_arm_left() {
                 Hum::new(ArmPose::Empty, main)
             } else {
                 Hum::new(main, ArmPose::Empty)
@@ -693,7 +693,7 @@ pub fn setup(
             } else {
                 ArmPose::Empty
             };
-            let mut h = if m.extra.main_hand_left {
+            let mut h = if m.main_arm_left() {
                 Hum::new(off, pose)
             } else {
                 Hum::new(pose, off)

crates/horizon-client/src/mobs/undead.rs

@@ -621,8 +621,10 @@ impl BowAttack {
         }
     }
 }
+/// `LivingEntity.isHolding(Items.BOW)`: the bow can sit in either hand.
 fn holding_bow(m: &Mob) -> bool {
     m.extra.main_hand.as_deref() == Some("minecraft:bow")
+        || m.extra.off_hand.as_deref() == Some("minecraft:bow")
 }
 impl Goal for BowAttack {
     goal_clone!();
@@ -715,7 +717,10 @@ impl Goal for BowAttack {
         } else {
             self.attack_time -= 1;
             if self.attack_time <= 0 && self.see_time >= -60 {
+                // mob.startUsingItem(ProjectileUtil.getWeaponHoldingHand):
+                // the off hand when the main one doesn't hold the bow.
                 m.extra.using_item = 1;
+                m.extra.using_off_hand = m.extra.main_hand.as_deref() != Some("minecraft:bow");
             }
         }
     }