Add Equipment support

Cargo.toml

@@ -19,6 +19,7 @@ default = [
     "advancement",
     "anvil",
     "boss_bar",
+    "equipment",
     "inventory",
     "log",
     "network",
@@ -32,6 +33,7 @@ default = [
 advancement = ["dep:valence_advancement"]
 anvil = ["dep:valence_anvil"]
 boss_bar = ["dep:valence_boss_bar"]
+equipment = ["dep:valence_equipment"]
 inventory = ["dep:valence_inventory"]
 log = ["dep:bevy_log"]
 network = ["dep:valence_network"]
@@ -59,6 +61,7 @@ valence_command = { workspace = true, optional = true }
 valence_command_macros = { workspace = true, optional = true }
 valence_ident_macros.workspace = true
 valence_ident.workspace = true
+valence_equipment = { workspace = true, optional = true }
 valence_inventory = { workspace = true, optional = true }
 valence_lang.workspace = true
 valence_network = { workspace = true, optional = true }
@@ -192,6 +195,7 @@ valence_entity = { path = "crates/valence_entity", version = "0.2.0-alpha.1" }
 valence_generated = { path = "crates/valence_generated", version = "0.2.0-alpha.1" }
 valence_ident = { path = "crates/valence_ident", version = "0.2.0-alpha.1" }
 valence_ident_macros = { path = "crates/valence_ident_macros", version = "0.2.0-alpha.1" }
+valence_equipment = { path = "crates/valence_equipment", version = "0.2.0-alpha.1" }
 valence_inventory = { path = "crates/valence_inventory", version = "0.2.0-alpha.1" }
 valence_lang = { path = "crates/valence_lang", version = "0.2.0-alpha.1" }
 valence_math = { path = "crates/valence_math", version = "0.2.0-alpha.1" }

crates/valence_equipment/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "valence_equipment"
+description = "Equipment support for Valence"
+readme = "README.md"
+version.workspace = true
+edition.workspace = true
+repository.workspace = true
+documentation.workspace = true
+license.workspace = true
+
+[lints]
+workspace = true
+
+[dependencies]
+bevy_app.workspace = true
+bevy_ecs.workspace = true
+derive_more.workspace = true
+tracing.workspace = true
+valence_server.workspace = true
+valence_inventory.workspace = true

crates/valence_equipment/README.md

@@ -0,0 +1,41 @@
+# `valence_equipment`
+Manages Minecraft's entity equipment (armor, held items) via the `Equipment` component.
+By default this is separated from an entities `Inventory` (which means that changes are only visible to other players), but it can be synced by attaching the `EquipmentInventorySync`
+component to a entity (currently only Players).
+
+## Example
+
+```rust 
+use bevy_ecs::prelude::*;
+use valence_equipment::*;
+use valence_server::{
+    ItemStack, ItemKind,
+    entity::player::PlayerEntity,
+};
+// Add equipment to players when they are added to the world.
+fn init_equipment(
+    mut clients: Query<
+        &mut Equipment,
+        (
+            Added<Equipment>,
+            With<PlayerEntity>,
+        ),
+    >,
+) {
+    for mut equipment in &mut clients
+    {
+        equipment.set_main_hand(ItemStack::new(ItemKind::DiamondSword, 1, None));
+        equipment.set_off_hand(ItemStack::new(ItemKind::Shield, 1, None));
+        equipment.set_feet(ItemStack::new(ItemKind::DiamondBoots, 1, None));
+        equipment.set_legs(ItemStack::new(ItemKind::DiamondLeggings, 1, None));
+        equipment.set_chest(ItemStack::new(ItemKind::DiamondChestplate, 1, None));
+        equipment.set_head(ItemStack::new(ItemKind::DiamondHelmet, 1, None));
+    }
+}
+```
+
+### See also
+
+Examples related to inventories in the `valence/examples/` directory:
+- `equipment`
+

crates/valence_equipment/src/inventory_sync.rs

@@ -0,0 +1,92 @@
+use valence_inventory::player_inventory::PlayerInventory;
+use valence_inventory::{HeldItem, Inventory, UpdateSelectedSlotEvent};
+use valence_server::entity::player::PlayerEntity;
+
+use super::*;
+
+/// This component will sync a player's [`Equipment`], which is visible to other
+/// players, with the player [`Inventory`].
+#[derive(Debug, Default, Clone, Component)]
+pub struct EquipmentInventorySync;
+
+/// Syncs the player [`Equipment`] with the [`Inventory`].
+/// If a change in the player's inventory and in the equipment occurs in the
+/// same tick, the equipment change has priority.
+/// Note: This system only handles direct changes to the held item (not actual
+/// changes from the client) see [`equipment_held_item_sync_from_client`]
+pub(crate) fn equipment_inventory_sync(
+    mut clients: Query<
+        (&mut Equipment, &mut Inventory, &mut HeldItem),
+        (
+            Or<(Changed<Equipment>, Changed<Inventory>, Changed<HeldItem>)>,
+            With<EquipmentInventorySync>,
+            With<PlayerEntity>,
+        ),
+    >,
+) {
+    for (mut equipment, mut inventory, held_item) in &mut clients {
+        // Equipment change has priority over held item changes
+        if equipment.changed & (1 << Equipment::MAIN_HAND_IDX) != 0 {
+            let item = equipment.main_hand().clone();
+            inventory.set_slot(held_item.slot(), item);
+        } else {
+            // If we change the inventory (e.g by pickung up an item)
+            // then the HeldItem slot wont be changed
+
+            // This will only be called if we change the held item from valence,
+            // the client change is handled in `equipment_held_item_sync_from_client`
+            let item = inventory.slot(held_item.slot()).clone();
+            equipment.set_main_hand(item);
+        }
+
+        let slots = [
+            (Equipment::OFF_HAND_IDX, PlayerInventory::SLOT_OFFHAND),
+            (Equipment::HEAD_IDX, PlayerInventory::SLOT_HEAD),
+            (Equipment::CHEST_IDX, PlayerInventory::SLOT_CHEST),
+            (Equipment::LEGS_IDX, PlayerInventory::SLOT_LEGS),
+            (Equipment::FEET_IDX, PlayerInventory::SLOT_FEET),
+        ];
+
+        // We cant rely on the changed bitfield of inventory here
+        // because that gets reset when the client changes the inventory
+
+        for (equipment_slot, inventory_slot) in slots {
+            // Equipment has priority over inventory changes
+            if equipment.changed & (1 << equipment_slot) != 0 {
+                let item = equipment.slot(equipment_slot).clone();
+                inventory.set_slot(inventory_slot, item);
+            } else if inventory.is_changed() {
+                let item = inventory.slot(inventory_slot).clone();
+                equipment.set_slot(equipment_slot, item);
+            }
+        }
+    }
+}
+
+/// Handles the case where the client changes the slot (the bevy change is
+/// suppressed for this)
+pub(crate) fn equipment_held_item_sync_from_client(
+    mut clients: Query<(&HeldItem, &Inventory, &mut Equipment), With<EquipmentInventorySync>>,
+    mut events: EventReader<UpdateSelectedSlotEvent>,
+) {
+    for event in events.read() {
+        let Ok((held_item, inventory, mut equipment)) = clients.get_mut(event.client) else {
+            continue;
+        };
+
+        let item = inventory.slot(held_item.slot()).clone();
+        equipment.set_main_hand(item);
+    }
+}
+
+pub(crate) fn on_attach_inventory_sync(
+    entities: Query<Option<&PlayerEntity>, (Added<EquipmentInventorySync>, With<Inventory>)>,
+) {
+    for entity in &entities {
+        if entity.is_none() {
+            tracing::warn!(
+                "EquipmentInventorySync attached to non-player entity, this will have no effect"
+            );
+        }
+    }
+}