start adding interact function

azalea-client/src/interact.rs

@@ -0,0 +1,68 @@
+use azalea_core::BlockPos;
+use azalea_ecs::{
+    app::{App, Plugin},
+    entity::Entity,
+    event::EventReader,
+    system::Query,
+};
+use azalea_protocol::packets::game::{
+    serverbound_interact_packet::InteractionHand,
+    serverbound_use_item_on_packet::ServerboundUseItemOnPacket,
+};
+use log::warn;
+
+use crate::{Client, LocalPlayer};
+
+/// A plugin that allows clients to interact with blocks in the world.
+pub struct InteractPlugin;
+impl Plugin for InteractPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_event::<BlockInteractEvent>()
+            .add_system(handle_block_interact_event);
+    }
+}
+
+impl Client {
+    /// Right click a block. The behavior of this depends on the target block,
+    /// and it'll either place the block you're holding in your hand or use the
+    /// block you clicked (like toggling a lever).
+    ///
+    /// Note that this may trigger anticheats as it doesn't take into account
+    /// whether you're actually looking at the block.
+    pub fn block_interact(&mut self, position: BlockPos) {
+        self.ecs.lock().send_event(BlockInteractEvent {
+            entity: self.entity,
+            position,
+        });
+    }
+}
+
+/// Right click a block. The behavior of this depends on the target block,
+/// and it'll either place the block you're holding in your hand or use the
+/// block you clicked (like toggling a lever).
+pub struct BlockInteractEvent {
+    /// The local player entity that's opening the container.
+    pub entity: Entity,
+    /// The coordinates of the container.
+    pub position: BlockPos,
+}
+
+fn handle_block_interact_event(
+    mut events: EventReader<BlockInteractEvent>,
+    query: Query<&LocalPlayer>,
+) {
+    for event in events.iter() {
+        let Ok(local_player) = query.get(event.entity) else {
+            warn!("Sent BlockInteractEvent for entity that isn't LocalPlayer");
+            continue;
+        };
+
+        // TODO: check to make sure we're within the world border
+
+        local_player.write_packet(ServerboundUseItemOnPacket {
+            hand: InteractionHand::MainHand,
+            block_hit: BlockHitResult,
+            sequence: 0,
+        })
+    }
+}

azalea-client/src/inventory.rs

@@ -63,6 +63,7 @@ impl InventoryComponent {
         }
     }
 }
+
 impl Default for InventoryComponent {
     fn default() -> Self {
         InventoryComponent {

azalea-client/src/lib.rs

@@ -18,6 +18,7 @@ pub mod disconnect;
 mod entity_query;
 mod events;
 mod get_mc_dir;
+pub mod interact;
 pub mod inventory;
 mod local_player;
 mod movement;

azalea-protocol/src/packets/game/serverbound_use_item_on_packet.rs

@@ -14,9 +14,15 @@ pub struct ServerboundUseItemOnPacket {
 
 #[derive(Clone, Debug)]
 pub struct BlockHitResult {
+    /// The block that we clicked.
     pub block_pos: BlockPos,
+    /// The face of the block that was clicked.
     pub direction: Direction,
+    /// The exact coordinates of the world where the block was clicked. In the
+    /// network, this is transmitted as the difference between the location and
+    /// block position.
     pub location: Vec3,
+    /// Whether the player's head is inside of a block.
     pub inside: bool,
 }