Add Pick block (Middle Mouse Click) (#418)

* Pick Item Changes

* Changed some logging

* Pick Item working for hotbar slots

* Basic functionality, changes needed to adhere to expected minecraft behaviour

* Clean up code

* Added todo for pick from entity

* Added item swapping

* Swapping and cleanup

* Fix for rebase

* Remove unused function

* Bugfix

* remove todo

---------

Co-authored-by: Alexander Medvedev <lilalexmed@proton.me>

pumpkin-inventory/src/player.rs

@@ -116,6 +116,35 @@ impl PlayerInventory {
         &mut self.items[self.selected + 36 - 9]
     }
 
+    pub fn get_slot_with_item(&self, item_id: u16) -> Option<usize> {
+        for slot in 9..=44 {
+            match &self.items[slot - 9] {
+                Some(item) if item.item_id == item_id => return Some(slot),
+                _ => continue,
+            }
+        }
+
+        None
+    }
+
+    pub fn get_pick_item_hotbar_slot(&self) -> usize {
+        if self.items[self.selected + 36 - 9].is_none() {
+            return self.selected;
+        }
+
+        for slot in 0..9 {
+            if self.items[slot + 36 - 9].is_none() {
+                return slot;
+            }
+        }
+
+        self.selected
+    }
+
+    pub fn get_empty_slot(&self) -> Option<usize> {
+        (9..=44).find(|&slot| self.items[slot - 9].is_none())
+    }
+
     pub fn slots(&self) -> Vec<Option<&ItemStack>> {
         let mut slots = vec![self.crafting_output.as_ref()];
         slots.extend(self.crafting.iter().map(|c| c.as_ref()));

pumpkin-protocol/src/server/play/mod.rs

@@ -10,6 +10,7 @@ mod s_confirm_teleport;
 mod s_cookie_response;
 mod s_interact;
 mod s_keep_alive;
+mod s_pick_item;
 mod s_ping_request;
 mod s_player_abilities;
 mod s_player_action;
@@ -37,6 +38,7 @@ pub use s_confirm_teleport::*;
 pub use s_cookie_response::*;
 pub use s_interact::*;
 pub use s_keep_alive::*;
+pub use s_pick_item::*;
 pub use s_ping_request::*;
 pub use s_player_abilities::*;
 pub use s_player_action::*;

pumpkin-protocol/src/server/play/s_pick_item.rs

@@ -0,0 +1,17 @@
+use pumpkin_core::math::position::WorldPosition;
+use pumpkin_macros::server_packet;
+use serde::Deserialize;
+
+#[derive(Deserialize)]
+#[server_packet("play:pick_item_from_block")]
+pub struct SPickItemFromBlock {
+    pub pos: WorldPosition,
+    pub include_data: bool,
+}
+
+#[derive(Deserialize)]
+#[server_packet("play:pick_item_from_entity")]
+pub struct SPickItemFromEntity {
+    pub id: i32,
+    pub include_data: bool,
+}

pumpkin/src/entity/player.rs

@@ -37,9 +37,10 @@ use pumpkin_protocol::{
     },
     server::play::{
         SChatCommand, SChatMessage, SClientCommand, SClientInformationPlay, SClientTickEnd,
-        SCommandSuggestion, SConfirmTeleport, SInteract, SPlayerAbilities, SPlayerAction,
-        SPlayerCommand, SPlayerInput, SPlayerPosition, SPlayerPositionRotation, SPlayerRotation,
-        SSetCreativeSlot, SSetHeldItem, SSetPlayerGround, SSwingArm, SUseItem, SUseItemOn,
+        SCommandSuggestion, SConfirmTeleport, SInteract, SPickItemFromBlock, SPlayerAbilities,
+        SPlayerAction, SPlayerCommand, SPlayerInput, SPlayerPosition, SPlayerPositionRotation,
+        SPlayerRotation, SSetCreativeSlot, SSetHeldItem, SSetPlayerGround, SSwingArm, SUseItem,
+        SUseItemOn,
     },
     RawPacket, ServerPacket, SoundCategory,
 };
@@ -675,6 +676,7 @@ impl Player {
         }
     }
 
+    #[allow(clippy::too_many_lines)]
     pub async fn handle_play_packet(
         self: &Arc<Self>,
         server: &Arc<Server>,
@@ -726,6 +728,10 @@ impl Player {
             SSetPlayerGround::PACKET_ID => {
                 self.handle_player_ground(&SSetPlayerGround::read(bytebuf)?);
             }
+            SPickItemFromBlock::PACKET_ID => {
+                self.handle_pick_item_from_block(SPickItemFromBlock::read(bytebuf)?)
+                    .await;
+            }
             SPlayerAbilities::PACKET_ID => {
                 self.handle_player_abilities(SPlayerAbilities::read(bytebuf)?)
                     .await;

pumpkin/src/net/packet/play.rs

@@ -18,7 +18,10 @@ use pumpkin_core::{
     text::TextComponent,
     GameMode,
 };
+use pumpkin_inventory::player::PlayerInventory;
 use pumpkin_inventory::InventoryError;
+use pumpkin_protocol::client::play::{CSetContainerSlot, CSetHeldItem};
+use pumpkin_protocol::codec::slot::Slot;
 use pumpkin_protocol::codec::var_int::VarInt;
 use pumpkin_protocol::server::play::SCookieResponse as SPCookieResponse;
 use pumpkin_protocol::{
@@ -32,13 +35,14 @@ use pumpkin_protocol::{
     },
     server::play::{
         Action, ActionType, SChatCommand, SChatMessage, SClientCommand, SClientInformationPlay,
-        SConfirmTeleport, SInteract, SPlayPingRequest, SPlayerAbilities, SPlayerAction,
-        SPlayerCommand, SPlayerPosition, SPlayerPositionRotation, SPlayerRotation,
-        SSetCreativeSlot, SSetHeldItem, SSwingArm, SUseItemOn, Status,
+        SConfirmTeleport, SInteract, SPickItemFromBlock, SPickItemFromEntity, SPlayPingRequest,
+        SPlayerAbilities, SPlayerAction, SPlayerCommand, SPlayerPosition, SPlayerPositionRotation,
+        SPlayerRotation, SSetCreativeSlot, SSetHeldItem, SSwingArm, SUseItemOn, Status,
     },
 };
 use pumpkin_world::block::{block_registry::get_block_by_item, BlockFace};
 use pumpkin_world::item::item_registry::get_item_by_id;
+use pumpkin_world::item::ItemStack;
 use thiserror::Error;
 
 fn modulus(a: f32, b: f32) -> f32 {
@@ -310,6 +314,101 @@ impl Player {
             .store(ground.on_ground, std::sync::atomic::Ordering::Relaxed);
     }
 
+    async fn update_single_slot(
+        &self,
+        inventory: &mut tokio::sync::MutexGuard<'_, PlayerInventory>,
+        slot: usize,
+        slot_data: Slot,
+    ) {
+        inventory.state_id += 1;
+        let dest_packet = CSetContainerSlot::new(0, inventory.state_id as i32, slot, &slot_data);
+        self.client.send_packet(&dest_packet).await;
+
+        if inventory
+            .set_slot(slot, slot_data.to_item(), false)
+            .is_err()
+        {
+            log::error!("Pick item set slot error!");
+        }
+    }
+
+    pub async fn handle_pick_item_from_block(&self, pick_item: SPickItemFromBlock) {
+        if !self.can_interact_with_block_at(&pick_item.pos, 1.0) {
+            return;
+        }
+
+        let Ok(block) = self.world().get_block(pick_item.pos).await else {
+            return;
+        };
+
+        if block.item_id == 0 {
+            // Invalid block id (blocks such as tall seagrass)
+            return;
+        }
+
+        let mut inventory = self.inventory().lock().await;
+
+        let source_slot = inventory.get_slot_with_item(block.item_id);
+        let mut dest_slot = inventory.get_pick_item_hotbar_slot();
+
+        let dest_slot_data = match inventory.get_slot(dest_slot + 36) {
+            Ok(Some(stack)) => Slot::from(&*stack),
+            _ => Slot::from(None),
+        };
+
+        // Early return if no source slot and not in creative mode
+        if source_slot.is_none() && self.gamemode.load() != GameMode::Creative {
+            return;
+        }
+
+        match source_slot {
+            Some(slot_index) if (36..=44).contains(&slot_index) => {
+                // Case where item is in hotbar
+                dest_slot = slot_index - 36;
+            }
+            Some(slot_index) => {
+                // Case where item is in inventory
+
+                // Update destination slot
+                let source_slot_data = match inventory.get_slot(slot_index) {
+                    Ok(Some(stack)) => Slot::from(&*stack),
+                    _ => return,
+                };
+                self.update_single_slot(&mut inventory, dest_slot + 36, source_slot_data)
+                    .await;
+
+                // Update source slot
+                self.update_single_slot(&mut inventory, slot_index, dest_slot_data)
+                    .await;
+            }
+            None if self.gamemode.load() == GameMode::Creative => {
+                // Case where item is not present, if in creative mode create the item
+                let item_stack = ItemStack::new(1, block.item_id);
+                let slot_data = Slot::from(&item_stack);
+                self.update_single_slot(&mut inventory, dest_slot + 36, slot_data)
+                    .await;
+
+                // Check if there is any empty slot in the player inventory
+                if let Some(slot_index) = inventory.get_empty_slot() {
+                    inventory.state_id += 1;
+                    self.update_single_slot(&mut inventory, slot_index, dest_slot_data)
+                        .await;
+                }
+            }
+            _ => return,
+        }
+
+        // Update held item
+        inventory.set_selected(dest_slot);
+        self.client
+            .send_packet(&CSetHeldItem::new(dest_slot as i8))
+            .await;
+    }
+
+    pub fn handle_pick_item_from_entity(&self, _pick_item: SPickItemFromEntity) {
+        // TODO: Implement and merge any redundant code with pick_item_from_block
+    }
+
     pub async fn handle_player_command(&self, command: SPlayerCommand) {
         if command.entity_id != self.entity_id().into() {
             return;