From 683de943c030306759ac3fd34bbcf2780546eb1f Mon Sep 17 00:00:00 2001
From: Alex Piechowski <alex@piechowski.io>
Date: Fri, 28 Jul 2023 12:50:04 -0500
Subject: [PATCH] Rewrite client to use a global tick loop

Only digging, use hand, change hotbar slot, and physics are part of this
loops sofar

Speed up the specs greatly using event emitter callbacks

Add apple to eating

Fix a ton of random anti-cheat issues

Fix a few inventory desync issues

Fixes the occasional eating problems

Resolves #98
Resolves #97
---
 spec/integration/attack_spec.cr               |  39 +---
 .../{dig_spec.cr => interactions_spec.cr}     |  35 +++-
 spec/integration/inventory_spec.cr            |  64 +++---
 spec/integration/movement_spec.cr             |  25 ++-
 src/rosegold/bot.cr                           |  41 ++--
 src/rosegold/client.cr                        |  24 ++-
 src/rosegold/control/interactions.cr          | 191 ++++++++++++------
 src/rosegold/control/inventory.cr             |   8 +-
 src/rosegold/control/physics.cr               |  24 +--
 src/rosegold/events/event.cr                  |   1 +
 src/rosegold/events/tick.cr                   |  14 ++
 src/rosegold/models/block.cr                  |  16 +-
 src/rosegold/models/event_emitter.cr          |   2 -
 .../packets/clientbound/destroy_entities.cr   |   1 -
 .../packets/clientbound/entity_position.cr    |   1 -
 src/rosegold/packets/clientbound/set_slot.cr  |   1 -
 .../packets/clientbound/spawn_entity.cr       |   1 -
 .../clientbound/spawn_living_entity.cr        |   3 +-
 src/rosegold/world/dimension.cr               |   2 +
 src/rosegold/world/entity.cr                  |   5 +-
 src/rosegold/world/slot.cr                    |  13 ++
 21 files changed, 314 insertions(+), 197 deletions(-)
 rename spec/integration/{dig_spec.cr => interactions_spec.cr} (56%)
 create mode 100644 src/rosegold/events/event.cr
 create mode 100644 src/rosegold/events/tick.cr

diff --git a/spec/integration/attack_spec.cr b/spec/integration/attack_spec.cr
index 76cc4d1a..677bcc49 100644
--- a/spec/integration/attack_spec.cr
+++ b/spec/integration/attack_spec.cr
@@ -6,33 +6,8 @@ Spectator.describe Rosegold::Bot do
       Rosegold::Bot.new(client).try do |bot|
         bot.chat "/kill @e[type=!minecraft:player]"
         bot.chat "/fill -10 -60 -10 10 0 10 minecraft:air"
-        sleep 1
-      end
-    end
-  end
-
-  it "should be able to attack" do
-    client.join_game do |client|
-      Rosegold::Bot.new(client).try do |bot|
-        bot.chat "/tp @p -9 -60 9"
-        bot.chat "/time set 13000"
-        bot.chat "/kill @e[type=!minecraft:player]"
-        bot.chat "/clear"
-        sleep 1
-        bot.chat "/give #{bot.username} minecraft:diamond_sword"
-        bot.chat "/summon minecraft:zombie -9 -60 8 {NoAI:1}"
-        sleep 1
-        bot.inventory.pick! "diamond_sword"
-        bot.yaw = 180
-        bot.pitch = 0
-        20.times do
-          break if client.dimension.entities.select { |_, e| e.entity_type == 107 }.empty?
-          bot.chat "attack!"
-          bot.attack
-          bot.wait_ticks 20
-        end
-        # no zombies left
-        expect(client.dimension.entities.select { |_, e| e.entity_type == 107 }).to be_empty
+        bot.chat "/fill -10 -61 -10 10 -61 10 minecraft:bedrock"
+        bot.wait_tick
       end
     end
   end
@@ -44,11 +19,11 @@ Spectator.describe Rosegold::Bot do
         bot.chat "/time set 13000"
         bot.chat "/kill @e[type=!minecraft:player]"
         bot.chat "/clear"
-        bot.wait_ticks 5
+        bot.wait_for Rosegold::Clientbound::SetSlot
+
         bot.chat "/give #{bot.username} minecraft:diamond_sword"
-        bot.wait_tick
+        bot.wait_for Rosegold::Clientbound::SetSlot
         bot.chat "/fill -10 -60 8 0 -58 6 minecraft:dirt"
-        bot.wait_tick
         bot.chat "/fill -9 -60 7 0 -58 7 minecraft:air"
         bot.wait_tick
         bot.chat "/fill -6 -60 7 -6 -60 7 minecraft:water"
@@ -56,7 +31,7 @@ Spectator.describe Rosegold::Bot do
         bot.chat "/fill -9 -59 8 -9 -59 8 minecraft:air"
         bot.wait_tick
         bot.chat "/summon minecraft:zombie -7 -60 7"
-        sleep 1
+
         bot.inventory.pick! "diamond_sword"
         bot.yaw = 180
         bot.pitch = 0
@@ -64,7 +39,7 @@ Spectator.describe Rosegold::Bot do
           break if client.dimension.entities.select { |_, e| e.entity_type == 107 }.empty?
           bot.chat "attack!"
           bot.attack
-          bot.wait_ticks 20
+          bot.wait_ticks 13
         end
         # no zombies left
         expect(client.dimension.entities.select { |_, e| e.entity_type == 107 }).to be_empty
diff --git a/spec/integration/dig_spec.cr b/spec/integration/interactions_spec.cr
similarity index 56%
rename from spec/integration/dig_spec.cr
rename to spec/integration/interactions_spec.cr
index 60a3a891..83d893fb 100644
--- a/spec/integration/dig_spec.cr
+++ b/spec/integration/interactions_spec.cr
@@ -1,13 +1,21 @@
 require "../spec_helper"
 
 Spectator.describe Rosegold::Bot do
+  before_all do
+    client.join_game do |client|
+      Rosegold::Bot.new(client).try do |bot|
+        bot.chat "/fill 8 -60 8 8 0 8 minecraft:air"
+        bot.wait_tick
+      end
+    end
+  end
+
   it "should be able to dig" do
     client.join_game do |client|
       Rosegold::Bot.new(client).try do |bot|
         bot.chat "/fill 8 -60 8 8 -57 8 minecraft:dirt"
-        sleep 2 # load chunks
         bot.chat "/tp 8 -56 8"
-        sleep 1 # teleport
+        bot.wait_tick
 
         bot.look &.down
         bot.start_digging
@@ -26,9 +34,8 @@ Spectator.describe Rosegold::Bot do
     client.join_game do |client|
       Rosegold::Bot.new(client).try do |bot|
         bot.chat "/fill 8 -60 8 8 -57 8 minecraft:dirt"
-        sleep 2 # load chunks
         bot.chat "/tp 8 -56 8"
-        sleep 1 # teleport
+        bot.wait_tick
 
         bot.look &.down
         bot.start_digging
@@ -40,4 +47,24 @@ Spectator.describe Rosegold::Bot do
       end
     end
   end
+
+  it "should be able to place blocks" do
+    client.join_game do |client|
+      Rosegold::Bot.new(client).try do |bot|
+        bot.chat "/give #{bot.username} dirt 64"
+        bot.wait_for Rosegold::Clientbound::SetSlot
+        starting_y = bot.feet.y
+
+        bot.pitch = 90
+        bot.inventory.pick! "dirt"
+        bot.start_using_hand
+        2.times do
+          bot.start_jump
+          bot.wait_ticks 20
+        end
+
+        expect(starting_y).to be < bot.feet.y
+      end
+    end
+  end
 end
diff --git a/spec/integration/inventory_spec.cr b/spec/integration/inventory_spec.cr
index b681866b..74a32fd1 100644
--- a/spec/integration/inventory_spec.cr
+++ b/spec/integration/inventory_spec.cr
@@ -7,7 +7,7 @@ Spectator.describe Rosegold::Bot do
         client.join_game do |client|
           Rosegold::Bot.new(client).try do |bot|
             bot.chat "/clear"
-            sleep 1
+            bot.wait_for Rosegold::Clientbound::SetSlot
 
             expect(bot.inventory.count("bucket")).to eq 0
           end
@@ -20,7 +20,7 @@ Spectator.describe Rosegold::Bot do
         client.join_game do |client|
           Rosegold::Bot.new(client).try do |bot|
             bot.chat "/clear"
-            sleep 1
+            bot.wait_for Rosegold::Clientbound::SetSlot
 
             bot.chat "/give #{bot.username} minecraft:bucket 16"
             bot.chat "/give #{bot.username} minecraft:bucket 1"
@@ -38,10 +38,10 @@ Spectator.describe Rosegold::Bot do
         client.join_game do |client|
           Rosegold::Bot.new(client).try do |bot|
             bot.chat "/clear"
-            sleep 1
+            bot.wait_for Rosegold::Clientbound::SetSlot
 
             bot.chat "/give #{bot.username} minecraft:bucket 513"
-            sleep 1
+            bot.wait_ticks 5
 
             expect(bot.inventory.count("bucket")).to eq 513
           end
@@ -56,8 +56,7 @@ Spectator.describe Rosegold::Bot do
         client.join_game do |client|
           Rosegold::Bot.new(client).try do |bot|
             bot.chat "/clear"
-
-            sleep 1
+            bot.wait_for Rosegold::Clientbound::SetSlot
 
             expect(bot.inventory.pick("diamond_pickaxe")).to eq false
             expect(bot.inventory.pick("stone")).to eq false
@@ -72,9 +71,11 @@ Spectator.describe Rosegold::Bot do
         client.join_game do |client|
           Rosegold::Bot.new(client).try do |bot|
             bot.chat "/clear"
+            bot.wait_for Rosegold::Clientbound::SetSlot
             bot.chat "/give #{bot.username} minecraft:stone 42"
+            bot.wait_for Rosegold::Clientbound::SetSlot
             bot.chat "/give #{bot.username} minecraft:grass_block 43"
-            sleep 1
+            bot.wait_for Rosegold::Clientbound::SetSlot
 
             expect(bot.inventory.pick("stone")).to eq true
             expect(bot.inventory.main_hand.item_id).to eq "stone"
@@ -90,9 +91,11 @@ Spectator.describe Rosegold::Bot do
         client.join_game do |client|
           Rosegold::Bot.new(client).try do |bot|
             bot.chat "/clear"
+            bot.wait_for Rosegold::Clientbound::SetSlot
             bot.chat "/give #{bot.username} minecraft:stone #{64*9}"
+            bot.wait_for Rosegold::Clientbound::SetSlot
             bot.chat "/give #{bot.username} minecraft:grass_block 1"
-            sleep 1
+            bot.wait_for Rosegold::Clientbound::SetSlot
 
             expect(bot.inventory.pick("grass_block")).to eq true
             expect(bot.inventory.main_hand.item_id).to eq "grass_block"
@@ -108,7 +111,7 @@ Spectator.describe Rosegold::Bot do
         client.join_game do |client|
           Rosegold::Bot.new(client).try do |bot|
             bot.chat "/clear"
-            sleep 1
+            bot.wait_for Rosegold::Clientbound::SetSlot
             expect { bot.inventory.pick!("diamond_pickaxe") }.to raise_error(Rosegold::Inventory::ItemNotFoundError)
           end
         end
@@ -120,7 +123,9 @@ Spectator.describe Rosegold::Bot do
         client.join_game do |client|
           Rosegold::Bot.new(client).try do |bot|
             bot.chat "/clear"
+            bot.wait_for Rosegold::Clientbound::SetSlot
             bot.chat "/give #{bot.username} minecraft:diamond_pickaxe{Damage:1550,Enchantments:[{id:efficiency,lvl:1}]} 1"
+            bot.wait_for Rosegold::Clientbound::SetSlot
             expect { bot.inventory.pick!("diamond_pickaxe") }.to raise_error(Rosegold::Inventory::ItemNotFoundError)
           end
         end
@@ -133,17 +138,17 @@ Spectator.describe Rosegold::Bot do
       client.join_game do |client|
         Rosegold::Bot.new(client).try do |bot|
           bot.chat "/fill ~ ~ ~ ~ ~ ~ minecraft:air"
-          sleep 1
+          bot.wait_tick
           bot.chat "/setblock ~ ~ ~ minecraft:chest{Items:[{Slot:7b, id: \"minecraft:diamond_sword\",Count:1b}]}"
           bot.chat "/clear"
-          sleep 1
+          bot.wait_for Rosegold::Clientbound::SetSlot
+          bot.wait_tick
 
           bot.pitch = 90
           bot.use_hand
-          sleep 1
-          expect(bot.inventory.withdraw_at_least(1, "diamond_sword")).to eq 1
+          bot.wait_for Rosegold::Clientbound::WindowItems
 
-          sleep 1
+          expect(bot.inventory.withdraw_at_least(1, "diamond_sword")).to eq 1
 
           local_inventory = bot.inventory.inventory.map &.dup
           local_hotbar = bot.inventory.hotbar.map &.dup
@@ -152,9 +157,9 @@ Spectator.describe Rosegold::Bot do
           expect((local_inventory + local_hotbar).map(&.item_id)).to contain "diamond_sword"
           expect(local_content.map(&.item_id)).not_to contain "diamond_sword"
 
-          sleep 1
           bot.use_hand
-          sleep 1
+          bot.wait_for Rosegold::Clientbound::WindowItems
+          bot.wait_tick
 
           expect(local_inventory.map(&.item_id)).to match_array bot.inventory.inventory.map(&.item_id)
           expect(local_hotbar.map(&.item_id)).to match_array bot.inventory.hotbar.map(&.item_id)
@@ -172,16 +177,16 @@ Spectator.describe Rosegold::Bot do
       client.join_game do |client|
         Rosegold::Bot.new(client).try do |bot|
           bot.chat "/fill ~ ~ ~ ~ ~ ~ minecraft:air"
-          sleep 1
+          bot.wait_tick
           bot.chat "/setblock ~ ~ ~ minecraft:chest{Items:[]}"
           bot.chat "/clear"
-          sleep 1
+          bot.wait_for Rosegold::Clientbound::SetSlot
           bot.chat "/give #{bot.username} minecraft:diamond_sword 1"
-          sleep 1
+          bot.wait_for Rosegold::Clientbound::SetSlot
 
           bot.pitch = 90
           bot.use_hand
-          sleep 1
+          bot.wait_for Rosegold::Clientbound::WindowItems
 
           expect(bot.inventory.deposit_at_least(1, "diamond_sword")).to eq 1
 
@@ -192,9 +197,8 @@ Spectator.describe Rosegold::Bot do
           expect((local_inventory + local_hotbar).map(&.item_id)).not_to contain "diamond_sword"
           expect(local_content.map(&.item_id)).to contain "diamond_sword"
 
-          sleep 1
           bot.use_hand
-          sleep 1
+          bot.wait_for Rosegold::Clientbound::WindowItems
 
           expect(local_inventory.map(&.item_id)).to match_array bot.inventory.inventory.map(&.item_id)
           expect(local_hotbar.map(&.item_id)).to match_array bot.inventory.hotbar.map(&.item_id)
@@ -213,21 +217,18 @@ Spectator.describe Rosegold::Bot do
       Rosegold::Bot.new(client).try do |bot|
         bot.chat "/tp #{bot.username} -10 -60 -10"
         bot.chat "/fill ~ ~ ~ ~ ~ ~ minecraft:air"
-        sleep 1
+        bot.wait_tick
         bot.chat "/setblock ~ ~ ~ minecraft:chest{Items:[{Slot:7b, id: \"minecraft:diamond_sword\",Count:1b}]}"
         bot.chat "/clear"
-        sleep 1
 
         bot.pitch = 90
         bot.use_hand
-        sleep 1
+        bot.wait_for Rosegold::Clientbound::WindowItems
         bot.inventory.withdraw_at_least(1, "diamond_sword")
 
-        sleep 1
-
         bot.inventory.close
 
-        sleep 1
+        bot.wait_tick
 
         slots_before_reload = bot.inventory.slots
 
@@ -251,14 +252,17 @@ Spectator.describe Rosegold::Bot do
       client.join_game do |client|
         Rosegold::Bot.new(client).try do |bot|
           bot.chat "/clear"
+          bot.wait_for Rosegold::Clientbound::SetSlot
           bot.chat "/give #{bot.username} minecraft:diamond_sword 4"
+          bot.wait_for Rosegold::Clientbound::SetSlot
           bot.chat "/give #{bot.username} minecraft:stone 200"
-          sleep 1
+          bot.wait_for Rosegold::Clientbound::SetSlot
 
+          bot.look = Rosegold::Look.new 0, 0
           expect(bot.inventory.throw_all_of "diamond_sword").to eq 4
           expect(bot.inventory.throw_all_of "stone").to eq 200
 
-          sleep 1
+          bot.wait_tick
 
           expect(bot.inventory.inventory.map(&.item_id)).not_to contain "diamond_sword"
           expect(bot.inventory.hotbar.map(&.item_id)).not_to contain "diamond_sword"
diff --git a/spec/integration/movement_spec.cr b/spec/integration/movement_spec.cr
index 95ab48df..4ae4cc69 100644
--- a/spec/integration/movement_spec.cr
+++ b/spec/integration/movement_spec.cr
@@ -1,12 +1,22 @@
 require "../spec_helper"
 
 Spectator.describe Rosegold::Bot do
+  before_all do
+    client.join_game do |client|
+      Rosegold::Bot.new(client).try do |bot|
+        bot.chat "/kill @e[type=!minecraft:player]"
+        bot.chat "/fill -10 -60 -10 10 0 10 minecraft:air"
+        bot.chat "/fill -10 -61 -10 10 -61 10 minecraft:bedrock"
+        bot.wait_tick
+      end
+    end
+  end
+
   it "should fall due to gravity" do
     client.join_game do |client|
       Rosegold::Bot.new(client).try do |bot|
-        sleep 2 # load chunks
         bot.chat "/tp 1 -58 1"
-        sleep 1 # teleport
+        bot.wait_tick
         until client.player.on_ground?
           bot.wait_tick
         end
@@ -18,9 +28,8 @@ Spectator.describe Rosegold::Bot do
   it "can move to location successfully" do
     client.join_game do |client|
       Rosegold::Bot.new(client).try do |bot|
-        sleep 2 # load chunks
         bot.chat "/tp 1 -60 1"
-        sleep 1 # teleport
+        bot.wait_tick
 
         bot.move_to 2, 2
         expect(bot.feet).to eq(Rosegold::Vec3d.new(2.5, -60, 2.5))
@@ -52,9 +61,8 @@ Spectator.describe Rosegold::Bot do
   it "should jump and fall" do
     client.join_game do |client|
       Rosegold::Bot.new(client).try do |bot|
-        sleep 2 # load chunks
         bot.chat "/tp 1 -60 1"
-        sleep 1 # teleport
+        bot.wait_tick
 
         initial_feet = bot.feet
 
@@ -77,17 +85,16 @@ Spectator.describe Rosegold::Bot do
       it "throws Physics::MovementStuck" do
         client.join_game do |client|
           Rosegold::Bot.new(client).try do |bot|
-            sleep 2 # load chunks
             bot.chat "/fill 1 -60 2 1 -60 2 minecraft:stone"
             bot.chat "/tp 1 -60 1"
-            sleep 1 # teleport
+            bot.wait_tick
 
             expect {
               bot.move_to 1, 2
             }.to raise_error(Rosegold::Physics::MovementStuck)
 
             bot.chat "/fill 1 -60 2 1 -60 2 minecraft:air"
-            sleep 1
+            bot.wait_tick
           end
         end
       end
diff --git a/src/rosegold/bot.cr b/src/rosegold/bot.cr
index 60adc2df..8f139965 100644
--- a/src/rosegold/bot.cr
+++ b/src/rosegold/bot.cr
@@ -8,8 +8,15 @@ class Rosegold::Bot < Rosegold::EventEmitter
 
   def initialize(@client)
     @inventory = Inventory.new client
-    @interact = Interactions.new client
-    client.on(Rosegold::Clientbound::ChatMessage) do |packet|
+
+    subscribe Rosegold::Clientbound::ChatMessage
+    subscribe Event::Tick
+    subscribe Rosegold::Clientbound::WindowItems
+    subscribe Rosegold::Clientbound::SetSlot
+  end
+
+  def subscribe(event_class : Class)
+    client.on event_class do |packet|
       emit_event packet
     end
   end
@@ -28,7 +35,7 @@ class Rosegold::Bot < Rosegold::EventEmitter
   delegate uuid, username, feet, eyes, health, food, saturation, gamemode, sneaking?, sprinting?, to: client.player
   delegate sneak, sprint, to: client.physics
   delegate main_hand, to: inventory
-  delegate stop_using_hand, stop_digging, to: @interact
+  delegate stop_using_hand, stop_digging, to: client.interactions
   delegate x, y, z, to: feet
 
   def disconnect_reason
@@ -56,13 +63,14 @@ class Rosegold::Bot < Rosegold::EventEmitter
     client.queue_packet Serverbound::ChatMessage.new message
   end
 
-  # Is adjusted to server TPS.
   def wait_ticks(ticks : Int32)
-    sleep ticks / 20 # TODO adjust to server TPS, changing over time
+    ticks.times do
+      wait_tick
+    end
   end
 
   def wait_tick
-    wait_ticks 1
+    wait_for Event::Tick, timeout: 1.second
   end
 
   # Direction the player is looking.
@@ -200,7 +208,6 @@ class Rosegold::Bot < Rosegold::EventEmitter
   # Selects the active (main hand) hotbar slot number (1-9).
   def hotbar_selection=(index : UInt8)
     # TODO check range
-    client.queue_packet Serverbound::HeldItemChange.new index - 1
     client.player.hotbar_selection = index - 1
   end
 
@@ -227,7 +234,7 @@ class Rosegold::Bot < Rosegold::EventEmitter
   # Activates the "use" button.
   def start_using_hand(hand : Hand = :main_hand)
     # can't delegate this because it wouldn't pick up the symbol as a Hand value
-    @interact.start_using_hand hand
+    client.interactions.start_using_hand hand
   end
 
   # Looks in the direction of `target`, then
@@ -248,21 +255,23 @@ class Rosegold::Bot < Rosegold::EventEmitter
     return if food >= 15 && full_health?
     return if food >= 18 # above healing threshold
 
-    Log.debug { "Eating because food is #{food} and health is #{health}" }
+    Log.info { "Eating because food is #{food} and health is #{health}" }
 
-    inventory.pick("baked_potato") ||
+    inventory.pick("apple") ||
+      inventory.pick("baked_potato") ||
       inventory.pick("bread") ||
       inventory.pick("carrot") ||
       raise "Bot food not found"
 
-    10.times do
-      client.send_packet! Serverbound::UseItem.new :main_hand
+    start_using_hand
+
+    until food >= 18
       wait_ticks 33
-      client.send_packet! Serverbound::PlayerDigging.new :finish_using_hand
-      break if food >= 18
     end
 
-    Log.debug { "Eating finished, food is #{food} and health is #{health}" }
+    stop_using_hand
+
+    Log.info { "Eating finished, food is #{food} and health is #{health}" }
   end
 
   def full_health?
@@ -273,7 +282,7 @@ class Rosegold::Bot < Rosegold::EventEmitter
   def start_digging(target : Vec3d? | Look? = nil)
     look_at target if target.is_a? Vec3d
     look target if target.is_a? Look
-    @interact.start_digging
+    client.interactions.start_digging
   end
 
   # Looks in the direction of target, then
diff --git a/src/rosegold/client.cr b/src/rosegold/client.cr
index 1f38646b..eb484d37 100644
--- a/src/rosegold/client.cr
+++ b/src/rosegold/client.cr
@@ -4,10 +4,9 @@ require "../minecraft/auth"
 require "./control/*"
 require "./models/*"
 require "./packets/*"
+require "./events/*"
 require "./world/*"
 
-abstract class Rosegold::Event; end # defined elsewhere, but otherwise it would be a module
-
 class Rosegold::Event::RawPacket < Rosegold::Event
   getter bytes : Bytes
 
@@ -29,6 +28,7 @@ class Rosegold::Client < Rosegold::EventEmitter
     access_token : String = "",
     dimension : Dimension = Dimension.new,
     physics : Physics,
+    interactions : Interactions,
     inventory : PlayerWindow,
     window : Window,
     offline : NamedTuple(uuid: String, username: String)? = nil
@@ -39,9 +39,11 @@ class Rosegold::Client < Rosegold::EventEmitter
       @port = port_str.to_i
     end
     @physics = uninitialized Physics
+    @interactions = uninitialized Interactions
     @inventory = uninitialized PlayerWindow
     @window = uninitialized Window
     @physics = Physics.new self
+    @interactions = Interactions.new self
     @inventory = PlayerWindow.new self
     @window = @inventory
   end
@@ -79,6 +81,8 @@ class Rosegold::Client < Rosegold::EventEmitter
       raise NotConnected.new "Took too long to join the game" if timeout_ticks <= 0
     end
 
+    start_ticker
+
     self
   end
 
@@ -90,6 +94,22 @@ class Rosegold::Client < Rosegold::EventEmitter
     self
   end
 
+  def start_ticker
+    spawn do
+      loop do
+        sleep 1.tick
+
+        break unless connected?
+
+        spawn do
+          interactions.tick
+          physics.tick
+          emit_event Event::Tick.new
+        end
+      end
+    end
+  end
+
   def connect
     raise NotConnected.new "Already connected" if connected?
 
diff --git a/src/rosegold/control/interactions.cr b/src/rosegold/control/interactions.cr
index 84dcf15a..d395d0aa 100644
--- a/src/rosegold/control/interactions.cr
+++ b/src/rosegold/control/interactions.cr
@@ -10,104 +10,133 @@ class Rosegold::Interactions
     def initialize(@intercept, @block, @face); end
   end
 
-  # not exposed, for rules compliance
-  @using_hand = false
+  @using_hand = nil
+  @queue_using_hand = nil
+  @using_hand_delay = 0_i32
   @digging_block : ReachedBlock?
   @dig_hand_swing_countdown = 0_i8
+  @attack_queued = false
+  @digging = false
+  @block_damage_progress = 0_f32
+  @last_tick_held_item : Slot = Slot.new
+  @sent_held_item_index : UInt8?
 
   getter client : Client
   property? digging : Bool = false
 
   def initialize(@client)
-    client.on Event::PhysicsTick do
-      on_physics_tick
-    end
   end
 
   # Activates the "use" button.
-  def start_using_hand(hand : Hand = :main_hand)
-    reached = reach_block_or_entity
-    if reached.is_a? ReachedBlock
-      place_block hand, reached
-    else
-      @using_hand = true
-      send_packet Serverbound::UseItem.new hand
-      send_packet Serverbound::SwingArm.new
-    end
+  def start_using_hand(hand : Hand = :main_hand) # TODO: Auto select hand each tick
+    @using_hand = hand
+    @queue_using_hand = hand
   end
 
   # Deactivates the "use" button.
   def stop_using_hand
     return unless @using_hand
-    @using_hand = false
+
+    @using_hand = nil
+    # TODO: seems to be only for eating
+    # move to tick loop
     send_packet Serverbound::PlayerDigging.new :finish_using_hand
   end
 
   # Activates the "attack" button.
   def start_digging
     return if digging?
+
     self.digging = true
+    @attack_queued = true
+  end
 
-    attack
-
-    spawn do
-      while digging? && client.connected?
-        cancel = false
-
-        case reached = wait_for_reached_block
-        when ReachedBlock
-          start_digging reached
-
-          client.dimension.block_state(reached.block).try do |block_state|
-            block = Block.from_block_state_id block_state
-            next sleep 1.tick if block.id_str == "air"
-
-            block.break_time(inventory.main_hand, client.player).to_i.times do
-              sleep 1.tick
-              reached = reach_block_or_entity
-              if reached.is_a?(Entity) || reached.try &.block != @digging_block.try &.block
-                cancel_digging
-                cancel = true
-                break
-              end
-            end
-          end
-
-          finish_digging if digging? && !cancel
-        else
-          next sleep 1.tick
-        end
-      end
-    end
+  # Deactivates the "attack" button.
+  def stop_digging
+    return unless digging?
+
+    self.digging = false
   end
 
-  def wait_for_reached_block
-    until reached = reach_block_or_entity
-      sleep 1.tick
-    end
+  def tick
+    tick_held_item
+    tick_attack
+    tick_digging
+    tick_using_hand
+    @last_tick_held_item = inventory.main_hand
+  end
 
-    reached
+  private def inventory
+    Inventory.new client
+  end
+
+  private def tick_held_item
+    if @sent_held_item_index != client.player.hotbar_selection
+      @sent_held_item_index = client.player.hotbar_selection
+      send_packet Serverbound::HeldItemChange.new client.player.hotbar_selection
+    end
   end
 
-  private def attack
-    if reached = reach_block_or_entity
-      return if reached.is_a? ReachedBlock
+  private def tick_attack
+    return unless @attack_queued
 
+    @attack_queued = false
+
+    case reached = reach_block_or_entity
+    when Entity
       send_packet Serverbound::InteractEntity.new reached.entity_id, :attack
       send_packet Serverbound::SwingArm.new
+    when ReachedBlock
+      start_digging reached
     end
   end
 
-  # Deactivates the "attack" button.
-  def stop_digging
-    return unless digging?
-    self.digging = false
-    cancel_digging
+  private def tick_digging
+    reached = reach_block_or_entity
+    if @digging_block
+      if !digging?
+        cancel_digging
+        return
+      end
+
+      case reached
+      when Entity
+        # do nothing, but retain @block_damage_progress like vanilla client
+      when ReachedBlock
+        tick_digging_block reached
+      when nil
+        cancel_digging
+      end
+    else
+      return unless digging?
+
+      if reached.is_a? ReachedBlock
+        start_digging reached
+      end
+    end
   end
 
-  private def on_physics_tick
-    # TODO if buttons are being held, keep placing more blocks or throwing/eating more items
-    if @digging_block
+  private def tick_digging_block(reached)
+    if digging_block = @digging_block
+      if reached.block != digging_block.block
+        cancel_digging
+      end
+
+      if @last_tick_held_item != inventory.main_hand
+        cancel_digging
+        return
+      end
+
+      client.dimension.block_state(digging_block.block).try do |block_state|
+        block = Block.from_block_state_id block_state
+        @block_damage_progress += block.break_damage inventory.main_hand, client.player
+      end
+
+      if @block_damage_progress >= 1.0
+        finish_digging
+        @block_damage_progress = 0.0
+      end
+
       @dig_hand_swing_countdown -= 1
       if @dig_hand_swing_countdown <= 0
         @dig_hand_swing_countdown = 6
@@ -116,8 +145,38 @@ class Rosegold::Interactions
     end
   end
 
+  private def tick_using_hand
+    @using_hand_delay -= 1 if @using_hand_delay > 0
+    return if @using_hand_delay > 0
+
+    if using_hand = @using_hand || @queue_using_hand
+      @using_hand_delay = using_hand_delay_for inventory.main_hand
+      @queue_using_hand = nil
+      case reached = reach_block_or_entity
+      when Entity
+        Log.warn { "Rosegold does not support using items on entities yet" }
+      when ReachedBlock
+        puts "place block"
+        place_block using_hand, reached
+        send_packet Serverbound::UseItem.new using_hand
+      else
+        puts "use item"
+        send_packet Serverbound::UseItem.new using_hand
+      end
+    end
+  end
+
+  # need a method to increase using_hand_delay if the item being used is a food item
+  def using_hand_delay_for(slot)
+    if slot.edible?
+      50
+    else
+      4
+    end
+  end
+
   private def send_packet(packet)
-    client.queue_packet packet
+    client.send_packet! packet
   end
 
   private def place_block(hand : Hand, reached : ReachedBlock)
@@ -137,7 +196,7 @@ class Rosegold::Interactions
     send_packet Serverbound::SwingArm.new
   end
 
-  def finish_digging
+  private def finish_digging
     reached = @digging_block
     return unless reached
     @digging_block = nil
@@ -145,11 +204,11 @@ class Rosegold::Interactions
       :finish, reached.block, reached.face
   end
 
-  # TODO decide finish/cancel based on block dig time
-  def cancel_digging
+  private def cancel_digging
     reached = @digging_block
     return unless reached
     @digging_block = nil
+    @block_damage_progress = 0.0
     send_packet Serverbound::PlayerDigging.new \
       :cancel, reached.block, reached.face
   end
diff --git a/src/rosegold/control/inventory.cr b/src/rosegold/control/inventory.cr
index 4d684ec0..9f58db3d 100644
--- a/src/rosegold/control/inventory.cr
+++ b/src/rosegold/control/inventory.cr
@@ -33,7 +33,6 @@ class Rosegold::Inventory
 
     hotbar.each_with_index do |slot, index|
       if slot.matches?(spec) && !slot.needs_repair?
-        client.send_packet! Serverbound::HeldItemChange.new index.to_u8
         client.player.hotbar_selection = index.to_u8
         return true
       end
@@ -83,10 +82,15 @@ class Rosegold::Inventory
     deposit_at_least(count, spec)
   end
 
+  # Finds an empty slot in the source
+  # In order to match vanilla:
+  # When source is the container, prioritize first empty #container slot
+  # When source is the player inventory, prioritize rightmost empty #hotbar slot
+  # then rightmost empty #inventory slot
   private def find_empty_slot(source)
     empty_slot = nil
 
-    source.each do |slot|
+    source.sort { |a, b| b.slot_number <=> a.slot_number }.each do |slot|
       if slot.empty?
         empty_slot = slot
         break
diff --git a/src/rosegold/control/physics.cr b/src/rosegold/control/physics.cr
index c9e147ca..b31411f9 100644
--- a/src/rosegold/control/physics.cr
+++ b/src/rosegold/control/physics.cr
@@ -1,18 +1,7 @@
 require "../client"
 require "./action"
 require "./raytrace"
-
-struct Int32
-  def ticks
-    self / 20
-  end
-
-  def tick
-    ticks
-  end
-end
-
-abstract class Rosegold::Event; end # defined elsewhere, but otherwise it would be a module
+require "../events/**"
 
 class Rosegold::Event::PhysicsTick < Rosegold::Event
   getter movement : Vec3d
@@ -34,7 +23,6 @@ class Rosegold::Physics
   VERY_CLOSE = 0.00001 # consider arrived at target if squared distance is closer than this
 
   private getter client : Rosegold::Client
-  private property ticker : Fiber?
   property? paused : Bool = true
   property? jump_queued : Bool = false
   private getter movement_action : Action(Vec3d)?
@@ -58,16 +46,6 @@ class Rosegold::Physics
   def handle_reset
     @paused = false
     player.velocity = Vec3d::ORIGIN
-
-    ticker.try do |t|
-      return unless t.dead?
-    end
-    self.ticker = spawn do
-      while client.connected?
-        tick
-        sleep 1/20
-      end
-    end
   end
 
   def handle_disconnect
diff --git a/src/rosegold/events/event.cr b/src/rosegold/events/event.cr
new file mode 100644
index 00000000..2a91da13
--- /dev/null
+++ b/src/rosegold/events/event.cr
@@ -0,0 +1 @@
+abstract class Rosegold::Event; end
diff --git a/src/rosegold/events/tick.cr b/src/rosegold/events/tick.cr
new file mode 100644
index 00000000..c193a28e
--- /dev/null
+++ b/src/rosegold/events/tick.cr
@@ -0,0 +1,14 @@
+require "./event"
+
+struct Int32
+  def ticks
+    1.second / 20
+  end
+
+  def tick
+    ticks
+  end
+end
+
+class Rosegold::Event::Tick < Rosegold::Event
+end
diff --git a/src/rosegold/models/block.cr b/src/rosegold/models/block.cr
index 903fb1ed..bad30593 100644
--- a/src/rosegold/models/block.cr
+++ b/src/rosegold/models/block.cr
@@ -46,8 +46,8 @@ class Rosegold::Block
     best_tool?(slot) || harvest_tools.try &.keys.includes? slot.item_id_int.to_s
   end
 
-  def break_time(main_hand : Slot, player : Player, creative : Bool = false) : Int32
-    return 0 if creative
+  def break_damage(main_hand : Slot, player : Player, creative : Bool = false) : Float64
+    return 0_f64 if creative
 
     speed_multiplier = 1.0
     if best_tool?(main_hand)
@@ -68,8 +68,16 @@ class Rosegold::Block
     damage = speed_multiplier / hardness
     damage /= can_harvest?(main_hand) ? 30 : 100
 
-    return 0 if damage > 1
+    return 0_f64 if damage > 1
+
+    damage
+  end
+
+  def break_time(main_hand : Slot, player : Player, creative : Bool = false) : Int32
+    break_damage = break_damage(main_hand, player, creative)
+
+    return 0 if break_damage.zero?
 
-    (1.0 / damage).ceil.to_i
+    (1.0 / break_damage).ceil.to_i
   end
 end
diff --git a/src/rosegold/models/event_emitter.cr b/src/rosegold/models/event_emitter.cr
index 4a85d822..913a1203 100644
--- a/src/rosegold/models/event_emitter.cr
+++ b/src/rosegold/models/event_emitter.cr
@@ -1,5 +1,3 @@
-abstract class Rosegold::Event; end
-
 require "uuid"
 
 class Rosegold::EventEmitter
diff --git a/src/rosegold/packets/clientbound/destroy_entities.cr b/src/rosegold/packets/clientbound/destroy_entities.cr
index 2f8b7b07..e1c6e7f2 100644
--- a/src/rosegold/packets/clientbound/destroy_entities.cr
+++ b/src/rosegold/packets/clientbound/destroy_entities.cr
@@ -23,7 +23,6 @@ class Rosegold::Clientbound::DestroyEntities < Rosegold::Clientbound::Packet
   end
 
   def callback(client)
-    Log.debug { "Received destroy entities packet for #{entity_ids.size} entities" }
     entity_ids.each { |entity_id| client.dimension.entities.delete(entity_id) }
   end
 end
diff --git a/src/rosegold/packets/clientbound/entity_position.cr b/src/rosegold/packets/clientbound/entity_position.cr
index cd5dd391..7d09c4ba 100644
--- a/src/rosegold/packets/clientbound/entity_position.cr
+++ b/src/rosegold/packets/clientbound/entity_position.cr
@@ -35,7 +35,6 @@ class Rosegold::Clientbound::EntityPosition < Rosegold::Clientbound::Packet
   end
 
   def callback(client)
-    Log.debug { "Received entity position packet for entity ID #{entity_id}, delta X #{delta_x}, delta Y #{delta_y}, delta Z #{delta_z}" }
     entity = client.dimension.entities[entity_id]?
 
     if entity.nil?
diff --git a/src/rosegold/packets/clientbound/set_slot.cr b/src/rosegold/packets/clientbound/set_slot.cr
index 60c6f218..f0ef32d4 100644
--- a/src/rosegold/packets/clientbound/set_slot.cr
+++ b/src/rosegold/packets/clientbound/set_slot.cr
@@ -29,7 +29,6 @@ class Rosegold::Clientbound::SetSlot < Rosegold::Clientbound::Packet
   end
 
   def callback(client)
-    Log.debug { "Server set slot #{slot}" }
     if window_id == -1 && slot.slot_number == -1
       client.window.cursor = slot
     elsif window_id == 0
diff --git a/src/rosegold/packets/clientbound/spawn_entity.cr b/src/rosegold/packets/clientbound/spawn_entity.cr
index ea3aa13b..df450f05 100644
--- a/src/rosegold/packets/clientbound/spawn_entity.cr
+++ b/src/rosegold/packets/clientbound/spawn_entity.cr
@@ -54,7 +54,6 @@ class Rosegold::Clientbound::SpawnEntity < Rosegold::Clientbound::Packet
   end
 
   def callback(client)
-    Log.debug { "Received spawn entity packet for entity ID #{entity_id}, UUID #{uuid}, type #{entity_type}" }
     client.dimension.entities[entity_id] = Rosegold::Entity.new \
       entity_id,
       uuid,
diff --git a/src/rosegold/packets/clientbound/spawn_living_entity.cr b/src/rosegold/packets/clientbound/spawn_living_entity.cr
index 8fbe3c73..2cef94df 100644
--- a/src/rosegold/packets/clientbound/spawn_living_entity.cr
+++ b/src/rosegold/packets/clientbound/spawn_living_entity.cr
@@ -60,6 +60,7 @@ class Rosegold::Clientbound::SpawnLivingEntity < Rosegold::Clientbound::Packet
       pitch,
       yaw,
       head_yaw,
-      Vec3d.new(velocity_x, velocity_y, velocity_z)
+      Vec3d.new(velocity_x, velocity_y, velocity_z),
+      living: true
   end
 end
diff --git a/src/rosegold/world/dimension.cr b/src/rosegold/world/dimension.cr
index 6f9c7faa..af139d55 100644
--- a/src/rosegold/world/dimension.cr
+++ b/src/rosegold/world/dimension.cr
@@ -64,6 +64,8 @@ class Rosegold::Dimension
     ray_end = start + look * max_distance
 
     entities.each_value do |entity|
+      next unless entity.living?
+
       bounding_box = entity.bounding_box
       distance = bounding_box.ray_intersection(start, ray_end)
       next if distance.nil?
diff --git a/src/rosegold/world/entity.cr b/src/rosegold/world/entity.cr
index fcc6d801..463f5946 100644
--- a/src/rosegold/world/entity.cr
+++ b/src/rosegold/world/entity.cr
@@ -29,9 +29,10 @@ class Rosegold::Entity
     effects : Array(EntityEffect) = [] of EntityEffect
 
   property? \
-    on_ground : Bool = true
+    on_ground : Bool = true,
+    living : Bool = false
 
-  def initialize(@entity_id, @uuid, @entity_type, @position, @pitch, @yaw, @head_yaw, @velocity, @on_ground = true)
+  def initialize(@entity_id, @uuid, @entity_type, @position, @pitch, @yaw, @head_yaw, @velocity, @on_ground = true, @living = false)
   end
 
   def metadata
diff --git a/src/rosegold/world/slot.cr b/src/rosegold/world/slot.cr
index e49a14d5..49702c26 100644
--- a/src/rosegold/world/slot.cr
+++ b/src/rosegold/world/slot.cr
@@ -135,6 +135,19 @@ class Rosegold::Slot
     other.nbt = tmp
   end
 
+  def edible? : Bool
+    [
+      "apple", "baked_potato", "beef", "beetroot", "beetroot_soup", "bread", "carrot",
+      "chicken", "chorus_fruit", "cod", "cooked_beef", "cooked_chicken", "cooked_cod",
+      "cooked_mutton", "cooked_porkchop", "cooked_rabbit", "cooked_salmon", "cookie",
+      "dried_kelp", "enchanted_golden_apple", "golden_apple", "golden_carrot",
+      "honey_bottle", "melon_slice", "mushroom_stew", "mutton", "poisonous_potato",
+      "porkchop", "potato", "pufferfish", "pumpkin_pie", "rabbit", "rabbit_stew",
+      "rotten_flesh", "salmon", "spider_eye", "suspicious_stew", "sweet_berries",
+      "glow_berries", "tropical_fish",
+    ].includes? item_id
+  end
+
   def to_s(io)
     inspect io
   end