Progress on getting back up to speed

apps/amethyst/lib/states/configuration.ex

@@ -130,6 +130,14 @@ defmodule Amethyst.ConnectionState.Configuration do
     allow_server_listings: allow_server_listings
   }, 767, state) do
     Logger.debug("Received client information")
+    send(self(), {:send_packet, %{
+      packet_type: :feature_flags,
+      flags: []
+    }})
+    send(self(), {:send_packet, %{
+      packet_type: :clientbound_known_packs,
+      packs: [%{namespace: "minecraft", id: "base", version: "1.21"}]
+    }})
     state
     |> Map.put(:locale, locale)
     |> Map.put(:view_distance, view_distance)
@@ -141,6 +149,154 @@ defmodule Amethyst.ConnectionState.Configuration do
     |> Map.put(:allow_server_listings, allow_server_listings)
   end
 
+  def handle(%{packet_type: :serverbound_known_packs, packs: _packs}, 767, _state) do
+    Logger.debug("Received known packs")
+    import Amethyst.NBT.Write
+    # TODO: Of course, the registries shouldn't be hard-coded
+    send(self(), {:send_packet, %{
+      packet_type: :registry_data,
+      id: "minecraft:dimension_type",
+      entries: [
+        %{id: "amethyst:basic", data: compound(%{
+          "has_skylight" => byte(1),
+          "has_ceiling" => byte(0),
+          "ultrawarm" => byte(0),
+          "natural" => byte(1),
+          "coordinate_scale" => float(1.0),
+          "bed_works" => byte(1),
+          "respawn_anchor_works" => byte(1),
+          "min_y" => int(0),
+          "height" => int(256),
+          "logical_height" => int(256),
+          "infiniburn" => string("#"),
+          "effects" => string("minecraft:overworld"),
+          "ambient_light" => float(0.0),
+          "piglin_safe" => byte(0),
+          "has_raids" => byte(1),
+          "monster_spawn_light_level" => int(0),
+          "monster_spawn_block_light_limit" => int(0)
+        })}
+      ]
+    }})
+    send(self(), {:send_packet, %{
+      packet_type: :registry_data,
+      id: "minecraft:painting_variant", entries: [
+        %{id: "minecraft:kebab", data: compound(%{
+          "asset_id" => string("minecraft:kebab"),
+          "height" => int(1),
+          "width" => int(1),
+        })}
+      ]
+    }})
+    send(self(), {:send_packet, %{
+      packet_type: :registry_data,
+      id: "minecraft:wolf_variant",
+      entries: [
+        %{id: "minecraft:wolf_ashen", data: compound(%{
+          "wild_texture" => string("minecraft:entity/wolf/wolf_ashen"),
+          "tame_texture" => string("minecraft:entity/wolf/wolf_ashen_tame"),
+          "angry_texture" => string("minecraft:entity/wolf/wolf_ashen_angry"),
+          "biomes" => string("amethyst:basic"),
+        })}
+      ]
+    }})
+    # https://gist.github.com/WinX64/ab8c7a8df797c273b32d3a3b66522906 minecraft:plains
+    basic_biome = compound(%{
+      "effects" => compound(%{
+        "sky_color" => int(7907327),
+        "water_fog_color" => int(329011),
+        "fog_color" => int(12638463),
+        "water_color" => int(4159204),
+        "mood_sound" => compound(%{
+          "tick_delay" => int(6000),
+          "offset" => float(2.0),
+          "sound" => string("minecraft:ambient.cave"),
+          "block_search_extent" => int(8)
+        }),
+      }),
+      "has_precipitation" => byte(1),
+      "temperature" => float(0.8),
+      "downfall" => float(0.4),
+    })
+    send(self(), {:send_packet, %{
+      packet_type: :registry_data,
+      id: "minecraft:worldgen/biome",
+      entries: [
+        %{id: "amethyst:basic", data: basic_biome},
+        %{id: "minecraft:plains", data: basic_biome}
+      ]
+    }})
+    # this game sucks
+    generic_damage = compound(%{
+      "scaling" => string("when_caused_by_living_non_player"),
+      "exhaustion" => float(0.0),
+      "message_id" => string("generic")
+    })
+    send(self(), {:send_packet, %{
+      packet_type: :registry_data,
+      id: "minecraft:damage_type",
+      entries: [
+        %{id: "minecraft:in_fire", data: generic_damage},
+        %{id: "minecraft:campfire", data: generic_damage},
+        %{id: "minecraft:lightning_bolt", data: generic_damage},
+        %{id: "minecraft:on_fire", data: generic_damage},
+        %{id: "minecraft:lava", data: generic_damage},
+        %{id: "minecraft:cramming", data: generic_damage},
+        %{id: "minecraft:drown", data: generic_damage},
+        %{id: "minecraft:starve", data: generic_damage},
+        %{id: "minecraft:cactus", data: generic_damage},
+        %{id: "minecraft:fall", data: generic_damage},
+        %{id: "minecraft:fly_into_wall", data: generic_damage},
+        %{id: "minecraft:out_of_world", data: generic_damage},
+        %{id: "minecraft:generic", data: generic_damage},
+        %{id: "minecraft:magic", data: generic_damage},
+        %{id: "minecraft:wither", data: generic_damage},
+        %{id: "minecraft:dragon_breath", data: generic_damage},
+        %{id: "minecraft:dry_out", data: generic_damage},
+        %{id: "minecraft:sweet_berry_bush", data: generic_damage},
+        %{id: "minecraft:freeze", data: generic_damage},
+        %{id: "minecraft:stalagmite", data: generic_damage},
+        %{id: "minecraft:outside_border", data: generic_damage},
+        %{id: "minecraft:generic_kill", data: generic_damage},
+      ]
+    }})
+    send(self(), {:send_packet, %{packet_type: :finish_configuration}})
+    :ok
+  end
+
+  def handle(%{packet_type: :acknowledge_finish_configuration}, 767, state) do
+    Logger.debug("Received acknowledge finish configuration")
+    send(self(), {:set_state, Amethyst.ConnectionState.Play})
+    game = Application.fetch_env!(:amethyst, :default_game) |> Amethyst.GameCoordinator.find_or_create()
+    state = state |> Map.put(:game, game)
+    if Amethyst.Api.Game.login(game, state) == :reject do
+      send(self(), {:disconnect, "Default game rejected connection"})
+    else
+      send(self(), {:send_packet, %{
+        packet_type: :login,
+        entity_id: 0,
+        is_hardcore: false,
+        dimensions: [%{name: "minecraft:overworld"}],
+        max_players: 0,
+        view_distance: 16,
+        simulation_distance: 16,
+        reduced_debug_info: false,
+        enable_respawn_screen: true,
+        do_limited_crafting: false,
+        dimension_type: 0,
+        dimension_name: "minecraft:overworld",
+        hashed_seed: 0,
+        game_mode: 3,
+        previous_game_mode: -1,
+        is_debug: false,
+        is_flat: false,
+        death_location: nil,
+        portal_cooldown: 0,
+        enforces_secure_chat: false
+      }})
+    end
+  end
+
   def disconnect(reason) do
     %{packet_type: :disconnect, reason: {:compound, %{
       "text" => {:string, reason}

apps/amethyst/lib/states/macros.ex

@@ -39,6 +39,14 @@ defmodule Amethyst.ConnectionState.Macros do
     names = Enum.map(signature, fn {name, _type} -> name end)
     {got, rest} = Enum.reduce(signature, Read.start(data), fn {_name, type}, {acc, rest, :reversed} ->
       case type do
+        {:optional, {:compound, signature}} ->
+          {[exists], rest} = Read.start(rest) |> Read.bool() |> Read.stop()
+          if exists do
+            {item, rest} = read_signature(rest, signature)
+            {[item | acc], rest, :reversed}
+          else
+            {[nil | acc], rest, :reversed}
+          end
         {:optional, t} ->
           {[exists], rest} = Read.start(rest) |> Read.bool() |> Read.stop()
           if exists do
@@ -64,6 +72,11 @@ defmodule Amethyst.ConnectionState.Macros do
     data = Enum.reduce(signature, "", fn {name, type}, acc ->
       #acc <> apply(Write, type, [Map.get(packet, name)])
       case type do
+        {:optional, {:compound, signature}} ->
+          case Map.get(packet, name) do
+            nil -> acc <> Write.bool(false)
+            _ -> acc <> Write.bool(true) <> write_signature(Map.get(packet, name), signature)
+          end
         {:optional, t} ->
           case Map.get(packet, name) do
             nil -> acc <> Write.bool(false)

apps/amethyst/lib/states/play.ex

@@ -0,0 +1,61 @@
+# Amethyst - An experimental Minecraft server written in Elixir.
+# Copyright (C) 2024 KodiCraft
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+defmodule Amethyst.ConnectionState.Play do
+  require Amethyst.ConnectionState.Macros
+  alias Amethyst.ConnectionState.Macros
+
+  require Logger
+
+  @moduledoc """
+  This module contains the packets and logic for the Play state.
+  """
+
+  Macros.defpacket_clientbound :disconnect, 0x1D, 767, [reason: :nbt]
+  Macros.defpacket_clientbound :login, 0x2B, 767, [
+    entity_id: :int,
+    is_hardcore: :bool,
+    dimensions: {:array, [name: :string]},
+    max_players: :varint,
+    view_distance: :varint,
+    simulation_distance: :varint,
+    reduced_debug_info: :bool,
+    enable_respawn_screen: :bool,
+    do_limited_crafting: :bool,
+    dimension_type: :varint,
+    dimension_name: :string,
+    hashed_seed: :long,
+    game_mode: :ubyte,
+    previous_game_mode: :byte,
+    is_debug: :bool,
+    is_flat: :bool,
+    death_location: {:optional, {:compound, [
+      dimension: :string,
+      location: :pos
+    ]}},
+    portal_cooldown: :varint,
+    enforces_secure_chat: :bool,
+  ]
+
+  def disconnect(reason) do
+    %{
+      packet_type: :disconnect,
+      reason: {:compound, %{
+        "text" => {:string, reason}
+      }}
+    }
+  end
+end