Some experimentation

apps/amethyst/lib/apps/connection_handler.ex

@@ -126,7 +126,7 @@ defmodule Amethyst.ConnectionHandler do
     import Amethyst.NBT.Write
     alias Amethyst.Minecraft.Write
 
-    chunk_array = Amethyst.API.Game.chunk(Map.get(state, :game), chunk)
+    chunk_array = Amethyst.Game.chunk(Map.get(state, :game), chunk)
     {cx, cz} = chunk
 
     # TODO: Actually do heightmaps
@@ -227,8 +227,12 @@ defmodule Amethyst.ConnectionHandler do
       end
     rescue
       e ->
+        if Mix.env() == :dev do
           Logger.error("Error handling packet with ID #{inspect(id, base: :hex)} in state #{connstate}: #{Exception.format(:error, e, __STACKTRACE__)}")
+        else
           send(self(), {:disconnect, "§cError handling packet #{inspect(id, base: :hex)}:\n#{Exception.format(:error, e, __STACKTRACE__)}"})
+          Logger.error("Error handling packet with ID #{inspect(id, base: :hex)} in state #{connstate}: #{Exception.format(:error, e, __STACKTRACE__)}")
+        end
         state
     end
   end

apps/amethyst/lib/game.ex

@@ -14,7 +14,7 @@
 # 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.API.Game do
+defmodule Amethyst.Game do
   @moduledoc """
   This behaviour should be implemented by any Amethyst Game. It additionally
   contains functions that the internal connection handler code uses to more

apps/amethyst/lib/states/configuration.ex

@@ -271,7 +271,7 @@ defmodule Amethyst.ConnectionState.Configuration do
     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)
-    login = Amethyst.API.Game.login(game, state)
+    login = Amethyst.Game.login(game, state)
     case login do
       :reject ->
         send(self(), {:disconnect, "Default game rejected connection"})
@@ -291,7 +291,7 @@ defmodule Amethyst.ConnectionState.Configuration do
           dimension_type: 0,
           dimension_name: "minecraft:overworld",
           hashed_seed: 0,
-          game_mode: 3,
+          game_mode: 1,
           previous_game_mode: -1,
           is_debug: false,
           is_flat: false,

apps/amethyst/lib/states/play.ex

@@ -176,31 +176,60 @@ defmodule Amethyst.ConnectionState.Play do
     pitch: :float,
     on_ground: :bool # I don't understand their obsession with this...
   ]
+  Macros.defpacket_serverbound :set_player_on_ground, 0x1D, 767, [on_ground: :bool]
+  Macros.defpacket_serverbound :player_command, 0x25, 767, [eid: :varint, action_id: :varint, jump_boost: :varint]
 
   def handle(%{packet_type: :confirm_teleportation, teleport_id: id}, 767, state) do
-    Amethyst.API.Game.accept_teleport(state[:game], id)
+    Amethyst.Game.accept_teleport(state[:game], id)
     :ok
   end
 
   def handle(%{packet_type: :set_player_position_and_rotation, x: x, feet_y: y, z: z, yaw: yaw, pitch: pitch, on_ground: _ground}, 767, state) do
     # I don't know why we would ever trust on_ground here... the server computes that
-    Amethyst.API.Game.player_position(state[:game], {x, y, z})
-    Amethyst.API.Game.player_rotation(state[:game], {yaw, pitch})
-    :ok
-  end
-  def handle(%{packet_type: :set_player_position, x: x, feet_y: y, z: z, on_ground: _ground}, 767, state) do
-    # I don't know why we would ever trust on_ground here... the server computes that
-    Amethyst.API.Game.player_position(state[:game], {x, y, z})
-    :ok
-  end
-  def handle(%{packet_type: :set_player_rotation, yaw: yaw, pitch: pitch, on_ground: _ground}, 767, state) do
-    # I don't know why we would ever trust on_ground here... the server computes that
-    Amethyst.API.Game.player_rotation(state[:game], {yaw, pitch})
+    Amethyst.Game.player_position(state[:game], {x, y, z})
+    Amethyst.Game.player_rotation(state[:game], {yaw, pitch})
     :ok
   end
   def handle(%{packet_type: :serverbound_plugin_message, channel: channel, data: _}, 767, _state) do
     Logger.debug("Got plugin message on #{channel}")
   end
+  def handle(%{packet_type: :set_player_position, x: x, feet_y: y, z: z, on_ground: _ground}, 767, state) do
+    # I don't know why we would ever trust on_ground here... the server computes that
+    Amethyst.Game.player_position(state[:game], {x, y, z})
+    :ok
+  end
+  def handle(%{packet_type: :set_player_rotation, yaw: yaw, pitch: pitch, on_ground: _ground}, 767, state) do
+    # I don't know why we would ever trust on_ground here... the server computes that
+    Amethyst.Game.player_rotation(state[:game], {yaw, pitch})
+    :ok
+  end
+  def handle(%{packet_type: :set_player_on_ground, on_ground: _}, 767, _state) do
+    :ok # Again, don't trust the client for something we can compute
+  end
+  def handle(%{packet_type: :player_command, eid: _eid, action_id: aid, jump_boost: _horse_jump}, 767, state) do
+    # TODO: Actually handle these events
+    case aid do
+      0 -> # Start sneaking
+      :ok
+      1 -> # Stop sneaking
+      :ok
+      2 -> # Leave bed
+      :ok
+      3 -> # Start sprinting
+      :ok
+      4 -> # Stop sprinting
+      :ok
+      5 -> # Start horse jump
+      :ok
+      6 -> # Stop horse jump
+      :ok
+      7 -> # Open vehicle inventory
+      :ok
+      8 -> # Start elytra flying
+      :ok
+      _ -> raise RuntimeError, "Unknown Player Command Action ID"
+    end
+  end
 
   def disconnect(reason) do
     %{

apps/amethyst/test/game_coordinator_test.exs

@@ -1,5 +1,5 @@
 defmodule GameCoordinatorTestGame do
-  @behaviour Amethyst.API.Game
+  @behaviour Amethyst.Game
 
   @moduledoc """
   This module is a sample game for the purpose of

apps/example_game/lib/example/game.ex

@@ -1,6 +1,6 @@
 defmodule Example.Game do
   require Logger
-  @behaviour Amethyst.API.Game
+  @behaviour Amethyst.Game
 
   @impl true
   def instantiate(supervisor) do
@@ -40,7 +40,7 @@ defmodule Example.Game do
   end
 
   @impl true
-  def chunk(from, {x, z}, _state_refs) do
+  def chunk(_from, {_x, _z}, _state_refs) do
     # Logger.info("Player at #{inspect(from)} wants to know chunk #{x}, #{z}")
     (0..255) |> Enum.map(fn y ->
       if y < 5 do
@@ -49,7 +49,7 @@ defmodule Example.Game do
         end)
       else
         (0..15) |> Enum.map(fn _z ->
-          (0..15) |> Enum.map(fn _x -> 0 end)
+          (0..15) |> Enum.map(fn _x -> 1 end)
         end)
       end
     end)