Make vertices diffable

apps/arena/lib/arena/game_updater.ex

@@ -770,6 +770,7 @@ defmodule Arena.GameUpdater do
   defp complete_entity(entity, category) do
     Map.update(entity, :category, nil, &to_string/1)
     |> Map.update(:shape, nil, &to_string/1)
+    |> Map.update(:vertices, nil, fn vertices -> %{positions: vertices} end)
     |> Map.put(:aditional_info, Entities.maybe_add_custom_info(Map.put(entity, :category, category)))
   end
 
@@ -1911,6 +1912,8 @@ defmodule Arena.GameUpdater do
     ## Following somen discussions we are going to have special handling for certain cases and essentially
     ## check the lists for exact matches (returning :no_diff) or for differences (returning the entire new list)
     case {old, new} do
+      ## TODO: to enable this we need a fix similar to the ListPositionPB in protobuf for the other fields
+      #
       # ## Lists of the same scalars we can compare directly. One assumption we currently do here is that lists
       # ## are homogeneous, all elements are of same type (they should, but FYI)
       # {[elem | _], [elem | _]} when is_atom(elem) or is_binary(elem) or is_boolean(elem) or is_number(elem) ->
@@ -1919,14 +1922,15 @@ defmodule Arena.GameUpdater do
       #     false -> {:ok, new}
       #   end
 
-      # ## Lists containing %{x: _, y: _} are treated as points (vertices) and this case we know we can
-      # ## do ===/2 comparison and it will verify the exactness. At the moment we don't want to do this
-      # ## for all lists of maps cause the exactness of this comparison of maps hasn't been verified by us
-      # {[%{x: _, y: _} | _], [%{x: _, y: _} | _]} ->
-      #   case old === new do
-      #     true -> :no_diff
-      #     false -> {:ok, new}
-      #   end
+      ## Lists containing %{x: _, y: _} are treated as points (vertices) and this case we know we can
+      ## do ===/2 comparison and it will verify the exactness. At the moment we don't want to do this
+      ## for all lists of maps cause the exactness of this comparison of maps hasn't been
+      ## verified (is it a deep === comparison for all keys and values?) and we don't know the performance impact
+      {[%{x: _, y: _} | _], [%{x: _, y: _} | _]} ->
+        case old === new do
+          true -> :no_diff
+          false -> {:ok, new}
+        end
 
       ## Anything else we still consider to risky to try and compare, so we return the new list
       _ ->

apps/arena/lib/arena/serialization/messages.pb.ex

@@ -90,6 +90,14 @@ defmodule Arena.Serialization.Position do
   field :y, 2, proto3_optional: true, type: :float
 end
 
+defmodule Arena.Serialization.ListPositionPB do
+  @moduledoc false
+
+  use Protobuf, syntax: :proto3, protoc_gen_elixir_version: "0.12.0"
+
+  field :positions, 1, repeated: true, type: Arena.Serialization.Position
+end
+
 defmodule Arena.Serialization.LobbyEvent do
   @moduledoc false
 
@@ -478,7 +486,7 @@ defmodule Arena.Serialization.Entity do
   field :name, 4, proto3_optional: true, type: :string
   field :position, 5, type: Arena.Serialization.Position
   field :radius, 6, proto3_optional: true, type: :float
-  field :vertices, 7, repeated: true, type: Arena.Serialization.Position
+  field :vertices, 7, proto3_optional: true, type: Arena.Serialization.ListPositionPB
   field :collides_with, 8, repeated: true, type: :uint64, json_name: "collidesWith"
   field :speed, 9, proto3_optional: true, type: :float
   field :direction, 10, type: Arena.Serialization.Direction

apps/serialization/messages.proto

@@ -20,6 +20,10 @@ message Position {
   optional float y = 2;
 }
 
+message ListPositionPB {
+  repeated Position positions = 1;
+}
+
 message LobbyEvent {
   oneof event {
     LeaveLobby leave = 1;
@@ -178,7 +182,7 @@ message Entity {
   optional string name = 4;
   Position position = 5;
   optional float radius = 6;
-  repeated Position vertices = 7;
+  optional ListPositionPB vertices = 7;
   repeated uint64 collides_with = 8;
   optional float speed = 9;
   Direction direction = 10;