Check if all players have the game before starting netplay

https://bugs.dolphin-emu.org/issues/8885

Source/Core/Core/NetPlayClient.cpp

@@ -356,6 +356,33 @@ unsigned int NetPlayClient::OnData(sf::Packet& packet)
 
     // update gui
     m_dialog->OnMsgChangeGame(m_selected_game);
+
+    sf::Packet spac;
+    spac << static_cast<MessageId>(NP_MSG_GAME_STATUS);
+
+    PlayerGameStatus status = m_dialog->FindGame(m_selected_game).empty() ?
+                                  PlayerGameStatus::NotFound :
+                                  PlayerGameStatus::Ok;
+
+    spac << static_cast<u32>(status);
+    Send(spac);
+  }
+  break;
+
+  case NP_MSG_GAME_STATUS:
+  {
+    PlayerId pid;
+    packet >> pid;
+
+    {
+      std::lock_guard<std::recursive_mutex> lkp(m_crit.players);
+      Player& player = m_players[pid];
+      u32 status;
+      packet >> status;
+      player.game_status = static_cast<PlayerGameStatus>(status);
+    }
+
+    m_dialog->Update();
   }
   break;
 
@@ -597,7 +624,26 @@ void NetPlayClient::GetPlayerList(std::string& list, std::vector<int>& pid_list)
     enumerate_player_controller_mappings(m_pad_map, player);
     enumerate_player_controller_mappings(m_wiimote_map, player);
 
-    ss << " |\nPing: " << player.ping << "ms\n\n";
+    ss << " |\nPing: " << player.ping << "ms\n";
+    ss << "Status: ";
+
+    switch (player.game_status)
+    {
+    case PlayerGameStatus::Ok:
+      ss << "ready";
+      break;
+
+    case PlayerGameStatus::NotFound:
+      ss << "game missing";
+      break;
+
+    default:
+      ss << "unknown";
+      break;
+    }
+
+    ss << "\n\n";
+
     pid_list.push_back(player.pid);
   }
 
@@ -1143,6 +1189,14 @@ void NetPlayClient::SendTimeBase()
   netplay_client->SendAsync(std::move(spac));
 }
 
+bool NetPlayClient::DoAllPlayersHaveGame()
+{
+  std::lock_guard<std::recursive_mutex> lkp(m_crit.players);
+
+  return std::all_of(std::begin(m_players), std::end(m_players),
+                     [](auto entry) { return entry.second.game_status == PlayerGameStatus::Ok; });
+}
+
 // stuff hacked into dolphin
 
 // called from ---CPU--- thread

Source/Core/Core/NetPlayClient.h

@@ -33,6 +33,14 @@ public:
   virtual void OnMsgStartGame() = 0;
   virtual void OnMsgStopGame() = 0;
   virtual bool IsRecording() = 0;
+  virtual std::string FindGame(const std::string& game) = 0;
+};
+
+enum class PlayerGameStatus
+{
+  Unknown,
+  Ok,
+  NotFound
 };
 
 class Player
@@ -42,6 +50,7 @@ public:
   std::string name;
   std::string revision;
   u32 ping;
+  PlayerGameStatus game_status;
 };
 
 class NetPlayClient : public TraversalClientClient
@@ -83,6 +92,7 @@ public:
   u8 LocalWiimoteToInGameWiimote(u8 local_pad);
 
   static void SendTimeBase();
+  bool DoAllPlayersHaveGame();
 
 protected:
   void ClearBuffers();

Source/Core/Core/NetPlayProto.h

@@ -53,6 +53,7 @@ enum
   NP_MSG_CHANGE_GAME = 0xA1,
   NP_MSG_STOP_GAME = 0xA2,
   NP_MSG_DISABLE_GAME = 0xA3,
+  NP_MSG_GAME_STATUS = 0xA4,
 
   NP_MSG_TIMEBASE = 0xB0,
   NP_MSG_DESYNC_DETECTED = 0xB1,

Source/Core/Core/NetPlayServer.cpp

@@ -318,9 +318,14 @@ unsigned int NetPlayServer::OnConnect(ENetPeer* socket)
   for (const auto& p : m_players)
   {
     spac.clear();
-    spac << (MessageId)NP_MSG_PLAYER_JOIN;
+    spac << static_cast<MessageId>(NP_MSG_PLAYER_JOIN);
     spac << p.second.pid << p.second.name << p.second.revision;
     Send(player.socket, spac);
+
+    spac.clear();
+    spac << static_cast<MessageId>(NP_MSG_GAME_STATUS);
+    spac << p.second.pid << static_cast<u32>(p.second.game_status);
+    Send(player.socket, spac);
   }
 
   // add client to the player list
@@ -592,6 +597,23 @@ unsigned int NetPlayServer::OnData(sf::Packet& packet, Client& player)
   }
   break;
 
+  case NP_MSG_GAME_STATUS:
+  {
+    u32 status;
+    packet >> status;
+
+    m_players[player.pid].game_status = static_cast<PlayerGameStatus>(status);
+
+    // send msg to other clients
+    sf::Packet spac;
+    spac << static_cast<MessageId>(NP_MSG_GAME_STATUS);
+    spac << player.pid;
+    spac << status;
+
+    SendToClients(spac);
+  }
+  break;
+
   case NP_MSG_TIMEBASE:
   {
     u32 x, y, frame;

Source/Core/Core/NetPlayServer.h

@@ -17,6 +17,8 @@
 #include "Common/TraversalClient.h"
 #include "Core/NetPlayProto.h"
 
+enum class PlayerGameStatus;
+
 class NetPlayUI;
 
 class NetPlayServer : public TraversalClientClient
@@ -64,6 +66,7 @@ private:
     PlayerId pid;
     std::string name;
     std::string revision;
+    PlayerGameStatus game_status;
 
     ENetPeer* socket;
     u32 ping;

Source/Core/DolphinWX/NetPlay/NetWindow.cpp

@@ -288,19 +288,33 @@ void NetPlayDialog::GetNetSettings(NetSettings& settings)
   settings.m_EXIDevice[1] = instance.m_EXIDevice[1];
 }
 
-std::string NetPlayDialog::FindGame()
+std::string NetPlayDialog::FindGame(const std::string& target_game)
 {
   // find path for selected game, sloppy..
   for (u32 i = 0; auto game = m_game_list->GetISO(i); ++i)
-    if (m_selected_game == BuildGameName(*game))
+    if (target_game == BuildGameName(*game))
       return game->GetFileName();
 
-  WxUtils::ShowErrorDialog(_("Game not found!"));
   return "";
 }
 
+std::string NetPlayDialog::FindCurrentGame()
+{
+  return FindGame(m_selected_game);
+}
+
 void NetPlayDialog::OnStart(wxCommandEvent&)
 {
+  bool should_start = true;
+  if (!netplay_client->DoAllPlayersHaveGame())
+  {
+    should_start = wxMessageBox(_("Not all players have the game. Do you really want to start?"),
+                                _("Warning"), wxYES_NO) == wxYES;
+  }
+
+  if (!should_start)
+    return;
+
   NetSettings settings;
   GetNetSettings(settings);
   netplay_server->SetNetSettings(settings);
@@ -442,7 +456,11 @@ void NetPlayDialog::OnThread(wxThreadEvent& event)
   case NP_GUI_EVT_START_GAME:
     // client start game :/
     {
-      netplay_client->StartGame(FindGame());
+      std::string game = FindCurrentGame();
+      if (game.empty())
+        WxUtils::ShowErrorDialog(_("Game not found!"));
+      else
+        netplay_client->StartGame(game);
     }
     break;
   case NP_GUI_EVT_STOP_GAME:

Source/Core/DolphinWX/NetPlay/NetWindow.h

@@ -73,7 +73,8 @@ private:
   void OnKick(wxCommandEvent& event);
   void OnPlayerSelect(wxCommandEvent& event);
   void GetNetSettings(NetSettings& settings);
-  std::string FindGame();
+  std::string FindCurrentGame();
+  std::string FindGame(const std::string& game);
 
   void OnCopyIP(wxCommandEvent&);
   void OnChoice(wxCommandEvent& event);