Netplay: Improve disconnection handling

src/common/windows_headers.h

@@ -27,3 +27,6 @@
 #if defined(DeleteFile)
 #undef DeleteFile
 #endif
+#if defined(GetMessage)
+#undef GetMessage
+#endif

src/core/netplay.h

@@ -9,8 +9,15 @@ enum : s32
 {
   // Maximum number of emulated controllers.
   MAX_PLAYERS = 2,
+
   // Maximum netplay prediction frames
   MAX_ROLLBACK_FRAMES = 8,
+
+  // Maximum length of a nickname
+  MAX_NICKNAME_LENGTH = 128,
+
+  // Maximum name of password for session
+  MAX_SESSION_PASSWORD_LENGTH = 128,
 };
 
 enum : u8
@@ -29,14 +36,14 @@ bool IsActive();
 
 /// Frees up resources associated with the current netplay session.
 /// Should only be called by System::ShutdownSystem().
-void CloseSession();
+void SystemDestroyed();
 
 /// Runs the VM and netplay loop. when the netplay loop cancels it switches to normal execute mode.
 void ExecuteNetplay();
 
 void CollectInput(u32 slot, u32 bind, float value);
 
-void SendMsg(std::string msg);
+void SendChatMessage(const std::string_view& msg);
 
 s32 GetPing();
 u32 GetMaxPrediction();

src/core/netplay_packets.h

@@ -0,0 +1,241 @@
+// SPDX-FileCopyrightText: 2023 Connor McLaughlin <stenzek@gmail.com> and contributors.
+// SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
+
+#pragma once
+
+#include "host.h"
+#include "types.h"
+
+#include "fmt/format.h"
+
+namespace Netplay {
+
+enum class SessionState
+{
+  Inactive,
+  Initializing,
+  Connecting,
+  Resetting,
+  Running,
+  ClosingSession,
+};
+
+enum class ControlMessage : u32
+{
+  // host->player
+  ConnectResponse,
+  Reset,
+  ResumeSession,
+  PlayerJoined,
+  DropPlayer,
+  CloseSession,
+
+  // player->host
+  ConnectRequest,
+  ResetComplete,
+  ResetRequest,
+
+  // bi-directional
+  SetNickname,
+  ChatMessage,
+};
+
+enum class DropPlayerReason : u32
+{
+  ConnectTimeout,
+  DisconnectedFromHost,
+};
+
+#pragma pack(push, 1)
+struct ControlMessageHeader
+{
+  ControlMessage type;
+  u32 size;
+};
+
+struct ConnectRequestMessage
+{
+  enum class Mode
+  {
+    Player,
+    Spectator,
+  };
+
+  ControlMessageHeader header;
+
+  Mode mode;
+  s32 requested_player_id;
+  char nickname[MAX_NICKNAME_LENGTH];
+  char session_password[MAX_SESSION_PASSWORD_LENGTH];
+
+  std::string_view GetNickname() const
+  {
+    const size_t len = strnlen(nickname, std::size(nickname));
+    return std::string_view(nickname, len);
+  }
+
+  std::string_view GetSessionPassword() const
+  {
+    const size_t len = strnlen(session_password, std::size(session_password));
+    return std::string_view(session_password, len);
+  }
+
+  static ControlMessage MessageType() { return ControlMessage::ConnectRequest; }
+};
+
+struct ConnectResponseMessage
+{
+  enum class Result : u32
+  {
+    Success = 0,
+    ServerFull,
+    PlayerIDInUse,
+    SessionClosed,
+  };
+
+  ControlMessageHeader header;
+
+  Result result;
+  s32 player_id;
+
+  static ControlMessage MessageType() { return ControlMessage::ConnectResponse; }
+};
+
+struct ResetMessage
+{
+  struct PlayerAddress
+  {
+    u32 host;
+    u16 port;
+    s16 controller_port; // -1 if not present
+    char nickname[MAX_NICKNAME_LENGTH];
+
+    std::string_view GetNickname() const
+    {
+      const size_t len = strnlen(nickname, std::size(nickname));
+      return std::string_view(nickname, len);
+    }
+  };
+
+  ControlMessageHeader header;
+  u32 cookie;
+  s32 num_players;
+  PlayerAddress players[MAX_PLAYERS];
+  u32 state_data_size;
+  // state_data_size bytes of state data follows
+
+  static ControlMessage MessageType() { return ControlMessage::Reset; }
+};
+
+struct ResetCompleteMessage
+{
+  ControlMessageHeader header;
+
+  u32 cookie;
+
+  static ControlMessage MessageType() { return ControlMessage::ResetComplete; }
+};
+
+struct ResumeSessionMessage
+{
+  ControlMessageHeader header;
+
+  static ControlMessage MessageType() { return ControlMessage::ResumeSession; }
+};
+
+struct PlayerJoinedMessage
+{
+  ControlMessageHeader header;
+  s32 player_id;
+
+  static ControlMessage MessageType() { return ControlMessage::PlayerJoined; }
+};
+
+struct DropPlayerMessage
+{
+  ControlMessageHeader header;
+  DropPlayerReason reason;
+  s32 player_id;
+
+  static ControlMessage MessageType() { return ControlMessage::DropPlayer; }
+};
+
+struct ResetRequestMessage
+{
+  enum class Reason : u32
+  {
+    ConnectionLost,
+  };
+
+  ControlMessageHeader header;
+  Reason reason;
+  s32 causing_player_id;
+
+  std::string ReasonToString() const
+  {
+    switch (reason)
+    {
+      case Reason::ConnectionLost:
+        return fmt::format(Host::TranslateString("Netplay", "Connection lost to player {}.").GetCharArray(),
+                           causing_player_id);
+      default:
+        return "Unknown";
+    }
+  }
+
+  static ControlMessage MessageType() { return ControlMessage::ResetRequest; }
+};
+
+struct CloseSessionMessage
+{
+  enum class Reason : u32
+  {
+    HostRequest,
+    HostShutdown,
+  };
+
+  ControlMessageHeader header;
+  Reason reason;
+
+  std::string ReasonToString() const
+  {
+    switch (reason)
+    {
+      case Reason::HostRequest:
+        return Host::TranslateStdString("Netplay", "Session closed due to host request.");
+
+      case Reason::HostShutdown:
+        return Host::TranslateStdString("Netplay", "Session closed due to host shutdown.");
+
+      default:
+        return "Unknown";
+    }
+  }
+
+  static ControlMessage MessageType() { return ControlMessage::CloseSession; }
+};
+
+struct SetNicknameMessage
+{
+  ControlMessageHeader header;
+
+  static ControlMessage MessageType() { return ControlMessage::SetNickname; }
+};
+
+struct ChatMessage
+{
+  ControlMessageHeader header;
+
+  std::string_view GetMessage() const
+  {
+    return (header.size > sizeof(ChatMessage)) ?
+             std::string_view(reinterpret_cast<const char*>(this) + sizeof(ChatMessage),
+                              header.size - sizeof(ChatMessage)) :
+             std::string_view();
+  }
+
+  static ControlMessage MessageType() { return ControlMessage::ChatMessage; }
+};
+#pragma pack(pop)
+
+} // namespace Netplay

src/core/system.cpp

@@ -3757,7 +3757,7 @@ void System::ShutdownSystem(bool save_resume_state)
     return;
 
   if (Netplay::IsActive())
-    Netplay::CloseSession();
+    Netplay::SystemDestroyed();
 
   if (save_resume_state)
     SaveResumeState();

src/duckstation-qt/qthost.cpp

@@ -2227,6 +2227,9 @@ int main(int argc, char* argv[])
   {
     Host::RunOnCPUThread([]() {
       const bool first = (s_netplay_test == 0);
+      if (!first)
+        QtHost::RunOnUIThread([]() { g_main_window->move(g_main_window->pos() + QPoint(500, 0)); });
+
       const int h = first ? 1 : 2;
       const int nh = first ? 2 : 1;
       const int port_base = 31200;

src/frontend-common/imgui_netplay.cpp

@@ -97,7 +97,7 @@ void ImGuiManager::DrawNetplayMessages()
   const float spacing = 5.0f * scale;
   const float msg_spacing = 2.0f * scale;
   ImFont* font = ImGuiManager::GetFixedFont();
-  float position_y = io.DisplaySize.y - margin - ((spacing + font->FontSize) * 2.0f) - font->FontSize;
+  float position_y = io.DisplaySize.y - margin - (100.0f * scale) - font->FontSize - spacing;
   ImDrawList* dl = ImGui::GetBackgroundDrawList();
 
   // drop expired messages.. because of the reverse iteration below, we can't do it in there :/
@@ -121,11 +121,9 @@ void ImGuiManager::DrawNetplayMessages()
     const char* text_end = text_start + iter->first.length();
     const ImVec2 text_size = font->CalcTextSizeA(font->FontSize, io.DisplaySize.x, 0.0f, text_start, text_end, nullptr);
 
-    dl->AddText(font, font->FontSize,
-                ImVec2(ImGui::GetIO().DisplaySize.x - margin - text_size.x + shadow_offset, position_y + shadow_offset),
+    dl->AddText(font, font->FontSize, ImVec2(margin + shadow_offset, position_y + shadow_offset),
                 IM_COL32(0, 0, 0, shadow_alpha), text_start, text_end);
-    dl->AddText(font, font->FontSize, ImVec2(ImGui::GetIO().DisplaySize.x - margin - text_size.x, position_y),
-                IM_COL32(255, 255, 255, alpha), text_start, text_end);
+    dl->AddText(font, font->FontSize, ImVec2(margin, position_y), IM_COL32(255, 255, 255, alpha), text_start, text_end);
 
     position_y -= text_size.y + msg_spacing;
   }
@@ -144,16 +142,13 @@ void ImGuiManager::DrawNetplayStats()
   const float margin = 10.0f * scale;
   const float spacing = 5.0f * scale;
   ImFont* font = ImGuiManager::GetFixedFont();
-  const float position_y = ImGui::GetIO().DisplaySize.y - margin - font->FontSize - spacing - font->FontSize;
+  const float position_y = ImGui::GetIO().DisplaySize.y - margin - (100.0f * scale);
 
   ImDrawList* dl = ImGui::GetBackgroundDrawList();
-  ImVec2 text_size = font->CalcTextSizeA(font->FontSize, std::numeric_limits<float>::max(), -1.0f, text,
-                                         text.GetCharArray() + text.GetLength(), nullptr);
-  dl->AddText(font, font->FontSize,
-              ImVec2(ImGui::GetIO().DisplaySize.x - margin - text_size.x + shadow_offset, position_y + shadow_offset),
-              IM_COL32(0, 0, 0, 100), text, text.GetCharArray() + text.GetLength());
-  dl->AddText(font, font->FontSize, ImVec2(ImGui::GetIO().DisplaySize.x - margin - text_size.x, position_y),
-              IM_COL32(255, 255, 255, 255), text, text.GetCharArray() + text.GetLength());
+  dl->AddText(font, font->FontSize, ImVec2(margin + shadow_offset, position_y + shadow_offset), IM_COL32(0, 0, 0, 100),
+              text, text.GetCharArray() + text.GetLength());
+  dl->AddText(font, font->FontSize, ImVec2(margin, position_y), IM_COL32(255, 255, 255, 255), text,
+              text.GetCharArray() + text.GetLength());
 }
 
 void ImGuiManager::DrawNetplayChatDialog()
@@ -178,7 +173,7 @@ void ImGuiManager::DrawNetplayChatDialog()
 
   // sending netplay message
   if (send_message && !s_netplay_chat_message.empty())
-    Netplay::SendMsg(s_netplay_chat_message);
+    Netplay::SendChatMessage(s_netplay_chat_message);
 
   const ImGuiIO& io = ImGui::GetIO();
   const ImGuiStyle& style = ImGui::GetStyle();