Rework (preloader) scene completion functionality (#22122)

* Remove the need for Scene::GetCompletionScene

* Replace SetCompletionScene with SetOnComplete

* Normalise return type for GetPreloaderScene

* Rename 'onFinish' to 'onComplete' for consistency

src/openrct2/Context.cpp

@@ -310,9 +310,7 @@ namespace OpenRCT2
             return EXIT_FAILURE;
         }
 
-        // NB: This takes some liberty in returning PreloaderScene* instead of IScene*.
-        // PreloaderScene adds some methods to Scene, which are used internally by Context.
-        PreloaderScene* GetPreloaderScene() override
+        IScene* GetPreloaderScene() override
         {
             if (auto* scene = _preloaderScene.get())
                 return scene;
@@ -520,7 +518,7 @@ namespace OpenRCT2
 
             if (!gOpenRCT2Headless)
             {
-                auto* preloaderScene = GetPreloaderScene();
+                auto* preloaderScene = static_cast<PreloaderScene*>(GetPreloaderScene());
                 SetActiveScene(preloaderScene);
 
                 // TODO: preload the title scene in another (parallel) job.
@@ -573,10 +571,7 @@ namespace OpenRCT2
             OpenProgress(STR_CHECKING_TITLE_SEQUENCES);
             TitleSequenceManager::Scan();
 
-            if (GetPreloaderScene()->GetCompletionScene() == GetTitleScene())
-                OpenProgress(STR_LOADING_TITLE_SEQUENCE);
-            else
-                OpenProgress(STR_LOADING_GENERIC);
+            OpenProgress(STR_LOADING_GENERIC);
         }
 
     public:
@@ -975,7 +970,7 @@ namespace OpenRCT2
             return true;
         }
 
-        IScene* DetermineStartUpScene()
+        void SwitchToStartUpScene()
         {
             if (gOpenRCT2Headless)
             {
@@ -993,16 +988,19 @@ namespace OpenRCT2
                 }
             }
 
+            IScene* nextScene{};
             switch (gOpenRCT2StartupAction)
             {
                 case StartupAction::Intro:
                 {
-                    return GetIntroScene();
+                    nextScene = GetIntroScene();
+                    break;
                 }
 
                 case StartupAction::Title:
                 {
-                    return GetTitleScene();
+                    nextScene = GetTitleScene();
+                    break;
                 }
 
                 case StartupAction::Open:
@@ -1016,14 +1014,16 @@ namespace OpenRCT2
                         auto data = DownloadPark(gOpenRCT2StartupActionPath);
                         if (data.empty())
                         {
-                            return GetTitleScene();
+                            nextScene = GetTitleScene();
+                            break;
                         }
 
                         auto ms = MemoryStream(data.data(), data.size(), MEMORY_ACCESS::READ);
                         if (!LoadParkFromStream(&ms, gOpenRCT2StartupActionPath, true))
                         {
                             Console::Error::WriteLine("Failed to load '%s'", gOpenRCT2StartupActionPath);
-                            return GetTitleScene();
+                            nextScene = GetTitleScene();
+                            break;
                         }
 #endif
                     }
@@ -1033,67 +1033,55 @@ namespace OpenRCT2
                         {
                             if (!LoadParkFromFile(gOpenRCT2StartupActionPath, true))
                             {
-                                return GetTitleScene();
+                                nextScene = GetTitleScene();
+                                break;
                             }
                         }
                         catch (const std::exception& ex)
                         {
                             Console::Error::WriteLine("Failed to load '%s'", gOpenRCT2StartupActionPath);
                             Console::Error::WriteLine("%s", ex.what());
-                            return GetTitleScene();
+                            nextScene = GetTitleScene();
+                            break;
                         }
                     }
 
                     // Successfully loaded a file
-                    return GetGameScene();
+                    nextScene = GetGameScene();
+                    break;
                 }
+
                 case StartupAction::Edit:
                 {
                     if (String::SizeOf(gOpenRCT2StartupActionPath) == 0)
                     {
                         Editor::Load();
-                        return GetGameScene();
+                        nextScene = GetGameScene();
                     }
                     else if (Editor::LoadLandscape(gOpenRCT2StartupActionPath))
                     {
-                        return GetGameScene();
+                        nextScene = GetGameScene();
                     }
-                    [[fallthrough]];
+                    else
+                    {
+                        nextScene = GetTitleScene();
+                    }
+                    break;
                 }
+
                 default:
                 {
-                    return GetTitleScene();
+                    nextScene = GetTitleScene();
                 }
             }
+
+            SetActiveScene(nextScene);
+            InitNetworkGame(nextScene == GetGameScene());
         }
 
-        /**
-         * Launches the game, after command line arguments have been parsed and processed.
-         */
-        void Launch()
+        void InitNetworkGame(bool isGameScene)
         {
-            if (!_versionCheckFuture.valid())
-            {
-                _versionCheckFuture = std::async(std::launch::async, [this] {
-                    _newVersionInfo = GetLatestVersion();
-                    if (!String::StartsWith(gVersionInfoTag, _newVersionInfo.tag))
-                    {
-                        _hasNewVersionInfo = true;
-                    }
-                });
-            }
-
-            auto* scene = DetermineStartUpScene();
-            if (!gOpenRCT2Headless)
-            {
-                _preloaderScene->SetCompletionScene(scene);
-            }
-            else
-            {
-                SetActiveScene(scene);
-            }
-
-            if (scene == GetGameScene())
+            if (isGameScene)
             {
 #ifndef DISABLE_NETWORK
                 if (gNetworkStart == NETWORK_MODE_SERVER)
@@ -1136,6 +1124,32 @@ namespace OpenRCT2
                 _network.BeginClient(gNetworkStartHost, gNetworkStartPort);
             }
 #endif // DISABLE_NETWORK
+        }
+
+        /**
+         * Launches the game, after command line arguments have been parsed and processed.
+         */
+        void Launch()
+        {
+            if (!_versionCheckFuture.valid())
+            {
+                _versionCheckFuture = std::async(std::launch::async, [this] {
+                    _newVersionInfo = GetLatestVersion();
+                    if (!String::StartsWith(gVersionInfoTag, _newVersionInfo.tag))
+                    {
+                        _hasNewVersionInfo = true;
+                    }
+                });
+            }
+
+            if (!gOpenRCT2Headless)
+            {
+                _preloaderScene->SetOnComplete([&]() { SwitchToStartUpScene(); });
+            }
+            else
+            {
+                SwitchToStartUpScene();
+            }
 
             _stdInOutConsole.Start();
             RunGameLoop();

src/openrct2/scenes/Scene.cpp

@@ -31,19 +31,13 @@ GameState_t& Scene::GetGameState()
 
 void Scene::FinishScene()
 {
-    if (_nextScene != nullptr)
+    if (_onComplete != nullptr)
     {
-        _context.SetActiveScene(_nextScene);
-        _nextScene = nullptr;
+        _onComplete();
     }
 }
 
-IScene* Scene::GetCompletionScene()
+void Scene::SetOnComplete(std::function<void()> onComplete)
 {
-    return _nextScene;
-}
-
-void Scene::SetCompletionScene(IScene* scene)
-{
-    _nextScene = scene;
+    _onComplete = onComplete;
 }

src/openrct2/scenes/Scene.h

@@ -11,6 +11,8 @@
 
 #include "../common.h"
 
+#include <functional>
+
 namespace OpenRCT2
 {
     struct GameState_t;
@@ -28,8 +30,7 @@ namespace OpenRCT2
         virtual void Tick() = 0;
         virtual void Stop() = 0;
 
-        virtual IScene* GetCompletionScene() = 0;
-        virtual void SetCompletionScene(IScene* scene) = 0;
+        virtual void SetOnComplete(std::function<void()>) = 0;
     };
 
     class Scene : public IScene
@@ -40,15 +41,14 @@ namespace OpenRCT2
         GameState_t& GetGameState() override;
         IContext& GetContext() override;
 
-        IScene* GetCompletionScene() override;
-        void SetCompletionScene(IScene* scene) override;
+        void SetOnComplete(std::function<void()>) override;
 
     protected:
         void FinishScene();
 
     protected:
         IContext& _context;
-        IScene* _nextScene = nullptr;
+        std::function<void()> _onComplete{};
     };
 
 } // namespace OpenRCT2

src/openrct2/scenes/title/TitleScene.cpp

@@ -121,6 +121,9 @@ void TitleScene::Load()
     ViewportInitAll();
     ContextOpenWindow(WindowClass::MainWindow);
     CreateWindows();
+
+    GetContext().OpenProgress(STR_LOADING_TITLE_SEQUENCE);
+
     TitleInitialise();
     OpenRCT2::Audio::PlayTitleMusic();
 
@@ -139,6 +142,8 @@ void TitleScene::Load()
         _sequencePlayer->Update();
     }
 
+    GetContext().CloseProgress();
+
     LOG_VERBOSE("TitleScene::Load() finished");
 }