Created GameLoop::ChangeGame analogous to GameLoop::ChangeTheme. Changed ChangeTheme to use the AfterThemeChangeScreen metric instead of a passed in screen name from the theme being changed away from. ChangeGame uses the AfterGameChangeScreen and AfterGameAndThemeChangeScreen metrics to pick the screen to load after the change. New metrics are optional and default to InitialScreen. Changed ScreenManager::ThemeChanged to not duplicate the code in ReloadOverlayScreens. Fixed ScreenManager::IsScreenNameValid to check with HasMetric before using GetMetric. Changed game ConfOption logic to set the preference and work in a similar way to the theme ConfOption. Added THEME:SetTheme lua function.

src/GameLoop.cpp

@@ -114,17 +114,24 @@ static void CheckFocus()
 }
 
 // On the next update, change themes, and load sNewScreen.
-static RString g_sNewTheme;
-static RString g_sNewScreen;
+static RString g_NewTheme;
 static bool g_bForceThemeReload;
-void GameLoop::ChangeTheme( const RString &sNewTheme, const RString &sNewScreen, bool bForced )
+static RString g_NewGame;
+void GameLoop::ChangeTheme( const RString &sNewTheme, bool bForced )
 {
-	g_sNewTheme = sNewTheme;
-	g_sNewScreen = sNewScreen;
+	g_NewTheme = sNewTheme;
 	g_bForceThemeReload = bForced;
 }
 
+void GameLoop::ChangeGame(const RString& new_game, const RString& new_theme)
+{
+	g_NewGame= new_game;
+	g_NewTheme= new_theme;
+}
+
 #include "StepMania.h" // XXX
+#include "GameManager.h"
+#include "Game.h"
 namespace
 {
 	void DoChangeTheme()
@@ -135,8 +142,8 @@ namespace
 		// In case the previous theme overloaded class bindings, reinitialize them.
 		LUA->RegisterTypes();
 
-		THEME->SwitchThemeAndLanguage( g_sNewTheme, THEME->GetCurLanguage(), PREFSMAN->m_bPseudoLocalize, g_bForceThemeReload );
-		PREFSMAN->m_sTheme.Set( g_sNewTheme );
+		THEME->SwitchThemeAndLanguage( g_NewTheme, THEME->GetCurLanguage(), PREFSMAN->m_bPseudoLocalize, g_bForceThemeReload );
+		PREFSMAN->m_sTheme.Set( g_NewTheme );
 
 		// Apply the new window title, icon and aspect ratio.
 		StepMania::ApplyGraphicOptions();
@@ -145,19 +152,97 @@ namespace
 
 		StepMania::ResetGame();
 		SCREENMAN->ThemeChanged();
-		// Not all themes use the same screen names!  Check whether the new
-		// screen is valid in the new theme before setting it.  Use the
-		// InitialScreen metric if it's not.
-		if(!SCREENMAN->IsScreenNameValid(g_sNewScreen))
+		// The previous system for changing the theme fetched the "NextScreen"
+		// metric from the current theme, then changed the theme, then tried to
+		// set the new screen to the name that had been fetched.
+		// If the new screen didn't exist in the new theme, there would be a
+		// crash.
+		// So now the correct thing to do is for a theme to specify its entry
+		// point after a theme change, ensuring that we are going to a valid
+		// screen and not crashing. -Kyz
+		RString new_screen= THEME->GetMetric("Common", "InitialScreen");
+		if(THEME->HasMetric("Common", "AfterThemeChangeScreen"))
 		{
-			g_sNewScreen= THEME->GetMetric("Common", "InitialScreen");
+			RString after_screen= THEME->GetMetric("Common", "AfterThemeChangeScreen");
+			if(SCREENMAN->IsScreenNameValid(after_screen))
+			{
+				new_screen= after_screen;
+			}
 		}
-		SCREENMAN->SetNewScreen( g_sNewScreen );
+		SCREENMAN->SetNewScreen(new_screen);
 
-		g_sNewTheme = RString();
-		g_sNewScreen = RString();
+		g_NewTheme = RString();
 	}
 
+	void DoChangeGame()
+	{
+		const Game* g= GAMEMAN->StringToGame(g_NewGame);
+		ASSERT(g != NULL);
+		GAMESTATE->SetCurGame(g);
+
+		bool theme_changing= false;
+		// The prefs allow specifying a different default theme to use for each
+		// game type.  So if a theme name isn't passed in, fetch from the prefs.
+		if(g_NewTheme.empty())
+		{
+			g_NewTheme= PREFSMAN->m_sTheme;
+		}
+		if(g_NewTheme != THEME->GetCurThemeName() && THEME->IsThemeSelectable(g_NewTheme))
+		{
+			theme_changing= true;
+		}
+
+		if(theme_changing)
+		{
+			SAFE_DELETE(SCREENMAN);
+			TEXTUREMAN->DoDelayedDelete();
+			LUA->RegisterTypes();
+			THEME->SwitchThemeAndLanguage(g_NewTheme, THEME->GetCurLanguage(),
+				PREFSMAN->m_bPseudoLocalize);
+			PREFSMAN->m_sTheme.Set(g_NewTheme);
+			StepMania::ApplyGraphicOptions();
+			SCREENMAN= new ScreenManager();
+		}
+		StepMania::ResetGame();
+		RString new_screen= THEME->GetMetric("Common", "InitialScreen");
+		RString after_screen;
+		if(theme_changing)
+		{
+			SCREENMAN->ThemeChanged();
+			if(THEME->HasMetric("Common", "AfterGameAndThemeChangeScreen"))
+			{
+				after_screen= THEME->GetMetric("Common", "AfterGameAndThemeChangeScreen");
+			}
+		}
+		else
+		{
+			if(THEME->HasMetric("Common", "AfterGameChangeScreen"))
+			{
+				after_screen= THEME->GetMetric("Common", "AfterGameChangeScreen");
+			}
+		}
+		if(SCREENMAN->IsScreenNameValid(after_screen))
+		{
+			new_screen= after_screen;
+		}
+		SCREENMAN->SetNewScreen(new_screen);
+
+		// Set the input scheme for the new game, and load keymaps.
+		if( INPUTMAPPER )
+		{
+			INPUTMAPPER->SetInputScheme(&g->m_InputScheme);
+			INPUTMAPPER->ReadMappingsFromDisk();
+		}
+		// aj's comment transplanted from ScreenOptionsMasterPrefs.cpp:GameSel. -Kyz
+		/* Reload metrics to force a refresh of CommonMetrics::DIFFICULTIES_TO_SHOW,
+		 * mainly if we're not switching themes. I'm not sure if this was the
+		 * case going from theme to theme, but if it was, it should be fixed
+		 * now. There's probably be a better way to do it, but I'm not sure
+		 * what it'd be. -aj */
+		THEME->ReloadMetrics();
+		g_NewGame= RString();
+		g_NewTheme= RString();
+	}
 }
 
 void GameLoop::RunGameLoop()
@@ -169,8 +254,14 @@ void GameLoop::RunGameLoop()
 
 	while( !ArchHooks::UserQuit() )
 	{
-		if( !g_sNewTheme.empty() )
+		if(!g_NewGame.empty())
+		{
+			DoChangeGame();
+		}
+		if(!g_NewTheme.empty())
+		{
 			DoChangeTheme();
+		}
 
 		// Update
 		float fDeltaTime = g_GameplayTimer.GetDeltaTime();