specify StyleTypes to use in ScreenDemonstration

stepmania/Themes/default/metrics.ini

@@ -3648,6 +3648,7 @@ StartScreen=@ScreenTitleBranch()
 PlayMusic=0
 ShowCourseModifiersProbability=0
 AllowAdvancedModifiers=0
+AllowStyleTypes=TwoPlayersTwoSides
 
 [ScreenJukebox]
 ShowCourseModifiersProbability=0

stepmania/src/GameConstantsAndTypes.h

@@ -353,7 +353,8 @@ enum StyleType
 	ONE_PLAYER_ONE_SIDE,	// e.g. single
 	TWO_PLAYERS_TWO_SIDES,	// e.g. versus
 	ONE_PLAYER_TWO_SIDES,	// e.g. double
-	NUM_STYLE_TYPES
+	NUM_STYLE_TYPES,
+	STYLE_TYPE_INVALID
 };
 const CString& StyleTypeToString( StyleType s );
 StyleType StringToStyleType( const CString& s );

stepmania/src/GameManager.cpp

@@ -1014,7 +1014,7 @@ Style g_Styles[] =
 		&g_Games[GAME_DANCE],					// m_Game
 		true,									// m_bUsedForGameplay
 		true,									// m_bUsedForEdit
-		false,									// m_bUsedForDemonstration
+		true,									// m_bUsedForDemonstration
 		true,									// m_bUsedForHowToPlay
 		"single",								// m_szName
 		STEPS_TYPE_DANCE_SINGLE,				// m_StepsType
@@ -1082,7 +1082,7 @@ Style g_Styles[] =
 		&g_Games[GAME_DANCE],				// m_Game
 		true,									// m_bUsedForGameplay
 		true,									// m_bUsedForEdit
-		false,									// m_bUsedForDemonstration
+		true,									// m_bUsedForDemonstration
 		false,									// m_bUsedForHowToPlay
 		"double",								// m_szName
 		STEPS_TYPE_DANCE_DOUBLE,				// m_StepsType
@@ -2613,17 +2613,18 @@ void GameManager::GetStepsTypesForGame( const Game *pGame, vector<StepsType>& aS
 	}
 }
 
-const Style* GameManager::GetDemonstrationStyleForGame( const Game *pGame ) const
+void GameManager::GetDemonstrationStylesForGame( const Game *pGame, vector<const Style*> &vpStylesOut ) const
 {
+	vpStylesOut.clear();
+
 	for( unsigned s=0; s<NUM_STYLES; s++ ) 
 	{
 		const Style* style = &g_Styles[s];
 		if( style->m_pGame == pGame && style->m_bUsedForDemonstration )
-			return style;
+			vpStylesOut.push_back( style );
 	}
 	
-	ASSERT(0);	// this Game is missing a Style that can be used with the demonstration
+	ASSERT( vpStylesOut.size()>0 );	// this Game is missing a Style that can be used with the demonstration
-	return NULL;
 }
 
 const Style* GameManager::GetHowToPlayStyleForGame( const Game *pGame ) const

stepmania/src/GameManager.h

@@ -19,7 +19,7 @@ public:
 	void	GetAllStyles( vector<const Style*>& aStylesAddTo, bool editor=false ) const;
 	void	GetStepsTypesForGame( const Game* pGame, vector<StepsType>& aStepsTypeAddTo ) const;
 	const Style*	GetEditorStyleForStepsType( StepsType st ) const;
-	const Style*	GetDemonstrationStyleForGame( const Game* pGame ) const;
+	void GetDemonstrationStylesForGame( const Game *pGame, vector<const Style*> &vpStylesOut ) const;
 	const Style*	GetHowToPlayStyleForGame( const Game* pGame ) const;
 
 	void GetEnabledGames( vector<const Game*>& aGamesOut ) const;

stepmania/src/ScreenDemonstration.cpp

@@ -9,10 +9,12 @@
 #include "RageSoundManager.h"
 #include "GameSoundManager.h"
 #include "GameManager.h"
+#include "Style.h"
 
 
 #define SECONDS_TO_SHOW			THEME->GetMetricF(m_sName,"SecondsToShow")
 #define NEXT_SCREEN				THEME->GetMetric (m_sName,"NextScreen")
+#define ALLOW_STYLE_TYPES		THEME->GetMetric (m_sName,"AllowStyleTypes")
 
 REGISTER_SCREEN_CLASS( ScreenDemonstration );
 ScreenDemonstration::ScreenDemonstration( CString sName ) : ScreenJukebox( sName )
@@ -23,7 +25,31 @@ ScreenDemonstration::ScreenDemonstration( CString sName ) : ScreenJukebox( sName
 
 void ScreenDemonstration::Init()
 {
-	GAMESTATE->m_pCurStyle.Set( GAMEMAN->GetDemonstrationStyleForGame(GAMESTATE->m_pCurGame) );
+	// Choose a Style
+	{
+		vector<CString> v;
+		split( ALLOW_STYLE_TYPES, ",", v );
+		vector<StyleType> vStyleTypeAllow;
+		FOREACH_CONST( CString, v, s )
+		{
+			StyleType st = StringToStyleType( *s );
+			ASSERT( st != STYLE_TYPE_INVALID );
+			vStyleTypeAllow.push_back( st );
+		}
+
+		vector<const Style*> vStylePossible;
+		GAMEMAN->GetDemonstrationStylesForGame( GAMESTATE->m_pCurGame, vStylePossible );
+		for( int i=(int)(vStylePossible.size())-1; i>=0; i-- )
+		{
+			bool bAllowThis = find( vStyleTypeAllow.begin(), vStyleTypeAllow.end(), vStylePossible[i]->m_StyleType ) != vStyleTypeAllow.end();
+			if( !bAllowThis )
+				vStylePossible.erase( vStylePossible.begin()+i );
+		}
+
+		ASSERT( vStylePossible.size() > 0 );
+		const Style* pStyle = vStylePossible[ rand() % vStylePossible.size() ];
+		GAMESTATE->m_pCurStyle.Set( pStyle );
+	}
 
 	GAMESTATE->m_PlayMode = PLAY_MODE_REGULAR;