Restrict course editor to playable songs.

This does not yet deal with songs with charts
in multiple game types.

...at least, as far as I know.

src/ScreenOptionsEditCourse.cpp

@@ -145,7 +145,7 @@ void ScreenOptionsEditCourse::Init()
 	sc.m_Tutorial = SongCriteria::Tutorial_No;
 	sc.m_Locked = SongCriteria::Locked_Unlocked;
 
-	SongUtil::FilterSongs( sc, SONGMAN->GetAllSongs(), m_vpSongs );
+	SongUtil::FilterSongs( sc, SONGMAN->GetAllSongs(), m_vpSongs, true );
 
 	SongUtil::SortSongPointerArrayByTitle( m_vpSongs );
 }

src/SongUtil.cpp

@@ -871,13 +871,15 @@ void SongUtil::GetAllSongGenres( vector<RString> &vsOut )
 	}
 }
 
-void SongUtil::FilterSongs( const SongCriteria &sc, const vector<Song*> &in, vector<Song*> &out )
+void SongUtil::FilterSongs( const SongCriteria &sc, const vector<Song*> &in,
+			   vector<Song*> &out, bool doCareAboutGame )
 {
 	out.reserve( in.size() );
 	FOREACH_CONST( Song*, in, s )
 	{
-		if( sc.Matches( *s ) )
+		if( sc.Matches( *s ) && (!doCareAboutGame || IsSongPlayable(*s) ) )
 		{
+			
 			out.push_back( *s );
 		}
 	}
@@ -963,6 +965,21 @@ bool SongUtil::IsStepsPlayable( Song *pSong, Steps *pSteps )
 	return find( vpSteps.begin(), vpSteps.end(), pSteps ) != vpSteps.end();
 }
 
+bool SongUtil::IsSongPlayable( Song *s )
+{
+	const vector<Steps*> & steps = s->GetAllSteps();
+	// I'm sure there is a foreach loop, but I don't
+	FOREACH( Steps*, const_cast<vector<Steps*>&>(steps), step )
+	{
+		if (IsStepsPlayable(s, *step))
+		{
+			return true;
+		}
+	}
+	
+	return false;
+}
+
 bool SongUtil::GetStepsTypeAndDifficultyFromSortOrder( SortOrder so, StepsType &stOut, Difficulty &dcOut )
 {
 	switch( so )

src/SongUtil.h

@@ -163,12 +163,25 @@ namespace SongUtil
 	bool ValidateCurrentStepsCredit( const RString &sAnswer, RString &sErrorOut );
 
 	void GetAllSongGenres( vector<RString> &vsOut );
-	void FilterSongs( const SongCriteria &sc, const vector<Song*> &in, vector<Song*> &out );
+	/**
+	 * @brief Filter the selection of songs to only match certain criteria.
+	 * @param sc the intended song criteria.
+	 * @param in the starting batch of songs.
+	 * @param out the resulting batch.
+	 * @param doCareAboutGame a flag to see if we should only get playable steps. */
+	void FilterSongs( const SongCriteria &sc, const vector<Song*> &in, vector<Song*> &out,
+			 bool doCareAboutGame = false );
 
 	void GetPlayableStepsTypes( const Song *pSong, set<StepsType> &vOut );
 	void GetPlayableSteps( const Song *pSong, vector<Steps*> &vOut );
 	bool IsStepsTypePlayable( Song *pSong, StepsType st );
 	bool IsStepsPlayable( Song *pSong, Steps *pSteps );
+	
+	/**
+	 * @brief Determine if the song has any playable steps in the present game.
+	 * @param s the current song.
+	 * @return true if the song has playable steps, false otherwise. */
+	bool IsSongPlayable( Song *s );
 
 	bool GetStepsTypeAndDifficultyFromSortOrder( SortOrder so, StepsType &st, Difficulty &dc );
 }