added random speed modifier (as an experiment for random variables in modifiers)

stepmania/Themes/default/metrics.ini

@@ -3669,7 +3669,7 @@ HelperY=SCREEN_CENTER_Y+80
 
 [ScreenOptionsMaster]
 # Player options
-Speed=11
+Speed=12
 SpeedDefault=mod,1x
 Speed,1=mod,0.25x;name,x0.25
 Speed,2=mod,0.50x;name,x0.50
@@ -3682,6 +3682,7 @@ Speed,8=mod,4x;name,x4
 Speed,9=mod,8x;name,x8
 Speed,10=mod,C200;name,C200
 Speed,11=mod,C400;name,C400
+Speed,12=mod,1,300% randomspeed;name,Random
 Accel=6
 AccelDefault=mod,no boost,no brake,no wave,no expand,no boomerang
 Accel,1=name,Off

stepmania/src/ArrowEffects.cpp

@@ -83,6 +83,17 @@ float ArrowGetYOffset( PlayerNumber pn, int iCol, float fNoteBeat )
 		fYOffset +=	fAccels[PlayerOptions::ACCEL_BOOMERANG] * (fYOffset * SCALE( fYOffset, 0.f, SCREEN_HEIGHT, 1.5f, 0.5f )- fYOffset);
 
 	float fScrollSpeed = GAMESTATE->m_CurrentPlayerOptions[pn].m_fScrollSpeed;
+	if ( GAMESTATE->m_CurrentPlayerOptions[pn].m_fRandomSpeed > 1.0f )
+	{
+		int seed = GAMESTATE->m_iRoundSeed + ( BeatToNoteRow( fNoteBeat ) << 8 ) + (iCol * 100);
+		float soRandom = RandomFloat( seed );
+
+		fScrollSpeed = GAMESTATE->m_CurrentPlayerOptions[pn].m_fScrollSpeed * 
+							SCALE( soRandom,
+								   0.0f, 1.0f,
+								   1.0f, GAMESTATE->m_CurrentPlayerOptions[pn].m_fRandomSpeed ); // min. scale shold be defined as a constatnt somewhere
+	}	
+
 
 	if( fAccels[PlayerOptions::ACCEL_EXPAND] > 0 )
 	{

stepmania/src/PlayerOptions.cpp

@@ -29,6 +29,7 @@ void PlayerOptions::Init()
 	m_fPerspectiveTilt = 0;		m_SpeedfPerspectiveTilt = 1.0f;
 	m_fSkew = 0;				m_SpeedfSkew = 1.0f;
 	m_fPassmark = 0;			m_SpeedfPassmark = 1.0f;
+	m_fRandomSpeed = 1.0f;      m_SpeedfRandomSpeed = 1.0f;
 	ZERO( m_bTurns );
 	ZERO( m_bTransforms );
 	m_bProTiming = false;
@@ -57,6 +58,7 @@ void PlayerOptions::Approach( const PlayerOptions& other, float fDeltaSeconds )
 	APP( fPerspectiveTilt );
 	APP( fSkew );
 	APP( fPassmark );
+	APP( fRandomSpeed );
 }
 
 static CString AddPart( float level, CString name )
@@ -170,6 +172,8 @@ CString PlayerOptions::GetString() const
 	if( !m_sNoteSkin.empty()  &&  m_sNoteSkin.CompareNoCase("default")!=0 )
 		sReturn += m_sNoteSkin + ", ";
 
+	if( m_fRandomSpeed > 1 )
+		sReturn += "RandomSpeed, ";
 	if( sReturn.GetLength() > 2 )
 		sReturn.erase( sReturn.GetLength()-2 );	// delete the trailing ", "
 	return sReturn;
@@ -309,6 +313,8 @@ void PlayerOptions::FromString( CString sOptions )
 			m_sNoteSkin = sBit;
 		else if( sBit == "noteskin" && !on ) /* "no noteskin" */
 			m_sNoteSkin = "default";
+		else if ( sBit == "randomspeed" ) SET_FLOAT( fRandomSpeed )
+
 	}
 }
 

stepmania/src/PlayerOptions.h

@@ -109,6 +109,8 @@ struct PlayerOptions
 	float		m_fPerspectiveTilt,		m_SpeedfPerspectiveTilt;		// -1 = near, 0 = overhead, +1 = space
 	float		m_fSkew,				m_SpeedfSkew;		// 0 = vanish point is in center of player, 1 = vanish point is in center of screen
 
+	float		m_fRandomSpeed,			m_SpeedfRandomSpeed;
+
 	/* If this is > 0, then the player must have life above this value at the end of
 	 * the song to pass.  This is independent of SongOptions::m_FailType. */
 	float		m_fPassmark,			m_SpeedfPassmark;