An attempt to make the arrows flash with the steps' timing. If it works then we can expand it to..... I don't know, lifebars?

src/Actor.cpp

@@ -18,6 +18,8 @@
 
 static Preference<bool> g_bShowMasks("ShowMasks", false);
 
+PlayerNumber Actor::m_ActivePlayerNumber = PLAYER_1;
+
 /**
  * @brief Set up a hidden Actor that won't be drawn.
  *
@@ -683,6 +685,11 @@ void Actor::UpdateInternal( float fDeltaTime )
 		m_fSecsIntoEffect = g_fCurrentBGMBeat;
 		break;
 
+	case CLOCK_BGM_BEAT_PLAYER_ACTIVE:
+		m_fEffectDelta = g_vfCurrentBGMBeatPlayer[m_ActivePlayerNumber] - m_fSecsIntoEffect;
+		m_fSecsIntoEffect = g_vfCurrentBGMBeatPlayerNoOffset[m_ActivePlayerNumber];
+		break;
+
 	case CLOCK_BGM_BEAT_PLAYER1:
 		m_fEffectDelta = g_vfCurrentBGMBeatPlayer[PLAYER_1] - m_fSecsIntoEffect;
 		m_fSecsIntoEffect = g_vfCurrentBGMBeatPlayerNoOffset[PLAYER_1];
@@ -847,7 +854,7 @@ void Actor::SetEffectClockString( const RString &s )
 {
 	if     (s.EqualsNoCase("timer"))	this->SetEffectClock( CLOCK_TIMER );
 	if     (s.EqualsNoCase("timerglobal"))	this->SetEffectClock( CLOCK_TIMER_GLOBAL );
-	else if(s.EqualsNoCase("beat"))		this->SetEffectClock( CLOCK_BGM_BEAT );
+	else if(s.EqualsNoCase("beat"))		this->SetEffectClock( CLOCK_BGM_BEAT_ACTIVE );
 	else if(s.EqualsNoCase("music"))	this->SetEffectClock( CLOCK_BGM_TIME );
 	else if(s.EqualsNoCase("bgm"))		this->SetEffectClock( CLOCK_BGM_BEAT ); // compat, deprecated
 	else if(s.EqualsNoCase("musicnooffset"))this->SetEffectClock( CLOCK_BGM_TIME_NO_OFFSET );

src/Actor.h

@@ -113,6 +113,13 @@ public:
 	static void SetPlayerBGMBeat( PlayerNumber pn, float fBeat, float fBeatNoOffset );
 	static void SetBGMLight( int iLightNumber, float fCabinetLights );
 
+	/**
+	 * @brief The actively-drawing player number. This is used as a hack
+	 * so that we don't need to tell each actor which player it belongs to.
+	 * This is used to figure out the right player for "beat" effect clock.
+	 */
+	static PlayerNumber m_ActivePlayerNumber;
+
 	/**
 	 * @brief The list of the different effects.
 	 *
@@ -135,6 +142,7 @@ public:
 		CLOCK_BGM_BEAT_NO_OFFSET,
 		CLOCK_BGM_BEAT_PLAYER1,
 		CLOCK_BGM_BEAT_PLAYER2,
+		CLOCK_BGM_BEAT_PLAYER_ACTIVE,
 		CLOCK_LIGHT_1 = 1000,
 		CLOCK_LIGHT_LAST = 1100,
 		NUM_CLOCKS

src/NoteField.cpp

@@ -19,6 +19,7 @@
 #include "BackgroundUtil.h"
 #include "Course.h"
 #include "NoteData.h"
+#include "Actor.h"
 
 static ThemeMetric<bool> SHOW_BOARD( "NoteField", "ShowBoard" );
 static ThemeMetric<bool> SHOW_BEAT_BARS( "NoteField", "ShowBeatBars" );
@@ -765,6 +766,10 @@ bool NoteField::IsOnScreen( float fBeat, int iCol, int iDrawDistanceAfterTargets
 
 void NoteField::DrawPrimitives()
 {
+
+	// XXX Hack: Set Actor's active player number so the notes get the flashing that matches the steps.
+	Actor::m_ActivePlayerNumber = m_pPlayerState->m_PlayerNumber;
+
 	//LOG->Trace( "NoteField::DrawPrimitives()" );
 
 	// This should be filled in on the first update.