Give actors the ability to undo the rate change triggered by holding

tilde or tab.

This is gated by a new boolean, `tab_tilde_scaling_enabled_`, and
applied only to banners by default.

src/Actor.cpp

@@ -13,6 +13,7 @@
 #include "LightsManager.h" // for NUM_CabinetLight
 #include "ActorUtil.h"
 #include "Preference.h"
+#include "GameLoop.h"
 
 #include <cmath>
 #include <cstddef>
@@ -166,9 +167,10 @@ Actor::Actor()
 	m_size = RageVector2( 1, 1 );
 	InitState();
 	m_pParent = nullptr;
-	m_FakeParent= nullptr;
+	m_FakeParent = nullptr;
 	m_bFirstUpdate = true;
-	m_tween_uses_effect_delta= false;
+	m_tween_uses_effect_delta = false;
+	tab_tilde_scaling_enabled_ = true;
 }
 
 Actor::~Actor()
@@ -872,6 +874,14 @@ bool Actor::IsFirstUpdate() const
 void Actor::Update( float fDeltaTime )
 {
 //	LOG->Trace( "Actor::Update( %f )", fDeltaTime );
+
+	float rate = GameLoop::GetUpdateRate();
+	if (rate != 1 && !tab_tilde_scaling_enabled_) {
+		if (rate != 0) {
+			fDeltaTime *= (1 / rate);
+		}
+	}
+
 	ASSERT_M( fDeltaTime >= 0, ssprintf("DeltaTime: %f",fDeltaTime) );
 
 	if( m_fHibernateSecondsLeft > 0 )

src/Actor.h

@@ -714,6 +714,9 @@ protected:
 	 * follow the effect clock.  Actor::Update must be called first. */
 	float GetEffectDeltaTime() const		{ return m_fEffectDelta; }
 
+	// Use this to disable scaling an actor's rate with tab or tilde.
+	void DisableTabTildeScaling() { tab_tilde_scaling_enabled_ = false; }
+
 	// todo: account for SSC_FUTURES by having these be vectors too -aj
 	RageColor	m_effectColor1;
 	RageColor	m_effectColor2;
@@ -753,6 +756,10 @@ protected:
 	static std::vector<float> g_vfCurrentBGMBeatPlayerNoOffset;
 
 private:
+	// Some actors shouldn't be scaled with tab or tilde. This bool does not
+	// guard against holding both at the same time (setting the rate to zero).
+	bool tab_tilde_scaling_enabled_;
+
 	// commands
 	std::map<RString, apActorCommands> m_mapNameToCommands;
 };

src/Banner.cpp

@@ -25,6 +25,7 @@ Banner::Banner()
 {
 	m_bScrolling = false;
 	m_fPercentScrolling = 0;
+	Actor::DisableTabTildeScaling();
 }
 
 // Ugly: if sIsBanner is false, we're actually loading something other than a banner.

src/GameLoop.cpp

@@ -40,6 +40,10 @@ void GameLoop::SetUpdateRate( float fUpdateRate )
 	g_fUpdateRate = fUpdateRate;
 }
 
+float GameLoop::GetUpdateRate() {
+	return g_fUpdateRate;
+}
+
 static void CheckGameLoopTimerSkips( float fDeltaTime )
 {
 	static int iLastFPS = 0;

src/GameLoop.h

@@ -5,7 +5,8 @@ namespace GameLoop
 {
 	void RunGameLoop();
 	void UpdateAllButDraw( bool bRunningFromVBLANK);
-	void SetUpdateRate( float fUpdateRate );
+	void SetUpdateRate(float fUpdateRate);
+	float GetUpdateRate();
 	void ChangeTheme(const RString &sNewTheme);
 	void ChangeGame(const RString& new_game, const RString& new_theme= "");
 	void StartConcurrentRendering();