optimize InputFilter::Update (.5ms -> .05ms on k7/1000)

stepmania/src/InputFilter.cpp

@@ -5,7 +5,23 @@
 #include "RageUtil.h"
 #include "RageThreads.h"
 #include "Preference.h"
+#include "Foreach.h"
 
+#include <set>
+namespace
+{
+	/* Maintain a set of all interesting buttons: buttons which are being held
+	 * down, or which were held down and need a RELEASE event.  We use this to
+	 * optimize InputFilter::Update, so we don't have to process every button
+	 * we know about when most of them aren't in use.  This set is protected
+	 * by queuemutex. */
+	typedef pair<InputDevice,DeviceButton> Button;
+	set<Button> g_ButtonsToProcess;
+	void ActivateButton( const DeviceInput &di )
+	{
+		g_ButtonsToProcess.insert( make_pair(di.device, di.button) );
+	}
+}
 /*
  * Some input devices require debouncing.  Do this on both press and release.  After
  * reporting a change in state, don't report another for the debounce period.  If a
@@ -101,6 +117,8 @@ void InputFilter::ButtonPressed( const DeviceInput &di, bool Down )
 		bs.m_BeingHeld = Down;
 		bs.m_BeingHeldTime = di.ts;
 	}
+
+	ActivateButton( di );
 }
 
 void InputFilter::SetButtonComment( const DeviceInput &di, const CString &sComment )
@@ -120,6 +138,7 @@ void InputFilter::ResetDevice( InputDevice device )
 
 void InputFilter::Update(float fDeltaTime)
 {
+RageTimer foo;
 	RageTimer now;
 
 	// Constructing the DeviceInput inside the nested loops caues terrible 
@@ -138,18 +157,14 @@ void InputFilter::Update(float fDeltaTime)
 	 * things like "key pressed, key release, key repeat". */
 	LockMut(*queuemutex);
 
-	// Don't reconstruct "di" inside the loop.  This line alone is 
-	// taking 4% of the CPU on a P3-666.
 	DeviceInput di( (InputDevice)0,0,1.0f,now);
 
-	FOREACH_InputDevice( d )
+	set<Button> Buttons( g_ButtonsToProcess );
+	FOREACHS( Button, Buttons, b )
 	{
-		di.device = d;
+		di.device = b->first;
-
+		di.button = b->second;
-		for( int b=0; b < GetNumDeviceButtons(d); b++ )	// foreach button
+		ButtonState &bs = m_ButtonState[di.device][di.button];
-		{
-			ButtonState &bs = m_ButtonState[d][b];
-			di.button = b;
 		di.level = bs.m_Level;
 
 		/* Generate IET_FIRST_PRESS and IET_RELEASE events. */
@@ -172,7 +187,10 @@ void InputFilter::Update(float fDeltaTime)
 
 		/* Generate IET_FAST_REPEAT and IET_SLOW_REPEAT events. */
 		if( !bs.m_bLastReportedHeld )
+		{
+			g_ButtonsToProcess.erase( make_pair(di.device, di.button) );
 			continue;
+		}
 
 		const float fOldHoldTime = bs.m_fSecsHeld;
 		bs.m_fSecsHeld += fDeltaTime;
@@ -217,8 +235,6 @@ void InputFilter::Update(float fDeltaTime)
 	}
 }
 
-}
-
 bool InputFilter::IsBeingPressed( const DeviceInput &di )
 {
 	return m_ButtonState[di.device][di.button].m_bLastReportedHeld;