Peak Controller: improve envelope calculation

plugins/peak_controller_effect/peak_controller_effect.cpp

@@ -28,6 +28,7 @@
 #include "song.h"
 #include "PeakController.h"
 #include "peak_controller_effect.h"
+#include "lmms_math.h"
 
 #include "embed.cpp"
 
@@ -63,9 +64,6 @@ PeakControllerEffect::PeakControllerEffect(
 	m_effectId( rand() ),
 	m_peakControls( this ),
 	m_lastSample( 0 ),
-	m_previousSample( 0 ),
-	m_lastRMS( -1 ),
-	m_lastRMSavail(false),
 	m_autoController( NULL )
 {
 	m_autoController = new PeakController( engine::getSong(), this );
@@ -86,22 +84,6 @@ PeakControllerEffect::~PeakControllerEffect()
 	}
 }
 
-namespace helpers
-{
-
-	//! returns 1.0f if val > 0.0f, -1.0 else
-	inline float sign( float val ) 
-	{ 
-		return -1.0f + 2.0f * ( val > 0.0f ); 
-	}
-
-	//! if val >= 0.0f, returns sqrtf(val), else: -sqrtf(-val)
-	inline float sqrt_neg( float val ) 
-	{
-		return sqrtf( fabs( val ) ) * helpers::sign( val );
-	}
-
-}
 
 bool PeakControllerEffect::processAudioBuffer( sampleFrame * _buf,
 							const fpp_t _frames )
@@ -132,8 +114,8 @@ bool PeakControllerEffect::processAudioBuffer( sampleFrame * _buf,
 		{
 			// the value is absolute because of squaring,
 			// so we need to correct it
-			sum += _buf[i][0] * _buf[i][0] * helpers::sign( _buf[i][0] )
-				+ _buf[i][1] * _buf[i][1] * helpers::sign( _buf[i][1] );
+			sum += _buf[i][0] * _buf[i][0] * sign( _buf[i][0] )
+				+ _buf[i][1] * _buf[i][1] * sign( _buf[i][1] );
 		}
 	}
 
@@ -147,35 +129,9 @@ bool PeakControllerEffect::processAudioBuffer( sampleFrame * _buf,
 		}
 	}
 
-	float curRMS = helpers::sqrt_neg( sum / _frames );
-	const float origRMS = curRMS;
-
-	if( !m_lastRMSavail )
-	{
-		m_lastRMSavail = true;
-		m_lastRMS = curRMS;
-	}
-	const float v = ( curRMS >= m_lastRMS ) ?
-				c.m_attackModel.value() :
-					c.m_decayModel.value();
-	const float a = helpers::sqrt_neg( helpers::sqrt_neg( v ) );
-	curRMS = (1-a)*curRMS + a*m_lastRMS;
-
+	float curRMS = sqrt_neg( sum / _frames );
 	const float amount = c.m_amountModel.value() * c.m_amountMultModel.value();
-	m_previousSample = m_lastSample;
-	m_lastSample = c.m_baseModel.value() + amount*curRMS;
-	m_lastRMS = curRMS;
-
-	// on greater buffer sizes our LP is updated less frequently, therfore
-	// replay a certain number of passes so the LP state is as if it was
-	// updated N times with buffer-size 1/N
-	const int timeOversamp = (4*_frames) / DEFAULT_BUFFER_SIZE-1;
-	for( int i = 0; i < timeOversamp; ++i )
-	{
-		m_lastRMS = (1-a)*origRMS + a*m_lastRMS;
-	}
-
-	//checkGate( out_sum / _frames );
+	m_lastSample = c.m_baseModel.value() + amount * curRMS;
 
 	return isRunning();
 }

plugins/peak_controller_effect/peak_controller_effect.h

@@ -48,15 +48,20 @@ public:
 		return m_lastSample;
 	}
 
-	float previousSample()
-	{
-		return m_previousSample;
-	}
-
 	PeakController * controller()
 	{
 		return m_autoController;
 	}
+	
+	FloatModel * attackModel()
+	{
+		return &( m_peakControls.m_attackModel );
+	}
+
+	FloatModel * decayModel()
+	{
+		return &( m_peakControls.m_decayModel );
+	}
 
 	int m_effectId;
 
@@ -64,9 +69,6 @@ private:
 	PeakControllerEffectControls m_peakControls;
 
 	float m_lastSample;
-	float m_previousSample;
-	float m_lastRMS;
-	bool m_lastRMSavail;
 
 	PeakController * m_autoController;