From 4266de78304ce5c6ffbde34601216f0878935ef9 Mon Sep 17 00:00:00 2001
From: Vesa <contact.diizy@nbl.fi>
Date: Sat, 13 Dec 2014 16:28:44 +0200
Subject: [PATCH] More fixes (Bitcrush, Linkwitz-Riley filter)

---
 include/BasicFilters.h        | 20 ++++++++++----------
 plugins/Bitcrush/Bitcrush.cpp |  7 ++++++-
 2 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/include/BasicFilters.h b/include/BasicFilters.h
index 98c69474ab9..e09d40c425f 100644
--- a/include/BasicFilters.h
+++ b/include/BasicFilters.h
@@ -75,34 +75,34 @@ class LinkwitzRiley
 	inline void setCoeffs( float freq )
 	{
 		// wc
-		const float wc = F_2PI * freq;
+		const float wc = F_2PI * freq / m_sampleRate;
 		const float wc2 = wc * wc;
 		const float wc3 = wc2 * wc;
 		m_wc4 = wc2 * wc2;
 
 		// k
-		const float k = wc / tanf( F_PI * freq / m_sampleRate );
+		const float k = wc / tan( wc * 0.5 );
 		const float k2 = k * k;
 		const float k3 = k2 * k;
 		m_k4 = k2 * k2;
 
 		// a
-		static const float sqrt2 = sqrtf( 2.0f );
+		static const double sqrt2 = sqrt( 2.0 );
 		const float sq_tmp1 = sqrt2 * wc3 * k;
 		const float sq_tmp2 = sqrt2 * wc * k3;
-		m_a = 4.0f * wc2 * k2 + 2.0f * sq_tmp1 + m_k4 + 2.0f * sq_tmp2 + m_wc4;
+		m_a = 1.0f / ( 4.0f * wc2 * k2 + 2.0f * sq_tmp1 + m_k4 + 2.0f * sq_tmp2 + m_wc4 );
 
 		// b
-		m_b1 = ( 4.0f * ( m_wc4 + sq_tmp1 - m_k4 - sq_tmp2 ) ) / m_a;
-		m_b2 = ( 6.0f * m_wc4 - 8.0f * wc2 * k2 + 6.0f * m_k4 ) / m_a;
-		m_b3 = ( 4.0f * ( m_wc4 - sq_tmp1 + sq_tmp2 - m_k4 ) ) / m_a;
-		m_b4 = ( m_k4 - 2.0f * sq_tmp1 + m_wc4 - 2.0f * sq_tmp2 + 4.0f * wc2 * k2 ) / m_a;
+		m_b1 = ( 4.0f * ( m_wc4 + sq_tmp1 - m_k4 - sq_tmp2 ) ) * m_a;
+		m_b2 = ( 6.0f * m_wc4 - 8.0f * wc2 * k2 + 6.0f * m_k4 ) * m_a;
+		m_b3 = ( 4.0f * ( m_wc4 - sq_tmp1 + sq_tmp2 - m_k4 ) ) * m_a;
+		m_b4 = ( m_k4 - 2.0f * sq_tmp1 + m_wc4 - 2.0f * sq_tmp2 + 4.0f * wc2 * k2 ) * m_a;
 	}
 
 	inline void setLowpass( float freq )
 	{
 		setCoeffs( freq );
-		m_a0 = m_wc4 / m_a;
+		m_a0 = m_wc4 * m_a;
 		m_a1 = 4.0f * m_a0;
 		m_a2 = 6.0f * m_a0;
 	}
@@ -110,7 +110,7 @@ class LinkwitzRiley
 	inline void setHighpass( float freq )
 	{
 		setCoeffs( freq );
-		m_a0 = m_k4 / m_a;
+		m_a0 = m_k4 * m_a;
 		m_a1 = 4.0f * m_a0;
 		m_a2 = 6.0f * m_a0;
 	}
diff --git a/plugins/Bitcrush/Bitcrush.cpp b/plugins/Bitcrush/Bitcrush.cpp
index 8a2822d608f..84f5b45ba0c 100644
--- a/plugins/Bitcrush/Bitcrush.cpp
+++ b/plugins/Bitcrush/Bitcrush.cpp
@@ -80,7 +80,7 @@ void BitcrushEffect::sampleRateChanged()
 {
 	m_sampleRate = Engine::mixer()->processingSampleRate();
 	m_filter.setSampleRate( m_sampleRate );
-	m_filter.setLowpass( m_sampleRate * CUTOFF_RATIO );
+	m_filter.setLowpass( m_sampleRate * ( CUTOFF_RATIO * OS_RATIO ) );
 	m_needsUpdate = true;
 }
 
@@ -97,6 +97,11 @@ inline float BitcrushEffect::noise( float amt )
 
 bool BitcrushEffect::processAudioBuffer( sampleFrame* buf, const fpp_t frames )
 {
+	if( !isEnabled() || !isRunning () )
+	{
+		return( false );
+	}
+
 	// update values
 	if( m_needsUpdate || m_controls.m_rateEnabled.isValueChanged() )
 	{