Multitap initial

include/Graph.h

@@ -137,7 +137,7 @@ public:
 
 	inline int length() const
 	{
-		return( m_samples.count() );
+		return m_length;
 	}
 
 	inline const float * samples() const
@@ -175,6 +175,7 @@ private:
 	void drawSampleAt( int x, float val );
 
 	QVector<float> m_samples;
+	int m_length;
 	float m_minValue;
 	float m_maxValue;
 	float m_step;

include/MixHelpers.h

@@ -42,6 +42,9 @@ void add( sampleFrame* dst, const sampleFrame* src, int frames );
 /*! \brief Add samples from src multiplied by coeffSrc to dst */
 void addMultiplied( sampleFrame* dst, const sampleFrame* src, float coeffSrc, int frames );
 
+/*! \brief Add samples from src multiplied by coeffSrc to dst, swap inputs */
+void addSwappedMultiplied( sampleFrame* dst, const sampleFrame* src, float coeffSrc, int frames );
+
 /*! \brief Add samples from src multiplied by coeffSrc and coeffSrcBuf to dst */
 void addMultipliedByBuffer( sampleFrame* dst, const sampleFrame* src, float coeffSrc, ValueBuffer * coeffSrcBuf, int frames );
 

include/RingBuffer.h

@@ -179,6 +179,24 @@ public:
  */
 	void writeAddingMultiplied( sampleFrame * src, float offset, f_cnt_t length, float level );
 
+/** \brief Mixes a buffer of sampleframes additively to the ringbuffer at specified position, with
+ * 	a specified multiplier applied to the frames, with swapped channels
+ * 	\param	src Pointer to the source buffer
+ * 	\param offset Offset in frames against current position, may *NOT* be negative
+ * 	\param length Length of the source buffer, if zero, period size is used - must not be higher than the size of the ringbuffer!
+ * 	\param level Multiplier applied to the frames before they're written to the ringbuffer
+ */
+	void writeSwappedAddingMultiplied( sampleFrame * src, f_cnt_t offset, f_cnt_t length, float level );
+
+/** \brief Mixes a buffer of sampleframes additively to the ringbuffer at specified position, with
+ * 	a specified multiplier applied to the frames, with swapped channels
+ * 	\param	src Pointer to the source buffer
+ * 	\param offset Offset in milliseconds against current position, may *NOT* be negative
+ * 	\param length Length of the source buffer, if zero, period size is used
+ * 	\param level Multiplier applied to the frames before they're written to the ringbuffer
+ */
+	void writeSwappedAddingMultiplied( sampleFrame * src, float offset, f_cnt_t length, float level );
+
 
 protected slots:
 	void updateSamplerate();

plugins/CMakeLists.txt

@@ -16,6 +16,7 @@ ADD_SUBDIRECTORY(LadspaEffect)
 ADD_SUBDIRECTORY(lb302)
 #ADD_SUBDIRECTORY(lb303)
 ADD_SUBDIRECTORY(MidiImport)
+ADD_SUBDIRECTORY(MultitapEcho)
 ADD_SUBDIRECTORY(monstro)
 ADD_SUBDIRECTORY(nes)
 ADD_SUBDIRECTORY(opl2)

plugins/MultitapEcho/CMakeLists.txt

@@ -0,0 +1,3 @@
+INCLUDE(BuildPlugin)
+
+BUILD_PLUGIN(multitapecho MultitapEcho.cpp MultitapEchoControls.cpp MultitapEchoControlDialog.cpp MOCFILES MultitapEchoControls.h MultitapEchoControlDialog.h EMBEDDED_RESOURCES "${CMAKE_CURRENT_SOURCE_DIR}/*.png")

plugins/MultitapEcho/MultitapEcho.cpp

@@ -0,0 +1,155 @@
+/*
+ * MultitapEcho.cpp - a multitap echo delay plugin
+ *
+ * Copyright (c) 2014 Vesa Kivimäki <contact/dot/diizy/at/nbl/dot/fi>
+ * Copyright (c) 2008-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ *
+ * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include "MultitapEcho.h"
+#include "embed.cpp"
+
+
+extern "C"
+{
+
+Plugin::Descriptor PLUGIN_EXPORT multitapecho_plugin_descriptor =
+{
+	STRINGIFY( PLUGIN_NAME ),
+	"Multitap Echo",
+	QT_TRANSLATE_NOOP( "pluginBrowser", "A multitap echo delay plugin" ),
+	"Vesa Kivimäki <contact/dot/diizy/at/nbl/dot/fi>",
+	0x0100,
+	Plugin::Effect,
+	new PluginPixmapLoader( "logo" ),
+	NULL,
+	NULL
+} ;
+
+}
+
+
+MultitapEchoEffect::MultitapEchoEffect( Model* parent, const Descriptor::SubPluginFeatures::Key* key ) :
+	Effect( &multitapecho_plugin_descriptor, parent, key ),
+	m_controls( this ),
+	m_buffer( 20000.0f ),
+	m_sampleRate( Engine::mixer()->processingSampleRate() ),
+	m_sampleRatio( 1.0f / m_sampleRate )
+{
+	updateFilters( 0, 19 );
+}
+
+
+MultitapEchoEffect::~MultitapEchoEffect()
+{
+}
+
+
+void MultitapEchoEffect::updateFilters( int begin, int end )
+{
+	for( int i = begin; i <= end; ++i )
+	{ 
+		m_filter[i][0].setFc( m_lpFreq[i] * m_sampleRatio );
+		m_filter[i][1].setFc( m_lpFreq[i] * m_sampleRatio );
+	}
+}
+
+
+void MultitapEchoEffect::runFilter( sampleFrame * dst, sampleFrame * src, StereoOnePole & filter, const fpp_t frames )
+{
+	for( int f = 0; f < frames; ++f )
+	{
+		dst[f][0] = filter[0].update( src[f][0] );
+		dst[f][1] = filter[1].update( src[f][1] );
+	}
+}
+
+
+bool MultitapEchoEffect::processAudioBuffer( sampleFrame * buf, const fpp_t frames )
+{
+	if( !isEnabled() || !isRunning () )
+	{
+		return( false );
+	}
+	
+	double outSum = 0.0;
+	const float d = dryLevel();
+	const float w = wetLevel();
+
+	// get processing vars
+	const int steps = m_controls.m_steps.value();
+	const float stepLength = m_controls.m_stepLength.value();
+	const float dryGain = dbvToAmp( m_controls.m_dryGain.value() );
+	const bool swapInputs = m_controls.m_swapInputs.value();
+	
+	// temp processing stackbuffer for lp-filtering
+	sampleFrame work [frames];
+	
+	// add dry buffer - never swap inputs for dry
+	m_buffer.writeAddingMultiplied( buf, 0, frames, dryGain );
+	
+	// swapped inputs?
+	if( swapInputs )
+	{
+		float offset = stepLength;
+		for( int i = 0; i < steps; ++i ) // add all steps swapped
+		{
+			runFilter( &work[0], buf, m_filter[i], frames );
+			m_buffer.writeSwappedAddingMultiplied( &work[0], offset, frames, m_amp[i] );
+			offset += stepLength;
+		}
+	}
+	else
+	{
+		float offset = stepLength;
+		for( int i = 0; i < steps; ++i ) // add all steps swapped
+		{
+			runFilter( &work[0], buf, m_filter[i], frames );
+			m_buffer.writeAddingMultiplied( &work[0], offset, frames, m_amp[i] );
+			offset += stepLength;
+		}
+	}
+	
+	// pop the buffer and mix it into output
+	m_buffer.pop( &work[0] );
+
+	for( int f = 0; f < frames; ++f )
+	{
+		buf[f][0] = d * buf[f][0] + w * work[f][0];
+		buf[f][1] = d * buf[f][1] + w * work[f][1];
+		outSum += buf[f][0]*buf[f][0] + buf[f][1]*buf[f][1];
+	}
+	
+	checkGate( outSum / frames );
+
+	return isRunning();	
+}
+
+
+extern "C"
+{
+
+// necessary for getting instance out of shared lib
+Plugin * PLUGIN_EXPORT lmms_plugin_main( Model* parent, void* data )
+{
+	return new MultitapEchoEffect( parent, static_cast<const Plugin::Descriptor::SubPluginFeatures::Key *>( data ) );
+}
+
+}

plugins/MultitapEcho/MultitapEcho.h

@@ -0,0 +1,95 @@
+/*
+ * MultitapEcho.h - a multitap echo delay plugin
+ *
+ * Copyright (c) 2014 Vesa Kivimäki <contact/dot/diizy/at/nbl/dot/fi>
+ * Copyright (c) 2008-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ *
+ * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+ 
+#ifndef MULTITAP_ECHO_H
+#define MULTITAP_ECHO_H
+
+#include "Effect.h"
+#include "MultitapEchoControls.h"
+#include "ValueBuffer.h"
+#include "RingBuffer.h"
+#include "lmms_math.h"
+
+class OnePole
+{
+public:
+	OnePole()
+	{
+		m_a0 = 1.0; 
+		m_b1 = 0.0; 
+		m_z1 = 0.0;
+	}
+	virtual ~OnePole() {}
+	
+	inline void setFc( float fc )
+	{
+		m_b1 = expf( -2.0f * F_PI * fc );
+		m_a0 = 1.0f - m_b1;
+	}
+	
+	inline float update( float s )
+	{
+		return m_z1 = s * m_a0 + m_z1 * m_b1;
+	}
+	
+private:
+	float m_a0, m_b1, m_z1;
+};
+
+typedef OnePole StereoOnePole [2];
+
+class MultitapEchoEffect : public Effect
+{
+public:
+	MultitapEchoEffect( Model* parent, const Descriptor::SubPluginFeatures::Key* key );
+	virtual ~MultitapEchoEffect();
+	virtual bool processAudioBuffer( sampleFrame* buf, const fpp_t frames );
+
+	virtual EffectControls* controls()
+	{
+		return &m_controls;
+	}
+
+private:
+	void updateFilters( int begin, int end );
+	void runFilter( sampleFrame * dst, sampleFrame * src, StereoOnePole & filter, const fpp_t frames );
+
+	MultitapEchoControls m_controls;
+	
+	float m_amp [20];
+	float m_lpFreq [20];
+
+	RingBuffer m_buffer;
+	StereoOnePole m_filter [20];
+	
+	float m_sampleRate;
+	float m_sampleRatio;
+
+	friend class MultitapEchoControls;
+
+};
+
+
+#endif

plugins/MultitapEcho/MultitapEchoControlDialog.cpp

@@ -0,0 +1,99 @@
+/*
+ * MultitapEchoControlDialog.cpp - a multitap echo delay plugin
+ *
+ * Copyright (c) 2014 Vesa Kivimäki <contact/dot/diizy/at/nbl/dot/fi>
+ * Copyright (c) 2008-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ *
+ * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <QLayout>
+
+#include "MultitapEchoControlDialog.h"
+#include "MultitapEchoControls.h"
+#include "embed.h"
+#include "Graph.h"
+#include "PixmapButton.h"
+#include "ToolTip.h"
+#include "LedCheckbox.h"
+#include "Knob.h"
+#include "TempoSyncKnob.h"
+#include "LcdSpinBox.h"
+
+
+MultitapEchoControlDialog::MultitapEchoControlDialog( MultitapEchoControls * controls ) :
+	EffectControlDialog( controls )
+{
+	setAutoFillBackground( true );
+	QPalette pal;
+	pal.setBrush( backgroundRole(),	PLUGIN_NAME::getIconPixmap( "artwork" ) );
+	setPalette( pal );
+	setFixedSize( 245, 300 );
+	
+	// graph widgets
+	
+	Graph * ampGraph = new Graph( this, Graph::BarStyle, 204, 105 );
+	Graph * lpGraph = new Graph( this, Graph::BarStyle, 204, 105 );
+	
+	ampGraph->move( 30, 10 );
+	lpGraph->move( 30, 125 );
+	
+	ampGraph->setModel( & controls->m_ampGraph );
+	lpGraph->setModel( & controls->m_lpGraph );
+	
+	pal = QPalette();
+	pal.setBrush( backgroundRole(),	PLUGIN_NAME::getIconPixmap("graph_bg") );
+	
+	ampGraph->setAutoFillBackground( true );
+	ampGraph->setPalette( pal );
+	ampGraph->setGraphColor( QColor( 48, 255, 117 ) );
+	ampGraph -> setMaximumSize( 204, 105 );
+	
+	lpGraph->setAutoFillBackground( true );
+	lpGraph->setPalette( pal );
+	lpGraph->setGraphColor( QColor( 48, 255, 117 ) );
+	lpGraph -> setMaximumSize( 204, 105 );
+	
+	// steps spinbox
+	
+	LcdSpinBox * steps = new LcdSpinBox( 2, this, "Steps" );
+	steps->move( 20, 240 );
+	steps->setModel( & controls->m_steps );
+	
+	// knobs
+
+	TempoSyncKnob * stepLength = new TempoSyncKnob( knobBright_26, this );
+	stepLength->move( 80, 240 );
+	stepLength->setModel( & controls->m_stepLength );
+	stepLength->setLabel( tr( "Length" ) );
+	stepLength->setHintText( tr( "Step length:" ) + " ", "ms" );
+	
+	Knob * dryGain = new Knob( knobBright_26, this );
+	dryGain->move( 130, 240 );
+	dryGain->setModel( & controls->m_dryGain );
+	dryGain->setLabel( tr( "Dry" ) );
+	dryGain->setHintText( tr( "Dry Gain:" ) + " ", "dBV" );
+	
+	// switch led
+	
+	LedCheckBox * swapInputs = new LedCheckBox( "Swap inputs", this, tr( "Swap in" ), LedCheckBox::Green );
+	swapInputs->move( 180, 240 );
+	swapInputs->setModel( & controls-> m_swapInputs );
+	ToolTip::add( swapInputs, tr( "Swap left and right channel for reflections" ) );
+}

plugins/MultitapEcho/MultitapEchoControlDialog.h

@@ -0,0 +1,44 @@
+/*
+ * MultitapEchoControlDialog.h - a multitap echo delay plugin
+ *
+ * Copyright (c) 2014 Vesa Kivimäki <contact/dot/diizy/at/nbl/dot/fi>
+ * Copyright (c) 2008-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ *
+ * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+
+#ifndef MULTITAP_ECHO_CONTROL_DIALOG_H
+#define MULTITAP_ECHO_CONTROL_DIALOG_H
+
+#include "EffectControlDialog.h"
+
+class MultitapEchoControls;
+
+class MultitapEchoControlDialog : public EffectControlDialog
+{
+	Q_OBJECT
+public:
+	MultitapEchoControlDialog( MultitapEchoControls * controls );
+	virtual ~MultitapEchoControlDialog()
+	{
+	}
+};
+
+#endif

plugins/MultitapEcho/MultitapEchoControls.cpp

@@ -0,0 +1,168 @@
+/*
+ * MultitapEchoControls.cpp - a multitap echo delay plugin
+ *
+ * Copyright (c) 2014 Vesa Kivimäki <contact/dot/diizy/at/nbl/dot/fi>
+ * Copyright (c) 2008-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ *
+ * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <QDomElement>
+
+#include "MultitapEchoControls.h"
+#include "MultitapEcho.h"
+#include "lmms_math.h"
+#include "base64.h"
+
+
+MultitapEchoControls::MultitapEchoControls( MultitapEchoEffect * eff ) :
+	EffectControls( eff ),
+	m_effect( eff ),
+	m_steps( 16, 4, 20, this, "Steps" ),
+	m_stepLength( 100.0f, 1.0f, 1000.0f, 0.1f, 1000.0f, this, "Step length" ),
+	m_dryGain( 0.0f, -80.0f, 20.0f, 0.1f, this, "Dry gain" ),
+	m_swapInputs( false, this, "Swap inputs" ),
+	m_ampGraph( -100.0f, 0.0f, 16, this ),
+	m_lpGraph( 0.0f, 3.0f, 16, this )
+{
+	connect( &m_ampGraph, SIGNAL( samplesChanged( int, int ) ), this, SLOT( ampSamplesChanged( int, int ) ) );
+	connect( &m_lpGraph, SIGNAL( samplesChanged( int, int ) ), this, SLOT( lpSamplesChanged( int, int ) ) );
+
+	connect( &m_steps, SIGNAL( dataChanged() ), this, SLOT( lengthChanged() ) );
+	connect( Engine::mixer(), SIGNAL( sampleRateChanged() ), this, SLOT( sampleRateChanged() ) );
+
+	setDefaultAmpShape();
+	setDefaultLpShape();
+}
+
+
+MultitapEchoControls::~MultitapEchoControls()
+{
+}
+
+
+void MultitapEchoControls::saveSettings( QDomDocument & doc, QDomElement & parent )
+{
+	m_steps.saveSettings( doc, parent, "steps" );
+	m_stepLength.saveSettings( doc, parent, "steplength" );
+	m_dryGain.saveSettings( doc, parent, "drygain" );
+	m_swapInputs.saveSettings( doc, parent, "swapinputs" );
+	
+	QString ampString;
+	base64::encode( (const char *) m_ampGraph.samples(), m_ampGraph.length() * sizeof(float), ampString );
+	parent.setAttribute( "ampsteps", ampString );
+	
+	QString lpString;
+	base64::encode( (const char *) m_lpGraph.samples(), m_lpGraph.length() * sizeof(float), lpString );
+	parent.setAttribute( "lpsteps", lpString );
+}
+
+
+void MultitapEchoControls::loadSettings( const QDomElement & elem )
+{
+	m_steps.loadSettings( elem, "steps" );
+	m_stepLength.loadSettings( elem, "steplength" );
+	m_dryGain.loadSettings( elem, "drygain" );
+	m_swapInputs.loadSettings( elem, "swapinputs" );
+	
+	int size = 0;
+	char * dst = 0;
+	
+	base64::decode( elem.attribute( "ampsteps"), &dst, &size );
+	m_ampGraph.setSamples( (float*) dst );
+
+	base64::decode( elem.attribute( "lpsteps"), &dst, &size );
+	m_lpGraph.setSamples( (float*) dst );
+	
+	delete[] dst;
+}
+
+
+void MultitapEchoControls::setDefaultAmpShape()
+{
+	const int length = m_steps.value();
+	
+	float samples [length];
+	for( int i = 0; i < length; ++i )
+	{
+		samples[i] = 0.0f;
+	}
+	
+	m_ampGraph.setSamples( &samples[0] );
+}
+
+
+void MultitapEchoControls::setDefaultLpShape()
+{
+	const int length = m_steps.value();
+	
+	float samples [length];
+	for( int i = 0; i < length; ++i )
+	{
+		samples[i] = 3.0f;
+	}
+	
+	m_lpGraph.setSamples( &samples[0] );
+}
+
+
+void MultitapEchoControls::ampSamplesChanged( int begin, int end )
+{
+	const float * samples = m_ampGraph.samples();
+	for( int i = begin; i <= end; ++i )
+	{
+		m_effect->m_amp[i] = dbvToAmp( samples[i] );
+	}
+}
+
+
+void MultitapEchoControls::ampResetClicked()
+{
+	setDefaultAmpShape();
+}
+
+
+void MultitapEchoControls::lpSamplesChanged( int begin, int end )
+{
+	const float * samples = m_lpGraph.samples();
+	for( int i = begin; i <= end; ++i )
+	{
+		m_effect->m_lpFreq[i] = 20.0f * exp10f( samples[i] );
+	}
+	m_effect->updateFilters( begin, end );
+}
+
+
+void MultitapEchoControls::lpResetClicked()
+{
+	setDefaultLpShape();
+}
+
+
+void MultitapEchoControls::lengthChanged()
+{
+	m_ampGraph.setLength( m_steps.value() );
+	m_lpGraph.setLength( m_steps.value() );
+}
+
+
+void MultitapEchoControls::sampleRateChanged()
+{
+	m_effect->updateFilters( 0, 19 );
+}

plugins/MultitapEcho/MultitapEchoControls.h

@@ -0,0 +1,90 @@
+/*
+ * MultitapEchoControls.h - a multitap echo delay plugin
+ *
+ * Copyright (c) 2014 Vesa Kivimäki <contact/dot/diizy/at/nbl/dot/fi>
+ * Copyright (c) 2008-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ *
+ * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+ 
+#ifndef MULTITAP_ECHO_CONTROLS_H
+#define MULTITAP_ECHO_CONTROLS_H
+
+#include "EffectControls.h"
+#include "MultitapEchoControlDialog.h"
+#include "Knob.h"
+#include "Graph.h"
+
+
+class MultitapEchoEffect;
+
+class MultitapEchoControls : public EffectControls
+{
+	Q_OBJECT
+public:
+	MultitapEchoControls( MultitapEchoEffect * eff );
+	virtual ~MultitapEchoControls();
+
+	virtual void saveSettings( QDomDocument & doc, QDomElement & parent );
+	virtual void loadSettings( const QDomElement & elem );
+	inline virtual QString nodeName() const
+	{
+		return( "multitapechocontrols" );
+	}
+
+	void setDefaultAmpShape();
+	void setDefaultLpShape();
+
+	virtual int controlCount()
+	{
+		return( 4 );
+	}
+
+	virtual EffectControlDialog * createView()
+	{
+		return( new MultitapEchoControlDialog( this ) );
+	}
+
+private slots:
+	void ampSamplesChanged( int, int );
+	void ampResetClicked();
+	
+	void lpSamplesChanged( int, int );
+	void lpResetClicked();
+	
+	void lengthChanged();
+	void sampleRateChanged();
+
+private:
+	MultitapEchoEffect * m_effect;
+	IntModel m_steps;
+	TempoSyncKnobModel m_stepLength;
+	
+	FloatModel m_dryGain;
+	BoolModel m_swapInputs;
+	
+	graphModel m_ampGraph;
+	graphModel m_lpGraph;
+
+	friend class MultitapEchoEffect;
+	friend class MultitapEchoControlDialog;
+};
+
+
+#endif

src/core/MixHelpers.cpp

@@ -124,6 +124,25 @@ void addMultiplied( sampleFrame* dst, const sampleFrame* src, float coeffSrc, in
 }
 
 
+struct AddSwappedMultipliedOp
+{
+	AddSwappedMultipliedOp( float coeff ) : m_coeff( coeff ) { }
+
+	void operator()( sampleFrame& dst, const sampleFrame& src ) const
+	{
+		dst[0] += src[1] * m_coeff;
+		dst[1] += src[0] * m_coeff;
+	}
+
+	const float m_coeff;
+};
+
+void addSwappedMultiplied( sampleFrame* dst, const sampleFrame* src, float coeffSrc, int frames )
+{
+	run<>( dst, src, frames, AddSwappedMultipliedOp(coeffSrc) );
+}
+
+
 void addMultipliedByBuffer( sampleFrame* dst, const sampleFrame* src, float coeffSrc, ValueBuffer * coeffSrcBuf, int frames )
 {
 	for( int f = 0; f < frames; ++f )

src/core/RingBuffer.cpp

@@ -272,6 +272,33 @@ void RingBuffer::writeAddingMultiplied( sampleFrame * src, float offset, f_cnt_t
 }
 
 
+void RingBuffer::writeSwappedAddingMultiplied( sampleFrame * src, f_cnt_t offset, f_cnt_t length, float level )
+{
+	const f_cnt_t pos = ( m_position + offset ) % m_size;
+	if( length == 0 ) { length = m_fpp; }
+	
+	if( pos + length <= m_size ) // we won't go over the edge so we can just memcpy here
+	{
+		MixHelpers::addSwappedMultiplied( m_buffer + ( pos * sizeof( sampleFrame ) ), src, level, length );
+	}
+	else
+	{
+		f_cnt_t first = m_size - pos;
+		f_cnt_t second = length - first;
+
+		MixHelpers::addSwappedMultiplied( m_buffer + ( pos * sizeof( sampleFrame ) ), src, level, first );
+		
+		MixHelpers::addSwappedMultiplied( m_buffer, src + ( first * sizeof( sampleFrame ) ), level, second );
+	}
+}
+
+
+void RingBuffer::writeSwappedAddingMultiplied( sampleFrame * src, float offset, f_cnt_t length, float level )
+{
+	writeSwappedAddingMultiplied( src, msToFrames( offset ), length, level );
+}
+
+
 void RingBuffer::updateSamplerate()
 {
 	float newsize = static_cast<float>( ( m_size - m_fpp ) * Engine::mixer()->processingSampleRate() ) / m_samplerate;

src/gui/widgets/Graph.cpp

@@ -444,6 +444,7 @@ graphModel::graphModel( float _min, float _max, int _length,
 			::Model * _parent, bool _default_constructed,  float _step ) :
 	Model( _parent, tr( "Graph" ), _default_constructed ),
 	m_samples( _length ),
+	m_length( _length ),
 	m_minValue( _min ),
 	m_maxValue( _max ),
 	m_step( _step )
@@ -482,9 +483,13 @@ void graphModel::setRange( float _min, float _max )
 
 void graphModel::setLength( int _length )
 {
-	if( _length != length() )
+	if( _length != m_length )
 	{
-		m_samples.resize( _length );
+		m_length = _length;
+		if( m_samples.size() < m_length )
+		{
+			m_samples.resize( m_length );
+		}
 		emit lengthChanged();
 	}
 }