lmms/plugins/plucked_string_synth/plucked_string_synth.cpp

/*
 * plucked_string_synth.cpp - instrument which uses the Karplus-Strong-algorithm
 *
 * Copyright (c) 2004-2007 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 "qt3support.h"

#ifdef QT4

#include <Qt/QtXml>

#else

#include <qdom.h>

#endif


#include "plucked_string_synth.h"
#include "engine.h"
#include "instrument_track.h"
#include "knob.h"
#include "note_play_handle.h"
#include "templates.h"

#undef SINGLE_SOURCE_COMPILE
#include "embed.cpp"


extern "C"
{

plugin::descriptor pluckedstringsynth_plugin_descriptor =
{
	STRINGIFY_PLUGIN_NAME( PLUGIN_NAME ),
	"PluckedStringSynth",
	QT_TRANSLATE_NOOP( "pluginBrowser",
				"cheap synthesis of guitar/harp-like sounds" ),
	"Tobias Doerffel <tobydox/at/users.sf.net>",
	0x0100,
	plugin::Instrument,
	new QPixmap( PLUGIN_NAME::getIconPixmap( "logo" ) ),
	NULL
} ;

}


// TODO: make this synth stereo for better better spacial (room) feeling and
// add distortion

pluckedStringSynth::pluckedStringSynth( instrumentTrack * _instrument_track ) :
	instrument( _instrument_track, &pluckedstringsynth_plugin_descriptor )
{
	m_pickKnob = new knob( knobDark_28, this, tr( "Pick position" ),
							_instrument_track );
	m_pickKnob->setRange( 0.0f, 0.5f, 0.005f );
 	m_pickKnob->setInitValue( 0.0f );
	m_pickKnob->move( 86, 134 );
	m_pickKnob->setHintText( tr( "Pick position:" ) + " ", "" );

	m_pickupKnob = new knob( knobDark_28, this, tr( "Pickup position" ),
							_instrument_track );
	m_pickupKnob->setRange( 0.0f, 0.5f, 0.005f );
	m_pickupKnob->setInitValue( 0.05f );
	m_pickupKnob->move( 138, 134 );
	m_pickupKnob->setHintText( tr( "Pickup position:" ) + " ", "" );
#ifdef QT4
	setAutoFillBackground( TRUE );
	QPalette pal;
	pal.setBrush( backgroundRole(), PLUGIN_NAME::getIconPixmap(
								"artwork" ) );
	setPalette( pal );
#else
	setErasePixmap( PLUGIN_NAME::getIconPixmap( "artwork" ) );
#endif
}




pluckedStringSynth::~pluckedStringSynth()
{
}




void pluckedStringSynth::saveSettings( QDomDocument & _doc,
							QDomElement & _this )
{
	m_pickKnob->saveSettings( _doc, _this, "pick" );
	m_pickupKnob->saveSettings( _doc, _this, "pickup" );
}




void pluckedStringSynth::loadSettings( const QDomElement & _this )
{
	m_pickKnob->loadSettings( _this, "pick" );
	m_pickupKnob->loadSettings( _this, "pickup" );
}




QString pluckedStringSynth::nodeName( void ) const
{
	return( pluckedstringsynth_plugin_descriptor.name );
}




void pluckedStringSynth::playNote( notePlayHandle * _n, bool )
{
	if ( _n->totalFramesPlayed() == 0 )
	{
		_n->m_pluginData = new pluckSynth( _n->frequency(),
					m_pickKnob->value(),
					m_pickupKnob->value(),
					engine::getMixer()->sampleRate() );
	}

	const fpp_t frames = _n->framesLeftForCurrentPeriod();
	sampleFrame * buf = new sampleFrame[frames];

	pluckSynth * ps = static_cast<pluckSynth *>( _n->m_pluginData );
	for( fpp_t frame = 0; frame < frames; ++frame )
	{
		const sample_t cur = ps->nextStringSample();
		for( Uint8 chnl = 0; chnl < DEFAULT_CHANNELS; ++chnl )
		{
			buf[frame][chnl] = cur;
		}
	}

	getInstrumentTrack()->processAudioBuffer( buf, frames, _n );

	delete[] buf;
}




void pluckedStringSynth::deleteNotePluginData( notePlayHandle * _n )
{
	delete static_cast<pluckSynth *>( _n->m_pluginData );
}





pluckSynth::delayLine * FASTCALL pluckSynth::initDelayLine( int _len )
{
	delayLine * dl = new pluckSynth::delayLine[_len];
	dl->length = _len;
	if( _len > 0 )
	{
		dl->data = new sample_t[_len];
	}
	else
	{
		dl->data = NULL;
	}

	dl->pointer = dl->data;
	dl->end = dl->data + _len - 1;

	return( dl );
}




void FASTCALL pluckSynth::freeDelayLine( delayLine * _dl )
{
	if( _dl )
	{
		delete[] _dl->data;
		delete[] _dl;
	}
}




pluckSynth::pluckSynth( const float _pitch, const float _pick,
			const float _pickup, const sample_rate_t _sample_rate )
{
	const float AMP = 1.5f;
	int rail_length = static_cast<int>( _sample_rate / 2 / _pitch ) + 1;
	// Round pick position to nearest spatial sample.
	// A pick position at x = 0 is not allowed.
	int pick_sample = static_cast<int>( tMax<float>( rail_length * _pick,
								1.0f ) );
	float initial_shape[rail_length];

	m_upperRail = pluckSynth::initDelayLine( rail_length );
	m_lowerRail = pluckSynth::initDelayLine( rail_length );

//#define METALLIC_PLUCK
#ifdef METALLIC_PLUCK
	for ( int i = 0; i < rail_length; i++ )
	{
		initial_shape[i] = rand() * AMP / RAND_MAX;
	}

	initial_shape[pick_sample] = 0.5;
	initial_shape[pick_sample+1] = 0.5;

#else
	float upslope = AMP / pick_sample;
	const float downslope = AMP / ( rail_length - pick_sample - 1 );

	for( int i = 0; i < pick_sample; i++ )
	{
		initial_shape[i] = upslope * i;
	}

	for( int i = pick_sample; i < rail_length; i++ )
	{
		initial_shape[i] = downslope * ( rail_length - 1 - i );
	}
#endif

	// Initial conditions for the ideal plucked string.
	// "Past history" is measured backward from the end of the array.
	pluckSynth::setDelayLine( m_lowerRail, initial_shape, 0.5f );
	pluckSynth::setDelayLine( m_upperRail, initial_shape, 0.5f );

	m_pickupLoc = static_cast<int>( _pickup * rail_length );
}




extern "C"
{

// neccessary for getting instance out of shared lib
plugin * lmms_plugin_main( void * _data )
{
	return( new pluckedStringSynth(
				static_cast<instrumentTrack *>( _data ) ) );
}


}