STK guitar model class. More...

#include <Guitar.h>

Inheritance diagram for stk::Guitar:

Public Member Functions
	Guitar (unsigned int nStrings=6, std::string bodyfile="")
	Class constructor, specifying an arbitrary number of strings (default = 6).

void	clear (void)
	Reset and clear all internal state.

void	setBodyFile (std::string bodyfile="")
	Set the string excitation, using either a soundfile or computed noise.

void	setPluckPosition (StkFloat position, int string=-1)
	Set the pluck position for one or all strings.

void	setLoopGain (StkFloat gain, int string=-1)
	Set the loop gain for one or all strings.

void	setFrequency (StkFloat frequency, unsigned int string=0)
	Set instrument parameters for a particular frequency.

void	noteOn (StkFloat frequency, StkFloat amplitude, unsigned int string=0)
	Start a note with the given frequency and amplitude.

void	noteOff (StkFloat amplitude, unsigned int string=0)
	Stop a note with the given amplitude (speed of decay).

void	controlChange (int number, StkFloat value, int string=-1)
	Perform the control change specified by number and value (0.0 - 128.0).

StkFloat	lastOut (void)
	Return the last computed output value.

StkFloat	tick (StkFloat input=0.0)
	Take an optional input sample and compute one output sample.

StkFrames &	tick (StkFrames &frames, unsigned int channel=0)
	Take a channel of the `iFrames` object as inputs to the class and write outputs to the `oFrames` object.

StkFrames &	tick (StkFrames &iFrames, StkFrames &oFrames, unsigned int iChannel=0, unsigned int oChannel=0)
	Take a channel of the `iFrames` object as inputs to the effect and write outputs to the `oFrames` object.

Public Member Functions inherited from stk::Stk
void	ignoreSampleRateChange (bool ignore=true)
	A function to enable/disable the automatic updating of class data when the STK sample rate changes.

Additional Inherited Members
Static Public Member Functions inherited from stk::Stk
static StkFloat	sampleRate (void)
	Static method that returns the current STK sample rate.

static void	setSampleRate (StkFloat rate)
	Static method that sets the STK sample rate.

static void	clear_alertList ()
	Static method that frees memory from alertList_.

static std::string	rawwavePath (void)
	Static method that returns the current rawwave path.

static void	setRawwavePath (std::string path)
	Static method that sets the STK rawwave path.

static void	swap16 (unsigned char *ptr)
	Static method that byte-swaps a 16-bit data type.

static void	swap32 (unsigned char *ptr)
	Static method that byte-swaps a 32-bit data type.

static void	swap64 (unsigned char *ptr)
	Static method that byte-swaps a 64-bit data type.

static void	sleep (unsigned long milliseconds)
	Static cross-platform method to sleep for a number of milliseconds.

static bool	inRange (StkFloat value, StkFloat min, StkFloat max)
	Static method to check whether a value is within a specified range.

static void	handleError (const char *message, StkError::Type type)
	Static function for error reporting and handling using c-strings.

static void	handleError (std::string message, StkError::Type type)
	Static function for error reporting and handling using c++ strings.

static void	showWarnings (bool status)
	Toggle display of WARNING and STATUS messages.

static void	printErrors (bool status)
	Toggle display of error messages before throwing exceptions.

Static Public Attributes inherited from stk::Stk
static const StkFormat	STK_SINT8

static const StkFormat	STK_SINT16

static const StkFormat	STK_SINT24

static const StkFormat	STK_SINT32

static const StkFormat	STK_FLOAT32

static const StkFormat	STK_FLOAT64

Protected Member Functions inherited from stk::Stk
	Stk (void)
	Default constructor.

virtual	~Stk (void)
	Class destructor.

virtual void	sampleRateChanged (StkFloat newRate, StkFloat oldRate)
	This function should be implemented in subclasses that depend on the sample rate.

void	addSampleRateAlert (Stk *ptr)
	Add class pointer to list for sample rate change notification.

void	removeSampleRateAlert (Stk *ptr)
	Remove class pointer from list for sample rate change notification.

void	handleError (StkError::Type type) const
	Internal function for error reporting that assumes message in `oStream_` variable.

Detailed Description

STK guitar model class.

This class implements a guitar model with an arbitrary number of strings (specified during instantiation). Each string is represented by an stk::Twang object. The model supports commuted synthesis, as discussed by Smith and Karjalainen. It also includes a basic body coupling model and supports feedback.

This class does not attempt voice management. Rather, most functions support a parameter to specify a particular string number and string (voice) management is assumed to occur externally. Note that this class does not inherit from stk::Instrmnt because of API inconsistencies.

This is a digital waveguide model, making its use possibly subject to patents held by Stanford University, Yamaha, and others.

Control Change Numbers:

Bridge Coupling Gain = 2
Pluck Position = 4
Loop Gain = 11
Coupling Filter Pole = 1
Pick Filter Pole = 128

by Gary P. Scavone, 2012.

Member Function Documentation

◆ setBodyFile()

void stk::Guitar::setBodyFile ( std::string bodyfile = "" )

Set the string excitation, using either a soundfile or computed noise.

If no argument is provided, the std::string is empty, or an error occurs reading the file data, an enveloped noise signal will be generated for use as the pluck excitation.

◆ setPluckPosition()

void stk::Guitar::setPluckPosition	(	StkFloat	position,
		int	string = `-1`
	)

Set the pluck position for one or all strings.

If the string argument is < 0, the pluck position is set for all strings.

◆ setLoopGain()

void stk::Guitar::setLoopGain	(	StkFloat	gain,
		int	string = `-1`
	)

Set the loop gain for one or all strings.

If the string argument is < 0, the loop gain is set for all strings.

◆ noteOn()

void stk::Guitar::noteOn	(	StkFloat	frequency,
		StkFloat	amplitude,
		unsigned int	string = `0`
	)

Start a note with the given frequency and amplitude.

If the amplitude parameter is less than 0.2, the string will be undamped but it will not be "plucked."

◆ controlChange()

void stk::Guitar::controlChange	(	int	number,
		StkFloat	value,
		int	string = `-1`
	)

Perform the control change specified by number and value (0.0 - 128.0).

If the string argument is < 0, then the control change is applied to all strings (if appropriate).

◆ tick() [1/2]

StkFrames & stk::Guitar::tick	(	StkFrames &	frames,
		unsigned int	channel = `0`
	)

inline

Take a channel of the iFrames object as inputs to the class and write outputs to the oFrames object.

The iFrames object reference is returned. Each channel argument must be less than the number of channels in the corresponding StkFrames argument (the first channel is specified by 0). However, range checking is only performed if STK_DEBUG is defined during compilation, in which case an out-of-range value will trigger an StkError exception.

{
#if defined(_STK_DEBUG_)
  if ( channel >= frames.channels() ) {
    oStream_ << "Guitar::tick(): channel and StkFrames arguments are incompatible!";
    handleError( StkError::FUNCTION_ARGUMENT );
  }
#endif
 
  StkFloat *samples = &frames[channel];
  unsigned int hop = frames.channels();
  for ( unsigned int i=0; i<frames.frames(); i++, samples += hop )
    *samples = tick( *samples );
 
  return frames;
}

◆ tick() [2/2]

StkFrames & stk::Guitar::tick	(	StkFrames &	iFrames,
		StkFrames &	oFrames,
		unsigned int	iChannel = `0`,
		unsigned int	oChannel = `0`
	)