stk::Chorus Class Reference

STK chorus effect class. More...

#include <Chorus.h>

Inheritance diagram for stk::Chorus:

Public Member Functions
	Chorus (StkFloat baseDelay=6000)
	Class constructor, taking the median desired delay length.
void	clear (void)
	Reset and clear all internal state.
void	setModDepth (StkFloat depth)
	Set modulation depth in range 0.0 - 1.0.
void	setModFrequency (StkFloat frequency)
	Set modulation frequency.
StkFloat	lastOut (unsigned int channel=0)
	Return the specified channel value of the last computed stereo frame.
StkFloat	tick (StkFloat input, unsigned int channel=0)
	Input one sample to the effect and return the specified channel value of the computed stereo frame.
StkFrames &	tick (StkFrames &frames, unsigned int channel=0)
	Take a channel of the StkFrames object as inputs to the effect and replace with stereo outputs.
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 stereo outputs to the oFrames object.
Public Member Functions inherited from stk::Effect
	Effect (void)
	Class constructor.
unsigned int	channelsOut (void) const
	Return the number of output channels for the class.
const StkFrames &	lastFrame (void) const
	Return an StkFrames reference to the last output sample frame.
virtual void	clear ()=0
	Reset and clear all internal state.
virtual void	setEffectMix (StkFloat mix)
	Set the mixture of input and "effected" levels in the output (0.0 = input only, 1.0 = effect only).
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 chorus effect class.

This class implements a chorus effect. It takes a monophonic input signal and produces a stereo output signal.

by Perry R. Cook and Gary P. Scavone, 1995–2023.

Constructor & Destructor Documentation

Chorus()

stk::Chorus::Chorus

(

StkFloat

baseDelay = 6000

)

Class constructor, taking the median desired delay length.

An StkError can be thrown if the rawwave path is incorrect.

Member Function Documentation

lastOut()

StkFloat stk::Chorus::lastOut ( unsigned int  channel = 0 )

inline

Return the specified channel value of the last computed stereo frame.

Use the lastFrame() function to get both values of the last computed stereo frame. The channel argument must be 0 or 1 (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 > 1 ) {
    oStream_ << "Chorus::lastOut(): channel argument must be less than 2!";
    handleError( StkError::FUNCTION_ARGUMENT );
  }
#endif
 
  return lastFrame_[channel];
}

tick() [1/3]

StkFloat stk::Chorus::tick ( StkFloat  input, unsigned int  channel = 0  )

inline

Input one sample to the effect and return the specified channel value of the computed stereo frame.

Use the lastFrame() function to get both values of the computed stereo output frame. The channel argument must be 0 or 1 (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 > 1 ) {
    oStream_ << "Chorus::tick(): channel argument must be less than 2!";
    handleError( StkError::FUNCTION_ARGUMENT );
  }
#endif
 
  delayLine_[0].setDelay( baseLength_ * 0.707 * ( 1.0 + modDepth_ * mods_[0].tick() ) );
  delayLine_[1].setDelay( baseLength_  * 0.5 *  ( 1.0 - modDepth_ * mods_[1].tick() ) );
  lastFrame_[0] = effectMix_ * ( delayLine_[0].tick( input ) - input ) + input;
  lastFrame_[1] = effectMix_ * ( delayLine_[1].tick( input ) - input ) + input;
  return lastFrame_[channel];
}

tick() [2/3]

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

inline

Take a channel of the StkFrames object as inputs to the effect and replace with stereo outputs.

The StkFrames argument reference is returned. The stereo outputs are written to the StkFrames argument starting at the specified channel. Therefore, the channel argument must be less than ( channels() - 1 ) of the 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() - 1 ) {
    oStream_ << "Chorus::tick(): channel and StkFrames arguments are incompatible!";
    handleError( StkError::FUNCTION_ARGUMENT );
  }
#endif
 
  StkFloat *samples = &frames[channel];
  unsigned int hop = frames.channels() - 1;
  for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
    delayLine_[0].setDelay( baseLength_ * 0.707 * ( 1.0 + modDepth_ * mods_[0].tick() ) );
    delayLine_[1].setDelay( baseLength_  * 0.5 *  ( 1.0 - modDepth_ * mods_[1].tick() ) );
    *samples = effectMix_ * ( delayLine_[0].tick( *samples ) - *samples ) + *samples;
    samples++;
    *samples = effectMix_ * ( delayLine_[1].tick( *samples ) - *samples ) + *samples;
  }
 
  lastFrame_[0] = *(samples-hop);
  lastFrame_[1] = *(samples-hop+1);
  return frames;
}

tick() [3/3]

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

inline

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

The iFrames object reference is returned. The iChannel argument must be less than the number of channels in the iFrames argument (the first channel is specified by 0). The oChannel argument must be less than ( channels() - 1 ) of the oFrames argument. 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 ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() - 1 ) {
    oStream_ << "Chorus::tick(): channel and StkFrames arguments are incompatible!";
    handleError( StkError::FUNCTION_ARGUMENT );
  }
#endif
 
  StkFloat *iSamples = &iFrames[iChannel];
  StkFloat *oSamples = &oFrames[oChannel];
  unsigned int iHop = iFrames.channels(), oHop = oFrames.channels();
  for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) {
    delayLine_[0].setDelay( baseLength_ * 0.707 * ( 1.0 + modDepth_ * mods_[0].tick() ) );
    delayLine_[1].setDelay( baseLength_  * 0.5 *  ( 1.0 - modDepth_ * mods_[1].tick() ) );
    *oSamples = effectMix_ * ( delayLine_[0].tick( *iSamples ) - *iSamples ) + *iSamples;
    *(oSamples+1) = effectMix_ * ( delayLine_[1].tick( *iSamples ) - *iSamples ) + *iSamples;
  }
 
  lastFrame_[0] = *(oSamples-oHop);
  lastFrame_[1] = *(oSamples-oHop+1);
  return iFrames;
}

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The documentation for this class was generated from the following file:

• Chorus.h