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stk::Echo Class Reference

STK echo effect class. More...

#include <Echo.h>

Inheritance diagram for stk::Echo:
stk::Effect stk::Stk

Public Member Functions

 Echo (unsigned long maximumDelay=(unsigned long) Stk::sampleRate())
 Class constructor, taking the longest desired delay length (one second default value). More...
 
void clear ()
 Reset and clear all internal state.
 
void setMaximumDelay (unsigned long delay)
 Set the maximum delay line length in samples.
 
void setDelay (unsigned long delay)
 Set the delay line length in samples.
 
StkFloat lastOut (void) const
 Return the last computed output value.
 
StkFloat tick (StkFloat input)
 Input one sample to the effect and return one output.
 
StkFramestick (StkFrames &frames, unsigned int channel=0)
 Take a channel of the StkFrames object as inputs to the effect and replace with corresponding outputs. More...
 
StkFramestick (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. More...
 
- 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 StkFrameslastFrame (void) const
 Return an StkFrames reference to the last output sample frame.
 
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. More...
 

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. More...
 
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 echo effect class.

This class implements an echo effect.

by Perry R. Cook and Gary P. Scavone, 1995–2014.

Constructor & Destructor Documentation

stk::Echo::Echo ( unsigned long  maximumDelay = (unsigned long) Stk::sampleRate())

Class constructor, taking the longest desired delay length (one second default value).

The default delay value is set to 1/2 the maximum delay length.

Member Function Documentation

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

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

The StkFrames argument reference is returned. The channel argument must be less than the number of channels in 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.

79 {
80 #if defined(_STK_DEBUG_)
81  if ( channel >= frames.channels() ) {
82  oStream_ << "Echo::tick(): channel and StkFrames arguments are incompatible!";
83  handleError( StkError::FUNCTION_ARGUMENT );
84  }
85 #endif
86 
87  StkFloat *samples = &frames[channel];
88  unsigned int hop = frames.channels();
89  for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
90  *samples = effectMix_ * ( delayLine_.tick( *samples ) - *samples ) + *samples;
91  }
92 
93  lastFrame_[0] = *(samples-hop);
94  return frames;
95 }
StkFrames & stk::Echo::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 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.

98 {
99 #if defined(_STK_DEBUG_)
100  if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) {
101  oStream_ << "Echo::tick(): channel and StkFrames arguments are incompatible!";
102  handleError( StkError::FUNCTION_ARGUMENT );
103  }
104 #endif
105 
106  StkFloat *iSamples = &iFrames[iChannel];
107  StkFloat *oSamples = &oFrames[oChannel];
108  unsigned int iHop = iFrames.channels(), oHop = oFrames.channels();
109  for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) {
110  *oSamples = effectMix_ * ( delayLine_.tick( *iSamples ) - *iSamples ) + *iSamples;
111  }
112 
113  lastFrame_[0] = *(oSamples-oHop);
114  return iFrames;
115 }

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

The Synthesis ToolKit in C++ (STK)
©1995--2014 Perry R. Cook and Gary P. Scavone. All Rights Reserved.