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stk::Delay Class Reference

STK non-interpolating delay line class. More...

#include <Delay.h>

Inheritance diagram for stk::Delay:
stk::Filter stk::Stk

Public Member Functions

 Delay (unsigned long delay=0, unsigned long maxDelay=4095)
 The default constructor creates a delay-line with maximum length of 4095 samples and zero delay. More...
 
 ~Delay ()
 Class destructor.
 
unsigned long getMaximumDelay (void)
 Get the maximum delay-line length.
 
void setMaximumDelay (unsigned long delay)
 Set the maximum delay-line length. More...
 
void setDelay (unsigned long delay)
 Set the delay-line length. More...
 
unsigned long getDelay (void) const
 Return the current delay-line length.
 
StkFloat tapOut (unsigned long tapDelay)
 Return the value at tapDelay samples from the delay-line input. More...
 
void tapIn (StkFloat value, unsigned long tapDelay)
 Set the value at tapDelay samples from the delay-line input.
 
StkFloat addTo (StkFloat value, unsigned long tapDelay)
 Sum the provided value into the delay line at tapDelay samples from the input. More...
 
StkFloat lastOut (void) const
 Return the last computed output value.
 
StkFloat nextOut (void)
 Return the value that will be output by the next call to tick(). More...
 
StkFloat energy (void) const
 Calculate and return the signal energy in the delay-line.
 
StkFloat tick (StkFloat input)
 Input one sample to the filter and return one output.
 
StkFramestick (StkFrames &frames, unsigned int channel=0)
 Take a channel of the StkFrames object as inputs to the filter 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 filter and write outputs to the oFrames object. More...
 
- Public Member Functions inherited from stk::Filter
 Filter (void)
 Class constructor.
 
unsigned int channelsIn (void) const
 Return the number of input channels for the class.
 
unsigned int channelsOut (void) const
 Return the number of output channels for the class.
 
virtual void clear (void)
 Clears all internal states of the filter.
 
void setGain (StkFloat gain)
 Set the filter gain. More...
 
StkFloat getGain (void) const
 Return the current filter gain.
 
StkFloat phaseDelay (StkFloat frequency)
 Return the filter phase delay at the specified frequency. More...
 
const StkFrameslastFrame (void) const
 Return an StkFrames reference to the last output sample frame.
 
- 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 non-interpolating delay line class.

This class implements a non-interpolating digital delay-line. If the delay and maximum length are not specified during instantiation, a fixed maximum length of 4095 and a delay of zero is set.

A non-interpolating delay line is typically used in fixed delay-length applications, such as for reverberation.

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

Constructor & Destructor Documentation

stk::Delay::Delay ( unsigned long  delay = 0,
unsigned long  maxDelay = 4095 
)

The default constructor creates a delay-line with maximum length of 4095 samples and zero delay.

An StkError will be thrown if the delay parameter is less than zero, the maximum delay parameter is less than one, or the delay parameter is greater than the maxDelay value.

Member Function Documentation

void stk::Delay::setMaximumDelay ( unsigned long  delay)

Set the maximum delay-line length.

This method should generally only be used during initial setup of the delay line. If it is used between calls to the tick() function, without a call to clear(), a signal discontinuity will likely occur. If the current maximum length is greater than the new length, no memory allocation change is made.

void stk::Delay::setDelay ( unsigned long  delay)

Set the delay-line length.

The valid range for delay is from 0 to the maximum delay-line length.

StkFloat stk::Delay::tapOut ( unsigned long  tapDelay)

Return the value at tapDelay samples from the delay-line input.

The tap point is determined modulo the delay-line length and is relative to the last input value (i.e., a tapDelay of zero returns the last input value).

StkFloat stk::Delay::addTo ( StkFloat  value,
unsigned long  tapDelay 
)

Sum the provided value into the delay line at tapDelay samples from the input.

The new value is returned. The tap point is determined modulo the delay-line length and is relative to the last input value (i.e., a tapDelay of zero sums into the last input value).

StkFloat stk::Delay::nextOut ( void  )
inline

Return the value that will be output by the next call to tick().

This method is valid only for delay settings greater than zero!

87 { return inputs_[outPoint_]; };
StkFrames & stk::Delay::tick ( StkFrames frames,
unsigned int  channel = 0 
)
inlinevirtual

Take a channel of the StkFrames object as inputs to the filter 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.

Implements stk::Filter.

142 {
143 #if defined(_STK_DEBUG_)
144  if ( channel >= frames.channels() ) {
145  oStream_ << "Delay::tick(): channel and StkFrames arguments are incompatible!";
146  handleError( StkError::FUNCTION_ARGUMENT );
147  }
148 #endif
149 
150  StkFloat *samples = &frames[channel];
151  unsigned int hop = frames.channels();
152  for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
153  inputs_[inPoint_++] = *samples * gain_;
154  if ( inPoint_ == inputs_.size() ) inPoint_ = 0;
155  *samples = inputs_[outPoint_++];
156  if ( outPoint_ == inputs_.size() ) outPoint_ = 0;
157  }
158 
159  lastFrame_[0] = *(samples-hop);
160  return frames;
161 }
StkFrames & stk::Delay::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 filter 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.

164 {
165 #if defined(_STK_DEBUG_)
166  if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) {
167  oStream_ << "Delay::tick(): channel and StkFrames arguments are incompatible!";
168  handleError( StkError::FUNCTION_ARGUMENT );
169  }
170 #endif
171 
172  StkFloat *iSamples = &iFrames[iChannel];
173  StkFloat *oSamples = &oFrames[oChannel];
174  unsigned int iHop = iFrames.channels(), oHop = oFrames.channels();
175  for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) {
176  inputs_[inPoint_++] = *iSamples * gain_;
177  if ( inPoint_ == inputs_.size() ) inPoint_ = 0;
178  *oSamples = inputs_[outPoint_++];
179  if ( outPoint_ == inputs_.size() ) outPoint_ = 0;
180  }
181 
182  lastFrame_[0] = *(oSamples-oHop);
183  return iFrames;
184 }

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.