The Synthesis ToolKit in C++ (STK)

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stk::TapDelay Class Reference

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

`#include <TapDelay.h>`

Inheritance diagram for stk::TapDelay:

## Public Member Functions
| TapDelay (std::vector< unsigned long > taps=std::vector< unsigned long >(1, 0), unsigned long maxDelay=4095)
| The default constructor creates a delay-line with maximum length of 4095 samples and a single tap at delay = 0. More...
| ~TapDelay ()
| Class destructor.
void | setMaximumDelay (unsigned long delay)
| Set the maximum delay-line length. More...
void | setTapDelays (std::vector< unsigned long > taps)
| Set the delay-line tap lengths. More...
std::vector< unsigned long > | getTapDelays (void) const
| Return the current delay-line length.
StkFloat | lastOut (unsigned int tap=0) const
| Return the specified tap value of the last computed frame. More...
StkFrames & | tick (StkFloat input, StkFrames &outputs)
| Input one sample to the delayline and return outputs at all tap positions. More...
StkFrames & | tick (StkFrames &frames, unsigned int channel=0)
| Take a channel of the StkFrames object as inputs to the filter and write outputs back to the same object. More...
StkFrames & | tick (StkFrames &iFrames, StkFrames &oFrames, unsigned int iChannel=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 StkFrames & | lastFrame (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 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 non-interpolating tapped delay line class.

This class implements a non-interpolating digital delay-line with an arbitrary number of output "taps". If the maximum length and tap delays are not specified during instantiation, a fixed maximum length of 4095 and a single tap 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, 1995–2021.

## Constructor & Destructor Documentation

## ◆ TapDelay()

stk::TapDelay::TapDelay | ( | std::vector< unsigned long > | taps = `std::vector< unsigned long >(1, 0)`,
|  | unsigned long | maxDelay = `4095`
| ) |  |

The default constructor creates a delay-line with maximum length of 4095 samples and a single tap at delay = 0.

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

## Member Function Documentation

## ◆ setMaximumDelay()

void stk::TapDelay::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 change will be made.

## ◆ setTapDelays()

void stk::TapDelay::setTapDelays | ( | std::vector< unsigned long > | taps | ) |

Set the delay-line tap lengths.

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

## ◆ lastOut()

StkFloat stk::TapDelay::lastOut | ( | unsigned int | tap = `0` | ) | const
| inline

Return the specified tap value of the last computed frame.

Use the lastFrame() function to get all tap values from the last computed frame. The `tap` argument must be less than the number of delayline taps (the first tap 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.

116{
117#if defined(_STK_DEBUG_)
118 if ( tap >= lastFrame_.size() ) {
119 oStream_ << "TapDelay::lastOut(): tap argument and number of taps are incompatible!";
120 handleError( StkError::FUNCTION_ARGUMENT );
121 }
122#endif
123
124 return lastFrame_[tap];
125}
stk::StkFrames::size
size_t size() const
Returns the total number of audio samples represented by the object.
Definition: Stk.h:374
stk::Stk::handleError
static void handleError(const char *message, StkError::Type type)
Static function for error reporting and handling using c-strings.

## ◆ tick() [1/3]

StkFrames & stk::TapDelay::tick | ( | StkFloat | input,
|  | StkFrames & | outputs
| ) |  |
| inline

Input one sample to the delayline and return outputs at all tap positions.

The StkFrames argument reference is returned. The output values are ordered according to the tap positions set using the setTapDelays() function (no sorting is performed). The StkFrames argument must contain at least as many channels as the number of taps. 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.

128{
129#if defined(_STK_DEBUG_)
130 if ( outputs.channels() < outPoint_.size() ) {
131 oStream_ << "TapDelay::tick(): number of taps > channels in StkFrames argument!";
132 handleError( StkError::FUNCTION_ARGUMENT );
133 }
134#endif
135
136 inputs_[inPoint_++] = input * gain_;
137
138 // Check for end condition
139 if ( inPoint_ == inputs_.size() )
140 inPoint_ = 0;
141
142 // Read out next values
143 StkFloat *outs = &outputs[0];
144 for ( unsigned int i=0; i<outPoint_.size(); i++ ) {
145 *outs++ = inputs_[outPoint_[i]];
146 lastFrame_[i] = *outs;
147 if ( ++outPoint_[i] == inputs_.size() )
148 outPoint_[i] = 0;
149 }
150
151 return outputs;
152}

## ◆ tick() [2/3]

StkFrames & stk::TapDelay::tick | ( | StkFrames & | frames,
|  | unsigned int | channel = `0`
| ) |  |
| inlinevirtual

Take a channel of the StkFrames object as inputs to the filter and write outputs back to the same object.

The StkFrames argument reference is returned. The output values are ordered according to the tap positions set using the setTapDelays() function (no sorting is performed). The StkFrames argument must contain at least as many channels as the number of taps. 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.

155{
156#if defined(_STK_DEBUG_)
157 if ( channel >= frames.channels() ) {
158 oStream_ << "TapDelay::tick(): channel and StkFrames arguments are incompatible!";
159 handleError( StkError::FUNCTION_ARGUMENT );
160 }
161 if ( frames.channels() < outPoint_.size() ) {
162 oStream_ << "TapDelay::tick(): number of taps > channels in StkFrames argument!";
163 handleError( StkError::FUNCTION_ARGUMENT );
164 }
165#endif
166
167 StkFloat *iSamples = &frames[channel];
168 StkFloat *oSamples = &frames[0];
169 std::size_t j;
170 unsigned int iHop = frames.channels();
171 std::size_t oHop = frames.channels() - outPoint_.size();
172 for ( unsigned long i=0; i<frames.frames(); i++, iSamples += iHop, oSamples += oHop ) {
173 inputs_[inPoint_++] = *iSamples * gain_;
174 if ( inPoint_ == inputs_.size() ) inPoint_ = 0;
175 for ( j=0; j<outPoint_.size(); j++ ) {
176 *oSamples++ = inputs_[outPoint_[j]];
177 if ( ++outPoint_[j] == inputs_.size() ) outPoint_[j] = 0;
178 }
179 }
180
181 oSamples -= frames.channels();
182 for ( j=0; j<outPoint_.size(); j++ ) lastFrame_[j] = *oSamples++;
183 return frames;
184}
stk::StkFrames::channels
unsigned int channels(void) const
Return the number of channels represented by the data.
Definition: Stk.h:416

## ◆ tick() [3/3]

StkFrames & stk::TapDelay::tick | ( | StkFrames & | iFrames,
|  | StkFrames & | oFrames,
|  | unsigned int | iChannel = `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. The output values are ordered according to the tap positions set using the setTapDelays() function (no sorting is performed). The `iChannel` argument must be less than the number of channels in the `iFrames` argument (the first channel is specified by 0). The `oFrames` argument must contain at least as many channels as the number of taps. 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.

187{
188#if defined(_STK_DEBUG_)
189 if ( iChannel >= iFrames.channels() ) {
190 oStream_ << "TapDelay::tick(): channel and StkFrames arguments are incompatible!";
191 handleError( StkError::FUNCTION_ARGUMENT );
192 }
193 if ( oFrames.channels() < outPoint_.size() ) {
194 oStream_ << "TapDelay::tick(): number of taps > channels in output StkFrames argument!";
195 handleError( StkError::FUNCTION_ARGUMENT );
196 }
197#endif
198
199 StkFloat *iSamples = &iFrames[iChannel];
200 StkFloat *oSamples = &oFrames[0];
201 std::size_t j;
202 unsigned int iHop = iFrames.channels();
203 std::size_t oHop = oFrames.channels() - outPoint_.size();
204 for ( unsigned long i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) {
205 inputs_[inPoint_++] = *iSamples * gain_;
206 if ( inPoint_ == inputs_.size() ) inPoint_ = 0;
207 for ( j=0; j<outPoint_.size(); j++ ) {
208 *oSamples++ = inputs_[outPoint_[j]];
209 if ( ++outPoint_[j] == inputs_.size() ) outPoint_[j] = 0;
210 }
211 }
212
213 oSamples -= oFrames.channels();
214 for ( j=0; j<outPoint_.size(); j++ ) lastFrame_[j] = *oSamples++;
215 return iFrames;
216}

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

- TapDelay.h

The Synthesis ToolKit in C++ (STK)
©1995--2021 Perry R. Cook and Gary P. Scavone. All Rights Reserved.