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stk::SineWave Class Reference

STK sinusoid oscillator class. More...

#include <SineWave.h>

Inheritance diagram for stk::SineWave:
stk::Generator stk::Stk

Public Member Functions

 SineWave (void)
 Default constructor.
 
 ~SineWave (void)
 Class destructor.
 
void reset (void)
 Clear output and reset time pointer to zero.
 
void setRate (StkFloat rate)
 Set the data read rate in samples. The rate can be negative. More...
 
void setFrequency (StkFloat frequency)
 Set the data interpolation rate based on a looping frequency. More...
 
void addTime (StkFloat time)
 Increment the read pointer by time in samples, modulo the table size.
 
void addPhase (StkFloat phase)
 Increment the read pointer by a normalized phase value. More...
 
void addPhaseOffset (StkFloat phaseOffset)
 Add a normalized phase offset to the read pointer. More...
 
StkFloat lastOut (void) const
 Return the last computed output value.
 
StkFloat tick (void)
 Compute and return one output sample.
 
StkFramestick (StkFrames &frames, unsigned int channel=0)
 Fill a channel of the StkFrames object with computed outputs. More...
 
- Public Member Functions inherited from stk::Generator
 Generator (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.
 
- 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.
 
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 sinusoid oscillator class.

This class computes and saves a static sine "table" that can be shared by multiple instances. It has an interface similar to the WaveLoop class but inherits from the Generator class. Output values are computed using linear interpolation.

The "table" length, set in SineWave.h, is 2048 samples by default.

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

Member Function Documentation

void stk::SineWave::setRate ( StkFloat  rate)
inline

Set the data read rate in samples. The rate can be negative.

If the rate value is negative, the data is read in reverse order.

41 { rate_ = rate; };
void stk::SineWave::setFrequency ( StkFloat  frequency)

Set the data interpolation rate based on a looping frequency.

This function determines the interpolation rate based on the file size and the current Stk::sampleRate. The frequency value corresponds to file cycles per second. The frequency can be negative, in which case the loop is read in reverse order.

void stk::SineWave::addPhase ( StkFloat  phase)

Increment the read pointer by a normalized phase value.

This function increments the read pointer by a normalized phase value, such that phase = 1.0 corresponds to a 360 degree phase shift. Positive or negative values are possible.

void stk::SineWave::addPhaseOffset ( StkFloat  phaseOffset)

Add a normalized phase offset to the read pointer.

A phaseOffset = 1.0 corresponds to a 360 degree phase offset. Positive or negative values are possible.

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

Fill a channel of the StkFrames object with computed outputs.

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::Generator.

121 {
122 #if defined(_STK_DEBUG_)
123  if ( channel >= frames.channels() ) {
124  oStream_ << "SineWave::tick(): channel and StkFrames arguments are incompatible!";
125  handleError( StkError::FUNCTION_ARGUMENT );
126  }
127 #endif
128 
129  StkFloat *samples = &frames[channel];
130  StkFloat tmp = 0.0;
131 
132  unsigned int hop = frames.channels();
133  for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
134 
135  // Check limits of time address ... if necessary, recalculate modulo
136  // TABLE_SIZE.
137  while ( time_ < 0.0 )
138  time_ += TABLE_SIZE;
139  while ( time_ >= TABLE_SIZE )
140  time_ -= TABLE_SIZE;
141 
142  iIndex_ = (unsigned int) time_;
143  alpha_ = time_ - iIndex_;
144  tmp = table_[ iIndex_ ];
145  tmp += ( alpha_ * ( table_[ iIndex_ + 1 ] - tmp ) );
146  *samples = tmp;
147 
148  // Increment time, which can be negative.
149  time_ += rate_;
150  }
151 
152  lastFrame_[0] = tmp;
153  return frames;
154 }

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.