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stk::StifKarp Class Reference

STK plucked stiff string instrument. More...

#include <StifKarp.h>

Inheritance diagram for stk::StifKarp:
stk::Instrmnt stk::Stk

List of all members.

Public Member Functions

 StifKarp (StkFloat lowestFrequency=8.0)
 Class constructor, taking the lowest desired playing frequency.
 ~StifKarp (void)
 Class destructor.
void clear (void)
 Reset and clear all internal state.
void setFrequency (StkFloat frequency)
 Set instrument parameters for a particular frequency.
void setStretch (StkFloat stretch)
 Set the stretch "factor" of the string (0.0 - 1.0).
void setPickupPosition (StkFloat position)
 Set the pluck or "excitation" position along the string (0.0 - 1.0).
void setBaseLoopGain (StkFloat aGain)
 Set the base loop gain.
void pluck (StkFloat amplitude)
 Pluck the string with the given amplitude using the current frequency.
void noteOn (StkFloat frequency, StkFloat amplitude)
 Start a note with the given frequency and amplitude.
void noteOff (StkFloat amplitude)
 Stop a note with the given amplitude (speed of decay).
void controlChange (int number, StkFloat value)
 Perform the control change specified by number and value (0.0 - 128.0).
StkFloat tick (unsigned int channel=0)
 Compute and return one output sample.
StkFramestick (StkFrames &frames, unsigned int channel=0)
 Fill a channel of the StkFrames object with computed outputs.

Detailed Description

STK plucked stiff string instrument.

This class implements a simple plucked string algorithm (Karplus Strong) with enhancements (Jaffe-Smith, Smith, and others), including string stiffness and pluck position controls. The stiffness is modeled with allpass filters.

This is a digital waveguide model, making its use possibly subject to patents held by Stanford University, Yamaha, and others.

Control Change Numbers:

by Perry R. Cook and Gary P. Scavone, 1995-2012.

Member Function Documentation

void stk::StifKarp::setBaseLoopGain ( StkFloat  aGain  ) 

Set the base loop gain.

The actual loop gain is set according to the frequency. Because of high-frequency loop filter roll-off, higher frequency settings have greater loop gains.

StkFrames & stk::StifKarp::tick ( StkFrames frames,
unsigned int  channel = 0 
) [inline, virtual]

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::Instrmnt.

00126 {
00127   unsigned int nChannels = lastFrame_.channels();
00128 #if defined(_STK_DEBUG_)
00129   if ( channel > frames.channels() - nChannels ) {
00130     oStream_ << "StifKarp::tick(): channel and StkFrames arguments are incompatible!";
00131     handleError( StkError::FUNCTION_ARGUMENT );
00132   }
00133 #endif
00135   StkFloat *samples = &frames[channel];
00136   unsigned int j, hop = frames.channels() - nChannels;
00137   if ( nChannels == 1 ) {
00138     for ( unsigned int i=0; i<frames.frames(); i++, samples += hop )
00139       *samples++ = tick();
00140   }
00141   else {
00142     for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
00143       *samples++ = tick();
00144       for ( j=1; j<nChannels; j++ )
00145         *samples++ = lastFrame_[j];
00146     }
00147   }
00149   return frames;
00150 }

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

The Synthesis ToolKit in C++ (STK)
©1995-2012 Perry R. Cook and Gary P. Scavone. All Rights Reserved.