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STK enhanced plucked string class. More...
#include <Twang.h>
Public Member Functions | |
Twang (StkFloat lowestFrequency=50.0) | |
Class constructor, taking the lowest desired playing frequency. | |
void | clear (void) |
Reset and clear all internal state. | |
void | setLowestFrequency (StkFloat frequency) |
Set the delayline parameters to allow frequencies as low as specified. | |
void | setFrequency (StkFloat frequency) |
Set the delayline parameters for a particular frequency. | |
void | setPluckPosition (StkFloat position) |
Set the pluck or "excitation" position along the string (0.0 - 1.0). | |
void | setLoopGain (StkFloat loopGain) |
Set the nominal loop gain. | |
void | setLoopFilter (std::vector< StkFloat > coefficients) |
Set the loop filter coefficients. | |
StkFloat | lastOut (void) |
Return an StkFrames reference to the last output sample frame. | |
StkFloat | tick (StkFloat input) |
Compute and return one output sample. | |
StkFrames & | tick (StkFrames &frames, unsigned int channel=0) |
Take a channel of the iFrames object as inputs to the class and write outputs to the oFrames object. | |
StkFrames & | tick (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. |
STK enhanced plucked string class.
This class implements an enhanced plucked-string physical model, a la Jaffe-Smith, Smith, Karjalainen and others. It includes a comb filter to simulate pluck position. The tick() function takes an input sample, which is added to the delayline input. This can be used to implement commuted synthesis (if the input samples are derived from the impulse response of a body filter) and/or feedback (as in an electric guitar model).
This is a digital waveguide model, making its use possibly subject to patents held by Stanford University, Yamaha, and others.
by Perry R. Cook and Gary P. Scavone, 1995-2012.
void stk::Twang::setLoopGain | ( | StkFloat | loopGain | ) |
Set the nominal loop gain.
The actual loop gain is based on the value set with this function, but scaled slightly according to the frequency. Higher frequency settings have greater loop gains because of high-frequency loop-filter roll-off.
void stk::Twang::setLoopFilter | ( | std::vector< StkFloat > | coefficients | ) |
Set the loop filter coefficients.
The loop filter can be any arbitrary FIR filter. By default, the coefficients are set for a first-order lowpass filter with coefficients b = [0.5 0.5].
StkFloat stk::Twang::lastOut | ( | void | ) | [inline] |
Return an StkFrames reference to the last output sample frame.
Return the last computed output value.
Take a channel of the iFrames
object as inputs to the class 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.
00123 { 00124 #if defined(_STK_DEBUG_) 00125 if ( channel >= frames.channels() ) { 00126 oStream_ << "Twang::tick(): channel and StkFrames arguments are incompatible!"; 00127 handleError( StkError::FUNCTION_ARGUMENT ); 00128 } 00129 #endif 00130 00131 StkFloat *samples = &frames[channel]; 00132 unsigned int hop = frames.channels(); 00133 for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) 00134 *samples = tick( *samples ); 00135 00136 return frames; 00137 }
StkFrames & stk::Twang::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.
00140 { 00141 #if defined(_STK_DEBUG_) 00142 if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) { 00143 oStream_ << "Twang::tick(): channel and StkFrames arguments are incompatible!"; 00144 handleError( StkError::FUNCTION_ARGUMENT ); 00145 } 00146 #endif 00147 00148 StkFloat *iSamples = &iFrames[iChannel]; 00149 StkFloat *oSamples = &oFrames[oChannel]; 00150 unsigned int iHop = iFrames.channels(), oHop = oFrames.channels(); 00151 for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) 00152 *oSamples = tick( *iSamples ); 00153 00154 return iFrames; 00155 }
The Synthesis ToolKit in C++ (STK) |
©1995-2012 Perry R. Cook and Gary P. Scavone. All Rights Reserved. |