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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. | |
~Twang (void) | |
Class destructor. | |
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. | |
const StkFrames & | lastFrame (void) const |
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, 1995-2011.
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].
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.
00121 { 00122 #if defined(_STK_DEBUG_) 00123 if ( channel >= frames.channels() ) { 00124 oStream_ << "Twang::tick(): channel and StkFrames arguments are incompatible!"; 00125 handleError( StkError::FUNCTION_ARGUMENT ); 00126 } 00127 #endif 00128 00129 StkFloat *samples = &frames[channel]; 00130 unsigned int hop = frames.channels(); 00131 for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) 00132 *samples = tick( *samples ); 00133 00134 return frames; 00135 }
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.
00138 { 00139 #if defined(_STK_DEBUG_) 00140 if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) { 00141 oStream_ << "Twang::tick(): channel and StkFrames arguments are incompatible!"; 00142 handleError( StkError::FUNCTION_ARGUMENT ); 00143 } 00144 #endif 00145 00146 StkFloat *iSamples = &iFrames[iChannel]; 00147 StkFloat *oSamples = &oFrames[oChannel]; 00148 unsigned int iHop = iFrames.channels(), oHop = oFrames.channels(); 00149 for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) 00150 *oSamples = tick( *iSamples ); 00151 00152 return iFrames; 00153 }
The Synthesis ToolKit in C++ (STK) |
©1995-2011 Perry R. Cook and Gary P. Scavone. All Rights Reserved. |