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135 lines
3.8 KiB
C++
135 lines
3.8 KiB
C++
#ifndef STK_FMVOICES_H
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#define STK_FMVOICES_H
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#include "FM.h"
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namespace stk {
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/***************************************************/
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/*! \class FMVoices
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\brief STK singing FM synthesis instrument.
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This class implements 3 carriers and a common
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modulator, also referred to as algorithm 6 of
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the TX81Z.
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\code
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Algorithm 6 is :
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/->1 -\
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4-|-->2 - +-> Out
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\->3 -/
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\endcode
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Control Change Numbers:
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- Vowel = 2
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- Spectral Tilt = 4
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- LFO Speed = 11
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- LFO Depth = 1
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- ADSR 2 & 4 Target = 128
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The basic Chowning/Stanford FM patent expired
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in 1995, but there exist follow-on patents,
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mostly assigned to Yamaha. If you are of the
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type who should worry about this (making
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money) worry away.
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by Perry R. Cook and Gary P. Scavone, 1995-2012.
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*/
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/***************************************************/
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class FMVoices : public FM
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{
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public:
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//! Class constructor.
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/*!
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An StkError will be thrown if the rawwave path is incorrectly set.
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*/
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FMVoices( void );
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//! Class destructor.
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~FMVoices( void );
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//! Set instrument parameters for a particular frequency.
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void setFrequency( StkFloat frequency );
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//! Start a note with the given frequency and amplitude.
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void noteOn( StkFloat frequency, StkFloat amplitude );
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//! Perform the control change specified by \e number and \e value (0.0 - 128.0).
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void controlChange( int number, StkFloat value );
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//! Compute and return one output sample.
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StkFloat tick( unsigned int channel = 0 );
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//! Fill a channel of the StkFrames object with computed outputs.
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/*!
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The \c channel argument must be less than the number of
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channels in the StkFrames argument (the first channel is specified
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by 0). However, range checking is only performed if _STK_DEBUG_
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is defined during compilation, in which case an out-of-range value
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will trigger an StkError exception.
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*/
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StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );
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protected:
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int currentVowel_;
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StkFloat tilt_[3];
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StkFloat mods_[3];
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};
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inline StkFloat FMVoices :: tick( unsigned int )
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{
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register StkFloat temp, temp2;
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temp = gains_[3] * adsr_[3]->tick() * waves_[3]->tick();
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temp2 = vibrato_.tick() * modDepth_ * 0.1;
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waves_[0]->setFrequency(baseFrequency_ * (1.0 + temp2) * ratios_[0]);
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waves_[1]->setFrequency(baseFrequency_ * (1.0 + temp2) * ratios_[1]);
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waves_[2]->setFrequency(baseFrequency_ * (1.0 + temp2) * ratios_[2]);
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waves_[3]->setFrequency(baseFrequency_ * (1.0 + temp2) * ratios_[3]);
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waves_[0]->addPhaseOffset(temp * mods_[0]);
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waves_[1]->addPhaseOffset(temp * mods_[1]);
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waves_[2]->addPhaseOffset(temp * mods_[2]);
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waves_[3]->addPhaseOffset( twozero_.lastOut() );
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twozero_.tick( temp );
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temp = gains_[0] * tilt_[0] * adsr_[0]->tick() * waves_[0]->tick();
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temp += gains_[1] * tilt_[1] * adsr_[1]->tick() * waves_[1]->tick();
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temp += gains_[2] * tilt_[2] * adsr_[2]->tick() * waves_[2]->tick();
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lastFrame_[0] = temp * 0.33;
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return lastFrame_[0];
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}
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inline StkFrames& FMVoices :: tick( StkFrames& frames, unsigned int channel )
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{
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unsigned int nChannels = lastFrame_.channels();
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#if defined(_STK_DEBUG_)
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if ( channel > frames.channels() - nChannels ) {
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oStream_ << "FMVoices::tick(): channel and StkFrames arguments are incompatible!";
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handleError( StkError::FUNCTION_ARGUMENT );
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}
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#endif
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StkFloat *samples = &frames[channel];
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unsigned int j, hop = frames.channels() - nChannels;
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if ( nChannels == 1 ) {
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for ( unsigned int i=0; i<frames.frames(); i++, samples += hop )
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*samples++ = tick();
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}
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else {
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for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
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*samples++ = tick();
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for ( j=1; j<nChannels; j++ )
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*samples++ = lastFrame_[j];
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}
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}
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return frames;
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}
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} // stk namespace
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#endif
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