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- #ifndef STK_CHORUS_H
- #define STK_CHORUS_H
-
- #include "Effect.h"
- #include "DelayL.h"
- #include "SineWave.h"
-
- namespace stk {
-
- /***************************************************/
- /*! \class Chorus
- \brief STK chorus effect class.
-
- This class implements a chorus effect. It takes a monophonic
- input signal and produces a stereo output signal.
-
- by Perry R. Cook and Gary P. Scavone, 1995--2017.
- */
- /***************************************************/
-
- class Chorus : public Effect
- {
- public:
- //! Class constructor, taking the median desired delay length.
- /*!
- An StkError can be thrown if the rawwave path is incorrect.
- */
- Chorus( StkFloat baseDelay = 6000 );
-
- //! Reset and clear all internal state.
- void clear( void );
-
- //! Set modulation depth in range 0.0 - 1.0.
- void setModDepth( StkFloat depth );
-
- //! Set modulation frequency.
- void setModFrequency( StkFloat frequency );
-
- //! Return the specified channel value of the last computed stereo frame.
- /*!
- Use the lastFrame() function to get both values of the last
- computed stereo frame. The \c channel argument must be 0 or 1
- (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.
- */
- StkFloat lastOut( unsigned int channel = 0 );
-
- //! Input one sample to the effect and return the specified \c channel value of the computed stereo frame.
- /*!
- Use the lastFrame() function to get both values of the computed
- stereo output frame. The \c channel argument must be 0 or 1 (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.
- */
- StkFloat tick( StkFloat input, unsigned int channel = 0 );
-
- //! Take a channel of the StkFrames object as inputs to the effect and replace with stereo outputs.
- /*!
- The StkFrames argument reference is returned. The stereo
- outputs are written to the StkFrames argument starting at the
- specified \c channel. Therefore, the \c channel argument must be
- less than ( channels() - 1 ) of 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.
- */
- StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );
-
- //! Take a channel of the \c iFrames object as inputs to the effect and write stereo outputs to the \c oFrames object.
- /*!
- The \c iFrames object reference is returned. The \c iChannel
- argument must be less than the number of channels in the \c
- iFrames argument (the first channel is specified by 0). The \c
- oChannel argument must be less than ( channels() - 1 ) of the \c
- oFrames argument. 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.
- */
- StkFrames& tick( StkFrames& iFrames, StkFrames &oFrames, unsigned int iChannel = 0, unsigned int oChannel = 0 );
-
- protected:
-
- DelayL delayLine_[2];
- SineWave mods_[2];
- StkFloat baseLength_;
- StkFloat modDepth_;
-
- };
-
- inline StkFloat Chorus :: lastOut( unsigned int channel )
- {
- #if defined(_STK_DEBUG_)
- if ( channel > 1 ) {
- oStream_ << "Chorus::lastOut(): channel argument must be less than 2!";
- handleError( StkError::FUNCTION_ARGUMENT );
- }
- #endif
-
- return lastFrame_[channel];
- }
-
- inline StkFloat Chorus :: tick( StkFloat input, unsigned int channel )
- {
- #if defined(_STK_DEBUG_)
- if ( channel > 1 ) {
- oStream_ << "Chorus::tick(): channel argument must be less than 2!";
- handleError( StkError::FUNCTION_ARGUMENT );
- }
- #endif
-
- delayLine_[0].setDelay( baseLength_ * 0.707 * ( 1.0 + modDepth_ * mods_[0].tick() ) );
- delayLine_[1].setDelay( baseLength_ * 0.5 * ( 1.0 - modDepth_ * mods_[1].tick() ) );
- lastFrame_[0] = effectMix_ * ( delayLine_[0].tick( input ) - input ) + input;
- lastFrame_[1] = effectMix_ * ( delayLine_[1].tick( input ) - input ) + input;
- return lastFrame_[channel];
- }
-
- inline StkFrames& Chorus :: tick( StkFrames& frames, unsigned int channel )
- {
- #if defined(_STK_DEBUG_)
- if ( channel >= frames.channels() - 1 ) {
- oStream_ << "Chorus::tick(): channel and StkFrames arguments are incompatible!";
- handleError( StkError::FUNCTION_ARGUMENT );
- }
- #endif
-
- StkFloat *samples = &frames[channel];
- unsigned int hop = frames.channels() - 1;
- for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
- delayLine_[0].setDelay( baseLength_ * 0.707 * ( 1.0 + modDepth_ * mods_[0].tick() ) );
- delayLine_[1].setDelay( baseLength_ * 0.5 * ( 1.0 - modDepth_ * mods_[1].tick() ) );
- *samples = effectMix_ * ( delayLine_[0].tick( *samples ) - *samples ) + *samples;
- samples++;
- *samples = effectMix_ * ( delayLine_[1].tick( *samples ) - *samples ) + *samples;
- }
-
- lastFrame_[0] = *(samples-hop);
- lastFrame_[1] = *(samples-hop+1);
- return frames;
- }
-
- inline StkFrames& Chorus :: tick( StkFrames& iFrames, StkFrames& oFrames, unsigned int iChannel, unsigned int oChannel )
- {
- #if defined(_STK_DEBUG_)
- if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() - 1 ) {
- oStream_ << "Chorus::tick(): channel and StkFrames arguments are incompatible!";
- handleError( StkError::FUNCTION_ARGUMENT );
- }
- #endif
-
- StkFloat *iSamples = &iFrames[iChannel];
- StkFloat *oSamples = &oFrames[oChannel];
- unsigned int iHop = iFrames.channels(), oHop = oFrames.channels();
- for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) {
- delayLine_[0].setDelay( baseLength_ * 0.707 * ( 1.0 + modDepth_ * mods_[0].tick() ) );
- delayLine_[1].setDelay( baseLength_ * 0.5 * ( 1.0 - modDepth_ * mods_[1].tick() ) );
- *oSamples = effectMix_ * ( delayLine_[0].tick( *iSamples ) - *iSamples ) + *iSamples;
- *(oSamples+1) = effectMix_ * ( delayLine_[1].tick( *iSamples ) - *iSamples ) + *iSamples;
- }
-
- lastFrame_[0] = *(oSamples-oHop);
- lastFrame_[1] = *(oSamples-oHop+1);
- return iFrames;
- }
-
- } // stk namespace
-
- #endif
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