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120 lines
3.7 KiB
C++
120 lines
3.7 KiB
C++
#ifndef STK_ECHO_H
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#define STK_ECHO_H
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#include "Effect.h"
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#include "Delay.h"
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namespace stk {
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/***************************************************/
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/*! \class Echo
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\brief STK echo effect class.
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This class implements an echo effect.
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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 Echo : public Effect
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{
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public:
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//! Class constructor, taking the longest desired delay length (one second default value).
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/*!
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The default delay value is set to 1/2 the maximum delay length.
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*/
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Echo( unsigned long maximumDelay = (unsigned long) Stk::sampleRate() );
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//! Reset and clear all internal state.
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void clear();
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//! Set the maximum delay line length in samples.
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void setMaximumDelay( unsigned long delay );
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//! Set the delay line length in samples.
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void setDelay( unsigned long delay );
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//! Return the last computed output value.
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StkFloat lastOut( void ) const { return lastFrame_[0]; };
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//! Input one sample to the effect and return one output.
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StkFloat tick( StkFloat input );
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//! Take a channel of the StkFrames object as inputs to the effect and replace with corresponding outputs.
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/*!
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The StkFrames argument reference is returned. The \c channel
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argument must be less than the number of channels in the
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StkFrames argument (the first channel is specified by 0).
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However, range checking is only performed if _STK_DEBUG_ is
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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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//! Take a channel of the \c iFrames object as inputs to the effect and write outputs to the \c oFrames object.
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/*!
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The \c iFrames object reference is returned. Each channel
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argument must be less than the number of channels in the
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corresponding 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& iFrames, StkFrames &oFrames, unsigned int iChannel = 0, unsigned int oChannel = 0 );
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protected:
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Delay delayLine_;
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unsigned long length_;
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};
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inline StkFloat Echo :: tick( StkFloat input )
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{
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lastFrame_[0] = effectMix_ * ( delayLine_.tick( input ) - input ) + input;
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return lastFrame_[0];
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}
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inline StkFrames& Echo :: tick( StkFrames& frames, unsigned int channel )
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{
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#if defined(_STK_DEBUG_)
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if ( channel >= frames.channels() ) {
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oStream_ << "Echo::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 hop = frames.channels();
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for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
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*samples = effectMix_ * ( delayLine_.tick( *samples ) - *samples ) + *samples;
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}
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lastFrame_[0] = *(samples-hop);
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return frames;
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}
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inline StkFrames& Echo :: tick( StkFrames& iFrames, StkFrames& oFrames, unsigned int iChannel, unsigned int oChannel )
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{
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#if defined(_STK_DEBUG_)
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if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) {
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oStream_ << "Echo::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 *iSamples = &iFrames[iChannel];
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StkFloat *oSamples = &oFrames[oChannel];
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unsigned int iHop = iFrames.channels(), oHop = oFrames.channels();
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for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) {
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*oSamples = effectMix_ * ( delayLine_.tick( *iSamples ) - *iSamples ) + *iSamples;
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}
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lastFrame_[0] = *(oSamples-oHop);
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return iFrames;
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}
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} // stk namespace
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#endif
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