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https://github.com/thestk/stk
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86 lines
2.7 KiB
C++
86 lines
2.7 KiB
C++
/***************************************************/
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/*! \class DelayL
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\brief STK linear interpolating delay line class.
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This Delay subclass implements a fractional-
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length digital delay-line using first-order
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linear interpolation. A fixed maximum length
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of 4095 and a delay of zero is set using the
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default constructor. Alternatively, the
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delay and maximum length can be set during
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instantiation with an overloaded constructor.
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Linear interpolation is an efficient technique
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for achieving fractional delay lengths, though
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it does introduce high-frequency signal
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attenuation to varying degrees depending on the
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fractional delay setting. The use of higher
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order Lagrange interpolators can typically
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improve (minimize) this attenuation characteristic.
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by Perry R. Cook and Gary P. Scavone, 1995 - 2004.
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*/
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/***************************************************/
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#ifndef STK_DELAYL_H
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#define STK_DELAYL_H
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#include "Delay.h"
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class DelayL : public Delay
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{
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public:
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//! Default constructor creates a delay-line with maximum length of 4095 samples and zero delay.
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DelayL();
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//! Overloaded constructor which specifies the current and maximum delay-line lengths.
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/*!
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An StkError will be thrown if the delay parameter is less than
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zero, the maximum delay parameter is less than one, or the delay
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parameter is greater than the maxDelay value.
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*/
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DelayL(StkFloat delay, unsigned long maxDelay);
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//! Class destructor.
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~DelayL();
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//! Set the delay-line length.
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/*!
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The valid range for \e theDelay is from 0 to the maximum delay-line length.
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*/
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void setDelay(StkFloat delay);
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//! Return the current delay-line length.
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StkFloat getDelay(void) const;
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//! Return the value which will be output by the next call to tick().
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/*!
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This method is valid only for delay settings greater than zero!
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*/
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StkFloat nextOut(void);
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//! Input one sample to the delay-line and return one output.
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StkFloat tick(StkFloat sample);
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//! Input \e vectorSize samples to the delay-line and return an equal number of outputs in \e vector.
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virtual StkFloat *tick(StkFloat *vector, unsigned int vectorSize);
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//! Take a channel of the StkFrames object as inputs to the delayline and replace with corresponding outputs.
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/*!
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The \c channel argument should be one or greater (the first
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channel is specified by 1). An StkError will be thrown if the \c
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channel argument is zero or it is greater than the number of
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channels in the StkFrames object.
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*/
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virtual StkFrames& tick( StkFrames& frames, unsigned int channel = 1 );
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protected:
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StkFloat alpha_;
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StkFloat omAlpha_;
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StkFloat nextOutput_;
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bool doNextOut_;
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};
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#endif
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