LFO Class Reference

The LFO object implements a mathematically perfect LFO generator for modulation uses only. It should not be used for audio frequencies except for the sinusoidal output which, though an approximation, has very low TDH. More...

#include <fxobjects.h>

Inheritance diagram for LFO:

Public Member Functions
virtual bool	reset (double _sampleRate)
OscillatorParameters	getParameters ()
void	setParameters (const OscillatorParameters &params)
virtual const SignalGenData	renderAudioOutput ()
	generates the oscillator output for one sample interval; note that there are multiple outputs.
virtual bool	reset (double _sampleRate)=0
virtual const SignalGenData	renderAudioOutput ()=0

Protected Member Functions
bool	checkAndWrapModulo (double &moduloCounter, double phaseInc)
bool	advanceAndCheckWrapModulo (double &moduloCounter, double phaseInc)
void	advanceModulo (double &moduloCounter, double phaseInc)
double	parabolicSine (double angle)

Protected Attributes
OscillatorParameters	lfoParameters
	obejcgt parameters
double	sampleRate = 0.0
	sample rate
double	modCounter = 0.0
	modulo counter [0.0, +1.0]
double	phaseInc = 0.0
	phase inc = fo/fs
double	modCounterQP = 0.25
	Quad Phase modulo counter [0.0, +1.0].
const double	B = 4.0 / kPi
const double	C = -4.0 / (kPi* kPi)
const double	P = 0.225

Detailed Description

The LFO object implements a mathematically perfect LFO generator for modulation uses only. It should not be used for audio frequencies except for the sinusoidal output which, though an approximation, has very low TDH.

Audio I/O:

• Output only object: low frequency generator.

Control I/F:

• Use OscillatorParameters structure to get/set object params.

Author

Will Pirkle http://www.willpirkle.com

Remarks

This object is included in Designing Audio Effects Plugins in C++ 2nd Ed. by Will Pirkle

Version

Revision : 1.0

Date

Date : 2018 / 09 / 7

Member Function Documentation

advanceAndCheckWrapModulo()

bool LFO::advanceAndCheckWrapModulo ( double &  moduloCounter, double  phaseInc  )

inlineprotected

advanvce the modulo counter, then check the modulo counter and wrap if needed

advanceModulo()

void LFO::advanceModulo ( double &  moduloCounter, double  phaseInc  )

inlineprotected

advanvce the modulo counter

checkAndWrapModulo()

bool LFO::checkAndWrapModulo ( double &  moduloCounter, double  phaseInc  )

inlineprotected

check the modulo counter and wrap if needed

getParameters()

OscillatorParameters LFO::getParameters ( )

inline

get parameters: note use of custom structure for passing param data

Returns

OscillatorParameters custom data structure

parabolicSine()

double LFO::parabolicSine ( double  angle )

inlineprotected

parabolic sinusoidal calcualtion; NOTE: input is -pi to +pi http://devmaster.net/posts/9648/fast-and-accurate-sine-cosine

renderAudioOutput()

const SignalGenData LFO::renderAudioOutput ( )

virtual

generates the oscillator output for one sample interval; note that there are multiple outputs.

render a new audio output structure

Implements IAudioSignalGenerator.

reset()

virtual bool LFO::reset ( double  _sampleRate )

inlinevirtual

reset members to initialized state

< modulo counter [0.0, +1.0]

<Quad Phase modulo counter [0.0, +1.0]

Implements IAudioSignalGenerator.

setParameters()

void LFO::setParameters ( const OscillatorParameters &  params )

inline

set parameters: note use of custom structure for passing param data

Parameters

OscillatorParameters

custom data structure

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The documentation for this class was generated from the following files:

• C:/RackAFX_v7/ASPIK_Doxygen/PluginObjects/fxobjects.h
• C:/RackAFX_v7/ASPIK_Doxygen/PluginObjects/fxobjects.cpp