SynthLab::RampModulator Class Reference

This is a tiny modulator object that produces an output that ramps up or down linearly between two values over a specified time in milliseconds. More...

#include <synthbase.h>

Public Member Functions
bool	startModulator (double startValue, double endValue, double modTime_mSec, double sampleRate)
	Setup the timers and start the ramp modulator running. The modulator produces an output on the range of [startValue, endValue] over a specified duration in mSec. More...
bool	setModTime (double modTime_mSec, double sampleRate)
	Change the modulation time; this is optional. More...
double	getNextModulationValue (uint32_t advanceClock=1)
	Get the current output of the modulator; this is called repeatedly over the ramp modulation time. More...
void	advanceClock (uint32_t ticks=1)
	Nudge the clock on the modulator; this is used for block processing where the modulator output outputs one value per audio block. This is called repeatedly to get the modulator clock "caught up" to where it needs to be for the next block of audio to process. More...
bool	isActive ()
	checks to see if the modulator is running, or completed

Protected Attributes
bool	timerActive = false
	state of modulator, running (true) or expired (false)
double	timerInc = 0.0
	timer incrementer value
double	countUpTimer = 0.0
	current timer value; this always counts UP regardless of the polarity of the modulation (up or down)
double	modRange = 1.0
	range of modulation output
double	modStart = 0.0
	ramp mod start value
double	modEnd = 1.0
	ramp mod end value

Detailed Description

This is a tiny modulator object that produces an output that ramps up or down linearly between two values over a specified time in milliseconds.

• used for LFO fade-in time
• can be used to fade-in or fade-out any kind of value, from audio samples to modulation values to modulation times
• the timer always counts UP regardless of the direction of the ramp

Author

Will Pirkle http://www.willpirkle.com

Remarks

This object is included and described in further detail in Designing Software Synthesizer Plugins in C++ 2nd Ed. by Will Pirkle

Version

Revision : 1.0

Date

Date : 2021 / 04 / 26

Member Function Documentation

advanceClock()

void SynthLab::RampModulator::advanceClock

(

uint32_t

ticks = 1

)

Nudge the clock on the modulator; this is used for block processing where the modulator output outputs one value per audio block. This is called repeatedly to get the modulator clock "caught up" to where it needs to be for the next block of audio to process.

manually advance the clock

Parameters

ticks

number of tics to advance the clock for the next value

getNextModulationValue()

double SynthLab::RampModulator::getNextModulationValue

(

uint32_t

advanceClock = 1

)

Get the current output of the modulator; this is called repeatedly over the ramp modulation time.

get the next modulation value - this is the main output function; auto advances the clock

• check the modulator to see when it is done, then stop calling this function

Parameters

advanceClock

number of tics to advance the clock for the next value

setModTime()

bool SynthLab::RampModulator::setModTime	(	double	modTime_mSec,
		double	sampleRate
	)

Change the modulation time; this is optional.

the mod time may be changed while running, normally not used but permitted

Parameters

modTime_mSec	time for the ramp-up or ramp-down across the values
sampleRate	fs for calculating timer increment

startModulator()

bool SynthLab::RampModulator::startModulator	(	double	startValue,
		double	endValue,
		double	modTime_mSec,
		double	sampleRate
	)

Setup the timers and start the ramp modulator running. The modulator produces an output on the range of [startValue, endValue] over a specified duration in mSec.

the main function that sets up and start the modulator

Parameters

startValue	starting modulator value
endValue	ending modulator value
modTime_mSec	time for the ramp-up or ramp-down across the values
sampleRate	fs for calculating timer increment

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

• C:/RackAFX Projects/SynthLab_SDK/source/synthbase.h
• C:/RackAFX Projects/SynthLab_SDK/source/synthbase.cpp