Holds a sample value for N samples or until externally triggered. More...

#include <SampleAndHold.h>

Public Types
enum class	Mode { Counter , Trigger }
	Defines the capture behavior of the processor. More...

Public Member Functions
void	setMode (Mode mode) noexcept
	Sets the operating mode.

void	setHoldSamples (int numSamples) noexcept
	Sets the hold duration for Counter mode in whole samples.

void	setHoldPeriod (double samples) noexcept
	Sets a fractional hold period for Counter mode, in samples.

double	getHoldPeriod () const noexcept
	Returns the Counter-mode hold period in samples.

void	setHoldRate (double targetRate, double actualRate) noexcept
	Sets the hold period from a target effective sample rate.

T	process (T input, bool trigger=false) noexcept
	Processes a single sample.

void	processBlock (T *data, int numSamples) noexcept
	Processes a block of samples in-place (Counter mode optimized).

void	processBlock (T data, const bool triggers, int numSamples) noexcept
	Processes a block of samples in-place using an external trigger buffer.

T	getHeldValue () const noexcept
	Retrieves the current held value without advancing the state.

void	reset (T initialValue=T(0)) noexcept
	Resets the processor state and sets an initial output value.

Detailed Description

template<FloatType T>
class dspark::SampleAndHold< T >

Holds a sample value for N samples or until externally triggered.

Template Parameters

T	Sample type (must satisfy FloatType concept).

Definition at line 39 of file SampleAndHold.h.

Member Enumeration Documentation

◆ Mode

template<FloatType T>

enum class dspark::SampleAndHold::Mode

strong

Defines the capture behavior of the processor.

Enumerator
Counter	Holds for a fixed number of samples automatically (Decimation).
Trigger	Holds until an external trigger captures a new value (level-sensitive).

Definition at line 43 of file SampleAndHold.h.

Member Function Documentation

◆ getHeldValue()

template<FloatType T>

T dspark::SampleAndHold< T >::getHeldValue ( ) const

inlinenoexcept

Retrieves the current held value without advancing the state.

Returns: The held sample value.

Definition at line 209 of file SampleAndHold.h.

◆ getHoldPeriod()

template<FloatType T>

double dspark::SampleAndHold< T >::getHoldPeriod ( ) const

inlinenoexcept

Returns the Counter-mode hold period in samples.

Definition at line 94 of file SampleAndHold.h.

◆ process()

template<FloatType T>

T dspark::SampleAndHold< T >::process	(	T	input,
		bool	trigger = `false`
	)

inlinenoexcept

Processes a single sample.

Warning: For optimal performance on blocks, use processBlock() instead, as this scalar method contains internal branching based on the Mode.

Parameters

input	The audio or modulation input sample.
trigger	External trigger state (ignored in Counter mode). The trigger is level-sensitive: while it stays true, the input is tracked sample-by-sample; send single-sample pulses for classic S&H capture.

Returns: The currently held output sample.

Definition at line 128 of file SampleAndHold.h.

◆ processBlock() [1/2]

template<FloatType T>

void dspark::SampleAndHold< T >::processBlock	(	T *	data,
		const bool *	triggers,
		int	numSamples
	)

inlinenoexcept

Processes a block of samples in-place using an external trigger buffer.

Only relevant when Mode is set to Trigger (level-sensitive, same semantics as process()). If Mode is Counter, the triggers buffer is safely ignored.

Parameters

data	Audio buffer to process in-place.
triggers	Array of boolean triggers, one per sample. A null pointer is treated as "no triggers" (the current value is held).
numSamples	Number of samples in the buffer.

Definition at line 184 of file SampleAndHold.h.

◆ processBlock() [2/2]

template<FloatType T>

void dspark::SampleAndHold< T >::processBlock	(	T *	data,
		int	numSamples
	)

inlinenoexcept

Processes a block of samples in-place (Counter mode optimized).

If the processor is in Trigger mode, calling this method will simply fill the buffer with the last held value. For Trigger mode processing, use the overloaded processBlock with the trigger buffer.

Parameters

data	Audio buffer to process in-place.
numSamples	Number of samples in the buffer.

Definition at line 148 of file SampleAndHold.h.

◆ reset()

template<FloatType T>

void dspark::SampleAndHold< T >::reset ( T initialValue = T(0) )

inlinenoexcept

Resets the processor state and sets an initial output value.

Parameters

initialValue Value to output until the next capture triggers.

Definition at line 216 of file SampleAndHold.h.

◆ setHoldPeriod()

template<FloatType T>

void dspark::SampleAndHold< T >::setHoldPeriod ( double samples )

inlinenoexcept

Sets a fractional hold period for Counter mode, in samples.

A non-integer period keeps the average capture rate exact, so a swept rate moves continuously instead of jumping between whole-sample periods (at 48 kHz those are 24 k, 16 k, 12 k, 9.6 k...). Each capture takes the input at its exact fractional instant, interpolated linearly between the two neighbouring samples; the held steps themselves still change on sample boundaries. Integer periods behave exactly as setHoldSamples().

Parameters

samples Hold period in samples. Values below 1 and NaN clamp to 1; huge values clamp to 2^31 - 1 (holds indefinitely).

Definition at line 83 of file SampleAndHold.h.

◆ setHoldRate()

template<FloatType T>

void dspark::SampleAndHold< T >::setHoldRate	(	double	targetRate,
		double	actualRate
	)

inlinenoexcept

Sets the hold period from a target effective sample rate.

The period is the exact ratio actualRate / targetRate (fractional, see setHoldPeriod()), so the effective rate is exactly targetRate on average.

Parameters

targetRate	The desired effective sample rate in Hz. Invalid values (non-positive or NaN, either argument) reset the period to 1.
actualRate	The current system sample rate in Hz.

Definition at line 106 of file SampleAndHold.h.

◆ setHoldSamples()

template<FloatType T>

void dspark::SampleAndHold< T >::setHoldSamples ( int numSamples )

inlinenoexcept

Sets the hold duration for Counter mode in whole samples.

A value of 1 passes the signal transparently. A value of N reduces the effective sample rate by a factor of N. Capture phase: after reset(), the first capture happens on the Nth call (the initial value is output for the first N-1 samples), then every N samples.

Parameters

numSamples Hold period in samples. Clamped to a minimum of 1.

Definition at line 65 of file SampleAndHold.h.

◆ setMode()

template<FloatType T>

void dspark::SampleAndHold< T >::setMode ( Mode mode )

inlinenoexcept

Sets the operating mode.

Parameters

mode	Mode::Counter or Mode::Trigger.

Definition at line 53 of file SampleAndHold.h.

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

SampleAndHold.h

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

◆ Mode

Member Function Documentation

◆ getHeldValue()

◆ getHoldPeriod()

◆ process()

◆ processBlock() [1/2]

◆ processBlock() [2/2]

◆ reset()

◆ setHoldPeriod()

◆ setHoldRate()

◆ setHoldSamples()

◆ setMode()