An energy-preserving Schroeder allpass with a fixed delay and optionally modulated gain. More...

#include <schroeder_allpass.h>

Public Member Functions
	TimeVaryingSchroederAllpass (uint32_t delay, float gain, const ModulationOptions &modulation)
	Constructs an allpass with sinusoidal gain modulation.

void	SetDelay (uint32_t delay)
	Sets the fixed integer delay in samples.

uint32_t	GetDelay () const noexcept SFFDN_NONBLOCKING
	Returns the delay in samples.

float	GetG () const noexcept SFFDN_NONBLOCKING
	Returns the base gain.

float	Tick (float input) noexcept SFFDN_NONBLOCKING
	Processes one sample using the configured sinusoidally modulated gain.

float	Tick (float input, float gain) noexcept SFFDN_NONBLOCKING
	Processes one sample with an explicit valid gain in the open interval (-1, 1).

void	ProcessBlock (std::span< const float > in, std::span< float > out) noexcept SFFDN_NONBLOCKING
	Processes a block using the configured sinusoidally modulated gain.

void	ProcessBlockAccumulate (std::span< const float > in, std::span< float > out) noexcept SFFDN_NONBLOCKING
	Processes a block and accumulates the result in `out`.

void	Clear ()
	Clears the delay state and restores the configured modulation phase.

Detailed Description

An energy-preserving Schroeder allpass with a fixed delay and optionally modulated gain.

The gain-varying path uses the normalized Type V recurrence:

\[ y = c w - g x,\quad u = c x + g w,\quad c = \sqrt{1 - g^2}. \]

The delay remains an integer number of samples, so every valid instantaneous gain applies an orthogonal transformation to the input and delayed sample.

Constructor & Destructor Documentation

◆ TimeVaryingSchroederAllpass()

sfFDN::TimeVaryingSchroederAllpass::TimeVaryingSchroederAllpass	(	uint32_t	delay,
		float	gain,
		const ModulationOptions &	modulation )

Constructs an allpass with sinusoidal gain modulation.

Note: The modulation frequency and amplitude must be non-zero, and abs(gain) + abs(modulation.amplitude) must be strictly less than one.

Member Function Documentation

◆ SetDelay()

void sfFDN::TimeVaryingSchroederAllpass::SetDelay ( uint32_t delay )

Sets the fixed integer delay in samples.

Exceptions

std::invalid_argument if delay is zero.

◆ Tick()

float sfFDN::TimeVaryingSchroederAllpass::Tick	(	float	input,
		float	gain )

noexcept

Processes one sample with an explicit valid gain in the open interval (-1, 1).

This overload is useful for externally scheduled gain trajectories. It does not alter the configured modulation state.

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