A tom, and the analogue electronic-drum voice it generalises. More...

#include <tom.hpp>

Classes
struct	PresetData

Public Types
enum class	LadderMathProfile : std::uint8_t { reference , realtime_efficient }
	The noise ladder's saturator, chosen per voice. More...
enum class	Wave { triangle , sine }
	Body waveform. More...
enum class	Preset { generic_tom , low_tom , mid_tom , hi_tom , bass , snary , zap , cosmic }

Public Member Functions
	TomVoice ()
void	set_tune_hz (double hz)
	Pitch the body settles at, in Hz.
void	set_bend_octaves (double octaves)
	Depth of the downward dive in octaves, and how quickly it lands.
void	set_bend_ms (double ms)
void	set_decay_ms (double ms)
	How long the note rings, as a T60. Unrelated to the bend.
void	set_wave (Wave wave)
void	set_noise_balance (double amount)
	Balance between the oscillator (0) and the filtered noise (1).
void	set_noise_cutoff_hz (double hz)
	Corner and resonance of the four-pole lowpass the noise runs through.
void	set_noise_resonance (double amount)
void	set_noise_color (NoiseColor color)
bool	set_ladder_math_profile (LadderMathProfile profile) noexcept
	Selects the noise ladder's saturation curve between hits.
LadderMathProfile	ladder_math_profile () const noexcept
void	set_click_level (double level)
	The beater.
void	set_click_cutoff_hz (double hz)
void	set_click_decay_ms (double ms)
void	apply_preset (Preset preset)
LofiChain &	body_lofi ()
	Independent degradation for the two halves of the drum.
const LofiChain &	body_lofi () const
LofiChain &	noise_lofi ()
const LofiChain &	noise_lofi () const
OutputStage &	output ()
const OutputStage &	output () const
OutputStage *	output_stage () noexcept override
	The terminal saturation and degradation stage, at the generic voice boundary.
int	latency_samples () const noexcept override
	Fixed host-rate delay introduced by this voice's selected output quality.
OutputOversampling	output_oversampling () const noexcept override
	Output quality at the generic voice boundary.
void	set_output_oversampling (OutputOversampling factor) override
void	prepare (double sample_rate)
	Fixes the sample rate and clears all state.
void	reset ()
	Silences the voice immediately, without a fade.
void	note_on (float velocity)
	Starts a hit. velocity is in [0, 1]; values outside are clamped.
void	choke (float fade_ms=4.0f)
	Fades the voice out over fade_ms and then silences it.
bool	is_active () const
	Whether the voice still has something to render.
VoiceState	state () const
float	velocity () const
double	sample_rate () const
const OutputStage *	output_stage () const noexcept
void	set_velocity_response (const VelocityResponse &r)
const VelocityResponse &	velocity_response () const
void	process (float *out, int num_samples)
	Adds num_samples of this voice's output into out.
void	process_stereo (float left, float right, int num_samples)
	Adds a stereo rendering to left and right.

Static Public Attributes
static constexpr std::array< PresetData, 8 >	presets
	Original Pulp-authored voicings of this one SDS-V-family topology.

Protected Member Functions
void	on_prepare (double sample_rate) override
	Sizes buffers and fixes coefficients.
void	on_reset () override
	Clears every piece of state the voice carries, so is_active() becomes false and the next render starts from silence.
void	on_note_on (float velocity) override
	Starts a hit at the given velocity, already clamped to [0, 1].
bool	on_is_active () const override
void	render_add (float *out, int num_samples) override
	Adds the voice's output into out. Must add, never assign.
virtual void	render_add_stereo (float left, float right, int num_samples)
	Optional stereo realization.

Detailed Description

A tom, and the analogue electronic-drum voice it generalises.

The defining property is that the pitch envelope and the amplitude envelope are decoupled. In most percussion voices the body's pitch and its level fall together, because one envelope drives both; here they are separate controls, so the pitch can finish its dive in a few tens of milliseconds while the note rings on for a second afterwards. That is the sound of the early electronic drum kits: a fast downward swoop that arrives at a pitch and then simply sustains there. Tying the two envelopes together cannot produce it – the swoop would take the level with it.

The generic tom and the electronic voice are the same topology, retuned. A short bend and a mostly-noise balance is an acoustic-sounding tom; a deep bend and a pure oscillator is the laser-like electronic voice; a long decay with a high tuning is the "cosmic" end. Presets differ only in numbers, so there is one implementation rather than one per named sound.

Velocity deepens the bend rather than only raising the level, which is the physical claim: a harder strike deflects the head further, so the pitch starts higher and falls through a wider range. The voice's default VelocityResponse enables this, and it is the clearest single example of the velocity-to-timbre contract in the whole percussion set.

The noise path runs through a four-pole resonant lowpass rather than the two-pole used elsewhere, because at high resonance a steeper filter rings enough to give the noise a pitch of its own – which is what lets the same voice cover a snare-like sound without a second oscillator.

RT contract: prepare() allocates nothing; every other method, including note_on and process, allocates nothing and takes no locks.

Member Enumeration Documentation

◆ LadderMathProfile

enum class pulp::signal::drum::TomVoice::LadderMathProfile : std::uint8_t

strong

The noise ladder's saturator, chosen per voice.

Each value runs the LadderSaturation of the same meaning explicitly, so the voice does not follow the build-time kDefaultLadderSaturation: reference is LadderSaturation::exact (std::tanh) and realtime_efficient is LadderSaturation::realtime_efficient (FastMath::tanh_minimax).

Enumerator
reference
realtime_efficient

◆ Preset

enum class pulp::signal::drum::TomVoice::Preset

strong

Enumerator
generic_tom
low_tom
mid_tom
hi_tom
bass
snary
zap
cosmic

◆ Wave

enum class pulp::signal::drum::TomVoice::Wave

strong

Body waveform.

Triangle is the authentic choice for the analogue electronic voices – their oscillators were triangle cores – and it carries odd harmonics that survive a small speaker where a sine does not.

Enumerator
triangle
sine

Constructor & Destructor Documentation

◆ TomVoice()

pulp::signal::drum::TomVoice::TomVoice ( )

inline

Member Function Documentation

◆ apply_preset()

void pulp::signal::drum::TomVoice::apply_preset ( Preset preset )

inline

◆ body_lofi() [1/2]

LofiChain & pulp::signal::drum::TomVoice::body_lofi ( )

inline

Independent degradation for the two halves of the drum.

A tom is an oscillator body under a filtered noise skin, and the machines this voice descends from crushed those paths separately – a bit-reduced body under clean hiss reads as a different instrument from a clean body under a decimated skin. One shared chain could only ever produce the average of the two.

◆ body_lofi() [2/2]

const LofiChain & pulp::signal::drum::TomVoice::body_lofi ( ) const

inline

◆ choke()

void pulp::signal::drum::Voice::choke ( float fade_ms = 4.0f )

inlineinherited

Fades the voice out over fade_ms and then silences it.

Used by choke groups; a shorter fade is more abrupt but never clicks the way an instant cut does.

◆ is_active()

bool pulp::signal::drum::Voice::is_active ( ) const

inlineinherited

Whether the voice still has something to render.

A kit uses this to skip voices entirely rather than summing silence.

◆ ladder_math_profile()

LadderMathProfile pulp::signal::drum::TomVoice::ladder_math_profile ( ) const

inlinenoexcept

◆ latency_samples()

int pulp::signal::drum::TomVoice::latency_samples ( ) const

inlineoverridevirtualnoexcept

Fixed host-rate delay introduced by this voice's selected output quality.

Generic registry consumers can report it without recovering the concrete voice type.

Reimplemented from pulp::signal::drum::Voice.

◆ noise_lofi() [1/2]

LofiChain & pulp::signal::drum::TomVoice::noise_lofi ( )

inline

◆ noise_lofi() [2/2]

const LofiChain & pulp::signal::drum::TomVoice::noise_lofi ( ) const

inline

◆ note_on()

void pulp::signal::drum::Voice::note_on ( float velocity )

inlineinherited

Starts a hit. velocity is in [0, 1]; values outside are clamped.

◆ on_is_active()

bool pulp::signal::drum::TomVoice::on_is_active ( ) const

inlineoverrideprotectedvirtual

Implements pulp::signal::drum::Voice.

◆ on_note_on()

void pulp::signal::drum::TomVoice::on_note_on ( float velocity )

inlineoverrideprotectedvirtual

Starts a hit at the given velocity, already clamped to [0, 1].

Implements pulp::signal::drum::Voice.

◆ on_prepare()

void pulp::signal::drum::TomVoice::on_prepare ( double sample_rate )

inlineoverrideprotectedvirtual

Sizes buffers and fixes coefficients.

The only hook allowed to allocate.

Implements pulp::signal::drum::Voice.

◆ on_reset()

void pulp::signal::drum::TomVoice::on_reset ( )

inlineoverrideprotectedvirtual

Clears every piece of state the voice carries, so is_active() becomes false and the next render starts from silence.

Implements pulp::signal::drum::Voice.

◆ output() [1/2]

OutputStage & pulp::signal::drum::TomVoice::output ( )

inline

◆ output() [2/2]

const OutputStage & pulp::signal::drum::TomVoice::output ( ) const

inline

◆ output_oversampling()

OutputOversampling pulp::signal::drum::TomVoice::output_oversampling ( ) const

inlineoverridevirtualnoexcept

Output quality at the generic voice boundary.

Kits use this surface to keep every registered path on one latency contract.

Reimplemented from pulp::signal::drum::Voice.

◆ output_stage() [1/2]

OutputStage * pulp::signal::drum::TomVoice::output_stage ( )

inlineoverridevirtualnoexcept

The terminal saturation and degradation stage, at the generic voice boundary.

A registry consumer reaches it without recovering the concrete voice type, so adding an engine cannot desynchronise a downcast from the engine it was selected for. A voice that ends without one returns nullptr.

Reimplemented from pulp::signal::drum::Voice.

◆ output_stage() [2/2]

const OutputStage * pulp::signal::drum::Voice::output_stage ( ) const

inlinenoexceptinherited

◆ prepare()

void pulp::signal::drum::Voice::prepare ( double sample_rate )

inlineinherited

Fixes the sample rate and clears all state.

The only method a derived voice may allocate in.

◆ process()

void pulp::signal::drum::Voice::process	(	float *	out,
		int	num_samples )

inlineinherited

Adds num_samples of this voice's output into out.

◆ process_stereo()

void pulp::signal::drum::Voice::process_stereo	(	float *	left,
		float *	right,
		int	num_samples )

inlineinherited

Adds a stereo rendering to left and right.

Voices that do not provide a stereo realization are placed in the centre with half their mono signal in each channel, so summing the two channels reproduces process() exactly. A stereo-capable voice may override render_add_stereo, but the shared choke fade remains here.

◆ render_add()

void pulp::signal::drum::TomVoice::render_add	(	float *	out,
		int	num_samples )

inlineoverrideprotectedvirtual

Adds the voice's output into out. Must add, never assign.

Implements pulp::signal::drum::Voice.

◆ render_add_stereo()

virtual void pulp::signal::drum::Voice::render_add_stereo	(	float *	left,
		float *	right,
		int	num_samples )

inlineprotectedvirtualinherited

Optional stereo realization.

The default is centre-panned and preserves exact mono-sum equivalence.

Reimplemented in pulp::signal::drum::ClapVoice.

◆ reset()

void pulp::signal::drum::Voice::reset ( )

inlineinherited

Silences the voice immediately, without a fade.

For transport stops and buffer-size changes, where a click cannot be heard because nothing is playing either side of it.

◆ sample_rate()

double pulp::signal::drum::Voice::sample_rate ( ) const

inlineinherited

◆ set_bend_ms()

void pulp::signal::drum::TomVoice::set_bend_ms ( double ms )

inline

◆ set_bend_octaves()

void pulp::signal::drum::TomVoice::set_bend_octaves ( double octaves )

inline

Depth of the downward dive in octaves, and how quickly it lands.

This envelope is independent of the amplitude decay below – that separation is the whole point of the voice.

◆ set_click_cutoff_hz()

void pulp::signal::drum::TomVoice::set_click_cutoff_hz ( double hz )

inline

◆ set_click_decay_ms()

void pulp::signal::drum::TomVoice::set_click_decay_ms ( double ms )

inline

◆ set_click_level()

void pulp::signal::drum::TomVoice::set_click_level ( double level )

inline

The beater.

Short and highpassed: a tom's attack is the stick, not the head.

◆ set_decay_ms()

void pulp::signal::drum::TomVoice::set_decay_ms ( double ms )

inline

How long the note rings, as a T60. Unrelated to the bend.

◆ set_ladder_math_profile()

bool pulp::signal::drum::TomVoice::set_ladder_math_profile ( LadderMathProfile profile )

inlinenoexcept

Selects the noise ladder's saturation curve between hits.

Reference is the default; realtime_efficient uses the bounded FastMath::tanh_minimax.

◆ set_noise_balance()

void pulp::signal::drum::TomVoice::set_noise_balance ( double amount )

inline

Balance between the oscillator (0) and the filtered noise (1).

◆ set_noise_color()

void pulp::signal::drum::TomVoice::set_noise_color ( NoiseColor color )

inline

◆ set_noise_cutoff_hz()

void pulp::signal::drum::TomVoice::set_noise_cutoff_hz ( double hz )

inline

Corner and resonance of the four-pole lowpass the noise runs through.

At high resonance it rings, which gives the noise a pitch.

◆ set_noise_resonance()

void pulp::signal::drum::TomVoice::set_noise_resonance ( double amount )

inline

◆ set_output_oversampling()

void pulp::signal::drum::TomVoice::set_output_oversampling ( OutputOversampling factor )

inlineoverridevirtual

Reimplemented from pulp::signal::drum::Voice.

◆ set_tune_hz()

void pulp::signal::drum::TomVoice::set_tune_hz ( double hz )

inline

Pitch the body settles at, in Hz.

◆ set_velocity_response()

void pulp::signal::drum::Voice::set_velocity_response ( const VelocityResponse & r )

inlineinherited

◆ set_wave()

void pulp::signal::drum::TomVoice::set_wave ( Wave wave )

inline

◆ state()

VoiceState pulp::signal::drum::Voice::state ( ) const

inlineinherited

◆ velocity()

float pulp::signal::drum::Voice::velocity ( ) const

inlineinherited

◆ velocity_response()

const VelocityResponse & pulp::signal::drum::Voice::velocity_response ( ) const

inlineinherited

Member Data Documentation

◆ presets

std::array<PresetData, 8> pulp::signal::drum::TomVoice::presets

staticconstexpr

Initial value:

{{
        {Preset::generic_tom, "Generic Tom", 130.0, 0.35, 30.0, 450.0,
         Wave::triangle, 0.25, 2200.0, 0.25, 0.35},
        {Preset::low_tom, "LowTom", 75.0, 0.80, 45.0, 700.0,
         Wave::triangle, 0.08, 1100.0, 0.25, 0.30},
        {Preset::mid_tom, "MidTom", 110.0, 0.90, 35.0, 550.0,
         Wave::triangle, 0.10, 1600.0, 0.28, 0.32},
        {Preset::hi_tom, "HiTom", 170.0, 1.00, 28.0, 400.0,
         Wave::triangle, 0.12, 2400.0, 0.30, 0.35},
        {Preset::bass, "Bass", 55.0, 0.55, 55.0, 1100.0,
         Wave::sine, 0.04, 900.0, 0.18, 0.22},
        {Preset::snary, "Snary", 155.0, 0.25, 18.0, 320.0,
         Wave::triangle, 0.70, 2500.0, 0.82, 0.50},
        {Preset::zap, "Zap", 210.0, 3.20, 55.0, 500.0,
         Wave::triangle, 0.02, 3200.0, 0.20, 0.15},
        {Preset::cosmic, "Cosmic", 280.0, 2.40, 180.0, 1800.0,
         Wave::sine, 0.20, 6000.0, 0.70, 0.25},
    }}

Original Pulp-authored voicings of this one SDS-V-family topology.

They are clean starting points, not values copied from a sample library or a commercial preset bank.

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

/home/runner/work/pulp/pulp/core/signal/include/pulp/signal/drum/tom.hpp

Pulp 1.88.0 Cross-platform audio plugin framework

Classes

Public Types

Public Member Functions

Static Public Attributes

Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ LadderMathProfile

◆ Preset

◆ Wave

Constructor & Destructor Documentation

◆ TomVoice()

Member Function Documentation

◆ apply_preset()

◆ body_lofi() [1/2]

◆ body_lofi() [2/2]

◆ choke()

◆ is_active()

◆ ladder_math_profile()

◆ latency_samples()

◆ noise_lofi() [1/2]

◆ noise_lofi() [2/2]

◆ note_on()

◆ on_is_active()

◆ on_note_on()

◆ on_prepare()

◆ on_reset()

◆ output() [1/2]

◆ output() [2/2]

◆ output_oversampling()

◆ output_stage() [1/2]

◆ output_stage() [2/2]

◆ prepare()

◆ process()

◆ process_stereo()

◆ render_add()

◆ render_add_stereo()

◆ reset()

◆ sample_rate()

◆ set_bend_ms()

◆ set_bend_octaves()

◆ set_click_cutoff_hz()

◆ set_click_decay_ms()

◆ set_click_level()

◆ set_decay_ms()

◆ set_ladder_math_profile()

◆ set_noise_balance()

◆ set_noise_color()

◆ set_noise_cutoff_hz()

◆ set_noise_resonance()

◆ set_output_oversampling()

◆ set_tune_hz()

◆ set_velocity_response()

◆ set_wave()

◆ state()

◆ velocity()

◆ velocity_response()

Member Data Documentation

◆ presets