The pulse-count stage sequencer. More...

#include <stage_sequencer.hpp>

Classes
struct	Frame
	One sample of sequencer output. More...

Public Member Functions
	StageSeqT ()
void	prepare (double sample_rate)
void	set_num_stages (int n)
int	num_stages () const
void	set_direction (SeqDirection d)
SeqDirection	direction () const
void	set_stage_pitch (int s, SampleType volts)
SampleType	stage_pitch (int s) const
void	set_stage_pulse_count (int s, int count)
int	stage_pulse_count (int s) const
void	set_stage_gate_mode (int s, StageGateMode m)
StageGateMode	stage_gate_mode (int s) const
void	set_stage_slide (int s, bool on)
bool	stage_slide (int s) const
void	set_stage_skip (int s, bool on)
bool	stage_skip (int s) const
void	set_slide_ms (double ms)
double	slide_ms () const
void	set_repeat_duty (double duty)
double	repeat_duty () const
void	set_seed (std::uint32_t seed)
void	apply_reset_edge ()
	The modular reset jack (verb 2): position to the top of the pattern, gate low, pitch CV held, RNG untouched.
void	reset ()
	The lifecycle verb (verb 1): everything apply_reset_edge() does, plus held outputs to zero, the clock-period measurement forgotten, and the RNG rewound to its seed.
bool	gate () const
SampleType	pitch_v () const
int	stage () const
int	pulse () const
	0-based pulse index inside the current stage.
bool	started () const
	True once the first clock after a reset has landed.
Frame	process (bool run_high, bool reset_edge, bool clock_edge)
	Advances one sample. See the header's order-of-operations rule.

Static Public Member Functions
static constexpr int	latency_samples ()

Static Public Attributes
static constexpr int	kMaxStages = 16
	Stage capacity.
static constexpr int	kDefaultStages = 8
static constexpr int	kMinPulseCount = 1
	Pulse count per stage. The 1–8 range is the cited hardware's.
static constexpr int	kMaxPulseCount = 8
static constexpr double	kRepeatDuty = 0.5
	High fraction of each pulse in repeat mode.
static constexpr double	kSlideMs = 30.0
	Constant-time portamento duration — "a constant time portamento very similar to the Roland TB-303" [Intellijel Metropolis Manual v1.30].
static constexpr std::uint32_t	kRandomSeed = 0x2A3Bu
	Seed for SeqDirection::random.
static constexpr int	kRandomDrawAttempts = 64
	Attempts a random draw makes before falling back to a deterministic forward scan.
static constexpr double	kMaxPeriodMs = 4000.0
	Longest clock period the repeat duty tracker will believe, in ms.
static constexpr double	kMaxSlideMs = 60000.0
	Ceiling on the slide time.

Detailed Description

template<typename SampleType = float>
class pulp::signal::StageSeqT< SampleType >

The pulse-count stage sequencer.

(lineage — informative) The Roland-System-100M-format Ryk M-185 and its Eurorack descendant the Intellijel Metropolis are stage sequencers rather than step sequencers: a small number of stages, each carrying a pitch, a pulse count (how many clocks that stage lasts) and a gate mode governing the gate across those pulses [Intellijel, Metropolis Manual v1.30, 2020 — "eight STAGES, each with its own assignable gate mode, pulse count, ratchet count, and pitch value"; "PULSE COUNT sets the number of repetitions from 1 to 8"]. Cited for concepts and topology only.

The pulse count is what makes this different from a step sequencer with a length knob: a stage that lasts three clocks is one musical event with a duration, so rest at pulse count 3 is three clocks of silence you can hear the shape of, and hold at pulse count 8 is a tied note. A step sequencer spells those with three or eight steps you then have to keep in sync when you edit the pattern.

USE. Acid basslines — eight stages, mostly single, one or two with slide, pulse counts of 1–2, into a TB-303-style voice: the interplay of slide and pulse count is the genre. Generative melody — random direction, a few rest stages, a QuantizeScaleT downstream: never repeating but always in key. Polymeter against drums — set N to 5 or 7 with repeat gates while a 4/4 drum clock runs, and the sequence drifts in and out of phase with the beat (the M-185 party trick). Long tension builds — one stage at pulse count 8 in hold: a note held for eight clocks, then release.

Ratchets are not baked in. The hardware's per-stage ratchet is a ClockMultT (kit) upstream of the clock input, or repeat mode. Duplicating the kit inside a sequencer is how two definitions of a subdivision end up in one library.

RT contract: as the header. Fixed-capacity arrays, no allocation anywhere.