Producers found the tracked plugins jumpy: the shared tracker switched notes
after 10 ms and retuned every 5 ms, so growls and formant basses flickered
and every tracked plugin acted on wrong notes.
Shared tracker (common-dsp):
- A new note needs a steady read for 40 ms; an octave down 80 ms, an octave
up 200 ms (an octave-up read still fits the note's period and counts as
agreeing). Inside a note the tuning only moves past a 0.25 semitone
deadband. Follow bends keeps the old fast behaviour as an option.
- A trust score turns the note unsure while reads disagree; Tracker::active
and NoteState report it, and Fallback latches "step back" across note ends.
- Notes end when the window start stays below the gate's release level for
20 ms, so short gaps between notes are seen without waiting for the gate.
- PitchSource replaces the old (midi, gate, glide) arguments: Audio, MIDI or
Note mode (a set note, no detection), plus a key lock (minor, major, root
only) that snaps reads to the key.
- stems.rs: synthetic stems (growls, wobble, reese, formant, 808 slide,
layered drop, noise riser) and a score; examples/tracker_report scores the
corpus or real WAV stems. On the corpus the old behaviour makes up to 28
extra note starts per second; the stable default makes none.
Plugins:
- Anvil, Lathe, Temper, Knurl, Planish, Braze and Forge gain the NOTE pitch
source, the key lock and Follow bends (shared common-params crate and a
shared header switch in common-ui).
- Unsure tracking: Anvil brings the original sub back in place of the sine,
Lathe passes the audio through, Knurl fades its texture out; Temper,
Planish and Braze hold their last sure tuning. Readouts show the note only
when it is sure.
- Anvil gains Mode: Replace or Enhance (keeps the original sub and adds the
sine under it).
- Planish slides its band edges over 6 ms on a new note instead of snapping.
- Ballast defaults to Grid parts, which need no tracking.
Add a Tracked trait and a Lookahead harness to common-dsp. Each engine is
now its tracker plus a module that follows note events aligned with its
input, so the same module can run behind a shared tracker.
Lathe and Temper output is bit-exact against the old engines. Knurl's
interpolation now reads one newer sample inside the module, so its
latency is one sample longer; the output matches within float rounding.
Each editor exposes body() and toggles() besides show(), so another
editor can draw a module's page.
Knurl follows the played note and treats every cycle of the wave on its
own: a repeating level pattern over 1-16 cycles makes subharmonics in tune
with every note, random level and timing per cycle add rattle, and a noise
burst per cycle, highpassed at a multiple of f0, adds grit. Amounts are
counted in cycles, so the texture is the same on F1 and on C2.
- Cycle clock from the shared note tracker, restarted at each note; the
audio is delayed by the lookahead plus 4.2 ms of timing-jitter headroom.
- Per-cycle randomness from a hash of the cycle number: Same every note
or Free.
- Patterns Off, Double, Triple, Fry (default), Gallop, Stutter or drawn;
grit switchable per step. Pattern persisted as knurl-pattern.
- Editor: last eight cycles overlaid, pattern bars with the playing step.
- Tests match the prototype: Double gives f0/2 at -8.19 dB, Triple f0/3
at -10.68 dB, equal on F1 and C2, no added clicks, bit-exact when off,
no allocation on the audio thread.
nvrl