Modular sub-engines computed amp_val as a pure function of mod_amp (the
matrix d08_amp destination sum), so once the MLP drove the matrix cells
every joystick movement had a chance to silence the voice: matrix cells
have signed range [-1, 1], sigmoid outputs near 0.5 denormalise to 0,
and the amp gate collapsed. Additive survived in scattered regions
because it only has one kill-switch (d08_amp); subtractive and fm were
almost always dead because they also have d05_cutoff and d01_op1_level.
Two changes:
1. DSP: each sub-engine gets a base_amp hslider (default 1.0) so
amp_val = clamp(base_amp + mod_amp) * level * vel_gain. At the
default the voice is always fully open and d08_amp modulation is
purely additive decoration; drop base_amp to 0 for classic
ADSR-gated VCA behaviour.
2. ModularEngine._rebuildParamMeta: restore the _exposedMatrixCells
gate (default empty). paramCount drops from 512 to 32 (4 ADSR * 4
+ 8 LFO * 2); matrix cells are opt-in via setExposeMatrixCell.
_applyDefaultPatch no longer writes s00_d08_amp since base_amp
keeps the voice audible without routing.
Tests updated for the new 32-param baseline; matrix-cell persistence
test now calls setExposeMatrixCell(1, 5, true) before asserting the
cell lands in paramMeta. Drive-by: engine-switching test bumped from
3 to 4 engine cards (stale since the modular engine was added).
Two fixes for Modular mode:
1. faust-worklet-processor.js: explicitly attach FaustWorkletProcessor
to globalThis. Class declarations at the top of a classic script are
lexically scoped to that script's evaluation context and do not
propagate across separate addModule() calls, so the base class was
invisible to subclass processors when they loaded in AudioWorklet-
GlobalScope. Symptom: "FaustWorkletProcessor is not defined" at the
extends clause of modular-subtractive-processor.js.
2. modular-ui.js + a-app.js: wire live matrix cell updates. Phase C
wired matrix cells for writes (click cycles, precise editor) but
not for reads — the MLP-driven values never propagated to the DOM.
modular-ui now exposes updateLive(outputs), called from routeOutputs
on every inference tick. Throttled to ~20 fps internally to avoid
DOM thrashing. Only visible sources (within adsrCount/lfoCount) are
updated; muted slots stay dark.
If faust isn't in PATH but nix-shell is, transparently re-exec the
script via `nix-shell -p faust --run` instead of erroring out with a
hint. NISPS_BUILD_IN_NIX_SHELL guards against infinite recursion if the
shell somehow still lacks faust.
New "Modular" engine in a-immersive with three hot-swappable Faust
sub-engines (subtractive/additive/fm) sharing a common modulation pool:
16 ADSR slots + 32 LFO slots (single-knob sine->tri->square->saw
wavemorph) routed through a 48-source x 10-destination matrix per
engine. Per-connection scalar amounts in [-1, 1], summed at each
destination. Default MLP output count is 512 (32 mod-source params +
480 matrix cells); model reinits on sub-engine swap, count change, or
engine-param exposure toggle.
Faust layer:
- mod-pool.lib: shared ADSR/LFO/source-bus library
- gen-modular-dsp.py: byte-reproducible generator (source of truth)
- modular-subtractive: faithful Minimoog (3 osc, ladder filter, no envs)
- modular-additive: 64-partial, spectral shape + formants, no envs/LFOs
- modular-fm: 4-op matrix + self-feedback, no envs
- All three share d08=amp, d09=pan conventions
- MODULAR_DESTINATIONS.md: authoritative destination table
JS layer:
- ModularEngine: self-contained SynthEngine with getState/setState,
setSubEngine, setModSourceCount, setExposeEngineParam
- modular-ui: drawer with sub-engine toggle, ADSR/LFO count steppers,
per-slot enable switches, matrix grid editor (tap-cycle, long-press
precise, right-click menu, negative amounts), preset overlay
- modular-presets: 6 named presets (Slow pad, Plucky bass, Crystal,
DX bell, Morphing drone + default)
- a-app.js: Modular mode registered, paramMeta:change -> resizeMLP,
modular DSP state persisted under modularDspState, window.__nisps
debug hooks for programmatic control
Tests: tests/e2e/modular-mode.spec.js (11 Playwright tests, all passing
including DSP state survives reload, sub-engine swap keeps paramCount,
preset apply verification).
Also fixes a pre-existing build.sh bug where the -e flag caused faust
to overwrite .wasm outputs with expanded DSP source text, leaving
additive/fm-matrix/eoc-* committed as invalid WebAssembly. Rebuilt all
affected engines with the corrected script. Added an early-message
buffer to faust-worklet-processor.js so setParam calls arriving before
wasm instantiation are queued rather than dropped (needed when the user
configures modular state before clicking Start Audio).
Resolved conflicts: merged all 6 module imports in eoc-chain-ui.js and index.js.
All moduleFactory cases now return real Faust WASM implementations — no stubs remain.
Faust DSP sources, compiled WASM + JSON descriptors, AudioWorklet processors,
and EOCModule subclasses for all three effects.
- meml-4b4: 4-band parametric EQ (fi.low_shelf, fi.peak_eq × 2, fi.high_shelf)
10 params: freq/gain per band, Q for the two mid bell bands
- meml-cpe: stereo feed-forward compressor (co.compressor_mono × 2)
7 params: threshold, ratio, attack, release, knee, makeup, mix (parallel)
- meml-wwc: zita reverb (re.zita_rev1_stereo) with pre-delay and M/S width
8 active params + mod_rate placeholder (zita internal mod not yet exposed)
All three DSPs compile cleanly under Faust 2.83.1. moduleFactory in
eoc-chain-ui.js now returns real instances for eq/compressor/reverb.
Adds the Faust DSP toolchain infrastructure: placeholder additive and FM DSP
files, build.sh (faust -lang wasm per .dsp), faustJsonToParamMeta() to convert
Faust JSON UI trees into the standard paramMeta format, FaustEngineBase
(SynthEngine subclass wiring init/setParam/noteOn/noteOff through AudioWorklet
messages), and FaustWorkletProcessor base class for concrete engine processors.
