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).
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).
Tests cover:
- Default state (C15, 126 params, heatmap cells)
- Engine switcher UI (3 cards, active state)
- Switch to Additive (48 params, outputs bounded, training works)
- Switch to FM Matrix (55 params, outputs bounded, training works)
- Round-trip switching (C15→Add→C15, C15→FM→Add→C15)
- Warm-start weight preservation across resize
- EOC chain accessibility across engines
- SynthVisualizer visibility across engines
- No console errors during any switch
Also fixes: faustJsonToParamMeta now filters [hidden:1] params,
giving correct counts (48 additive, 55 FM) instead of including
freq/gate/_vel control inputs.
- Add window.__nisps debug probe (gated on ?debug=1) exposing iml state,
getOutputs/getLoss/getWeights/getExampleCount, and action triggers
(thumbsUp/thumbsDown/train/randomise/clearExamples/saveState)
- Fix WasmIML bug: this.dataset was a plain object; import Dataset and
use new Dataset(100) so computeWeights() is available for training
- Fix WasmIML.addExample/clearDataset to use Dataset API methods
- 44 Playwright e2e tests across 4 spec files:
- ml-engine.spec.js: WASM inference bounds, training loss, thumbs
up/down behavior, async training, example capture semantics
- ui-interactions.spec.js: drawer open/close, mode switching,
heatmap bar counts, preset chips, keyboard shortcuts (1/2/Z)
- input-pipeline.spec.js: input→output variation, clamping, joystick
drag, post-training output bounds across the full input space
- persistence.spec.js: URL params (?preset, ?spread), localStorage
round-trip, saveState probe
