Hand tracking at 30fps was writing 126 params per frame to the C15 ring
buffer (capacity 512), flooding it and starving arpeggiator noteOn/noteOff
messages — causing stuck/dropped notes.
Three-part fix:
- Arpeggiator now runs in a dedicated Web Worker with direct
SharedArrayBuffer access, bypassing the main thread entirely for
note timing. Worker setInterval isn't subject to main thread jank.
- RingBufferWriter uses CAS (Atomics.compareExchange) for multi-producer
safety — both main thread (params) and worker (notes) write safely.
- routeOutputs throttles synth parameter sends: dead-zone filter
(0.2% change threshold) + rate cap (~20fps), reducing ring buffer
pressure from ~3800 msg/s to ~50-100 msg/s of actual changes.
4 tiers of progressive complexity (Beginner 15 params → Expert 126),
13 presets total with per-param min/max/curve overrides that bias
distributions without clamping extremes. Preset dropdown in UI,
persisted to localStorage, supports ?preset= URL param.
Merge Examples/RL tabs into single unified toolbar across all four UIs.
Users can now freely mix supervised learning (Add Example + Train) with
RL feedback (thumbs up/down) without switching modes. Param bar dragging
is always enabled.
Add Web MIDI input module (js/synth/midi-input.js) for external MIDI
controllers — routes note on/off to C15 synth, CC 1/2 to joystick.
Add gamepad module (js/ui/gamepad.js) with auto-detection, deadzone,
and axis normalization across all UIs.
Fix synth parameter sync: routeOutputs() now called after trainModel()
in onThumbsUp and loadState to prevent stale params on first joystick
move. Add separate Clear Examples button (dataset only, keeps weights).
- Insert DynamicsCompressorNode as always-on brick-wall limiter after
master gain (threshold -6dB, ratio 20:1, 2ms attack)
- Add devmode tame parameter (0-1) controlling range constraining:
- ?tame=0.7 URL param (default) or window.setTameLevel(n)
- 0 = no mitigation, 1 = strongest constraining
- Constrain 20 volume/buildup-sensitive params with safeMin/safeMax:
- Envelope release/decay2 times capped to prevent infinite ringing
- Envelope gains kept in moderate range
- All 5 drive stages (ShpA/B, FB, Out, Cabinet) capped
- Output mixer levels given floor and ceiling
- Echo feedback and reverb size limited to prevent wash buildup
- Fix Comb Filter group count (8, not 9) in comments and color generator
Control all sonically meaningful C15 parameters through NISPS ML outputs.
Excludes hardware routing, macros, scale/tuning, key tracking, velocity,
envelope mod depths, discrete switches, and dangerous volume/pitch params.
- Expand param-map.js with 126 curated params grouped by synthesis section
- Widen MLP architecture from [3,10,10,14,20] to [3,32,48,64,126]
- Add ParamDisplay.rebuild() for mode-dependent bar count (20 visual, 126 synth)
- Add scrollable compact layout for synth mode param bars
- Pad visual presets and old saves to 126 outputs for backward compatibility
Adds a secondary Synth mode (toggled via collapsible left side panel)
where the NISPS ML engine's 20 outputs control curated C15 synthesizer
parameters (oscillator PM, shapers, filters, reverb, echo, flanger,
output mixer) through a WASM AudioWorklet bridge.
Includes a chord progression arpeggiator with controls for tempo (BPM),
octave range, octave offset, and 4 selectable progressions. The C15
engine runs in an AudioWorklet with lock-free SharedArrayBuffer ring
buffer communication.
New files: c15/ (WASM assets), js/synth/ (bridge, arpeggiator, param map),
serve-coop.py (COOP/COEP headers for SharedArrayBuffer support).
