diff --git a/packages/superdough/synth.mjs b/packages/superdough/synth.mjs index 255e0342b..4e876caff 100644 --- a/packages/superdough/synth.mjs +++ b/packages/superdough/synth.mjs @@ -13,9 +13,9 @@ import { } from './helpers.mjs'; import { getNoiseMix, getNoiseOscillator } from './noise.mjs'; -const getFrequencyFromValue = (value) => { +const getFrequencyFromValue = (value, defaultNote = 36) => { let { note, freq } = value; - note = note || 36; + note = note || defaultNote; if (typeof note === 'string') { note = noteToMidi(note); // e.g. c3 => 48 } @@ -42,6 +42,17 @@ const waveformAliases = [ ['sin', 'sine'], ]; +function makeSaturationCurve(amount, n_samples) { + const k = typeof amount === 'number' ? amount : 50; + const curve = new Float32Array(n_samples); + + for (let i = 0; i < n_samples; i++) { + const x = (i * 2) / n_samples - 1; + curve[i] = Math.tanh(x * k); + } + return curve; +} + export function registerSynthSounds() { [...waveforms].forEach((s) => { registerSound( @@ -84,6 +95,75 @@ export function registerSynthSounds() { { type: 'synth', prebake: true }, ); }); + + registerSound( + 'sbd', + (t, value, onended) => { + const { duration, decay = 0.5, pdecay = 0.5, penv = 36, clip } = value; + const ctx = getAudioContext(); + const attackhold = 0.02; + const noiselvl = 1.2; + const noisedecay = 0.025; + const mixGain = 1; + + const o = ctx.createOscillator(); + o.type = 'triangle'; + o.frequency.value = getFrequencyFromValue(value, 29); + o.detune.setValueAtTime(penv * 100, 0); + o.detune.setValueAtTime(penv * 100, t); + o.detune.exponentialRampToValueAtTime(0.001, t + pdecay); + const g = gainNode(1); + g.gain.setValueAtTime(1, t + attackhold); + g.gain.exponentialRampToValueAtTime(0.001, t + attackhold + decay); + o.start(t); + + const noise = getNoiseOscillator('brown', t, 2); + const noiseGain = gainNode(1); + noiseGain.gain.setValueAtTime(noiselvl, t); + noiseGain.gain.exponentialRampToValueAtTime(0.001, t + noisedecay); + + const sat = new WaveShaperNode(ctx); + // tri to sine diode shaper emulation + sat.curve = makeSaturationCurve(2, ctx.sampleRate); + + const mix = gainNode(mixGain); + + o.onended = () => { + o.disconnect(); + g.disconnect(); + sat.disconnect(); + noise.node.disconnect(); + noiseGain.disconnect(); + mix.disconnect(); + onended(); + }; + + const node = o.connect(sat).connect(g).connect(mix); + noise.node.connect(noiseGain).connect(mix); + + const holdEnd = t + decay; + let end = holdEnd + 0.01; + if (clip != null) { + end = Math.min(t + clip * duration, end); + } + + // prevent clicking + mix.gain.setValueAtTime(mixGain, end - 0.01); + mix.gain.linearRampToValueAtTime(0, end); + + o.stop(end); + noise.stop(end); + + return { + node, + stop: (endTime) => { + o.stop(endTime); + }, + }; + }, + { type: 'synth', prebake: true }, + ); + registerSound( 'supersaw', (begin, value, onended) => {