TURNCRAFT/src/audio/sfx.ts

// TURNCRAFT — Lane E. One-shot diegetic SFX, all synthesized and short.
// Each function synthesizes into `dest` (AudioEngine routes `dest` through a
// PannerNode when a world position is supplied). None of these hold state.

import type { BlockDef } from '../core/blocks';

type SoundCat = BlockDef['sound']; // 'metal'|'wood'|'plastic'|'soft'|'glass'|'none'

/** Short filtered noise burst, body tuned per surface category. */
function noiseHit(
  ctx: BaseAudioContext, dest: AudioNode, noise: AudioBuffer, t: number,
  o: { type: BiquadFilterType; freq: number; q: number; dur: number; gain: number },
): void {
  const src = ctx.createBufferSource();
  src.buffer = noise;
  src.loop = true;
  const f = ctx.createBiquadFilter();
  f.type = o.type;
  f.frequency.value = o.freq;
  f.Q.value = o.q;
  const g = ctx.createGain();
  g.gain.setValueAtTime(o.gain, t);
  g.gain.exponentialRampToValueAtTime(0.0001, t + o.dur);
  src.connect(f); f.connect(g); g.connect(dest);
  src.start(t);
  src.stop(t + o.dur + 0.02);
}

const STEP_BY_CAT: Record<SoundCat, { type: BiquadFilterType; freq: number; q: number; dur: number; gain: number }> = {
  metal:   { type: 'bandpass', freq: 3200, q: 3,   dur: 0.06, gain: 0.18 },
  wood:    { type: 'lowpass',  freq: 900,  q: 1,   dur: 0.07, gain: 0.22 },
  plastic: { type: 'highpass', freq: 1800, q: 0.7, dur: 0.045, gain: 0.16 },
  soft:    { type: 'lowpass',  freq: 420,  q: 0.7, dur: 0.09, gain: 0.20 },
  glass:   { type: 'bandpass', freq: 6000, q: 6,   dur: 0.05, gain: 0.14 },
  none:    { type: 'lowpass',  freq: 700,  q: 1,   dur: 0.05, gain: 0.10 },
};

export function footstep(
  ctx: BaseAudioContext, dest: AudioNode, noise: AudioBuffer, t: number, cat: SoundCat,
): void {
  const p = STEP_BY_CAT[cat] ?? STEP_BY_CAT.none;
  noiseHit(ctx, dest, noise, t, p);
}

/** Land thump: low body scaled by impact speed + a surface tick. */
export function land(
  ctx: BaseAudioContext, dest: AudioNode, noise: AudioBuffer, t: number,
  impactSpeed: number, cat: SoundCat,
): void {
  const amt = Math.min(1, impactSpeed / 12);
  const g = ctx.createGain();
  g.gain.setValueAtTime(0.0001, t);
  g.gain.exponentialRampToValueAtTime(0.25 + 0.5 * amt, t + 0.005);
  g.gain.exponentialRampToValueAtTime(0.0001, t + 0.12 + 0.1 * amt);
  g.connect(dest);
  const osc = ctx.createOscillator();
  osc.type = 'sine';
  osc.frequency.setValueAtTime(120 + 60 * amt, t);
  osc.frequency.exponentialRampToValueAtTime(50, t + 0.12);
  osc.connect(g);
  osc.start(t); osc.stop(t + 0.24);
  const p = STEP_BY_CAT[cat] ?? STEP_BY_CAT.none;
  noiseHit(ctx, dest, noise, t, { ...p, gain: p.gain * (0.6 + amt) });
}

/** Break/place click: brighter for break, softer for place, category-flavoured. */
export function blockHit(
  ctx: BaseAudioContext, dest: AudioNode, noise: AudioBuffer, t: number,
  cat: SoundCat, kind: 'break' | 'place',
): void {
  const p = STEP_BY_CAT[cat] ?? STEP_BY_CAT.none;
  const dur = kind === 'break' ? 0.09 : 0.05;
  noiseHit(ctx, dest, noise, t, { ...p, dur, gain: p.gain * (kind === 'break' ? 1.4 : 0.9) });
  if (kind === 'break') {
    // little pitch-down thock so breaks feel chunkier
    const g = ctx.createGain();
    g.gain.setValueAtTime(0.14, t);
    g.gain.exponentialRampToValueAtTime(0.0001, t + 0.08);
    g.connect(dest);
    const osc = ctx.createOscillator();
    osc.type = 'triangle';
    osc.frequency.setValueAtTime(320, t);
    osc.frequency.exponentialRampToValueAtTime(120, t + 0.08);
    osc.connect(g); osc.start(t); osc.stop(t + 0.1);
  }
}

/** Fader zip: filtered noise sweep, quick. */
export function faderZip(ctx: BaseAudioContext, dest: AudioNode, noise: AudioBuffer, t: number): void {
  const src = ctx.createBufferSource();
  src.buffer = noise; src.loop = true;
  const bp = ctx.createBiquadFilter();
  bp.type = 'bandpass'; bp.Q.value = 4;
  bp.frequency.setValueAtTime(1200, t);
  bp.frequency.exponentialRampToValueAtTime(3600, t + 0.12);
  const g = ctx.createGain();
  g.gain.setValueAtTime(0.12, t);
  g.gain.exponentialRampToValueAtTime(0.0001, t + 0.13);
  src.connect(bp); bp.connect(g); g.connect(dest);
  src.start(t); src.stop(t + 0.15);
}

/** Button clunk: short low thock with a click. */
export function buttonClunk(ctx: BaseAudioContext, dest: AudioNode, t: number): void {
  const g = ctx.createGain();
  g.gain.setValueAtTime(0.3, t);
  g.gain.exponentialRampToValueAtTime(0.0001, t + 0.09);
  g.connect(dest);
  const osc = ctx.createOscillator();
  osc.type = 'sine';
  osc.frequency.setValueAtTime(220, t);
  osc.frequency.exponentialRampToValueAtTime(90, t + 0.08);
  osc.connect(g); osc.start(t); osc.stop(t + 0.1);
}

/** RCA plug seating: "clunk-clunk-CLICK", three rising transients. */
export function rcaClick(ctx: BaseAudioContext, dest: AudioNode, noise: AudioBuffer, t: number): void {
  const steps = [
    { off: 0.0,  f: 140, g: 0.22 },
    { off: 0.12, f: 200, g: 0.26 },
    { off: 0.26, f: 340, g: 0.34 },
  ];
  for (const s of steps) {
    const g = ctx.createGain();
    g.gain.setValueAtTime(s.g, t + s.off);
    g.gain.exponentialRampToValueAtTime(0.0001, t + s.off + 0.06);
    g.connect(dest);
    const osc = ctx.createOscillator();
    osc.type = 'triangle';
    osc.frequency.setValueAtTime(s.f, t + s.off);
    osc.frequency.exponentialRampToValueAtTime(s.f * 0.6, t + s.off + 0.05);
    osc.connect(g); osc.start(t + s.off); osc.stop(t + s.off + 0.08);
  }
  noiseHit(ctx, dest, noise, t + 0.26, { type: 'highpass', freq: 4000, q: 2, dur: 0.04, gain: 0.18 });
}

/** Fuse zap: buzzy electric discharge. */
export function fuseZap(ctx: BaseAudioContext, dest: AudioNode, noise: AudioBuffer, t: number): void {
  const src = ctx.createBufferSource();
  src.buffer = noise; src.loop = true;
  const bp = ctx.createBiquadFilter();
  bp.type = 'bandpass'; bp.frequency.value = 2200; bp.Q.value = 8;
  const g = ctx.createGain();
  g.gain.setValueAtTime(0.28, t);
  g.gain.setValueAtTime(0.05, t + 0.02);
  g.gain.setValueAtTime(0.24, t + 0.05);
  g.gain.exponentialRampToValueAtTime(0.0001, t + 0.22);
  src.connect(bp); bp.connect(g); g.connect(dest);
  src.start(t); src.stop(t + 0.24);
  // buzzy saw underneath
  const osc = ctx.createOscillator();
  osc.type = 'sawtooth';
  osc.frequency.setValueAtTime(320, t);
  osc.frequency.exponentialRampToValueAtTime(80, t + 0.2);
  const og = ctx.createGain();
  og.gain.setValueAtTime(0.12, t);
  og.gain.exponentialRampToValueAtTime(0.0001, t + 0.2);
  osc.connect(og); og.connect(dest); osc.start(t); osc.stop(t + 0.22);
}

/** Tonearm cue lever creak: slow filtered-noise groan. */
export function cueCreak(ctx: BaseAudioContext, dest: AudioNode, noise: AudioBuffer, t: number): void {
  const src = ctx.createBufferSource();
  src.buffer = noise; src.loop = true;
  const bp = ctx.createBiquadFilter();
  bp.type = 'bandpass'; bp.Q.value = 12;
  bp.frequency.setValueAtTime(420, t);
  bp.frequency.linearRampToValueAtTime(280, t + 0.3);
  const g = ctx.createGain();
  g.gain.setValueAtTime(0.0001, t);
  g.gain.linearRampToValueAtTime(0.1, t + 0.06);
  g.gain.exponentialRampToValueAtTime(0.0001, t + 0.34);
  src.connect(bp); bp.connect(g); g.connect(dest);
  src.start(t); src.stop(t + 0.36);
}

/** Needle drop: crackle burst as the stylus meets the groove (used at win). */
export function needleDrop(ctx: BaseAudioContext, dest: AudioNode, noise: AudioBuffer, t: number): void {
  const src = ctx.createBufferSource();
  src.buffer = noise; src.loop = true;
  const g = ctx.createGain();
  g.gain.setValueAtTime(0.0001, t);
  g.gain.linearRampToValueAtTime(0.35, t + 0.01);
  g.gain.exponentialRampToValueAtTime(0.04, t + 0.18);
  g.gain.exponentialRampToValueAtTime(0.0001, t + 0.5);
  const hp = ctx.createBiquadFilter();
  hp.type = 'highpass'; hp.frequency.value = 1500;
  src.connect(hp); hp.connect(g); g.connect(dest);
  src.start(t); src.stop(t + 0.55);
  // the "thunk" of the tonearm landing
  const tg = ctx.createGain();
  tg.gain.setValueAtTime(0.3, t);
  tg.gain.exponentialRampToValueAtTime(0.0001, t + 0.12);
  tg.connect(dest);
  const osc = ctx.createOscillator();
  osc.type = 'sine';
  osc.frequency.setValueAtTime(90, t);
  osc.frequency.exponentialRampToValueAtTime(45, t + 0.1);
  osc.connect(tg); osc.start(t); osc.stop(t + 0.14);
}

export type SfxName =
  | 'footstep' | 'land' | 'break' | 'place'
  | 'fader' | 'button' | 'rca' | 'fuse' | 'cue' | 'needle';