// Low-pass gate: one envelope opens filter and volume together – the typical "plonk".
module lpg "LPG" hp 4 {
  desc de "Low-Pass-Gate: Jeder Trigger lässt Lautstärke und Helligkeit gemeinsam ausklingen – wie ein angeschlagenes Instrument."
  desc en "Low-pass gate: each trigger lets volume and brightness decay together – like a struck instrument."

  knob decay "DECAY" 0.02..3 = 0.4 log unit s
  knob tone  "TONE"  0..1 = 0.6
  in   x     "IN"    audio
  in   trig  "TRIG"  gate
  out  y     "OUT"   audio
  led  env   green

  process {
    e = ad(rise(trig), 0.002, decay)
    cutoff = 80 * exp2(e * (2 + tone * 6))
    y = lp(x, cutoff, 0.1) * e
    env = e
  }
}