const sawtooth = (t) => 2 * (t % 1) - 1;
const random = () => Math.random() * 2 - 1;

const osc = synth.def(
	class {
		constructor(options) {
		    this.pan = 0;
			this.phase = 0;
			this.targetPan = random();
			if (Math.abs(this.targetPan) < 0.5) {
			    this.targetPan *= 2.0;
			}
			this.startFreq = this.currentFreq = 300 + random() * 100;
			this.detune = 1 + 0.01 * random();
			this.targetFreq = midi_to_hz(options.note) * this.detune;
		}

		process(note, env, tick, options) {
			if (tick < 8) {
				// For 8 ticks, move slowly and randomly
				this.currentFreq = this.startFreq * (1 + 0.1 * Math.sin(ditty.time / 1000));
			} else {
				// After 8 ticks, move to target
			    this.pan = lerp(this.pan, this.targetPan, 0.00003);
				this.currentFreq = lerp(this.currentFreq, this.targetFreq, 0.00003);
			}
			
			this.phase += this.currentFreq * ditty.dt;

			let boost = 1;
			if (tick > 20 && this.currentFreq < 220) {
				boost = 1.5;
			}

			return sawtooth(this.phase) * env.value * boost;
		}
	}, {
		amp: 0.1,
		attack: 8,
		duration: 30,
		release: 3
	}
);

// THX chord
// https://twitter.com/THX/status/1000077588415447040
for (let i = 0; i < 4; i++) {
	[d1, d2, a2, d3, a3, d4, a4, d5, a5, d6, fs6].forEach((n) => osc.play(n));
}