const delay = filter.def(class {
    constructor(options) {
        this.index = 0;
        this.length = options.interval * ditty.sampleRate * 60 / ditty.bpm | 0;
        this.left  = new Float32Array(this.length);
        this.right = new Float32Array(this.length); 
    }

    process(input, options) {
        if (input) {
            const s = options.strength;
            this.index = (this.index + 1) % this.length;
            const hist = (this.index + 1) % this.length;
            
            this.left [this.index] = input[1] + s * this.right[hist];
            this.right[this.index] = input[0] + s * this.left [hist];
            
            return [ this.left[this.index], this.right[this.index] ];
        }
    }
}, { interval: 1/3, strength: 0.25 }); 

loop((i) => {
    sine.play([c3,c4,c3,c5,c3,c4,f3,g5, c3,c4,c3,c5,c3,c4,g5,d5 ][i%16] + (i/32|0)%2*2, { attack: 0.05 * Math.random(), release: 0.2, pan: 0.5 + Math.random() });
    sleep(0.5);
}, { name: '📢' })
.connect( delay.create( { interval: 1.25, strength: 0.25 }) )
.connect( delay.create( { interval: 2/3, strength: 0.15 }) )
.connect( delay.create( { interval: 1/2, strength: 0.25 }) )
.connect( delay.create( { interval: 1.5, strength: 0.33 }) )