CouldSound

coolsound.js

/*!
 *
 * welcome to wavepot
 * ------------------
 *
 * this is a live editor. you create a function named `dsp`
 * that accepts the parameter `t`, the coefficient of time,
 * which you use to generate a single sample (range -1..1)
 *
 * below is the smallest example possible, a simple sine wave
 * generator. check out more complex demos on the right ---->
 *
 * have fun!
 *
 */
 var tau = Math.PI*2
 
 function sub(wave, mul, t){
  return Math.sin(wave * mul + tau * t);
}

function sin(x, t){
  return Math.sin(tau * t * x);
}

function tri(x, t){
  return Math.abs(1 - (2 * t * x) % 2) * 2 - 1;
}
function perc(wave, decay, o, t){
  var env = Math.max(0, 0.889 - (o * decay) / ((o * decay) + 1));
  return wave * env;
}
function arp(measure, x, y, z, t){
  var ts = t / 2 % measure;
  return Math.sin(x * (Math.exp(-ts * y))) * Math.exp(-ts * z);
}

function midi(n,octave) {
  return Math.pow(2, (
    n + 0 - 33 + (12 * (octave || 0))
  ) / 12) * 440; // A4 tuning
}

function sequence(t,m,s) {
  return s[((t/m)%s.length)|0];
}
var note = [midi(32),midi(34),midi(36),midi(37),midi(39),midi(37),midi(34)];

var t, pt;
function dsp(_t) {
  t = _t;
  pt = (t%0.5)*2;
  return 0 
  //+ sub(sin(440,t),sin(0.2,t)*5,t*8)
  + arp(1/4, 100 + pt*0.5, 50+pt*2, 10,t)
  + sub(sin(sequence(t, t%1/2,note),t),0.5,t)
}