rkeys/ui/lib/noise.js

A platform for creating tablet/HTML5 virtual-keyboard apps to send keystrokes to remote X11

// Generated by LiveScript 1.3.0
(function(){
  module.exports = {
    createBrownNoise: function(bufferSize){
      var last;
      last = 0;
      return _.map(whiteNoise(bufferSize), function(white){
        var out;
        last = out = (last + 0.02 * white) / 1.02;
        return out * 3.5;
      });
    },
    createPinkNoise: function(bufferSize){
      var b;
      b = [0, 0, 0, 0, 0, 0];
      return _.map(whiteNoise(bufferSize), function(white){
        var out;
        b[0] = 0.99886 * b[0] + white * 0.0555179;
        b[1] = 0.99332 * b[1] + white * 0.0750759;
        b[2] = 0.96900 * b[2] + white * 0.1538520;
        b[3] = 0.86650 * b[3] + white * 0.3104856;
        b[4] = 0.55000 * b[4] + white * 0.5329522;
        b[5] = -0.7616 * b[5] - white * 0.0168980;
        out = _.reduce(b, function(sum, n){
          return sum + n;
        });
        b[6] = white * 0.115926;
        out += white * 0.5362;
        return out * 0.11;
      });
    },
    createWhiteNoise: function(bufferSize){
      return _.map(whiteNoise(bufferSize), function(it){
        return it * 0.2;
      });
    }
  };
  function whiteNoise(bufferSize){
    var i$, to$, i, results$ = [];
    for (i$ = 0, to$ = bufferSize - 1; i$ <= to$; ++i$) {
      i = i$;
      results$.push(2 * Math.random() - 1);
    }
    return results$;
  }
}).call(this);