rkeys/ui/lib/audio.js

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

// Generated by LiveScript 1.3.0
(function(){
  var Noise, CACHESIZE, MONO, SAMPLERATE;
  Noise = require('./noise');
  CACHESIZE = 3;
  MONO = 1;
  SAMPLERATE = 44100;
  module.exports = {
    createBeep: createBeep,
    createNoise: createNoise,
    beep: createBeep(),
    blip: createBeep({
      type: 'square',
      freq: 9000
    }),
    blop: createBeep({
      type: 'square',
      freq: 100
    }),
    drop: createBeep({
      toFreq: 0
    }),
    rise: createBeep({
      toFreq: 2000
    }),
    noise: {
      brown: createNoise({
        type: 'brown'
      }),
      pink: createNoise({
        type: 'pink'
      }),
      white: createNoise({
        type: 'white'
      })
    }
  };
  function createBeep(arg$){
    var ref$, freq, ref1$, dur, toFreq, type;
    ref$ = arg$ != null
      ? arg$
      : {}, freq = (ref1$ = ref$.freq) != null ? ref1$ : 1000, dur = (ref1$ = ref$.dur) != null ? ref1$ : 0.025, toFreq = ref$.toFreq, type = ref$.type;
    return renderCacheOffline(dur, function(ctx){
      var x$;
      x$ = ctx.createOscillator();
      x$.frequency.value = freq;
      if (toFreq != null) {
        x$.frequency.setTargetAtTime(toFreq, 0, dur);
      }
      if (type != null) {
        x$.type = type;
      }
      return x$;
    });
  }
  function createNoise(arg$){
    var ref$, dur, ref1$, type, GENS;
    ref$ = arg$ != null
      ? arg$
      : {}, dur = (ref1$ = ref$.dur) != null ? ref1$ : 0.025, type = (ref1$ = ref$.type) != null ? ref1$ : 'white';
    GENS = {
      brown: Noise.createBrownNoise,
      pink: Noise.createPinkNoise,
      white: Noise.createWhiteNoise
    };
    return renderCacheOffline(dur, function(ctx, size){
      var b, samples, data, i$, to$, i, x$;
      b = ctx.createBuffer(MONO, size, SAMPLERATE);
      samples = GENS[type](size);
      data = b.getChannelData(0);
      for (i$ = 0, to$ = size - 1; i$ <= to$; ++i$) {
        i = i$;
        data[i] = samples[i];
      }
      x$ = ctx.createBufferSource();
      x$.buffer = b;
      return x$;
    });
  }
  function createCache(){
    var audio, p;
    audio = [];
    p = 0;
    return {
      init: function(samples){
        var data, i$, to$, i, results$ = [];
        data = WavEncoder.encode(samples);
        for (i$ = 0, to$ = CACHESIZE - 1; i$ <= to$; ++i$) {
          i = i$;
          results$.push(audio[i] = new Audio(data));
        }
        return results$;
      },
      play: function(){
        var ref$;
        return (ref$ = audio[p++ % CACHESIZE]) != null ? ref$.play() : void 8;
      }
    };
  }
  function renderCacheOffline(dur, createGenerator){
    var size, c, x$, generator, cache;
    size = SAMPLERATE * dur;
    c = new OfflineAudioContext(MONO, size, SAMPLERATE);
    x$ = generator = createGenerator(c, size);
    x$.connect(c.destination);
    x$.start();
    x$.stop(dur);
    cache = createCache();
    c.oncomplete = function(it){
      return cache.init(it.renderedBuffer.getChannelData(0));
    };
    c.startRendering();
    return cache.play;
  }
}).call(this);