<!DOCTYPE HTML>
<html>
<head>
  <title>Test AudioParam with pre-gain </title>
  <script src="/tests/SimpleTest/SimpleTest.js"></script>
  <script type="text/javascript" src="webaudio.js"></script>
  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
</head>
<body>
<pre id="test">
<script class="testbody" type="text/javascript">

SimpleTest.waitForExplicitFinish();

var ctx = new AudioContext();
var source = ctx.createOscillator();
var lfo = ctx.createOscillator();
var lfoIntensity = ctx.createGain();
var effect = ctx.createGain();
var sp = ctx.createScriptProcessor(2048, 1);

source.frequency.value = 440;
lfo.frequency.value = 2;
// Very low gain, so the LFO should have very little influence
// on the source, its RMS value should be close to the nominal value
// for a sine wave.
lfoIntensity.gain.value = 0.0001;

lfo.connect(lfoIntensity);
lfoIntensity.connect(effect.gain);
source.connect(effect);
effect.connect(sp);

sp.onaudioprocess = function(e) {
  var buffer = e.inputBuffer.getChannelData(0);
  var rms = 0;
  for (var i = 0; i < buffer.length; i++) {
    rms += buffer[i] * buffer[i];
  }

  rms /= buffer.length;
  rms = Math.sqrt(rms);

  // 1 / Math.sqrt(2) is the theoretical RMS value for a sine wave.
  ok(fuzzyCompare(rms, 1 / Math.sqrt(2)),
      "Gain correctly applied to the AudioParam.");

  ctx = null;
  sp.onaudioprocess = null;
  lfo.stop(0);
  source.stop(0);

  SimpleTest.finish();
}

lfo.start(0);
source.start(0);

</script>
</pre>
</body>
