<!DOCTYPE HTML>
<html>
<head>
  <title>Test repeating audio is not distorted</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">

function gcd(a, b) {
  if (b === 0) {
    return a;
  }
  return gcd(b, a % b);
}

var SAMPLE_PLACEMENT = 128;

var gTest = {
  length: 2048,
  numberOfChannels: 1,

  createGraph(context) {
    var freq = Math.round(context.sampleRate / SAMPLE_PLACEMENT);
    var dur = context.sampleRate / gcd(freq, context.sampleRate);
    var buffer = context.createBuffer(1, dur, context.sampleRate);

    for (var i = 0; i < context.sampleRate; ++i) {
      buffer.getChannelData(0)[i] = Math.sin(freq * 2 * Math.PI * i / context.sampleRate);
    }

    var source = context.createBufferSource();
    source.buffer = buffer;
    source.loop = true;
    source.playbackRate.setValueAtTime(0.5, SAMPLE_PLACEMENT / context.sampleRate);
    source.start(0);

    return source;
  },

  createExpectedBuffers(context) {
    var freq = Math.round(context.sampleRate / SAMPLE_PLACEMENT);
    var expectedBuffer = context.createBuffer(1, 2048, context.sampleRate);
    var c = expectedBuffer.getChannelData(0);
    for (var i = 0; i < c.length; ++i) {
      if (i < SAMPLE_PLACEMENT) {
        c[i] = Math.sin(freq * 2 * Math.PI * i / context.sampleRate);
      } else {
        c[i] = Math.sin(freq / 2 * 2 * Math.PI * (i + SAMPLE_PLACEMENT) / context.sampleRate);
      }
    }

    return expectedBuffer;
  },
};

runTest();
</script>
</pre>
</body>
</html>
