<!DOCTYPE HTML>
<html>
<head>
  <title>Test OscillatorNode type change after it has started and triangle phase</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();

const bufferSize = 1024;

function startTest() {
  var ctx = new AudioContext();

  var oscillator1 = ctx.createOscillator();
  oscillator1.connect(ctx.destination);
  oscillator1.start(0);

  // Assuming the above Web Audio operations have already scheduled an event
  // to run in stable state and start the graph thread, schedule a subsequent
  // event to change the type of oscillator1.
  SimpleTest.executeSoon(function() {
    oscillator1.type = "triangle";

    // Another triangle wave with -1 gain should cancel the first.  This is
    // starting at the same time as the type change, assuming that the phase
    // is reset on type change.  A negative frequency should achieve the same
    // as the -1 gain but for bug 916285.
    var oscillator2 = ctx.createOscillator();
    oscillator2.type = "triangle";
    oscillator2.start(0);

    var processor = ctx.createScriptProcessor(bufferSize, 1, 0);
    oscillator1.connect(processor);
    var gain = ctx.createGain();
    gain.gain.value = -1;
    gain.connect(processor);
    oscillator2.connect(gain);

    processor.onaudioprocess = function(e) {
      compareChannels(e.inputBuffer.getChannelData(0),
                      new Float32Array(bufferSize));
      e.target.onaudioprocess = null;
      SimpleTest.finish();
    }
  });
};

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