test_waveShaper.html

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<html>

<head>

  <title>Test WaveShaperNode with no curve</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">

var gTest = {

  length: 4096,

  numberOfChannels: 1,

  createGraph(context) {

    var source = context.createBufferSource();

    source.buffer = this.buffer;

    var shaper = new WaveShaperNode(context);

    shaper.curve = this.curve;

    source.connect(shaper);

    source.start(0);

    return shaper;

},

  createExpectedBuffers(context) {

    this.buffer = context.createBuffer(1, 4096, context.sampleRate);

    for (var i = 1; i < 4095; ++i) {

      this.buffer.getChannelData(0)[i] = 2 * (i / 4096) - 1;

    // Two out of range values

    this.buffer.getChannelData(0)[0] = -2;

    this.buffer.getChannelData(0)[4095] = 2;

    this.curve = new Float32Array(2048);

    for (var i = 0; i < 2048; ++i) {

      this.curve[i] = Math.sin(100 * Math.PI * (i + 1) / context.sampleRate);

    var expectedBuffer = context.createBuffer(1, 4096, context.sampleRate);

    for (var i = 1; i < 4095; ++i) {

      var input = this.buffer.getChannelData(0)[i];

      var index = Math.floor(this.curve.length * (input + 1) / 2);

      index = Math.max(0, Math.min(this.curve.length - 1, index));

      expectedBuffer.getChannelData(0)[i] = this.curve[index];

    expectedBuffer.getChannelData(0)[0] = this.curve[0];

    expectedBuffer.getChannelData(0)[4095] = this.curve[2047];

    return expectedBuffer;

},

};

runTest();

</script>

</pre>

</body>

</html>