test_audioParamSetCurveAtTime.html

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<!DOCTYPE HTML>

<html>

<head>

  <title>Test AudioParam.linearRampToValue</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 T0 = 0;

var gTest = {

  length: 2048,

  numberOfChannels: 1,

  createGraph(context) {

    var source = context.createConstantSource();

    var gain = context.createGain();

    gain.gain.setValueCurveAtTime(this.curve, T0, this.duration);

    source.connect(gain);

    source.start(0);

    return gain;

},

  createExpectedBuffers(context) {

    this.duration = 1024 / context.sampleRate;

    this.curve = new Float32Array([1.0, 0.5, 0.75, 0.25]);

    var expectedBuffer = context.createBuffer(1, 2048, context.sampleRate);

    var data = expectedBuffer.getChannelData(0);

    var step = 1024 / 3;

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

      if (i < step) {

        data[i] = 1.0 - 0.5*i/step;

      } else if (i < 2*step) {

        data[i] = 0.5 + 0.25*(i - step)/step;

      } else if (i < 3*step) {

        data[i] = 0.75 - 0.5*(i - 2*step)/step;

      } else {

        data[i] = 0.25;

    return expectedBuffer;

},

};

runTest();

</script>

</pre>

</body>

</html>