test_periodicWaveDisableNormalization.html

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<head>

  <title>Test PeriodicWave disableNormalization Parameter</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" />

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<pre id="test">

<script class="testbody" type="text/javascript">

SimpleTest.waitForExplicitFinish();

// We create PerodicWave instances containing two tones and compare it to

// buffers created directly in JavaScript by adding the two waves together.

// Two of the PeriodicWaves are normalized, the other is not. This test is

// a modification of test_periodicWave.html.

//

// These constants are borrowed from test_periodicWave.html and modified

// so that the realPeak (which is the normalization factor) will be small

// enough that the errors are within the bounds for the test.

const realMax = 99;

var real = new Float32Array(realMax + 1);

real[1] = 2.0; // fundamental

real[realMax] = 0.25;

const realPeak = real[1] + real[realMax];

const realFundamental = 19.0;

const testLength = 4096;

addLoadEvent(function() {

  runTest();

});

var gTest = {

  createGraph(context) {

    var merger = context.createChannelMerger();

    var osc0 = context.createOscillator();

    var osc1 = context.createOscillator();

    var osc2 = context.createOscillator();

    osc0.setPeriodicWave(context.

                         createPeriodicWave(real,

                                            new Float32Array(real.length),

                                            {disableNormalization: false}));

    osc1.setPeriodicWave(context.

                         createPeriodicWave(real,

                                            new Float32Array(real.length)));

    osc2.setPeriodicWave(context.

                         createPeriodicWave(real,

                                            new Float32Array(real.length),

                                            {disableNormalization: true}));

    osc0.frequency.value = realFundamental;

    osc1.frequency.value = realFundamental;

    osc2.frequency.value = realFundamental;

    osc0.start();

    osc1.start();

    osc2.start();

    osc0.connect(merger, 0, 0);

    osc1.connect(merger, 0, 1);

    osc2.connect(merger, 0, 2);

    return merger;

},

  createExpectedBuffers(context) {

    var buffer = context.createBuffer(3, testLength, context.sampleRate);

    for (var i = 0; i < buffer.length; ++i) {

      buffer.getChannelData(0)[i] = 1.0 / realPeak *

        (real[1] * Math.cos(2 * Math.PI * realFundamental * i /

                            context.sampleRate) +

         real[realMax] * Math.cos(2 * Math.PI * realMax * realFundamental * i /

                            context.sampleRate));

      buffer.getChannelData(1)[i] = buffer.getChannelData(0)[i];

      buffer.getChannelData(2)[i] =

        (real[1] * Math.cos(2 * Math.PI * realFundamental * i /

                            context.sampleRate) +

         real[realMax] * Math.cos(2 * Math.PI * realMax * realFundamental * i /

                            context.sampleRate));

    return buffer;

},

  'numberOfChannels': 3,

};

</script>

</pre>

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