retrospective-setTargetAtTime.html

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This test has a WPT meta file that expects 1 subtest issues.
This WPT test may be referenced by the following Test IDs:
- /webaudio/the-audio-api/the-audioparam-interface/retrospective-setTargetAtTime.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<meta charset=utf-8>

<html>

  <head>

    <title>Test setTargetAtTime with start time in the past</title>

    <script src="/resources/testharness.js"></script>

    <script src="/resources/testharnessreport.js"></script>

  </head>

  <body>

    <script>

      const suspendFrame = 128;

      promise_test(async () => {

        // Use a sample rate that is a power of two to eliminate round-off

        // in computing the currentTime.

        const context = new OfflineAudioContext(2, 16384, 16384);

        const source = new ConstantSourceNode(context);

        const test = new GainNode(context);

        const reference = new GainNode(context);

        source.connect(test);

        source.connect(reference);

        const merger = new ChannelMergerNode(

            context, {numberOfInputs: context.destination.channelCount});

        test.connect(merger, 0, 0);

        reference.connect(merger, 0, 1);

        merger.connect(context.destination);

        context.suspend(suspendFrame / context.sampleRate).then(() => {

          // Call setTargetAtTime with a time in the past

          test.gain.setTargetAtTime(0.1, 0.5*context.currentTime, 0.1);

          reference.gain.setTargetAtTime(0.1, context.currentTime, 0.1);

          context.resume();

});

        source.start();

        const resultBuffer = await context.startRendering();

        const testValue = resultBuffer.getChannelData(0);

        const referenceValue = resultBuffer.getChannelData(1);

        // Until the suspendFrame, both should be exactly equal to 1.

        assert_array_equals(

            testValue.slice(0, suspendFrame),

            new Float32Array(suspendFrame).fill(1),

            `Test[0:${suspendFrame - 1}]`);

        assert_array_equals(

            referenceValue.slice(0, suspendFrame),

            new Float32Array(suspendFrame).fill(1),

            `Reference[0:${suspendFrame - 1}]`);

        // After the suspendFrame, both should be equal (and not constant)

        assert_array_equals(

            testValue.slice(suspendFrame),

            referenceValue.slice(suspendFrame),

            `Test[${suspendFrame}:]`);

      }, 'Test setTargetAtTime with start time in the past');

    </script>

  </body>

</html>