retrospective-setValueAtTime.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-setValueAtTime.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<html>

  <head>

    <title>Test setValueAtTime with startTime in the past</title>

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

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

    <script src="/webaudio/resources/audit-util.js"></script>

    <script src="retrospective-test.js"></script>

  </head>

  <body>

    <script>

      // Test setValueAtTime with startTime in the past

      promise_test(async () => {

        const {context, source, test, reference} = setupRetrospectiveGraph();

        // Suspend the context at this frame so we can synchronously set up

        // automations.

        const suspendFrame = 128;

        // Use a ramp of slope 1 per frame to measure time.

        // The end value is the extent of exact precision in single

        // precision float.

        const rampEnd = context.length - suspendFrame;

        const rampEndSeconds = context.length / context.sampleRate;

        context.suspend(suspendFrame / context.sampleRate)

            .then(() => {

              // Call setValueAtTime with a time in the past

              test.gain.setValueAtTime(0.0, 0.5 * context.currentTime);

              test.gain.linearRampToValueAtTime(rampEnd, rampEndSeconds);

              reference.gain.setValueAtTime(0.0, context.currentTime);

              reference.gain.linearRampToValueAtTime(

                  rampEnd, rampEndSeconds);

              context.resume();

});

        source.start();

        const resultBuffer = await context.startRendering();

        const actualChannelData = resultBuffer.getChannelData(0);

        const expectedChannelData = resultBuffer.getChannelData(1);

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

        assert_constant_value(

            actualChannelData.slice(0, suspendFrame),

1,

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

        assert_constant_value(

            expectedChannelData.slice(0, suspendFrame),

1,

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

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

        assert_array_equals_exact(

            actualChannelData.slice(suspendFrame),

            expectedChannelData.slice(suspendFrame),

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

      }, 'Test setValueAtTime with startTime in the past');

    </script>

  </body>

</html>