note-grain-on-play.html

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<html>

  <head>

    <title>

      note-grain-on-play.html

    </title>

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

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

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

    <script src="/webaudio/resources/note-grain-on-testing.js"></script>

  </head>

  <body>

    <div id="description"></div>

    <div id="console"></div>

    <script>

      // To test noteGrainOn, a single ramp signal is created.

      // Various sections of the ramp are rendered by noteGrainOn() at

      // different times, and we verify that the actual output

      // consists of the correct section of the ramp at the correct

      // time.

      let linearRampBuffer;

      // Array of the grain offset used for each ramp played.

      let grainOffsetTime = [];

      // Verify the received signal is a ramp from the correct section

      // of our ramp signal.

      function verifyGrain(renderedData, startFrame, endFrame, grainIndex) {

        const grainOffsetFrame =

            timeToSampleFrame(grainOffsetTime[grainIndex], sampleRate);

        const grainFrameLength = endFrame - startFrame;

        const ramp = linearRampBuffer.getChannelData(0);

        let isCorrect = true;

        let expected;

        let actual;

        let frame;

        for (let k = 0; k < grainFrameLength; ++k) {

          if (renderedData[startFrame + k] != ramp[grainOffsetFrame + k]) {

            expected = ramp[grainOffsetFrame + k];

            actual = renderedData[startFrame + k];

            frame = startFrame + k;

            isCorrect = false;

            break;

        return {

          verified: isCorrect,

          expected: expected,

          actual: actual,

          frame: frame,

};

      function checkResult(buffer) {

        renderedData = buffer.getChannelData(0);

        const startEndFrames = findStartAndEndSamples(renderedData);

        verifyStartAndEndFrames_W3CTH(startEndFrames);

        for (let k = 0; k < startEndFrames.start.length; ++k) {

          const result =

              verifyGrain(

                  renderedData, startEndFrames.start[k],

                  startEndFrames.end[k], k);

          assert_true(

              result.verified,

              `Pulse ${k} contained the expected data. Frame: ${result.frame}` +

                  ` Expected: ${result.expected} Actual: ${result.actual}`);

      promise_test(async (t) => {

        context =

            new OfflineAudioContext(2, sampleRate * renderTime, sampleRate);

        // Use a linear ramp for testing noteGrainOn(). The ramp to start

        // with 1, not 0.

        linearRampBuffer = createSignalBuffer(context, (k) => k + 1);

        const grainInfo =

            playAllGrains(context, linearRampBuffer, numberOfTests);

        grainOffsetTime = grainInfo.grainOffsetTimes;

        const renderedBuffer = await context.startRendering();

        checkResult(renderedBuffer);

      }, 'Test noteGrainOn offset rendering');

    </script>

  </body>

</html>