panner-equalpower.html

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  <head>

    <title>

      panner-equalpower.html

    </title>

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

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

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

    <script src="../../resources/panner-model-testing.js"></script>

  </head>

  <body>

    <script>

      // To test the panner, we create a number of panner nodes

      // equally spaced on a semicircle at unit distance.  The

      // semicircle covers the azimuth range from -90 to 90 deg,

      // covering full left to full right.  Each source is an impulse

      // turning at a different time and we check that the rendered

      // impulse has the expected gain.

      promise_test(async () => {

        const context = new OfflineAudioContext(

            2, sampleRate * renderLengthSeconds, sampleRate);

        await createTestAndRun_W3CTH(

            context, nodesToCreate, 1,

            (panner, x, y, z) => panner.setPosition(x, y, z));

      }, 'Equal-power panner model of AudioPannerNode');

      // Test that a mono source plays out on both the left and right channels

      // when the source and listener positions are the same.

      promise_test(async () => {

        const context =

            new OfflineAudioContext(2, 0.25 * sampleRate, sampleRate);

        // Arbitrary position for source and listener.  Just so we don't use

        // defaults positions.

        const x = 1;

        const y = 2;

        const z = 3;

        context.listener.setPosition(x, y, z);

        const source = new OscillatorNode(context);

        const panner = new PannerNode(context, {

          panningModel: 'equalpower',

          positionX: x,

          positionY: y,

          positionZ: z,

});

        source.connect(panner).connect(context.destination);

        source.start();

        const renderedBuffer = await context.startRendering();

        // The rendered left and right channels should be identical.

        const left = renderedBuffer.getChannelData(0);

        const right = renderedBuffer.getChannelData(1);

        assert_array_equals(

            left, right,

            'Mono: left and right channels should contain identical samples.');

      }, 'Mono source and listener at the same position');

      // Test that a stereo source plays out on both the left and right channels

      // when the source and listener positions are the same.

      promise_test(async () => {

        const context =

            new OfflineAudioContext(2, 0.25 * sampleRate, sampleRate);

        // Arbitrary position for source and listener.  Just so we don't use

        // defaults positions.

        const x = 1;

        const y = 2;

        const z = 3;

        context.listener.setPosition(x, y, z);

        const source = new OscillatorNode(context);

        const merger = new ChannelMergerNode(context, {numberOfInputs: 2});

        const panner = new PannerNode(context, {

          panningModel: 'equalpower',

          positionX: x,

          positionY: y,

          positionZ: z,

});

        // Make the oscillator a stereo signal (identical signals on each

        // channel).

        source.connect(merger, 0, 0);

        source.connect(merger, 0, 1);

        merger.connect(panner).connect(context.destination);

        source.start();

        const renderedBuffer = await context.startRendering();

        // The rendered left and right channels should be identical.

        const left = renderedBuffer.getChannelData(0);

        const right = renderedBuffer.getChannelData(1);

        assert_array_equals(

            left, right,

            'Stereo: left and right channels should contain identical ' +

            'samples.');

      }, 'Stereo source and listener at the same position');

    </script>

  </body>

</html>