<!DOCTYPE html>
<html>
  <head>
    <title>
      Test AudioParam.exponentialRampToValueAtTime
    </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/audit.js"></script>
    <script src="/webaudio/resources/audioparam-testing.js"></script>
  </head>
  <body>
    <script id="layout-test-code">
      let audit = Audit.createTaskRunner();

      // Play a long DC signal out through an AudioGainNode, and call
      // setValueAtTime() and exponentialRampToValueAtTime() at regular
      // intervals to set the starting and ending values for an exponential
      // ramp.  Each time interval has a ramp with a different starting and
      // ending value so that there is a discontinuity at each time interval
      // boundary.  The discontinuity is for testing timing.  Also, we alternate
      // between an increasing and decreasing ramp for each interval.

      // Number of tests to run.
      let numberOfTests = 100;

      // Max allowed difference between the rendered data and the expected
      // result.
      let maxAllowedError = 1.222e-5;

      // The AudioGainNode starts with this value instead of the default value.
      let initialValue = 100;

      // Set the gain node value to the specified value at the specified time.
      function setValue(value, time) {
        gainNode.gain.setValueAtTime(value, time);
      }

      // Generate an exponential ramp ending at time |endTime| with an ending
      // value of |value|.
      function generateRamp(value, startTime, endTime){
          // |startTime| is ignored because the exponential ramp
          // uses the value from the setValueAtTime() call above.
          gainNode.gain.exponentialRampToValueAtTime(value, endTime)}

      audit.define(
          {
            label: 'test',
            description:
                'AudioParam exponentialRampToValueAtTime() functionality'
          },
          function(task, should) {
            createAudioGraphAndTest(
                task, should, numberOfTests, initialValue, setValue,
                generateRamp, 'exponentialRampToValueAtTime()', maxAllowedError,
                createExponentialRampArray);
          });

      audit.run();
    </script>
  </body>
</html>
