Source code
Revision control
Copy as Markdown
Other Tools
<!DOCTYPE html>
<html>
<head>
<title> AudioParam.setValueCurveAtTime </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/audioparam-testing.js"></script>
</head>
<body>
<script>
// Play a long DC signal out through an AudioGainNode and for each time
// interval call setValueCurveAtTime() to set the values for the duration
// of the interval. Each curve is a sine wave, and we assume that the
// time interval is not an exact multiple of the period. This causes a
// discontinuity between time intervals which is used to test timing.
const numberOfTests = 20;
const sineAmplitude = 1;
const freqHz = 440;
// Max allowed difference between the rendered data and the expected
// result. Because of the linear interpolation, the rendered curve isn't
// exactly the same as the reference. This value is experimentally
// determined.
const maxAllowedError = 3.7194e-6;
/* global helpers from audioparam-testing.js */
const { timeInterval, sampleRate } = window;
/* curve used by the automation scheduler */
const curve = createSineWaveArray(
timeInterval, freqHz, sineAmplitude, sampleRate);
/**
* Minimum required functionality for createAudioGraphAndTest.
*/
function should(actual, description) {
return {
beLessThan(expected) {
assert_true(actual < expected,
`${description}: ${actual} ≥ ${expected}`);
},
beLessThanOrEqualTo(expected) {
assert_true(actual <= expected,
`${description}: ${actual} > ${expected}`);
},
beEqualTo(expected) {
assert_equals(actual, expected, description);
},
beTrue() {
assert_true(!!actual, description);
}
};
}
function automation(value, startTime, endTime) {
/* |value| is unused – mirrors the original test. */
gainNode.gain.setValueCurveAtTime(
curve, startTime, endTime - startTime);
}
promise_test(() => {
/* Return a real Promise so promise_test is satisfied. */
return new Promise(resolve => {
/* dummy task object exposing only .done() */
const task = { done: resolve };
/* No value needs to be set at each interval. */
const noopSetValue = () => {};
createAudioGraphAndTest(
task,
should,
numberOfTests,
sineAmplitude,
noopSetValue,
automation,
'setValueCurveAtTime()',
maxAllowedError,
createReferenceSineArray,
2 * Math.PI * sineAmplitude * freqHz / sampleRate,
differenceErrorMetric);
});
}, 'AudioParam.setValueCurveAtTime() reproduces the expected waveform');
</script>
</body>
</html>