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- This WPT test may be referenced by the following Test IDs:
- /webaudio/the-audio-api/the-audioparam-interface/exponentialRamp-special-cases.html - WPT Dashboard Interop Dashboard
<!DOCTYPE html>
<title>Test exponentialRampToValueAtTime() special cases</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
promise_test(async function() {
const bufferSize = 5;
const sampleRate = 16384;
const startSample = 3;
const offset0 = 2.;
const offset1 = -3.;
const context = new OfflineAudioContext(1, bufferSize, sampleRate);
const source = new ConstantSourceNode(context);
source.start();
// Explicit event to work around
source.offset.setValueAtTime(offset0, 0.);
source.offset.exponentialRampToValueAtTime(offset1, startSample/sampleRate);
source.connect(context.destination);
const buffer = await context.startRendering();
assert_equals(buffer.length, bufferSize, "output buffer length");
const output = buffer.getChannelData(0);
for (let i = 0; i < startSample; ++i) {
assert_equals(output[i], offset0, "initial offset at sample " + i);
}
for (let i = startSample; i < bufferSize; ++i) {
assert_equals(output[i], offset1, "scheduled value at sample " + i);
}
}, "v0 and v1 have opposite signs");
promise_test(async function() {
const bufferSize = 4;
const sampleRate = 16384;
const startSample = 2;
const offset = -2.;
const context = new OfflineAudioContext(1, bufferSize, sampleRate);
const source = new ConstantSourceNode(context);
source.start();
// Explicit event to work around
source.offset.setValueAtTime(0, 0.);
source.offset.exponentialRampToValueAtTime(offset, startSample/sampleRate);
source.connect(context.destination);
const buffer = await context.startRendering();
assert_equals(buffer.length, bufferSize, "output buffer length");
const output = buffer.getChannelData(0);
for (let i = 0; i < startSample; ++i) {
assert_equals(output[i], 0., "initial offset at sample " + i);
}
for (let i = startSample; i < bufferSize; ++i) {
assert_equals(output[i], offset, "scheduled value at sample " + i);
}
}, "v0 is zero");
</script>