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<!DOCTYPE html>
<title>Test setTargetAtTime after an event in the same processing block</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
promise_test(function() {
const bufferSize = 179;
const valueStartOffset = 42;
const targetStartOffset = 53;
const sampleRate = 48000;
const scheduledValue = -0.5;
var context = new OfflineAudioContext(1, bufferSize, sampleRate);
var gain = context.createGain();
gain.gain.setValueAtTime(scheduledValue, valueStartOffset/sampleRate);
gain.gain.setTargetAtTime(scheduledValue, targetStartOffset/sampleRate,
128/sampleRate);
gain.connect(context.destination);
// Apply unit DC signal to gain node.
var source = context.createBufferSource();
source.buffer =
function() {
var buffer = context.createBuffer(1, 1, context.sampleRate);
buffer.getChannelData(0)[0] = 1.0;
return buffer;
}();
source.loop = true;
source.start();
source.connect(gain);
return context.startRendering().
then(function(buffer) {
assert_equals(buffer.length, bufferSize, "output buffer length");
var output = buffer.getChannelData(0);
var i = 0;
for (; i < valueStartOffset; ++i) {
// "Its default value is 1."
assert_equals(output[i], 1.0, "default gain at sample " + i);
}
for (; i < buffer.length; ++i) {
// "If the next event (having time T1) after this SetValue event is
// not of type LinearRampToValue or ExponentialRampToValue, then, for
// T0≤t<T1: v(t)=V".
// "Start exponentially approaching the target value at the given time
// with a rate having the given time constant."
// The target is the same value, and so the SetValue value continues.
assert_equals(output[i], scheduledValue,
"scheduled value at sample " + i);
}
});
});
</script>
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