| <!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> |
