| <!DOCTYPE html> |
| <html> |
| <head> |
| <title> |
| Test setTargetAtTime with timeConstant=0 |
| </title> |
| <script src="../../imported/w3c/web-platform-tests/resources/testharness.js"></script> |
| <script src="../../resources/testharnessreport.js"></script> |
| <script src="../resources/audit.js"></script> |
| </head> |
| <body> |
| <script id="layout-test-code"> |
| // Fairly arbitrary sample rate and number of frames, so choose a low |
| // sample rate, and short rendering length. |
| let sampleRate = 8000; |
| let renderFrames = 128; |
| |
| // Array specifying parameters for setTargetAtTime. |frame| is the frame |
| // (not necessarily an integer) at which setTargetAtTime starts, and |
| // |value| is the target value. Non-integral values for |frame| tests |
| // that we started the setTargetAtTime at the right time. |
| let targetValueInfo = [ |
| {frame: 10.1, value: 0}, {frame: 20.3, value: 0.5}, |
| {frame: 100.5, value: 1} |
| ]; |
| |
| let audit = Audit.createTaskRunner(); |
| |
| audit.define('timeconstant-0', (task, should) => { |
| let context = new OfflineAudioContext(1, renderFrames, sampleRate); |
| |
| // Simple constant source for testing. |
| |
| let src = new ConstantSourceNode(context); |
| |
| // We're going to automate the gain node to test setTargetAtTime. |
| let gain = new GainNode(context, {gain: 1}); |
| |
| src.connect(gain).connect(context.destination); |
| |
| for (let k = 0; k < targetValueInfo.length; ++k) { |
| gain.gain.setTargetAtTime( |
| targetValueInfo[k].value, |
| targetValueInfo[k].frame / context.sampleRate, 0); |
| } |
| |
| src.start(); |
| |
| context.startRendering() |
| .then(function(resultBuffer) { |
| let result = resultBuffer.getChannelData(0); |
| let success = true; |
| |
| // Because the time constant is 0, the automation should instantly |
| // jump to the target value at the start time. Verify that the |
| // output has the expected value. |
| for (let k = 0; k < targetValueInfo.length; ++k) { |
| let startFrame = Math.ceil(targetValueInfo[k].frame); |
| let endFrame = k < targetValueInfo.length - 1 ? |
| Math.ceil(targetValueInfo[k + 1].frame) : |
| renderFrames; |
| let value = targetValueInfo[k].value; |
| |
| should( |
| result.slice(startFrame, endFrame), |
| 'Output for frame [' + startFrame + ', ' + endFrame + ')') |
| .beConstantValueOf(value); |
| } |
| |
| }) |
| .then(() => task.done()); |
| }); |
| |
| audit.run(); |
| </script> |
| </body> |
| </html> |
