<!doctype html>
<meta charset=utf-8>
<title>Test the ConstantSourceNode Interface</title>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<script>
test(function(t) {
var ac = new AudioContext();
var csn = ac.createConstantSource();
assert_true(csn.offset.value == 1.0, "Default offset is 1.0");
csn = new ConstantSourceNode(ac);
assert_true(csn.offset.value == 1.0, "Default offset is 1.0");
csn = new ConstantSourceNode(ac, {offset: -0.25});
assert_true(csn.offset.value == -0.25, "Offset can be set during construction");
}, "ConstantSourceNode can be constructed");
test(function(t) {
var ac = new AudioContext();
var csn = ac.createConstantSource();
assert_throws("InvalidStateError", function() {
csn.stop(1);
}, "Start must be called before stop");
assert_throws("NotSupportedError", function() {
csn.start(-1);
}, "When can not be negative");
csn.start(0);
assert_throws("NotSupportedError", function() {
csn.stop(-1);
}, "When can not be negative");
}, "ConstantSourceNode stop and start");
async_test(function(t) {
var ac = new OfflineAudioContext(1, 2048, 44100);
var csn = ac.createConstantSource();
csn.connect(ac.destination);
csn.start()
csn.stop(1024/44100)
csn.onended = function(e) {
t.step(function() {
assert_true(e.type == "ended", "Event type should be 'ended', received: " + e.type);
});
t.done();
}
ac.startRendering();
}, "ConstantSourceNode onended event");
async_test(function(t) {
var ac = new OfflineAudioContext(1, 2048, 44100);
var csn = ac.createConstantSource();
csn.connect(ac.destination);
csn.start(512/44100)
csn.stop(1024/44100)
ac.oncomplete = function(e) {
t.step(function() {
var result = e.renderedBuffer.getChannelData(0);
for (var i = 0; i < 2048; ++i) {
if (i >= 512 && i < 1024) {
assert_true(result[i] == 1.0, "sample " + i + " should equal 1.0");
} else {
assert_true(result[i] == 0.0, "sample " + i + " should equal 0.0");
}
}
});
t.done();
}
ac.startRendering();
}, "ConstantSourceNode start and stop when work");
async_test(function(t) {
var ac = new OfflineAudioContext(1, 2048, 44100);
var csn = ac.createConstantSource();
csn.offset.value = 0.25;
csn.connect(ac.destination);
csn.start()
ac.oncomplete = function(e) {
t.step(function() {
var result = e.renderedBuffer.getChannelData(0);
for (var i = 0; i < 2048; ++i) {
assert_true(result[i] == 0.25, "sample " + i + " should equal 0.25");
}
});
t.done();
}
ac.startRendering();
}, "ConstantSourceNode with no automation");
async_test(function(t) {
var ac = new OfflineAudioContext(1, 2048, 44100);
var timeConstant = 2.0;
var offsetStart = 0.25;
var offsetEnd = 0.1;
var csn = ac.createConstantSource();
csn.offset.value = offsetStart;
csn.offset.setTargetAtTime(offsetEnd, 1024/ac.sampleRate, timeConstant);
csn.connect(ac.destination);
csn.start()
ac.oncomplete = function(e) {
t.step(function() {
// create buffer with expected values
var buffer = ac.createBuffer(1, 2048, ac.sampleRate);
for (var i = 0; i < 2048; ++i) {
if (i < 1024) {
buffer.getChannelData(0)[i] = offsetStart;
} else {
time = (i-1024)/ac.sampleRate;
buffer.getChannelData(0)[i] = offsetEnd + (offsetStart - offsetEnd)*Math.exp(-time/timeConstant);
}
}
var result = e.renderedBuffer.getChannelData(0);
var expected = buffer.getChannelData(0);
for (var i = 0; i < 2048; ++i) {
assert_true(Math.abs(result[i] - expected[i]) < 1e-6, "sample " + i + " should equal " + expected[i]);
}
});
t.done();
}
ac.startRendering();
}, "ConstantSourceNode with automation");
</script>