blob: e1d144319c4d13f3acfb8b5076ee6b2661941402 [file] [log] [blame]
var sampleRate = 44100.0;
// How many grains to play.
var numberOfTests = 100;
// Duration of each grain to be played
var duration = 0.01;
// Time step between the start of each grain.
var timeStep = duration + .005;
// Time step between the start for each grain.
var grainOffsetStep = 0.001;
// How long to render to cover all of the grains.
var renderTime = (numberOfTests + 1) * timeStep;
var context;
var renderedData;
// Create a buffer containing the data that we want. The function f
// returns the desired value at sample frame k.
function createSignalBuffer(context, f) {
// Make sure the buffer has enough data for all of the possible
// grain offsets and durations. Need to include the extra frames
// for HRTF. The additional 1 is for any round-off errors.
var signalLength = Math.floor(1 + sampleRate * (numberOfTests * grainOffsetStep + duration));
var buffer = context.createBuffer(2, signalLength, sampleRate);
var data = buffer.getChannelData(0);
for (var k = 0; k < signalLength; ++k) {
data[k] = f(k);
}
return buffer;
}
// From the data array, find the start and end sample frame for each
// grain. This depends on the data having 0's between grain, and
// that the grain is always strictly non-zero.
function findStartAndEndSamples(data) {
var nSamples = data.length;
var startTime = [];
var endTime = [];
var lookForStart = true;
// Look through the rendered data to find the start and stop
// times of each grain.
for (var k = 0; k < nSamples; ++k) {
if (lookForStart) {
// Find a non-zero point and record the start. We're not
// concerned with the value in this test, only that the
// grain started here.
if (renderedData[k]) {
startTime.push(k);
lookForStart = false;
}
} else {
// Find a zero and record the end of the grain.
if (!renderedData[k]) {
endTime.push(k);
lookForStart = true;
}
}
}
return {start : startTime, end : endTime};
}
function playGrain(context, source, time, offset, duration) {
var bufferSource = context.createBufferSource();
bufferSource.buffer = source;
bufferSource.connect(context.destination);
bufferSource.start(time, offset, duration);
}
// Play out all grains. Returns a object containing two arrays, one
// for the start time and one for the grain offset time.
function playAllGrains(context, source, numberOfNotes) {
var startTimes = new Array(numberOfNotes);
var offsets = new Array(numberOfNotes);
for (var k = 0; k < numberOfNotes; ++k) {
var timeOffset = k * timeStep;
var grainOffset = k * grainOffsetStep;
playGrain(context, source, timeOffset, grainOffset, duration);
startTimes[k] = timeOffset;
offsets[k] = grainOffset;
}
return { startTimes : startTimes, grainOffsetTimes : offsets };
}
// Verify that the start and end frames for each grain match our
// expected start and end frames.
function verifyStartAndEndFrames(startEndFrames) {
var startFrames = startEndFrames.start;
var endFrames = startEndFrames.end;
var success = true;
// Count of how many grains started at the incorrect time.
var errorCountStart = 0;
// Count of how many grains ended at the incorrect time.
var errorCountEnd = 0;
if (startFrames.length != endFrames.length) {
testFailed("Could not find the beginning or end of a grain.");
success = false;
}
if (startFrames.length == numberOfTests && endFrames.length == numberOfTests) {
testPassed("Found all " + numberOfTests + " grains.");
} else {
testFailed("Did not find all " + numberOfTests + " grains.");
}
// Examine the start and stop times to see if they match our
// expectations.
for (var k = 0; k < startFrames.length; ++k) {
var expectedStart = timeToSampleFrame(k * timeStep, sampleRate);
// The end point is the duration, plus the extra frames
// for HRTF.
var expectedEnd = expectedStart + grainLengthInSampleFrames(k * grainOffsetStep, duration, sampleRate);
if (startFrames[k] != expectedStart) {
testFailed("Pulse " + k + " started at " + startFrames[k] + " but expected at " + expectedStart);
++errorCountStart;
success = false;
}
if (endFrames[k] != expectedEnd) {
testFailed("Pulse " + k + " ended at " + endFrames[k] + " but expected at " + expectedEnd);
++errorCountEnd;
success = false;
}
}
// Check that all the grains started or ended at the correct time.
if (!errorCountStart) {
if (startFrames.length == numberOfTests) {
testPassed("All " + numberOfTests + " grains started at the correct time.");
} else {
testFailed("All grains started at the correct time, but only " + startFrames.length + " grains found.");
success = false;
}
} else {
testFailed(errorCountStart + " out of " + numberOfTests + " grains started at the wrong time.");
success = false;
}
if (!errorCountEnd) {
if (endFrames.length == numberOfTests) {
testPassed("All " + numberOfTests + " grains ended at the correct time.");
} else {
testFailed("All grains ended at the correct time, but only " + endFrames.length + " grains found.");
success = false;
}
} else {
testFailed(errorCountEnd + " out of " + numberOfTests + " grains ended at the wrong time.");
success = false;
}
return success;
}