private void RecordDatum(bool immediate)
{
// If recording is stopped (which is it by default), loop back around next frame.
if (recordingStopped)
{
return;
}
if (!immediate) // we run in the same thread as unity we can update the transformations in a synchronized way
{
UpdateFoveInterfaceMatrices(false);
}
Matrix4x4 transformMat;
lock (foveInterfaceTransfo)
{
switch (raysCoordinateSpace)
{
case CoordinateSpace.World:
transformMat = foveInterfaceTransfo.HMDToWorld;
break;
case CoordinateSpace.Local:
transformMat = foveInterfaceTransfo.HMDToLocal;
break;
default:
transformMat = Matrix4x4.identity;
break;
}
}
var leftEyeOffset = FoveManager.GetLeftEyeOffset(immediate);
var rightEyeOffset = FoveManager.GetRightEyeOffset(immediate);
var leftEyeVector = FoveManager.GetLeftEyeVector(immediate);
var rightEyeVector = FoveManager.GetRightEyeVector(immediate);
Ray leftRay, rightRay;
Utils.CalculateGazeRays(ref transformMat, ref leftEyeVector, ref rightEyeVector, ref leftEyeOffset, ref rightEyeOffset, out leftRay, out rightRay);
// If you add new fields, be sure to write them here.
var datum = new RecordingDatum
{
frameTime = stopwatch.Elapsed.TotalSeconds,
leftGaze = leftRay,
rightGaze = rightRay,
};
dataSlice.Add(datum);
if (dataSlice.Count >= writeAtDataCount)
{
// Make sure we have exclusive access by locking the mutex, but only wait for up to 30 milliseconds.
if (!writingDataMutex.WaitOne(30))
{
// If we got here, it means that we couldn't acquire exclusive access within the specified time
// limit. Likely this means an error happened, but it could also mean that more data was being
// written than it took to gather another set of data -- in which case you may need to extend the
// timeout duration, though that will cause a noticeable frame skip in your application.
// For now, the best thing we can do is continue the loop and try writing data again next frame.
long excess = dataSlice.Count - writeAtDataCount;
if (excess > 1)
{
Debug.LogError("Data slice is " + excess + " entries over where it should be; this is" +
"indicative of a major performance concern in the data recording and writing" +
"process.");
}
return;
}
CheckForNullDataToWrite();
// Move our current slice over to dataToWrite, and then create a new slice.
dataToWrite = dataSlice;
dataSlice = new List <RecordingDatum>((int)(writeAtDataCount + 1));
// Release our claim on the mutex.
writingDataMutex.ReleaseMutex();
if (!threadWaitHandle.Set())
{
Debug.LogError("Error setting the event to wake up the file writer thread");
}
}
}
