/// <summary>
/// Gets the value at a particular time.
/// </summary>
/// <param name="time">The time at which to get the value.</param>
/// <param name="isTimeAbsolute">Whether or not the specified time is absolute.</param>
/// <returns>The value at the specified time.</returns>
public T Get(double time, bool isTimeAbsolute = false)
{
T result;
lock (_entryLock)
{
// check that there is at least one value in the timeline
if (_firstEntry == null)
{
return(default(T));
}
double absoluteTime = isTimeAbsolute ? time : _now + time;
TimelineContext <T> currentContext = new TimelineContext <T>();
currentContext._time = absoluteTime;
// set Context
if (currentContext._time == _now) // time 0 so no need to search
{
currentContext._prev = _prevEntry;
}
else // starting at _lastEntry search back in time
{
currentContext._prev = _lastEntry;
while (currentContext._prev != null && currentContext._prev._time > absoluteTime)
{
currentContext._prev = currentContext._prev._prev;
}
}
if (currentContext._prev == null) // all entries are after the requested time
{
return(_firstEntry._value);
}
if (currentContext._prev._time == absoluteTime)
{
return(currentContext._prev._value);
}
currentContext._next = currentContext._prev._next;
currentContext._prevPrev = currentContext._prev._prev;
if (currentContext._next == null)
{
result = Extrapolate(this, currentContext);
}
else
{
result = Interpolate(this, currentContext);
}
}
return(result);
}
/// <summary>
/// Filters timeline value sends based on extrapolation, but also forces a send
/// periodically even if the value has not changed
/// </summary>
public static TimelineSendFilter <T> BuildDeltaRateFilter <T>
(Func <T, T, float> getDelta, Func <float> getThreshold, Func <float> getRate)
{
return((timeline, entry) =>
{
TimelineContext <T> currentContext = new TimelineContext <T>();
currentContext._prev = timeline.LastSentEntry;
currentContext._prevPrev = timeline.LastLastSentEntry;
currentContext._time = entry._time;
return (getDelta(entry._value, timeline.Extrapolate(timeline, currentContext)) > getThreshold()) ||
(DateTime.Now.Subtract(timeline.LastSendTime).TotalSeconds >= (1f / getRate()));
});
}
/// <summary>
/// Filters timeline value sends based on extrapolation
/// </summary>
public static TimelineSendFilter <T> BuildExtrapolatedDeltaFilter <T>
(Func <T, T, float> getDelta, Func <float> getThreshold)
{
return((timeline, entry) =>
{
if (timeline.LastSentEntry == null)
{
return true;
}
TimelineContext <T> currentContext = new TimelineContext <T>();
currentContext._prev = timeline.LastSentEntry;
currentContext._prevPrev = timeline.LastLastSentEntry;
currentContext._time = entry._time;
return getDelta(entry._value, timeline.Extrapolate(timeline, currentContext)) > getThreshold();
});
}
/// <summary>
/// Stepping extrapolation
/// </summary>
public static T SteppingExtrapolate <T>(Timeline <T> timeline, TimelineContext <T> context)
{
return(context.Prev != null ? context.Prev.Value : default(T));
}