public float Evaluate(CompressedTimeSpan time)
{
SetTime(time);
var startTime = data.ValueStart.Time;
var endTime = data.ValueEnd.Time;
if (currentTime < startTime || currentTime > endTime)
{
}
// Sampling before start (should not really happen because we add a keyframe at TimeSpan.Zero, but let's keep it in case it changes later.
if (currentTime <= startTime)
{
return(data.ValueStart.Value);
}
// Sampling after end
if (currentTime >= endTime)
{
return(data.ValueEnd.Value);
}
// Sampling with catmull rom implicit approximation
float factor = (float)(currentTime - startTime).Ticks / (float)(endTime - startTime).Ticks;
return(data.Evaluate(factor));
}
public float EvaluateCubic(CompressedTimeSpan time)
{
int keyIndex;
for (keyIndex = 0; keyIndex < KeyFrames.Count - 1; ++keyIndex)
{
if (time < KeyFrames[keyIndex + 1].Time)
{
break;
}
}
// TODO: Check if before or after curve (and on those limits)
// Exact value, just returns it.
if (time == KeyFrames[keyIndex].Time)
{
return(KeyFrames[keyIndex].Value);
}
// http://en.wikipedia.org/wiki/Cubic_Hermite_spline#Interpolation_on_the_unit_interval_without_exact_derivatives
long timeStart = KeyFrames[keyIndex + 0].Time.Ticks;
long timeEnd = KeyFrames[keyIndex + 1].Time.Ticks;
float t = ((float)time.Ticks - (float)timeStart) / ((float)timeEnd - (float)timeStart);
var evaluator = new EvaluatorData();
evaluator.ValuePrev = KeyFrames[keyIndex > 0 ? keyIndex - 1 : 0];
evaluator.ValueStart = KeyFrames[keyIndex + 0];
evaluator.ValueEnd = KeyFrames[keyIndex + 1];
evaluator.ValueNext = KeyFrames[keyIndex + 2 < KeyFrames.Count ? keyIndex + 2 : KeyFrames.Count - 1];
return(evaluator.Evaluate(t));
}
