protected double CalculateDifficulty()
{
double ActualStrainStep = STRAIN_STEP * TimeRate;
// Find the highest strain value within each strain step
List <double> HighestStrains = new List <double>();
double IntervalEndTime = ActualStrainStep;
double MaximumStrain = 0; // We need to keep track of the maximum strain in the current interval
DifficultyHitObjectTaiko PreviousHitObject = null;
foreach (DifficultyHitObjectTaiko hitObject in DifficultyHitObjects)
{
// While we are beyond the current interval push the currently available maximum to our strain list
while (hitObject.BaseHitObject.StartTime > IntervalEndTime)
{
HighestStrains.Add(MaximumStrain);
// The maximum strain of the next interval is not zero by default! We need to take the last hitObject we encountered, take its strain and apply the decay
// until the beginning of the next interval.
if (PreviousHitObject == null)
{
MaximumStrain = 0;
}
else
{
double Decay = Math.Pow(DifficultyHitObjectTaiko.DECAY_BASE, (double)(IntervalEndTime - PreviousHitObject.BaseHitObject.StartTime) / 1000);
MaximumStrain = PreviousHitObject.Strain * Decay;
}
// Go to the next time interval
IntervalEndTime += ActualStrainStep;
}
// Obtain maximum strain
if (hitObject.Strain > MaximumStrain)
{
MaximumStrain = hitObject.Strain;
}
PreviousHitObject = hitObject;
}
// Build the weighted sum over the highest strains for each interval
double Difficulty = 0;
double Weight = 1;
HighestStrains.Sort((a, b) => b.CompareTo(a)); // Sort from highest to lowest strain.
foreach (double Strain in HighestStrains)
{
Difficulty += Weight * Strain;
Weight *= DECAY_WEIGHT;
}
return(Difficulty);
}
protected bool CalculateStrainValues()
{
// Traverse hitObjects in pairs to calculate the strain value of NextHitObject from the strain value of CurrentHitObject and environment.
List <DifficultyHitObjectTaiko> .Enumerator HitObjectsEnumerator = DifficultyHitObjects.GetEnumerator();
if (HitObjectsEnumerator.MoveNext() == false)
{
return(false);
}
DifficultyHitObjectTaiko CurrentHitObject = HitObjectsEnumerator.Current;
DifficultyHitObjectTaiko NextHitObject;
// First hitObject starts at strain 1. 1 is the default for strain values, so we don't need to set it here. See DifficultyHitObject.
while (HitObjectsEnumerator.MoveNext())
{
NextHitObject = HitObjectsEnumerator.Current;
NextHitObject.CalculateStrains(CurrentHitObject, TimeRate);
CurrentHitObject = NextHitObject;
}
return(true);
}