// Caution: The subjective values are strong with this one
private static double spacingWeight(double distance, OsuDifficultyCalculator.DifficultyType type)
{
switch (type)
{
case OsuDifficultyCalculator.DifficultyType.Speed:
if (distance > single_spacing_threshold)
{
return(2.5);
}
else if (distance > stream_spacing_threshold)
{
return(1.6 + 0.9 * (distance - stream_spacing_threshold) / (single_spacing_threshold - stream_spacing_threshold));
}
else if (distance > almost_diameter)
{
return(1.2 + 0.4 * (distance - almost_diameter) / (stream_spacing_threshold - almost_diameter));
}
else if (distance > almost_diameter / 2)
{
return(0.95 + 0.25 * (distance - almost_diameter / 2) / (almost_diameter / 2));
}
else
{
return(0.95);
}
case OsuDifficultyCalculator.DifficultyType.Aim:
return(Math.Pow(distance, 0.99));
}
Debug.Assert(false, "Invalid osu difficulty hit object type.");
return(0);
}
private void calculateSpecificStrain(OsuHitObjectDifficulty previousHitObject, OsuDifficultyCalculator.DifficultyType type, double timeRate)
{
double addition = 0;
double timeElapsed = (BaseHitObject.StartTime - previousHitObject.BaseHitObject.StartTime) / timeRate;
double decay = Math.Pow(DECAY_BASE[(int)type], timeElapsed / 1000);
if (BaseHitObject.Type == HitObjectType.Spinner)
{
// Do nothing for spinners
}
else if (BaseHitObject.Type == HitObjectType.Slider)
{
switch (type)
{
case OsuDifficultyCalculator.DifficultyType.Speed:
// For speed strain we treat the whole slider as a single spacing entity, since "Speed" is about how hard it is to click buttons fast.
// The spacing weight exists to differentiate between being able to easily alternate or having to single.
addition =
spacingWeight(previousHitObject.lazySliderLength +
DistanceTo(previousHitObject), type) *
spacing_weight_scaling[(int)type];
break;
case OsuDifficultyCalculator.DifficultyType.Aim:
// For Aim strain we treat each slider segment and the jump after the end of the slider as separate jumps, since movement-wise there is no difference
// to multiple jumps.
addition =
(
spacingWeight(previousHitObject.lazySliderLength, type) +
spacingWeight(DistanceTo(previousHitObject), type)
) *
spacing_weight_scaling[(int)type];
break;
}
}
else if (BaseHitObject.Type == HitObjectType.Circle)
{
addition = spacingWeight(DistanceTo(previousHitObject), type) * spacing_weight_scaling[(int)type];
}
// Scale addition by the time, that elapsed. Filter out HitObjects that are too close to be played anyway to avoid crazy values by division through close to zero.
// You will never find maps that require this amongst ranked maps.
addition /= Math.Max(timeElapsed, 50);
Strains[(int)type] = previousHitObject.Strains[(int)type] * decay + addition;
}