public static double EvaluateDifficultyOf(DifficultyHitObject current, bool hidden)
{
if (current.BaseObject is Spinner)
{
return(0);
}
var osuCurrent = (OsuDifficultyHitObject)current;
var osuHitObject = (OsuHitObject)(osuCurrent.BaseObject);
double scalingFactor = 52.0 / osuHitObject.Radius;
double smallDistNerf = 1.0;
double cumulativeStrainTime = 0.0;
double result = 0.0;
OsuDifficultyHitObject lastObj = osuCurrent;
// This is iterating backwards in time from the current object.
for (int i = 0; i < Math.Min(current.Index, 10); i++)
{
var currentObj = (OsuDifficultyHitObject)current.Previous(i);
var currentHitObject = (OsuHitObject)(currentObj.BaseObject);
if (!(currentObj.BaseObject is Spinner))
{
double jumpDistance = (osuHitObject.StackedPosition - currentHitObject.EndPosition).Length;
cumulativeStrainTime += lastObj.StrainTime;
// We want to nerf objects that can be easily seen within the Flashlight circle radius.
if (i == 0)
{
smallDistNerf = Math.Min(1.0, jumpDistance / 75.0);
}
// We also want to nerf stacks so that only the first object of the stack is accounted for.
double stackNerf = Math.Min(1.0, (currentObj.LazyJumpDistance / scalingFactor) / 25.0);
// Bonus based on how visible the object is.
double opacityBonus = 1.0 + max_opacity_bonus * (1.0 - osuCurrent.OpacityAt(currentHitObject.StartTime, hidden));
result += stackNerf * opacityBonus * scalingFactor * jumpDistance / cumulativeStrainTime;
}
lastObj = currentObj;
}
result = Math.Pow(smallDistNerf * result, 2.0);
// Additional bonus for Hidden due to there being no approach circles.
if (hidden)
{
result *= 1.0 + hidden_bonus;
}
return(result);
}
public static double EvaluateDifficultyOf(DifficultyHitObject current, double greatWindow)
{
if (current.BaseObject is Spinner)
{
return(0);
}
// derive strainTime for calculation
var osuCurrObj = (OsuDifficultyHitObject)current;
var osuPrevObj = current.Index > 0 ? (OsuDifficultyHitObject)current.Previous(0) : null;
var osuNextObj = (OsuDifficultyHitObject)current.Next(0);
double strainTime = osuCurrObj.StrainTime;
double greatWindowFull = greatWindow * 2;
double doubletapness = 1;
// Nerf doubletappable doubles.
if (osuNextObj != null)
{
double currDeltaTime = Math.Max(1, osuCurrObj.DeltaTime);
double nextDeltaTime = Math.Max(1, osuNextObj.DeltaTime);
double deltaDifference = Math.Abs(nextDeltaTime - currDeltaTime);
double speedRatio = currDeltaTime / Math.Max(currDeltaTime, deltaDifference);
double windowRatio = Math.Pow(Math.Min(1, currDeltaTime / greatWindowFull), 2);
doubletapness = Math.Pow(speedRatio, 1 - windowRatio);
}
// Cap deltatime to the OD 300 hitwindow.
// 0.93 is derived from making sure 260bpm OD8 streams aren't nerfed harshly, whilst 0.92 limits the effect of the cap.
strainTime /= Math.Clamp((strainTime / greatWindowFull) / 0.93, 0.92, 1);
// derive speedBonus for calculation
double speedBonus = 1.0;
if (strainTime < min_speed_bonus)
{
speedBonus = 1 + 0.75 * Math.Pow((min_speed_bonus - strainTime) / speed_balancing_factor, 2);
}
double travelDistance = osuPrevObj?.TravelDistance ?? 0;
double distance = Math.Min(single_spacing_threshold, travelDistance + osuCurrObj.MinimumJumpDistance);
return((speedBonus + speedBonus * Math.Pow(distance / single_spacing_threshold, 3.5)) * doubletapness / strainTime);
}
protected override double CalculateInitialStrain(double time, DifficultyHitObject current) => CurrentStrain *strainDecay(time - current.Previous(0).StartTime);
protected override double CalculateInitialStrain(double offset, DifficultyHitObject current) => applyDecay(individualStrain, offset - current.Previous(0).StartTime, individual_decay_base) + applyDecay(overallStrain, offset - current.Previous(0).StartTime, overall_decay_base);
public static double EvaluateDifficultyOf(DifficultyHitObject current, double greatWindow)
{
if (current.BaseObject is Spinner)
{
return(0);
}
int previousIslandSize = 0;
double rhythmComplexitySum = 0;
int islandSize = 1;
double startRatio = 0; // store the ratio of the current start of an island to buff for tighter rhythms
bool firstDeltaSwitch = false;
int historicalNoteCount = Math.Min(current.Index, 32);
int rhythmStart = 0;
while (rhythmStart < historicalNoteCount - 2 && current.StartTime - current.Previous(rhythmStart).StartTime < history_time_max)
{
rhythmStart++;
}
for (int i = rhythmStart; i > 0; i--)
{
OsuDifficultyHitObject currObj = (OsuDifficultyHitObject)current.Previous(i - 1);
OsuDifficultyHitObject prevObj = (OsuDifficultyHitObject)current.Previous(i);
OsuDifficultyHitObject lastObj = (OsuDifficultyHitObject)current.Previous(i + 1);
double currHistoricalDecay = (history_time_max - (current.StartTime - currObj.StartTime)) / history_time_max; // scales note 0 to 1 from history to now
currHistoricalDecay = Math.Min((double)(historicalNoteCount - i) / historicalNoteCount, currHistoricalDecay); // either we're limited by time or limited by object count.
double currDelta = currObj.StrainTime;
double prevDelta = prevObj.StrainTime;
double lastDelta = lastObj.StrainTime;
double currRatio = 1.0 + 6.0 * Math.Min(0.5, Math.Pow(Math.Sin(Math.PI / (Math.Min(prevDelta, currDelta) / Math.Max(prevDelta, currDelta))), 2)); // fancy function to calculate rhythmbonuses.
double windowPenalty = Math.Min(1, Math.Max(0, Math.Abs(prevDelta - currDelta) - greatWindow * 0.6) / (greatWindow * 0.6));
windowPenalty = Math.Min(1, windowPenalty);
double effectiveRatio = windowPenalty * currRatio;
if (firstDeltaSwitch)
{
if (!(prevDelta > 1.25 * currDelta || prevDelta * 1.25 < currDelta))
{
if (islandSize < 7)
{
islandSize++; // island is still progressing, count size.
}
}
else
{
if (current.Previous(i - 1).BaseObject is Slider) // bpm change is into slider, this is easy acc window
{
effectiveRatio *= 0.125;
}
if (current.Previous(i).BaseObject is Slider) // bpm change was from a slider, this is easier typically than circle -> circle
{
effectiveRatio *= 0.25;
}
if (previousIslandSize == islandSize) // repeated island size (ex: triplet -> triplet)
{
effectiveRatio *= 0.25;
}
if (previousIslandSize % 2 == islandSize % 2) // repeated island polartiy (2 -> 4, 3 -> 5)
{
effectiveRatio *= 0.50;
}
if (lastDelta > prevDelta + 10 && prevDelta > currDelta + 10) // previous increase happened a note ago, 1/1->1/2-1/4, dont want to buff this.
{
effectiveRatio *= 0.125;
}
rhythmComplexitySum += Math.Sqrt(effectiveRatio * startRatio) * currHistoricalDecay * Math.Sqrt(4 + islandSize) / 2 * Math.Sqrt(4 + previousIslandSize) / 2;
startRatio = effectiveRatio;
previousIslandSize = islandSize; // log the last island size.
if (prevDelta * 1.25 < currDelta) // we're slowing down, stop counting
{
firstDeltaSwitch = false; // if we're speeding up, this stays true and we keep counting island size.
}
islandSize = 1;
}
}
else if (prevDelta > 1.25 * currDelta) // we want to be speeding up.
{
// Begin counting island until we change speed again.
firstDeltaSwitch = true;
startRatio = effectiveRatio;
islandSize = 1;
}
}
return(Math.Sqrt(4 + rhythmComplexitySum * rhythm_multiplier) / 2); //produces multiplier that can be applied to strain. range [1, infinity) (not really though)
}
public static double EvaluateDifficultyOf(DifficultyHitObject current, bool withSliders)
{
if (current.BaseObject is Spinner || current.Index <= 1 || current.Previous(0).BaseObject is Spinner)
{
return(0);
}
var osuCurrObj = (OsuDifficultyHitObject)current;
var osuLastObj = (OsuDifficultyHitObject)current.Previous(0);
var osuLastLastObj = (OsuDifficultyHitObject)current.Previous(1);
// Calculate the velocity to the current hitobject, which starts with a base distance / time assuming the last object is a hitcircle.
double currVelocity = osuCurrObj.LazyJumpDistance / osuCurrObj.StrainTime;
// But if the last object is a slider, then we extend the travel velocity through the slider into the current object.
if (osuLastObj.BaseObject is Slider && withSliders)
{
double travelVelocity = osuLastObj.TravelDistance / osuLastObj.TravelTime; // calculate the slider velocity from slider head to slider end.
double movementVelocity = osuCurrObj.MinimumJumpDistance / osuCurrObj.MinimumJumpTime; // calculate the movement velocity from slider end to current object
currVelocity = Math.Max(currVelocity, movementVelocity + travelVelocity); // take the larger total combined velocity.
}
// As above, do the same for the previous hitobject.
double prevVelocity = osuLastObj.LazyJumpDistance / osuLastObj.StrainTime;
if (osuLastLastObj.BaseObject is Slider && withSliders)
{
double travelVelocity = osuLastLastObj.TravelDistance / osuLastLastObj.TravelTime;
double movementVelocity = osuLastObj.MinimumJumpDistance / osuLastObj.MinimumJumpTime;
prevVelocity = Math.Max(prevVelocity, movementVelocity + travelVelocity);
}
double wideAngleBonus = 0;
double acuteAngleBonus = 0;
double sliderBonus = 0;
double velocityChangeBonus = 0;
double aimStrain = currVelocity; // Start strain with regular velocity.
if (Math.Max(osuCurrObj.StrainTime, osuLastObj.StrainTime) < 1.25 * Math.Min(osuCurrObj.StrainTime, osuLastObj.StrainTime)) // If rhythms are the same.
{
if (osuCurrObj.Angle != null && osuLastObj.Angle != null && osuLastLastObj.Angle != null)
{
double currAngle = osuCurrObj.Angle.Value;
double lastAngle = osuLastObj.Angle.Value;
double lastLastAngle = osuLastLastObj.Angle.Value;
// Rewarding angles, take the smaller velocity as base.
double angleBonus = Math.Min(currVelocity, prevVelocity);
wideAngleBonus = calcWideAngleBonus(currAngle);
acuteAngleBonus = calcAcuteAngleBonus(currAngle);
if (osuCurrObj.StrainTime > 100) // Only buff deltaTime exceeding 300 bpm 1/2.
{
acuteAngleBonus = 0;
}
else
{
acuteAngleBonus *= calcAcuteAngleBonus(lastAngle) // Multiply by previous angle, we don't want to buff unless this is a wiggle type pattern.
* Math.Min(angleBonus, 125 / osuCurrObj.StrainTime) // The maximum velocity we buff is equal to 125 / strainTime
* Math.Pow(Math.Sin(Math.PI / 2 * Math.Min(1, (100 - osuCurrObj.StrainTime) / 25)), 2) // scale buff from 150 bpm 1/4 to 200 bpm 1/4
* Math.Pow(Math.Sin(Math.PI / 2 * (Math.Clamp(osuCurrObj.LazyJumpDistance, 50, 100) - 50) / 50), 2); // Buff distance exceeding 50 (radius) up to 100 (diameter).
}
// Penalize wide angles if they're repeated, reducing the penalty as the lastAngle gets more acute.
wideAngleBonus *= angleBonus * (1 - Math.Min(wideAngleBonus, Math.Pow(calcWideAngleBonus(lastAngle), 3)));
// Penalize acute angles if they're repeated, reducing the penalty as the lastLastAngle gets more obtuse.
acuteAngleBonus *= 0.5 + 0.5 * (1 - Math.Min(acuteAngleBonus, Math.Pow(calcAcuteAngleBonus(lastLastAngle), 3)));
}
}
if (Math.Max(prevVelocity, currVelocity) != 0)
{
// We want to use the average velocity over the whole object when awarding differences, not the individual jump and slider path velocities.
prevVelocity = (osuLastObj.LazyJumpDistance + osuLastLastObj.TravelDistance) / osuLastObj.StrainTime;
currVelocity = (osuCurrObj.LazyJumpDistance + osuLastObj.TravelDistance) / osuCurrObj.StrainTime;
// Scale with ratio of difference compared to 0.5 * max dist.
double distRatio = Math.Pow(Math.Sin(Math.PI / 2 * Math.Abs(prevVelocity - currVelocity) / Math.Max(prevVelocity, currVelocity)), 2);
// Reward for % distance up to 125 / strainTime for overlaps where velocity is still changing.
double overlapVelocityBuff = Math.Min(125 / Math.Min(osuCurrObj.StrainTime, osuLastObj.StrainTime), Math.Abs(prevVelocity - currVelocity));
// Reward for % distance slowed down compared to previous, paying attention to not award overlap
double nonOverlapVelocityBuff = Math.Abs(prevVelocity - currVelocity)
// do not award overlap
* Math.Pow(Math.Sin(Math.PI / 2 * Math.Min(1, Math.Min(osuCurrObj.LazyJumpDistance, osuLastObj.LazyJumpDistance) / 100)), 2);
// Choose the largest bonus, multiplied by ratio.
velocityChangeBonus = Math.Max(overlapVelocityBuff, nonOverlapVelocityBuff) * distRatio;
// Penalize for rhythm changes.
velocityChangeBonus *= Math.Pow(Math.Min(osuCurrObj.StrainTime, osuLastObj.StrainTime) / Math.Max(osuCurrObj.StrainTime, osuLastObj.StrainTime), 2);
}
if (osuLastObj.TravelTime != 0)
{
// Reward sliders based on velocity.
sliderBonus = osuLastObj.TravelDistance / osuLastObj.TravelTime;
}
// Add in acute angle bonus or wide angle bonus + velocity change bonus, whichever is larger.
aimStrain += Math.Max(acuteAngleBonus * acute_angle_multiplier, wideAngleBonus * wide_angle_multiplier + velocityChangeBonus * velocity_change_multiplier);
// Add in additional slider velocity bonus.
if (withSliders)
{
aimStrain += sliderBonus * slider_multiplier;
}
return(aimStrain);
}
