/// <summary>
/// Calculates the movement time, effective distance and other details for the movement from objPrev to objCurr.
/// </summary>
/// <param name="fourthLastObject">Hit object four objects ago, relative to <paramref name="currentObject"/>.</param>
/// <param name="secondLastObject">Hit object immediately preceding <paramref name="lastObject"/></param>
/// <param name="lastObject">Hit object immediately preceding <paramref name="currentObject"/>.</param>
/// <param name="currentObject">The hit object being currently considered.</param>
/// <param name="nextObject">Hit object immediately succeeding <paramref name="currentObject"/>.</param>
/// <param name="tapStrain">The tap strain of the current object.</param> TODO: does this have to be passed down? maybe store in the object?
/// <param name="noteDensity">The visual note density of the current object.</param> TODO: above
/// <param name="gameplayRate">The current rate of the gameplay clock.</param>
/// <param name="hidden">Whether the hidden mod is active.</param>
/// <returns>List of movements performed in attempt to hit the current object.</returns>
public static List <OsuMovement> Extract(
[CanBeNull] OsuHitObject secondLastObject,
OsuHitObject lastObject,
OsuHitObject currentObject,
[CanBeNull] OsuHitObject nextObject,
double tapStrain,
double gameplayRate,
bool hidden,
double noteDensity,
[CanBeNull] OsuHitObject fourthLastObject = null)
{
var movement = new OsuMovement();
var parameters = new MovementExtractionParameters(fourthLastObject, secondLastObject, lastObject, currentObject, nextObject, gameplayRate);
movement.RawMovementTime = parameters.LastToCurrent.TimeDelta;
movement.StartTime = currentObject.StartTime / 1000.0;
if (currentObject is Spinner || lastObject is Spinner)
{
movement.Throughput = 0;
movement.Distance = 0;
movement.MovementTime = 1;
movement.Cheesablility = 0;
movement.CheeseWindow = 0;
return(new List <OsuMovement> {
movement
});
}
movement.EndsOnSlider = currentObject is Slider;
double movementThroughput = FittsLaw.Throughput(parameters.LastToCurrent.RelativeLength, parameters.LastToCurrent.TimeDelta);
movement.Throughput = movementThroughput;
movement.Distance = correctMovementDistance(parameters, movementThroughput, tapStrain, hidden, noteDensity);
calculateCheeseWindow(parameters, movementThroughput);
movement.MovementTime = parameters.LastToCurrent.TimeDelta;
movement.Cheesablility = parameters.Cheesability;
movement.CheeseWindow = parameters.CheeseWindow;
var movementWithNested = new List <OsuMovement> {
movement
};
// add zero difficulty movements corresponding to slider ticks/slider ends so combo is reflected properly
int extraNestedCount = currentObject.NestedHitObjects.Count - 1;
for (int i = 0; i < extraNestedCount; i++)
{
movementWithNested.Add(OsuMovement.Empty(movement.StartTime));
}
return(movementWithNested);
}
/// <summary>
/// Correction #5 - Cheesing
/// The player might make the movement from previous object to current easier by hitting former early and latter late.
/// Here we estimate the amount of such cheesing to update MovementTime accordingly.
/// </summary>
private static void calculateCheeseWindow(MovementExtractionParameters p, double movementThroughput)
{
double timeEarly = 0;
double timeLate = 0;
double cheesabilityEarly = 0;
double cheesabilityLate = 0;
if (p.LastToCurrent.RelativeLength > 0)
{
double secondLastToLastReciprocalMovementLength;
double secondLastToLastThroughput;
if (p.SecondLastObject != null)
{
Debug.Assert(p.SecondLastToLast != null);
secondLastToLastReciprocalMovementLength = 1 / (p.SecondLastToLast.Value.TimeDelta + 1e-10);
secondLastToLastThroughput = FittsLaw.Throughput(p.SecondLastToLast.Value.RelativeLength, p.SecondLastToLast.Value.TimeDelta);
}
else
{
secondLastToLastReciprocalMovementLength = 0;
secondLastToLastThroughput = 0;
}
cheesabilityEarly = SpecialFunctions.Logistic((secondLastToLastThroughput / movementThroughput - 0.6) * (-15)) * 0.5;
timeEarly = cheesabilityEarly * (1 / (1 / (p.LastToCurrent.TimeDelta + 0.07) + secondLastToLastReciprocalMovementLength));
double currentToNextReciprocalMovementLength;
double currentToNextThroughput;
if (p.NextObject != null)
{
Debug.Assert(p.CurrentToNext != null);
currentToNextReciprocalMovementLength = 1 / (p.CurrentToNext.Value.TimeDelta + 1e-10);
currentToNextThroughput = FittsLaw.Throughput(p.CurrentToNext.Value.RelativeLength, p.CurrentToNext.Value.TimeDelta);
}
else
{
currentToNextReciprocalMovementLength = 0;
currentToNextThroughput = 0;
}
cheesabilityLate = SpecialFunctions.Logistic((currentToNextThroughput / movementThroughput - 0.6) * (-15)) * 0.5;
timeLate = cheesabilityLate * (1 / (1 / (p.LastToCurrent.TimeDelta + 0.07) + currentToNextReciprocalMovementLength));
}
p.Cheesability = cheesabilityEarly + cheesabilityLate;
p.CheeseWindow = (timeEarly + timeLate) / (p.LastToCurrent.TimeDelta + 1e-10);
}
