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osu-lazer/osu.Game.Rulesets.Catch/Difficulty/CatchDifficultyHitObject.cs
2018-11-20 17:14:59 +09:00

131 lines
5.6 KiB
C#

// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
using System;
using osu.Game.Rulesets.Catch.Objects;
using osu.Game.Rulesets.Catch.UI;
using osuTK;
namespace osu.Game.Rulesets.Catch.Difficulty
{
public class CatchDifficultyHitObject
{
internal static readonly double DECAY_BASE = 0.20;
private const float normalized_hitobject_radius = 41.0f;
private const float absolute_player_positioning_error = 16f;
private readonly float playerPositioningError;
internal CatchHitObject BaseHitObject;
/// <summary>
/// Measures jump difficulty. CtB doesn't have something like button pressing speed or accuracy
/// </summary>
internal double Strain = 1;
/// <summary>
/// This is required to keep track of lazy player movement (always moving only as far as necessary)
/// Without this quick repeat sliders / weirdly shaped streams might become ridiculously overrated
/// </summary>
internal float PlayerPositionOffset;
internal float LastMovement;
internal float NormalizedPosition;
internal float ActualNormalizedPosition => NormalizedPosition + PlayerPositionOffset;
internal CatchDifficultyHitObject(CatchHitObject baseHitObject, float catcherWidthHalf)
{
BaseHitObject = baseHitObject;
// We will scale everything by this factor, so we can assume a uniform CircleSize among beatmaps.
float scalingFactor = normalized_hitobject_radius / catcherWidthHalf;
playerPositioningError = absolute_player_positioning_error; // * scalingFactor;
NormalizedPosition = baseHitObject.X * CatchPlayfield.BASE_WIDTH * scalingFactor;
}
private const double direction_change_bonus = 12.5;
internal void CalculateStrains(CatchDifficultyHitObject previousHitObject, double timeRate)
{
// Rather simple, but more specialized things are inherently inaccurate due to the big difference playstyles and opinions make.
// See Taiko feedback thread.
double timeElapsed = (BaseHitObject.StartTime - previousHitObject.BaseHitObject.StartTime) / timeRate;
double decay = Math.Pow(DECAY_BASE, timeElapsed / 1000);
// Update new position with lazy movement.
PlayerPositionOffset =
MathHelper.Clamp(
previousHitObject.ActualNormalizedPosition,
NormalizedPosition - (normalized_hitobject_radius - playerPositioningError),
NormalizedPosition + (normalized_hitobject_radius - playerPositioningError)) // Obtain new lazy position, but be stricter by allowing for an error of a certain degree of the player.
- NormalizedPosition; // Subtract HitObject position to obtain offset
LastMovement = DistanceTo(previousHitObject);
double addition = spacingWeight(LastMovement);
if (NormalizedPosition < previousHitObject.NormalizedPosition)
{
LastMovement = -LastMovement;
}
CatchHitObject previousHitCircle = previousHitObject.BaseHitObject;
double additionBonus = 0;
double sqrtTime = Math.Sqrt(Math.Max(timeElapsed, 25));
// Direction changes give an extra point!
if (Math.Abs(LastMovement) > 0.1)
{
if (Math.Abs(previousHitObject.LastMovement) > 0.1 && Math.Sign(LastMovement) != Math.Sign(previousHitObject.LastMovement))
{
double bonus = direction_change_bonus / sqrtTime;
// Weight bonus by how
double bonusFactor = Math.Min(playerPositioningError, Math.Abs(LastMovement)) / playerPositioningError;
// We want time to play a role twice here!
addition += bonus * bonusFactor;
// Bonus for tougher direction switches and "almost" hyperdashes at this point
if (previousHitCircle != null && previousHitCircle.DistanceToHyperDash <= 10.0f / CatchPlayfield.BASE_WIDTH)
{
additionBonus += 0.3 * bonusFactor;
}
}
// Base bonus for every movement, giving some weight to streams.
addition += 7.5 * Math.Min(Math.Abs(LastMovement), normalized_hitobject_radius * 2) / (normalized_hitobject_radius * 6) / sqrtTime;
}
// Bonus for "almost" hyperdashes at corner points
if (previousHitCircle != null && previousHitCircle.DistanceToHyperDash <= 10.0f / CatchPlayfield.BASE_WIDTH)
{
if (!previousHitCircle.HyperDash)
{
additionBonus += 1.0;
}
else
{
// After a hyperdash we ARE in the correct position. Always!
PlayerPositionOffset = 0;
}
addition *= 1.0 + additionBonus * ((10 - previousHitCircle.DistanceToHyperDash * CatchPlayfield.BASE_WIDTH) / 10);
}
addition *= 850.0 / Math.Max(timeElapsed, 25);
Strain = previousHitObject.Strain * decay + addition;
}
private static double spacingWeight(float distance)
{
return Math.Pow(distance, 1.3) / 500;
}
internal float DistanceTo(CatchDifficultyHitObject other)
{
return Math.Abs(ActualNormalizedPosition - other.ActualNormalizedPosition);
}
}
}