osu/osu.Game.Rulesets.Taiko/Difficulty/Preprocessing/TaikoDifficultyHitObject.cs

95 lines
4.3 KiB
C#

// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.
using System;
using System.Linq;
using osu.Game.Rulesets.Difficulty.Preprocessing;
using osu.Game.Rulesets.Objects;
using osu.Game.Rulesets.Taiko.Objects;
namespace osu.Game.Rulesets.Taiko.Difficulty.Preprocessing
{
/// <summary>
/// Represents a single hit object in taiko difficulty calculation.
/// </summary>
public class TaikoDifficultyHitObject : DifficultyHitObject
{
/// <summary>
/// The rhythm required to hit this hit object.
/// </summary>
public readonly TaikoDifficultyHitObjectRhythm Rhythm;
/// <summary>
/// The hit type of this hit object.
/// </summary>
public readonly HitType? HitType;
/// <summary>
/// The index of the object in the beatmap.
/// </summary>
public readonly int ObjectIndex;
/// <summary>
/// Whether the object should carry a penalty due to being hittable using special techniques
/// making it easier to do so.
/// </summary>
public bool StaminaCheese;
/// <summary>
/// Creates a new difficulty hit object.
/// </summary>
/// <param name="hitObject">The gameplay <see cref="HitObject"/> associated with this difficulty object.</param>
/// <param name="lastObject">The gameplay <see cref="HitObject"/> preceding <paramref name="hitObject"/>.</param>
/// <param name="lastLastObject">The gameplay <see cref="HitObject"/> preceding <paramref name="lastObject"/>.</param>
/// <param name="clockRate">The rate of the gameplay clock. Modified by speed-changing mods.</param>
/// <param name="objectIndex">The index of the object in the beatmap.</param>
public TaikoDifficultyHitObject(HitObject hitObject, HitObject lastObject, HitObject lastLastObject, double clockRate, int objectIndex)
: base(hitObject, lastObject, clockRate)
{
var currentHit = hitObject as Hit;
Rhythm = getClosestRhythm(lastObject, lastLastObject, clockRate);
HitType = currentHit?.Type;
ObjectIndex = objectIndex;
}
/// <summary>
/// List of most common rhythm changes in taiko maps.
/// </summary>
/// <remarks>
/// The general guidelines for the values are:
/// <list type="bullet">
/// <item>rhythm changes with ratio closer to 1 (that are <i>not</i> 1) are harder to play,</item>
/// <item>speeding up is <i>generally</i> harder than slowing down (with exceptions of rhythm changes requiring a hand switch).</item>
/// </list>
/// </remarks>
private static readonly TaikoDifficultyHitObjectRhythm[] common_rhythms =
{
new TaikoDifficultyHitObjectRhythm(1, 1, 0.0),
new TaikoDifficultyHitObjectRhythm(2, 1, 0.3),
new TaikoDifficultyHitObjectRhythm(1, 2, 0.5),
new TaikoDifficultyHitObjectRhythm(3, 1, 0.3),
new TaikoDifficultyHitObjectRhythm(1, 3, 0.35),
new TaikoDifficultyHitObjectRhythm(3, 2, 0.6), // purposefully higher (requires hand switch in full alternating gameplay style)
new TaikoDifficultyHitObjectRhythm(2, 3, 0.4),
new TaikoDifficultyHitObjectRhythm(5, 4, 0.5),
new TaikoDifficultyHitObjectRhythm(4, 5, 0.7)
};
/// <summary>
/// Returns the closest rhythm change from <see cref="common_rhythms"/> required to hit this object.
/// </summary>
/// <param name="lastObject">The gameplay <see cref="HitObject"/> preceding this one.</param>
/// <param name="lastLastObject">The gameplay <see cref="HitObject"/> preceding <paramref name="lastObject"/>.</param>
/// <param name="clockRate">The rate of the gameplay clock.</param>
private TaikoDifficultyHitObjectRhythm getClosestRhythm(HitObject lastObject, HitObject lastLastObject, double clockRate)
{
double prevLength = (lastObject.StartTime - lastLastObject.StartTime) / clockRate;
double ratio = DeltaTime / prevLength;
return common_rhythms.OrderBy(x => Math.Abs(x.Ratio - ratio)).First();
}
}
}