// 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. #nullable disable using System; using System.Collections.Generic; using System.Linq; using osu.Game.Beatmaps; using osu.Game.Rulesets.Difficulty; using osu.Game.Rulesets.Difficulty.Preprocessing; using osu.Game.Rulesets.Difficulty.Skills; using osu.Game.Rulesets.Mods; using osu.Game.Rulesets.Osu.Difficulty.Preprocessing; using osu.Game.Rulesets.Osu.Difficulty.Skills; using osu.Game.Rulesets.Osu.Mods; using osu.Game.Rulesets.Osu.Objects; using osu.Game.Rulesets.Osu.Scoring; using osu.Game.Rulesets.Scoring; namespace osu.Game.Rulesets.Osu.Difficulty { public class OsuDifficultyCalculator : DifficultyCalculator { private const double difficulty_multiplier = 0.0675; public override int Version => 20241007; public OsuDifficultyCalculator(IRulesetInfo ruleset, IWorkingBeatmap beatmap) : base(ruleset, beatmap) { } protected override DifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate) { if (beatmap.HitObjects.Count == 0) return new OsuDifficultyAttributes { Mods = mods }; double aimRating = Math.Sqrt(skills[0].DifficultyValue()) * difficulty_multiplier; double aimRatingNoSliders = Math.Sqrt(skills[1].DifficultyValue()) * difficulty_multiplier; double speedRating = Math.Sqrt(skills[2].DifficultyValue()) * difficulty_multiplier; double speedNotes = ((Speed)skills[2]).RelevantNoteCount(); double flashlightRating = 0.0; if (mods.Any(h => h is OsuModFlashlight)) flashlightRating = Math.Sqrt(skills[3].DifficultyValue()) * difficulty_multiplier; double sliderFactor = aimRating > 0 ? aimRatingNoSliders / aimRating : 1; double aimDifficultyStrainCount = ((OsuStrainSkill)skills[0]).CountDifficultStrains(); double speedDifficultyStrainCount = ((OsuStrainSkill)skills[2]).CountDifficultStrains(); if (mods.Any(m => m is OsuModTouchDevice)) { aimRating = Math.Pow(aimRating, 0.8); flashlightRating = Math.Pow(flashlightRating, 0.8); } if (mods.Any(h => h is OsuModRelax)) { aimRating *= 0.9; speedRating = 0.0; flashlightRating *= 0.7; } double baseAimPerformance = OsuStrainSkill.DifficultyToPerformance(aimRating); double baseSpeedPerformance = OsuStrainSkill.DifficultyToPerformance(speedRating); double baseFlashlightPerformance = 0.0; if (mods.Any(h => h is OsuModFlashlight)) baseFlashlightPerformance = Flashlight.DifficultyToPerformance(flashlightRating); double basePerformance = Math.Pow( Math.Pow(baseAimPerformance, 1.1) + Math.Pow(baseSpeedPerformance, 1.1) + Math.Pow(baseFlashlightPerformance, 1.1), 1.0 / 1.1 ); double starRating = basePerformance > 0.00001 ? Math.Cbrt(OsuPerformanceCalculator.PERFORMANCE_BASE_MULTIPLIER) * 0.027 * (Math.Cbrt(100000 / Math.Pow(2, 1 / 1.1) * basePerformance) + 4) : 0; double preempt = IBeatmapDifficultyInfo.DifficultyRange(beatmap.Difficulty.ApproachRate, 1800, 1200, 450) / clockRate; double drainRate = beatmap.Difficulty.DrainRate; int hitCirclesCount = beatmap.HitObjects.Count(h => h is HitCircle); int sliderCount = beatmap.HitObjects.Count(h => h is Slider); int spinnerCount = beatmap.HitObjects.Count(h => h is Spinner); HitWindows hitWindows = new OsuHitWindows(); hitWindows.SetDifficulty(beatmap.Difficulty.OverallDifficulty); double hitWindowGreat = hitWindows.WindowFor(HitResult.Great) / clockRate; OsuDifficultyAttributes attributes = new OsuDifficultyAttributes { StarRating = starRating, Mods = mods, AimDifficulty = aimRating, SpeedDifficulty = speedRating, SpeedNoteCount = speedNotes, FlashlightDifficulty = flashlightRating, SliderFactor = sliderFactor, AimDifficultStrainCount = aimDifficultyStrainCount, SpeedDifficultStrainCount = speedDifficultyStrainCount, ApproachRate = preempt > 1200 ? (1800 - preempt) / 120 : (1200 - preempt) / 150 + 5, OverallDifficulty = (80 - hitWindowGreat) / 6, DrainRate = drainRate, MaxCombo = beatmap.GetMaxCombo(), HitCircleCount = hitCirclesCount, SliderCount = sliderCount, SpinnerCount = spinnerCount, }; return attributes; } protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate) { List<DifficultyHitObject> objects = new List<DifficultyHitObject>(); // The first jump is formed by the first two hitobjects of the map. // If the map has less than two OsuHitObjects, the enumerator will not return anything. for (int i = 1; i < beatmap.HitObjects.Count; i++) { var lastLast = i > 1 ? beatmap.HitObjects[i - 2] : null; objects.Add(new OsuDifficultyHitObject(beatmap.HitObjects[i], beatmap.HitObjects[i - 1], lastLast, clockRate, objects, objects.Count)); } return objects; } protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) { var skills = new List<Skill> { new Aim(mods, true), new Aim(mods, false), new Speed(mods) }; if (mods.Any(h => h is OsuModFlashlight)) skills.Add(new Flashlight(mods)); return skills.ToArray(); } protected override Mod[] DifficultyAdjustmentMods => new Mod[] { new OsuModTouchDevice(), new OsuModDoubleTime(), new OsuModHalfTime(), new OsuModEasy(), new OsuModHardRock(), new OsuModFlashlight(), new MultiMod(new OsuModFlashlight(), new OsuModHidden()) }; } }