osu-lazer/osu.Game.Rulesets.Taiko/Mods/TaikoModHidden.cs

// 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 osu.Framework.Graphics;
using osu.Game.Beatmaps;
using osu.Game.Beatmaps.ControlPoints;
using osu.Game.Rulesets.Mods;
using osu.Game.Rulesets.Objects;
using osu.Game.Rulesets.Objects.Drawables;
using osu.Game.Rulesets.Scoring;
using osu.Game.Rulesets.Taiko.Objects.Drawables;

namespace osu.Game.Rulesets.Taiko.Mods
{
    public class TaikoModHidden : ModHidden
    {
        public override string Description => @"Beats fade out before you hit them!";
        public override double ScoreMultiplier => 1.06;

        private ControlPointInfo controlPointInfo;

        protected override void ApplyIncreasedVisibilityState(DrawableHitObject hitObject, ArmedState state)
        {
            ApplyNormalVisibilityState(hitObject, state);
        }

        protected double MultiplierAt(double position)
        {
            double beatLength = controlPointInfo.TimingPointAt(position).BeatLength;
            double speedMultiplier = controlPointInfo.DifficultyPointAt(position).SpeedMultiplier;

            return speedMultiplier * TimingControlPoint.DEFAULT_BEAT_LENGTH / beatLength;
        }

        protected override void ApplyNormalVisibilityState(DrawableHitObject hitObject, ArmedState state)
        {
            switch (hitObject)
            {
                case DrawableDrumRollTick _:
                case DrawableHit _:
                    double preempt = 10000 / MultiplierAt(hitObject.HitObject.StartTime);
                    double start = hitObject.HitObject.StartTime - preempt * 0.6;
                    double duration = preempt * 0.3;

                    using (hitObject.BeginAbsoluteSequence(start))
                    {
                        hitObject.FadeOut(duration);

                        // DrawableHitObject sets LifetimeEnd to LatestTransformEndTime if it isn't manually changed.
                        // in order for the object to not be killed before its actual end time (as the latest transform ends earlier), set lifetime end explicitly.
                        hitObject.LifetimeEnd = state == ArmedState.Idle || !hitObject.AllJudged
                            ? hitObject.HitObject.GetEndTime() + hitObject.HitObject.HitWindows.WindowFor(HitResult.Miss)
                            : hitObject.HitStateUpdateTime;
                    }

                    break;
            }
        }

        public override void ApplyToBeatmap(IBeatmap beatmap)
        {
            controlPointInfo = beatmap.ControlPointInfo;
        }
    }
}