osu-lazer/osu.Game/Rulesets/Mods/ModDoubleTime.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.Audio;
using osu.Framework.Bindables;
using osu.Framework.Graphics.Sprites;
using osu.Framework.Localisation;
using osu.Game.Configuration;
using osu.Game.Graphics;

namespace osu.Game.Rulesets.Mods
{
    public abstract class ModDoubleTime : ModRateAdjust
    {
        public override string Name => "Double Time";
        public override string Acronym => "DT";
        public override IconUsage? Icon => OsuIcon.ModDoubleTime;
        public override ModType Type => ModType.DifficultyIncrease;
        public override LocalisableString Description => "Zoooooooooom...";

        [SettingSource("Speed increase", "The actual increase to apply")]
        public override BindableNumber<double> SpeedChange { get; } = new BindableDouble(1.5)
        {
            MinValue = 1.01,
            MaxValue = 2,
            Precision = 0.01,
        };

        private IAdjustableAudioComponent? track;

        [SettingSource("Adjust pitch", "Should pitch be adjusted with speed")]
        public virtual BindableBool AdjustPitch { get; } = new BindableBool(false);

        protected ModDoubleTime()
        {
            AdjustPitch.BindValueChanged(adjustPitchChanged);
        }

        private void adjustPitchChanged(ValueChangedEvent<bool> adjustPitchSetting)
        {
            track?.RemoveAdjustment(adjustmentForPitchSetting(adjustPitchSetting.OldValue), SpeedChange);
            track?.AddAdjustment(adjustmentForPitchSetting(adjustPitchSetting.NewValue), SpeedChange);
        }

        private AdjustableProperty adjustmentForPitchSetting(bool adjustPitchSettingValue)
            => adjustPitchSettingValue ? AdjustableProperty.Frequency : AdjustableProperty.Tempo;

        public override void ApplyToTrack(IAdjustableAudioComponent track)
        {
            this.track = track;
            AdjustPitch.TriggerChange();
        }

        public override double ScoreMultiplier
        {
            get
            {
                // Round to the nearest multiple of 0.1.
                double value = (int)(SpeedChange.Value * 10) / 10.0;

                // Offset back to 0.
                value -= 1;

                // Each 0.1 multiple changes score multiplier by 0.02.
                value /= 5;

                return 1 + value;
            }
        }
    }
}