osu-lazer/osu.Game.Rulesets.Mania/Mods/ManiaModHidden.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 System;
using System.Linq;
using osu.Framework.Localisation;
using osu.Game.Rulesets.Mania.UI;
using osu.Framework.Bindables;
using osu.Game.Rulesets.Scoring;

namespace osu.Game.Rulesets.Mania.Mods
{
    public class ManiaModHidden : ManiaModPlayfieldCover
    {
        /// <summary>
        /// osu!stable is referenced to 480px.
        /// </summary>
        private const float playfield_height = 480;

        private const float min_coverage = 160f / playfield_height;
        private const float max_coverage = 400f / playfield_height;
        private const float coverage_increase_per_combo = 0.5f / playfield_height;

        public override LocalisableString Description => @"Keys fade out before you hit them!";
        public override double ScoreMultiplier => 1;
        public override Type[] IncompatibleMods => base.IncompatibleMods.Append(typeof(ManiaModFadeIn)).ToArray();

        public override BindableNumber<float> Coverage { get; } = new BindableFloat(min_coverage);
        protected override CoverExpandDirection ExpandDirection => CoverExpandDirection.AgainstScroll;

        private readonly BindableInt combo = new BindableInt();

        public override void ApplyToScoreProcessor(ScoreProcessor scoreProcessor)
        {
            base.ApplyToScoreProcessor(scoreProcessor);

            combo.UnbindAll();
            combo.BindTo(scoreProcessor.Combo);
            combo.BindValueChanged(c => Coverage.Value = Math.Min(max_coverage, min_coverage + c.NewValue * coverage_increase_per_combo), true);
        }
    }
}