osu-lazer/osu.Game.Rulesets.Osu/Mods/OsuModArrange.cs

using System;
using System.Collections.Generic;
using osu.Framework.Extensions.IEnumerableExtensions;
using osu.Framework.Graphics;
using osu.Game.Graphics;
using osu.Game.Rulesets.Mods;
using osu.Game.Rulesets.Objects.Drawables;
using osu.Game.Rulesets.Osu.Objects;
using OpenTK;

namespace osu.Game.Rulesets.Osu.Mods
{
    internal class OsuModArrange : Mod, IApplicableToDrawableHitObjects
    {
        public override string Name => "Arrange";
        public override string ShortenedName => "Arrange";
        public override FontAwesome Icon => FontAwesome.fa_arrows;
        public override ModType Type => ModType.DifficultyIncrease;
        public override string Description => "Everything rotates. EVERYTHING";
        public override bool Ranked => true;
        public override double ScoreMultiplier => 1.05;

        public void ApplyToDrawableHitObjects(IEnumerable<DrawableHitObject> drawables)
        {
            drawables.ForEach(drawable => drawable.ApplyCustomUpdateState += drawableOnApplyCustomUpdateState);
        }

        private float theta = 0;

        private void drawableOnApplyCustomUpdateState(DrawableHitObject drawable, ArmedState state)
        {
            var hitObject = (OsuHitObject) drawable.HitObject;

            Vector2 origPos;

            if (hitObject is RepeatPoint rp)
            {
                return;
            }
            else
            {
                origPos = drawable.Position;
            }

            using (drawable.BeginAbsoluteSequence(hitObject.StartTime - hitObject.TimeFadeIn - 1000, true))
            {
                drawable
                    .MoveToOffset(new Vector2((float)Math.Cos(theta), (float)Math.Sin(theta)) * 250)
                    .MoveTo(origPos, hitObject.TimeFadeIn + 1000, Easing.InOutSine);
            }

            if (hitObject is HitCircle || hitObject is Slider)
                theta += 0.4f;
        }
    }
}