beat transmitter using UniRx

BeatTransmitter.cs

using System;
using UniRx;
using UnityEngine;

namespace KotonohaAnone.Presenter
{
    public class BeatTransmitter : MonoBehaviour
    {
        [SerializeField] private AudioSource audioSource;
        [SerializeField] private float bpm;

        private readonly Subject<Unit> beatSubject = new Subject<Unit>();

        //  曲の何ビート目か(前Update時)
        private int previousBeatCount = 0;

        private void Update()
        {
            float beatTime = 60f / bpm;

            int currentBeatCount = Mathf.FloorToInt(audioSource.time / beatTime);
            if(currentBeatCount != previousBeatCount)
            {
                beatSubject.OnNext(Unit.Default);
            }

            previousBeatCount = currentBeatCount;
        }

        private void OnDestroy()
        {
            beatSubject.Dispose();
        }

        //  ビートを観測する
        //  1拍ごとに発行される
        public IObservable<Unit> ObserveBeat()
        {
            return beatSubject;
        }
    }

    //  利用側
    class Usage : MonoBehaviour
    {
        void SomeMethod()
        {
            BeatTransmitter beat = GetComponent<BeatTransmitter>();
            beat.ObserveBeat()
                .Subscribe(_=>
                {
                    //  ビートごとに何かする
                })
                .AddTo(this);
        }
    }

}