test/Assets/PerfectWorld/Scripts/AnimTestScene/GameSpeedModifier.cs

using UnityEngine;
using UnityEngine.UI;
using TMPro;

namespace BrewMonster
{
    public class GameSpeedModifier : MonoBehaviour
    {
        [SerializeField] private Button _speedUpButton;
        [SerializeField] private Button _speedDownButton;
        [SerializeField] private TextMeshProUGUI _gameSpeedText;

        private readonly float[] _speedStages = { 0.25f, 0.5f, 0.75f, 1f, 2f };
        private int _currentSpeedIndex = 3; // Default = 1x
        private void Awake()
        {
            _speedUpButton.onClick.AddListener(OnSpeedUpButtonClicked);
            _speedDownButton.onClick.AddListener(OnSpeedDownButtonClicked);
            _currentSpeedIndex = 3; // Default = 1x
            Time.timeScale = 1.0f;
            ApplySpeed();
        }

        private void OnSpeedUpButtonClicked()
        {
            if (_currentSpeedIndex >= _speedStages.Length - 1)
                return;

            _currentSpeedIndex++;
            ApplySpeed();
        }

        private void OnSpeedDownButtonClicked()
        {
            if (_currentSpeedIndex <= 0)
                return;

            _currentSpeedIndex--;
            ApplySpeed();
        }

        private void ApplySpeed()
        {
            float speed = _speedStages[_currentSpeedIndex];

            Time.timeScale = speed;
            _gameSpeedText.text = speed.ToString("0.##X");
        }
    }
}