画像で数字を表示する（3桁）

ImageNumViewer.cs

namespace com.etc.utility
{
    using UnityEngine;

    public class ImageNumViewer : MonoBehaviour
    {
        [SerializeField]
        private ImageNumViewUnit[] numViewUnits;
        private int currentNum;

        public void ShowNum(int num)
        {
            this.numViewUnits[1].GetComponent<CanvasGroup>().alpha = num < 10 ? 0 : 1;
            this.numViewUnits[2].GetComponent<CanvasGroup>().alpha = num < 100 ? 0 : 1;

            for (int i = 0; i < num.ToString().Length; i++)
            {
                int currentDigits_ = this.GetNthDigitNum(this.currentNum, i + 1);
                int newDigits = this.GetNthDigitNum(num, i + 1);
                if (newDigits != currentDigits_)
                {
                    this.numViewUnits[i].ShowNum(newDigits);
                }
            }

            this.currentNum = num;
        }

        private void Start()
        {
            this.ShowNum(0);
        }

        private int GetNthDigitNum(int num, int digit)
        {
            int currentDigitNum = 1;
            num = System.Math.Abs(num);
            while (num > 0)
            {
                if (currentDigitNum == digit)
                {
                    return num % 10;
                }

                num /= 10;
                currentDigitNum++;
            }

            return 0;
        }
    }
}