Add countdown and animation

Assets/StartScreen.cs

@@ -0,0 +1,70 @@
+using DG.Tweening;
+using UnityEngine;
+using UnityEngine.Events;
+
+namespace Netherlands3D.Twin
+{
+    public class StartScreen : MonoBehaviour
+    {
+        public UnityEvent getReady = new();
+        public UnityEvent startGame = new ();
+        [SerializeField] private CanvasGroup canvasGroup;
+        [SerializeField] private CanvasGroup CountdownOne;
+        [SerializeField] private CanvasGroup CountdownTwo;
+        [SerializeField] private CanvasGroup CountdownThree;
+        [SerializeField] private float fadeDuration = .3f;
+        [SerializeField] private float countDownDuration = 1f;
+        [SerializeField] private float countDownTargetScale = .5f;
+
+        private void Start()
+        {
+            Show();
+        }
+
+        private void OnEnable()
+        {
+            CountdownThree.alpha = 1f;
+            CountdownThree.gameObject.SetActive(false);
+            CountdownTwo.alpha = 1f;
+            CountdownTwo.gameObject.SetActive(false);
+            CountdownOne.alpha = 1f;
+            CountdownOne.gameObject.SetActive(false);
+        }
+
+        public void Show()
+        {
+            gameObject.SetActive(true);
+        }
+
+        public void StartGame()
+        {
+            var sequence = DOTween.Sequence(this);
+            sequence.Append(canvasGroup.DOFade(0, fadeDuration).OnComplete(TriggerGetReady));
+            sequence.AppendCallback(() => CountdownThree.gameObject.SetActive(true));
+            sequence.Append(CountdownThree.transform.DOScale(countDownTargetScale, countDownDuration));
+            sequence.Join(CountdownThree.DOFade(0, countDownDuration).SetEase(Ease.InQuad));
+            sequence.AppendCallback(() => CountdownThree.gameObject.SetActive(false));
+            sequence.AppendCallback(() => CountdownTwo.gameObject.SetActive(true));
+            sequence.Append(CountdownTwo.transform.DOScale(countDownTargetScale, countDownDuration));
+            sequence.Join(CountdownTwo.DOFade(0, countDownDuration).SetEase(Ease.InQuad));
+            sequence.AppendCallback(() => CountdownTwo.gameObject.SetActive(false));
+            sequence.AppendCallback(() => CountdownOne.gameObject.SetActive(true));
+            sequence.Append(CountdownOne.transform.DOScale(countDownTargetScale, countDownDuration));
+            sequence.Join(CountdownOne.DOFade(0, countDownDuration).SetEase(Ease.InQuad));
+            sequence.AppendCallback(() => CountdownOne.gameObject.SetActive(false));
+            sequence.AppendCallback(TriggerStartOfGame);
+            sequence.Play();
+        }
+
+        private void TriggerGetReady()
+        {
+            gameObject.SetActive(false);
+            getReady.Invoke();
+        }
+
+        private void TriggerStartOfGame()
+        {
+            startGame.Invoke();
+        }
+    }
+}