[Update] Update Missile movement, Bind missile event

MissileCommander/Assets/_Scripts/BuildingManager.cs

@@ -19,6 +19,11 @@ public BuildingManager(Building buildingPrefab, Transform[] buildingLocators)
             Debug.Assert(this._buildingLocators != null, "BuildingManager : Locators are null!");
         }
 
+        public void OnGameStart()
+        {
+            SpawnBuildings();
+        }
+
         public void SpawnBuildings()
         {
             if (_buildings.Count > 0)
@@ -35,9 +40,11 @@ public void SpawnBuildings()
             }
         }
 
-        public void OnGameStart()
+        public Vector3 GetRandomBuildingPosition()
         {
-            SpawnBuildings();
+            Debug.Assert(_buildings.Count > 0, "BuildingManager : No Building left in the list!");
+            Building building = _buildings[Random.Range(0, _buildings.Count)];
+            return building.transform.position;
         }
     }
 }

MissileCommander/Assets/_Scripts/Bullet.cs

@@ -6,6 +6,7 @@ namespace MissileCommander
     public class Bullet : RecyclableObject
     {
         [SerializeField] private float moveSpeed = 5f;
+        // squApproximateOffset is squared value.
         [SerializeField] private float sqrApproximateOffset = 0.01f;
 
         private void Update()

MissileCommander/Assets/_Scripts/GameManager.cs

@@ -52,13 +52,15 @@ private void BindEvents()
             _mouseGameController.OnFireButtonPressed += _launcher.OnFireButtonPressed;
             _timeMgr.onGameStart += _buildingMgr.OnGameStart;
             _timeMgr.onGameStart += _launcher.OnGameStart;
+            _timeMgr.onGameStart += _missileMgr.OnGameStart;
         }
 
         private void UnbindEvents()
         {
             _mouseGameController.OnFireButtonPressed -= _launcher.OnFireButtonPressed;
             _timeMgr.onGameStart -= _buildingMgr.OnGameStart;
             _timeMgr.onGameStart -= _launcher.OnGameStart;
+            _timeMgr.onGameStart -= _missileMgr.OnGameStart;
         }
     }
 }

MissileCommander/Assets/_Scripts/Missile.cs

@@ -1,10 +1,13 @@
-using UnityEngine;
+using System;
+using UnityEngine;
 
 namespace MissileCommander
 {
     [RequireComponent(typeof(Rigidbody2D), typeof(BoxCollider2D))]
     public class Missile : RecyclableObject
     {
+        [SerializeField] private float moveSpeed = 3f;
+
         private Rigidbody2D _rigidbody2D;
         private BoxCollider2D _boxCollider2D;
 
@@ -16,5 +19,26 @@ private void Awake()
             _rigidbody2D.bodyType = RigidbodyType2D.Kinematic;
             _boxCollider2D.isTrigger = true;
         }
+
+        private void Update()
+        {
+            if (!isActivated) { return; }
+
+            CachedTransform.position += Time.deltaTime * moveSpeed * transform.up;
+        }
+
+        private void OnTriggerEnter2D(Collider2D other)
+        {
+            if (other.TryGetComponent(out Building building))
+            {
+                DestroySelf();
+            }
+        }
+
+        private void DestroySelf()
+        {
+            isActivated = false;
+            onDestroyed?.Invoke(this);
+        }
     }
 }

MissileCommander/Assets/_Scripts/MissileManager.cs

@@ -1,4 +1,6 @@
-using UnityEngine;
+using System;
+using UnityEngine;
+using Random = UnityEngine.Random;
 
 namespace MissileCommander
 {
@@ -9,6 +11,12 @@ public class MissileManager : MonoBehaviour
         private BuildingManager _buildingMgr;
 
         private bool _isInitialized = false;
+        private Camera _mainCamera;
+
+        private void Awake()
+        {
+            _mainCamera = Camera.main != null ? Camera.main : FindObjectOfType<Camera>();
+        }
 
         public void Initialize(Factory missileFactory, BuildingManager buildingMgr)
         {
@@ -22,5 +30,38 @@ public void Initialize(Factory missileFactory, BuildingManager buildingMgr)
 
             _isInitialized = true;
         }
+
+        public void OnGameStart()
+        {
+            SpawnMissile();
+        }
+
+        private void SpawnMissile()
+        {
+            Debug.Assert(_missileFactory != null, "MissileManager : Missile Factory is null!");
+            Debug.Assert(_buildingMgr != null, "MissileManager : BuildingManager is null!");
+
+            RecyclableObject missile = _missileFactory.Get();
+            missile.Activate(GetMissileSpawnPosition(), _buildingMgr.GetRandomBuildingPosition());
+
+            missile.onDestroyed += this.OnMissileDestroyed;
+        }
+
+        private Vector3 GetMissileSpawnPosition()
+        {
+            Vector3 spawnPosition = Vector3.zero;
+            spawnPosition.x = Random.Range(0f, 1f);
+            spawnPosition.y = 1f;
+
+            spawnPosition = _mainCamera.ViewportToWorldPoint(spawnPosition);
+            spawnPosition.z = 0f;
+            return spawnPosition;
+        }
+
+        private void OnMissileDestroyed(RecyclableObject missile)
+        {
+            missile.onDestroyed -= this.OnMissileDestroyed;
+            _missileFactory.ReturnToPool(missile);
+        }
     }
 }

MissileCommander/Assets/_Scripts/RecyclableObject.cs

@@ -12,7 +12,6 @@ public class RecyclableObject : MonoBehaviour
         private Transform _cachedTransform;
         public Transform CachedTransform => _cachedTransform ? _cachedTransform : (_cachedTransform = transform);
 
-
         public virtual void Activate(Vector3 position)
         {
             isActivated = true;
@@ -24,8 +23,9 @@ public virtual void Activate(Vector3 startPos, Vector3 targetPos)
             this.targetPosition = targetPos;
 
             Vector3 direction = (targetPos - startPos).normalized;
-            CachedTransform.SetPositionAndRotation(startPos,
-                Quaternion.LookRotation(CachedTransform.forward, direction));
+            CachedTransform.SetPositionAndRotation
+                (startPos,
+                 Quaternion.LookRotation(CachedTransform.forward, direction));
             isActivated = true;
         }
     }