add gruid buildingsystem

Assets/Scripts/Building.cs

@@ -0,0 +1,25 @@
+using UnityEngine;
+
+public class Building : MonoBehaviour
+{
+  public bool isPlaced = false;
+  public PlaceableObject placeableObject;
+
+  public void Place()
+  {
+    isPlaced = true;
+    BuildingManager.buildings.Add(this);
+  }
+
+  public void Demolish()
+  {
+    isPlaced = false;
+    BuildingManager.buildings.Remove(this);
+    Destroy(gameObject);
+  }
+
+  public Vector3Int GetGridPosition()
+  {
+    return new Vector3Int(Mathf.RoundToInt(transform.position.x), Mathf.RoundToInt(transform.position.y), 0);
+  }
+}