added basic inventory system

Assets/Scripts/Inventory.cs

@@ -1,34 +1,84 @@
-using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
-
 public class Inventory : MonoBehaviour
 {
-  [SerializeField] private int slots = 10;
-  [SerializeField] private int stackSize = 100;
-  [SerializeField] private List<Item> items = new List<Item>();
+  public int maxSlots = 20; // maximum number of slots in the inventory
+  public List<InventoryItem> items = new List<InventoryItem>(); // list of items in the inventory
 
-
-  public Item Add(Item item)
+  // adds an item to the inventory, returns the quantity of items which could not be added
+  public int Add(Item item, int count)
   {
-    foreach (Item i in items)
+    int remainingCount = count;
+
+    // check if the item is stackable
+    if (item.stackable)
     {
-      if (i.uuid == item.uuid) // item already is in list
+      // look for an existing stack of the same item in the inventory
+      foreach (InventoryItem invItem in items)
       {
-        if (i.quantity + item.quantity <= stackSize)
-        {// enough space
-          i.quantity += item.quantity;
-          item.quantity = 0;
-        }
-        else
-        {// Not enough space
-          i.quantity = stackSize;
-          item.quantity = Mathf.Max(0, i.quantity - item.quantity);
+        if (invItem.item == item && invItem.count < item.maxStackSize)
+        {
+          // add as many items as possible to the stack
+          int space = item.maxStackSize - invItem.count;
+          int toAdd = Mathf.Min(space, remainingCount);
+          invItem.count += toAdd;
+          remainingCount -= toAdd;
+
+          // exit the loop if all items have been added
+          if (remainingCount == 0)
+          {
+            return 0;
+          }
         }
       }
     }
-    return item;
 
+    // if there is still remaining count, add new stacks of the item
+    while (remainingCount > 0 && items.Count < maxSlots)
+    {
+      int toAdd = Mathf.Min(item.maxStackSize, remainingCount);
+      items.Add(new InventoryItem(item, toAdd));
+      remainingCount -= toAdd;
+    }
+
+    // return the quantity of items which could not be added
+    return remainingCount;
   }
 
+
+  // removes an item from the inventory, returns the quantity of items which could not be removed
+  public int Remove(Item item, int count)
+  {
+    int remainingCount = count;
+
+    // look for an existing stack of the item in the inventory
+    for (int i = 0; i < items.Count; i++)
+    {
+      InventoryItem invItem = items[i];
+      if (invItem.item == item)
+      {
+        // remove as many items as possible from the stack
+        int toRemove = Mathf.Min(invItem.count, remainingCount);
+        invItem.count -= toRemove;
+        remainingCount -= toRemove;
+
+        // remove the stack if it's now empty
+        if (invItem.count == 0)
+        {
+          items.RemoveAt(i);
+        }
+
+        // exit the loop if all items have been removed
+        if (remainingCount == 0)
+        {
+          return 0;
+        }
+      }
+    }
+
+    // return the quantity of items which could not be removed
+    return remainingCount;
+  }
 }
+
+

Assets/Scripts/InventoryItem.cs

@@ -0,0 +1,18 @@
+using UnityEngine;
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+// represents an item in the inventory and its count
+[System.Serializable]
+public class InventoryItem
+{
+  public Item item;
+  public int count;
+
+  public InventoryItem(Item item, int count)
+  {
+    this.item = item;
+    this.count = count;
+  }
+}

Assets/Scripts/InventoryItem.cs.meta

@@ -0,0 +1,11 @@
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+guid: 352cc16dc45cea64b92b7fd088daff22
+MonoImporter:
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+  serializedVersion: 2
+  defaultReferences: []
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+  assetBundleVariant: 

Assets/Scripts/Item.cs

@@ -8,5 +8,15 @@ public class Item : ScriptableObject
   public string uuid;
   public string itemName;
 
-  public int quantity = 1;
+  public bool stackable = true;
+  public int maxStackSize = 100;
+
+
+  private void OnEnable()
+  {
+    if (!stackable)
+    {
+      maxStackSize = 1;
+    }
+  }
 }

Assets/Scripts/PlayerController.cs

@@ -0,0 +1,60 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class PlayerController : MonoBehaviour
+{
+
+  public Item testItem1;
+  public Item testItem2;
+  // Start is called before the first frame update
+  void Start()
+  {
+
+  }
+
+  // Update is called once per frame
+  void Update()
+  {
+    Inventory inventory = GetComponent<Inventory>();
+
+    if (Input.GetKeyDown(KeyCode.U))
+    {
+      // add 5 apples
+      int remainingCount = inventory.Add(testItem1, 5);
+      Debug.Log("Added " + (5 - remainingCount) + " apples to inventory.");
+    }
+
+    if (Input.GetKeyDown(KeyCode.I))
+    { // add 15 more apples
+      int remainingCount = inventory.Add(testItem1, 15);
+      Debug.Log("Added " + (15 - remainingCount) + " apples to inventory.");
+    }
+
+    if (Input.GetKeyDown(KeyCode.O))
+    {
+      // add 10 bananas
+      int remainingCount = inventory.Add(testItem2, 10);
+      Debug.Log("Added " + (10 - remainingCount) + " bananas to inventory.");
+    }
+
+
+    if (Input.GetKeyDown(KeyCode.J))
+    {
+      int count = 3;
+      int applesRemaining = inventory.Remove(testItem1, count);
+      Debug.Log("Removed " + (count - applesRemaining) + " apples.");
+
+    }
+
+    if (Input.GetKeyDown(KeyCode.K))
+    {
+      int count = 5;
+      int bananasRemaining = inventory.Remove(testItem2, count);
+      Debug.Log("Removed " + (count - bananasRemaining) + " bananas.");
+
+    }
+
+
+  }
+}

Assets/Scripts/PlayerController.cs.meta

@@ -0,0 +1,11 @@
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