Fruitomation/Assets/Scripts/Game/Items/ItemBehaviour.cs

using System;
using Fruitomation.Global;
using UnityEngine;

namespace Fruitomation.Game.Items
{
    public enum ItemType
    {
        Apple,
        Grape,
        Banana,
        Kiwi,
        Mango,
        Pitaya,
        Durian,
        BuddhasHand
    }
    
    public class ItemBehaviour : MonoBehaviour
    {
        protected RectTransform RectTransform { get; private set; }
        protected Rigidbody2D Body2D { get; private set; }
        protected Canvas AttachedCanvas { get; private set; }
        protected bool EnteredCanvas { get; private set; }

        private ItemType InternalItemType;

        public ItemType CurrentType
        {
            get => InternalItemType;
            set
            {
                InternalItemType = value;
            }
        }
        
        protected virtual void OnInitialized() { }
        
        public void InitBehaviour(Canvas canvas)
        {
            RectTransform = transform.GetComponent<RectTransform>();
            Body2D = transform.GetComponent<Rigidbody2D>();
            
            AttachedCanvas = canvas;
            EnteredCanvas = false;
            
            OnInitialized();
        }

        private void UpdateItem()
        {
        }

        protected void Update()
        {
            if (!GameStateController.Is(GameState.Simulation))
            {
                TriggerDestruction(false);
            }
        }

        private void FixedUpdate()
        {
            bool contained = IsWithinCanvas(RectTransform, AttachedCanvas.GetComponent<RectTransform>());
            EnteredCanvas = EnteredCanvas || contained;

            if (!contained && EnteredCanvas)
            {
                TriggerDestruction();
            }
        }

        private static bool IsWithinCanvas(RectTransform element, RectTransform canvas)
        {
            Vector3[] elementCorners = new Vector3[4];
            Vector3[] canvasCorners = new Vector3[4];

            element.GetWorldCorners(elementCorners);
            canvas.GetWorldCorners(canvasCorners);

            Rect bounds = new
            (
                canvasCorners[0].x,
                canvasCorners[0].y,
                canvasCorners[2].x - canvasCorners[0].x,
                canvasCorners[2].y - canvasCorners[0].y
            );

            foreach (Vector3 corner in elementCorners)
            {
                if (bounds.Contains(corner))
                {
                    return true;
                }
            }

            return false;
        }

        public void TriggerDestruction(bool harvest = true)
        {
            Destroy(gameObject);
        }
    }
}