Danro/Assets/Scripts/Behaviour/Projectiles/Projectile2D.cs

using System.Collections;
using UnityEngine;

using RR.Game2D.Core.Managers.Interfaces;

namespace RR.Game2D.Entities.Projectiles
{
    [RequireComponent(typeof(Rigidbody2D), typeof(Collider2D))]
    public abstract class Projectile2D : MonoBehaviour, ILaunchable
    {
        [Header("Базовые настройки")]
        [SerializeField] protected float initialSpeed = 15f;
        [SerializeField] protected float ignoreOwnerTime = 0.1f;
        [SerializeField] protected float projectileDamage = 1f;
        public float maxLifetime = 5f;

        [Header("Столкновения/пробивания")]
        [SerializeField] protected LayerMask hitLayers = ~0;
        [SerializeField] protected int maxPierce = 0;

        [Header("FX")]
        [SerializeField] protected GameObject hitVfxPrefab;
        [SerializeField] protected AudioClip hitSfx;
        [SerializeField] protected float sfxVolume = 1f;

        [Header("Другое")]
        [SerializeField] private bool alignRotationToVelocity = true;

        protected Rigidbody2D _rb;
        protected Collider2D _col;

        protected int _remainingPierce;
        protected bool _launched;
        protected float _launchTime;
        public GameObject owner;

        protected virtual void Awake()
        {
            _rb = GetComponent<Rigidbody2D>();
            _col = GetComponent<Collider2D>();
        }

        protected virtual void OnEnable()
        {
            _remainingPierce = maxPierce;
        }

        protected virtual void FixedUpdate()
        {
            if (!_launched) return;

            if (alignRotationToVelocity && _rb.linearVelocity.sqrMagnitude > 0.0001f)
            {
                float angle = Mathf.Atan2(_rb.linearVelocity.y, _rb.linearVelocity.x) * Mathf.Rad2Deg;
                _rb.SetRotation(angle);
            }
        }

        protected virtual void OnCollisionEnter2D(Collision2D collision)
        {
            if (!IsInHitLayer(collision.collider.gameObject.layer)) return;
            Vector2 point = collision.GetContact(0).point;
            OnHit(collision, point, collision.relativeVelocity);
        }

        protected virtual void OnTriggerEnter2D(Collider2D other)
        {
            if (!_col.isTrigger) return;
            if (!IsInHitLayer(other.gameObject.layer)) return;

            Vector2 point = other.ClosestPoint(transform.position);
            OnHit(other, point, _rb.linearVelocity);
        }

        public virtual void Launch(Vector2 direction, float speed = -1f, GameObject thrower = null)
        {
            this.owner = thrower;
            _launched = true;

            float finalSpeed = (speed > 0f) ? speed : initialSpeed;
            _rb.linearVelocity = direction.normalized * finalSpeed;

            if (thrower != null && ignoreOwnerTime > 0f)
                StartCoroutine(IgnoreOwnerTemporarily(thrower, ignoreOwnerTime));

            _launchTime = Time.time;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="who"></param>
        /// <param name="time"></param>
        protected virtual IEnumerator IgnoreOwnerTemporarily(GameObject who, float time)
        {
            Collider2D[] ownerColliders = who.GetComponentsInChildren<Collider2D>();
            foreach (var oc in ownerColliders)
                if (oc && _col) Physics2D.IgnoreCollision(_col, oc, true);

            yield return new WaitForSeconds(time);

            foreach (var oc in ownerColliders)
                if (oc && _col) Physics2D.IgnoreCollision(_col, oc, false);
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="layer"></param>
        /// <returns></returns>
        protected bool IsInHitLayer(int layer)
        {
            return ((1 << layer) & hitLayers.value) != 0;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="target"></param>
        /// <param name="hitPoint"></param>
        /// <param name="relativeVelocity"></param>
        protected virtual void TryDealDamage(Collider2D target, Vector2 hitPoint, Vector2 relativeVelocity)
        {
            //var dmg = target.GetComponentInParent<IDamageable2D>();
            //if (dmg != null)
            //{
            //    Vector2 force = (rb != null && rb.linearVelocity.sqrMagnitude > 0.001f)
            //        ? rb.linearVelocity.normalized * knockback
            //        : Vector2.zero;
            //    dmg.ApplyDamage(damage, hitPoint, force, owner ?? gameObject);
            //}
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="collision"></param>
        /// <param name="point"></param>
        /// <param name="relativeVelocity"></param>
        protected virtual void OnHit(Collision2D collision, Vector2 point, Vector2 relativeVelocity)
        {
            TryDealDamage(collision.collider, point, relativeVelocity);

            PlayFX(point);

            if (_remainingPierce > 0)
            {
                _remainingPierce--;
                return;
            }

            OnImpactFinal(collision);
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="otherCol"></param>
        /// <param name="point"></param>
        /// <param name="relativeVelocity"></param>
        protected virtual void OnHit(Collider2D otherCol, Vector2 point, Vector2 relativeVelocity)
        {
            TryDealDamage(otherCol, point, relativeVelocity);
            PlayFX(point);

            if (_remainingPierce > 0)
            {
                _remainingPierce--;
                return;
            }

            OnImpactFinal(otherCol);
        }

        /// <summary>
        /// Метод воспроизведения эффектов в определённой точке
        /// Может отрабатывать при любом поведении снаряда (столкновение, истечение времени жизни и т.д.)
        /// </summary>
        /// <param name="point">Точка воспроизведения FX</param>
        protected virtual void PlayFX(Vector2 point)
        {
            if (hitVfxPrefab != null)
            {
                Instantiate(hitVfxPrefab, point, Quaternion.identity);
            }
            if (hitSfx != null)
            {
                AudioSource.PlayClipAtPoint(hitSfx, point, sfxVolume);
            }
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="collision"></param>
        protected virtual void OnImpactFinal(Collision2D collision) => Despawn();

        /// <summary>
        /// 
        /// </summary>
        /// <param name="other"></param>
        protected virtual void OnImpactFinal(Collider2D other) => Despawn();

        /// <summary>
        /// 
        /// </summary>
        public virtual void Despawn()
        {
            Destroy(gameObject);
        }
    }
}