ShantiManti/Assets/game/enemy/Bird/scripts/EnemyAI.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Pathfinding;

public class EnemyAI : MonoBehaviour
{

    public Transform target;
    public float speed = 200f;
    public float nextWaypointDistance = 3f;

    private Transform enemyGFX;

    Path path;
    int currentWaypoint = 0;
    // ↓ uncomment every comment with reachedEndOfPath if you need it. In this case it isnt usefull
    //bool reachedEndOfPath = false;

    Seeker seeker;
    Rigidbody2D rb;

    void Start()
    {
        seeker = GetComponent<Seeker>();
        rb = GetComponent<Rigidbody2D>();
        enemyGFX = GetComponentInChildren<SpriteRenderer>().transform;

        InvokeRepeating("UpdatePath", 0f, .5f);
    }

    void UpdatePath()
    {
        if (seeker.IsDone())
        {
            seeker.StartPath(rb.position, target.position, OnPathComplete);
        }
    }

    void OnPathComplete (Path p)
    {
        if (!p.error)
        {
            path = p;
            currentWaypoint = 0;
        }
    }

    void FixedUpdate()
    {
        if (Pause.IsPause == false)
        {
            if (path == null)
            {
                return;
            }
            if (currentWaypoint >= path.vectorPath.Count)
            {
                //reachedEndOfPath = true;
                return;
            }
            else
            {
                //reachedEndOfPath = false;
            }

            Vector2 direction = ((Vector2)path.vectorPath[currentWaypoint] -rb.position).normalized;
            Vector2 force = direction * speed * Time.deltaTime;

            rb.AddForce(force);

            float distance = Vector2.Distance(rb.position, path.vectorPath[currentWaypoint]);

            if (distance < nextWaypointDistance)
            {
                currentWaypoint++;
            }
            //You can make look it differently, if you delete 'rb.velocity' and add 'force' instead.
            if (rb.linearVelocity.x >= 0.01f)
            {
                enemyGFX.transform.localScale = new Vector3(-1f, 1f, 1f);
            }
            else if (rb.linearVelocity.x <= -0.01f)
            {
                enemyGFX.transform.localScale = new Vector3(1f, 1f, 1f);
            }
        }
        
    }
}