ClientServer/Client/Assets/Scripts/NPC/LocalNPC.cs

using System.Collections;
using System.Collections.Generic;
using TMPro;
using UnityEngine;
using UnityEngine.AI;
using UnityEngine.VFX;
using DG.Tweening;


public class LocalNPC
{

    public NPC n;

	//get nav mesh agent
	private NavMeshAgent agent;

	Vector2 smoothDeltaPosition = Vector2.zero;
    Vector2 velocity = Vector2.zero;

    private float lastBiteTime;
    private float lastUpdateTime;

    private bool attacking = false;



    public LocalNPC(NPC n)
	{
		this.n = n;
	}

    public void Start()
	{
        //assign nav mesh agent
        agent = n.gameObject.AddComponent<NavMeshAgent>();
        n.animator = n.gameObject.GetComponent<Animator>();
        agent.updatePosition = false;
        lastBiteTime = Time.time;
        n.forcePositionUpdate = false;
        //agent.speed = 4.0f;
        agent.radius = 1.0f;
        lastUpdateTime = Time.time;

        agent.obstacleAvoidanceType = ObstacleAvoidanceType.LowQualityObstacleAvoidance;
        
	}


	public void FixedUpdate()
	{
        if (Time.time - lastUpdateTime > 0.5f)
		{
            agent.destination = Player.Instance.gameObject.transform.position;
            lastUpdateTime = Time.time;
        }

        if (this.attacking) // don't move if attacking
		{
            return;
		}

        if (n.isDead)
		{
            agent.updateRotation = false;
            agent.updatePosition = false;
            agent.isStopped = true;
            return;
		}

        if (Player.Instance.IsDead())
		{
            n.animator.SetFloat("Speed", 0.0f);
            agent.speed = 0.0f;
            agent.angularSpeed = 0.0f;
            return;
		}

        //get the distance from the player
        float distance = Vector3.Distance(Player.Instance.transform.position, n.gameObject.transform.position);

        if (distance > 2.0f)
		{
            Vector3 worldDeltaPosition = agent.nextPosition - n.transform.position;

            // Map 'worldDeltaPosition' to local space
            float dx = Vector3.Dot(n.transform.right, worldDeltaPosition);
            float dy = Vector3.Dot(n.transform.forward, worldDeltaPosition);
            Vector2 deltaPosition = new Vector2(dx, dy);

            // Low-pass filter the deltaMove
            float smooth = Mathf.Min(1.0f, Time.deltaTime / 0.15f);
            smoothDeltaPosition = Vector2.Lerp(smoothDeltaPosition, deltaPosition, smooth);

            // Update velocity if time advances
            if (Time.deltaTime > 1e-5f)
                velocity = smoothDeltaPosition / Time.deltaTime;

            bool shouldMove = velocity.magnitude > 0.5f && agent.remainingDistance > agent.radius;

            n.transform.position = agent.nextPosition;

            n.animator.SetFloat("Speed", velocity.magnitude);
            //Debug.Log(velocity.magnitude);

        } else
		{
            n.animator.SetFloat("Speed", 0.0f);

            if (Time.time - lastBiteTime > 4.0f)
			{
                n.animator.Play("Kick_Attack");
                n.StartCoroutine(bitePlayer());
                n.transform.position = agent.nextPosition;
                lastBiteTime = Time.time;
            }
        }


        
    }
    


    public IEnumerator bitePlayer()
	{
        this.attacking = true;
        Player.Instance.speedMultiplier = 0.15f;
        yield return new WaitForSeconds(1.2f);
        if (!n.isDead)
		{
            if (Vector3.Distance(agent.gameObject.transform.position, Player.Instance.transform.position) < 3f)
            {
                PacketManager.sendNPCAttack(n.type);
            }
        }
        this.attacking = false;
        Player.Instance.speedMultiplier = 1.0f;
        yield return null;
	}

    public void setMoveSpeed(float moveSpeed)
	{
        agent.speed = moveSpeed;
	}
}