AI.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityStandardAssets.Characters.ThirdPerson;

using System.Linq;
using UnityEngine.AI;


public class AI : MonoBehaviour
{
    public int deathTimeout = 5;

    // all zombies Health
    public static int ZombieHealth = 5;

    public void kill()
    {
        Debug.Log(ZombieHealth);
        this.state = AIState.DEAD;
        if (ZombieHealth < ZombieHealth/3)
        {
            state = AIState.CRAZY;
        }
        ZombieHealth--;
    }

    private enum AIState { WANDERING, CHASING, DEAD, CRAZY };
    private AICharacterControl characterController;
    private GameObject[] allWaypoints;
    private int currentWaypoint = 0;
    private ThirdPersonCharacter tpCharacter;
    private AIState state = AIState.WANDERING;

    public static bool Pubstate;

    protected bool CanSeePlayer()
    {
        //function to determine whether the AI character can see the player

        Vector3 playerPosition = GameObject.FindGameObjectWithTag("Player").transform.position; // get player position

        //we only want to look ahead so we check if the player in a 90 degree arc. (Vec3.angle returns an absolute value, so 45 degrees either way means <=45)
        if (Vector3.Angle(transform.forward, playerPosition - transform.position) <= 45f)
        {
            LayerMask layerMask = LayerMask.NameToLayer("Zombie");// a mask used for the raycast to ignore any zombies

            RaycastHit hit;// variable to store the hit so we can check it

            //We now check if a ray cast from us (the zombie) to the player hits anything (except zombies) also move it up a little to avoid the floor
            if (Physics.Raycast(transform.position + new Vector3(0f, 0.5f, 0f), playerPosition - transform.position, out hit, Mathf.Infinity, layerMask))
            {
                // health --
                if (ThirdPersonCharacter.health > 0)
                { ThirdPersonCharacter.health--; }
                return (hit.collider.tag.Equals("Player"));//return whether or not the thing we hit is the player
            }
        }//or if any of these tests failed, i can't see them.
        return false;
    }

    // Use this for initialization
    void Start()
    {
        //store the controllers in variables for easy access later
        characterController = GetComponent<AICharacterControl>();
        tpCharacter = GetComponent<ThirdPersonCharacter>();
        //store all the waypoints too
        allWaypoints = GameObject.FindGameObjectsWithTag("Waypoint");
        //shuffle array to make unique wandering path
        System.Random rnd = new System.Random(System.DateTime.Now.Millisecond);
        allWaypoints = allWaypoints.OrderBy(x => rnd.Next()).ToArray();

    }

    // Update is called once per frame
    void Update()
    {
        switch (state)
        {
            case AIState.WANDERING:
                characterController.SetTarget(allWaypoints[currentWaypoint].transform);
                //if i'm wandering...
                if ((Vector3.Distance(characterController.target.transform.position, transform.position) < 2.0f))
                {
                    //...make me target the next one
                    currentWaypoint++;
                    //make sure that we don't fall off the end of the array but lop back round
                    currentWaypoint %= allWaypoints.Length;
                }
                //can i see the player? if so, the chase is on!
                if (CanSeePlayer())
                {
                    state = AIState.CHASING;
                }
                break;
            case AIState.CHASING:
                characterController.SetTarget(GameObject.FindGameObjectWithTag("Player").transform);
                if (!CanSeePlayer())
                {
                    //i can't see him, so back to wandering...
                    state = AIState.WANDERING;
                }
                break;
            case AIState.CRAZY:
                Pubstate = true;
                characterController.SetTarget(GameObject.FindGameObjectWithTag("Player").transform);
                this.GetComponent<NavMeshAgent>().speed = 100;
                this.GetComponent<NavMeshAgent>().autoRepath = true;
                deathTimeout = 1;
                
                if (!CanSeePlayer())
                {
                    Pubstate = false;
                    //i can't see him, so back to wandering...
                    state = AIState.WANDERING;
                }
                break;
            case AIState.DEAD:
                this.GetComponent<Animator>().enabled = false; //stop trying to animate myself
                this.GetComponent<NavMeshAgent>().enabled = false; //stop trying to navigate
                this.GetComponent<AICharacterControl>().enabled = false; // stop the AI

                this.GetComponent<Rigidbody>().isKinematic = true; //Make myself kinematic (ragdoll)

                foreach (Rigidbody rbody in GetComponentsInChildren<Rigidbody>())
                {
                    rbody.isKinematic = false;
                }

                foreach (Collider col in GetComponentsInChildren<Collider>())
                {
                    col.enabled = true;
                }

                Destroy(gameObject, deathTimeout); // remove myself from the game after timeout
                break;
        }
    }
}