unity官方demo学习之Stealth（二十四）敌人AI

using UnityEngine;
using System.Collections;

public class DoneEnemyAI : MonoBehaviour
{
public float patrolSpeed = 2f;							// The nav mesh agent's speed when patrolling.
public float chaseSpeed = 5f;							// The nav mesh agent's speed when chasing.
public float chaseWaitTime = 5f;						// The amount of time to wait when the last sighting is reached.
public float patrolWaitTime = 1f;						// The amount of time to wait when the patrol way point is reached.
public Transform[] patrolWayPoints;						// An array of transforms for the patrol route.

private DoneEnemySight enemySight;						// Reference to the EnemySight script.
private NavMeshAgent nav;								// Reference to the nav mesh agent.
private Transform player;								// Reference to the player's transform.
private DonePlayerHealth playerHealth;					// Reference to the PlayerHealth script.
private DoneLastPlayerSighting lastPlayerSighting;		// Reference to the last global sighting of the player.
private float chaseTimer;								// A timer for the chaseWaitTime.
private float patrolTimer;								// A timer for the patrolWaitTime.
private int wayPointIndex;								// A counter for the way point array.

void Awake ()
{
// Setting up the references.
enemySight = GetComponent<DoneEnemySight>();
nav = GetComponent<NavMeshAgent>();
player = GameObject.FindGameObjectWithTag(DoneTags.player).transform;
playerHealth = player.GetComponent<DonePlayerHealth>();
lastPlayerSighting = GameObject.FindGameObjectWithTag(DoneTags.gameController).GetComponent<DoneLastPlayerSighting>();
}

void Update ()
{
// If the player is in sight and is alive...
if(enemySight.playerInSight && playerHealth.health > 0f)
// ... shoot.
Shooting();

// If the player has been sighted and isn't dead...
else if(enemySight.personalLastSighting != lastPlayerSighting.resetPosition && playerHealth.health > 0f)
// ... chase.
Chasing();

// Otherwise...
else
// ... patrol.
Patrolling();
}

void Shooting ()
{
// Stop the enemy where it is.
nav.Stop();
}

void Chasing ()
{
// Create a vector from the enemy to the last sighting of the player.
Vector3 sightingDeltaPos = enemySight.personalLastSighting - transform.position;

// If the the last personal sighting of the player is not close...
if(sightingDeltaPos.sqrMagnitude > 4f)
// ... set the destination for the NavMeshAgent to the last personal sighting of the player.
nav.destination = enemySight.personalLastSighting;

// Set the appropriate speed for the NavMeshAgent.
nav.speed = chaseSpeed;

// If near the last personal sighting...
if(nav.remainingDistance < nav.stoppingDistance)
{
// ... increment the timer.
chaseTimer += Time.deltaTime;

// If the timer exceeds the wait time...
if(chaseTimer >= chaseWaitTime)
{
// ... reset last global sighting, the last personal sighting and the timer.
lastPlayerSighting.position = lastPlayerSighting.resetPosition;
enemySight.personalLastSighting = lastPlayerSighting.resetPosition;
chaseTimer = 0f;
}
}
else
// If not near the last sighting personal sighting of the player, reset the timer.
chaseTimer = 0f;
}

void Patrolling ()
{
// Set an appropriate speed for the NavMeshAgent.
nav.speed = patrolSpeed;

// If near the next waypoint or there is no destination...
if(nav.destination == lastPlayerSighting.resetPosition || nav.remainingDistance < nav.stoppingDistance)
{
// ... increment the timer.
patrolTimer += Time.deltaTime;

// If the timer exceeds the wait time...
if(patrolTimer >= patrolWaitTime)
{
// ... increment the wayPointIndex.
if(wayPointIndex == patrolWayPoints.Length - 1)
wayPointIndex = 0;
else
wayPointIndex++;

// Reset the timer.
patrolTimer = 0;
}
}
else
// If not near a destination, reset the timer.
patrolTimer = 0;

// Set the destination to the patrolWayPoint.
nav.destination = patrolWayPoints[wayPointIndex].position;
}
}