敌人波产卵者统一

Question

I'm trying to create a wave spawner for a top down game that I'm creating. I have created the wave spawner script but when I hit play, nothing happens. The countdown doesn't begin. Ideally it should start from 2, once it reaches 0, the first wave should spawn with one enemy. Once that enemy is killed, the countdown should begin from 5 and once 0 is reached, the next wave with 2 enemies should begin and so on. The new wave should not begin until all the current enemies are destroyed.

public enum SpawnState { SPAWNING, WAITING, COUNTING };

public SpawnState state = SpawnState.COUNTING;

public Transform enemy;

public float timeBetweenWaves = 5f;
public float countDown = 2f;

private int waveIndex = 0;

public float searchCountdown = 1f;   

void Update()
{        
  if (state == SpawnState.WAITING)
  {           
    if (!EnemyisAlive())
       {
          WaveCompleted();
        }
        else
        {                
            return;
        }
    }

  if (countDown <= 0f)
  {          
      if (state != SpawnState.SPAWNING)
      {              
          StartCoroutine(SpawnWave());
          countDown = timeBetweenWaves;
      }
      else
      {              
          countDown -= Time.deltaTime;
      }

  }

}

void WaveCompleted()
{        
    state = SpawnState.COUNTING;
    countDown = timeBetweenWaves;
    SpawnWave();        
}

bool EnemyisAlive()
{        
    searchCountdown -= Time.deltaTime;
    if (searchCountdown <= 0)
    {
        searchCountdown = 1f;
        if (GameObject.FindGameObjectsWithTag("Enemy").Length == 0)
        {
            return false;
        }
    }
    return true;
 }

IEnumerator SpawnWave()
 {        
    state = SpawnState.SPAWNING;
    waveIndex++;
    for (int i = 0; i < waveIndex; i++)
    {
        SpawnEnemy();
        yield return new WaitForSeconds(0.5f);

    }
    state = SpawnState.WAITING;
    yield break;
 }

void SpawnEnemy()
 {
    Instantiate(enemy, transform.position, transform.rotation);
 }   

Answer 1

I would recommend you to use a Coroutine for all of it. That makes some things easier. You can eg simply wait until another Ienumertaor is finished. Then I would simply add the spawned enemies to a list, filter it for null entries and use the count. Using Find or in your case FindGameObjectsWithTag each frame is highly inefficient!

using System.Linq;
using System.Collections.Generic;

...

public Transform enemy;

public float timeBetweenWaves = 5f;
public float countDown = 2f;

//public float searchCountdown = 1f; 

private List<Transform> enemies = new List<Transform>();
private int waveIndex = 0;

private void Start()
{
    StartCoroutine(RunSpawner());
}

// this replaces your Update method
private IEnumerator RunSpawner()
{        
    // first time wait 2 seconds
    yield return new WaitForSeconds(countDown);

    // run this routine infinite
    while(true)
    {
        state = SpawnState.SPAWNING;    

        // do the spawning and at the same time wait until it's finished
        yield return SpawnWave();

        state = SpawnState.WAITING;

        // wait until all enemies died (are destroyed)
        yield return new WaitWhile(EnemyisAlive);

        state = SpawnState.COUNTING

        // wait 5 seconds
        yield return new WaitForSeconds(timeBetweenWaves);
    }
}

private bool EnemyisAlive()
{        
    // uses Linq to filter out null (previously detroyed) entries
    enemies = enemies.Where(e => e != null).ToList();

    return enemies.Count > 0;
}

private IEnumerator SpawnWave()
{        
    waveIndex++;
    for (int i = 0; i < waveIndex; i++)
    {
        SpawnEnemy();
        yield return new WaitForSeconds(0.5f);
    }
}

private void SpawnEnemy()
{
    enemies.Add(Instantiate(enemy, transform.position, transform.rotation));
}

---

To be slightly more efficient you could also avoid instantiating and destroying but rather use Object Pooling - only enabling and disabling the objects and eventually spawn new ones only when needed.