Rouser GameManager

using UnityEngine;

using System.Collections;

namespace Completed

{
using System.Collections.Generic;//Allows us to use Lists. 
using UnityEngine.UI;//Allows us to use UI.

public class GameManager : MonoBehaviour
{
public float levelStartDelay = 2f;//Time to wait before starting level, in seconds.
public float turnDelay = 0.1f;//Delay between each Player turn.
public int playerFoodPoints = 100;//Starting value for Player food points.
public static GameManager instance = null;//Static instance of GameManager which allows it to be accessed by any other script.
[HideInInspector] public bool playersTurn = true;//Boolean to check if it's players turn, hidden in inspector but public.

private Text levelText;//Text to display current level number.
private GameObject levelImage;//Image to block out level as levels are being set up, background for levelText.
private BoardManager boardScript;//Store a reference to our BoardManager which will set up the level.
private int level = 1;//Current level number, expressed in game as "Day 1".
private List<Enemy> enemies;//List of all Enemy units, used to issue them move commands.
private bool enemiesMoving;//Boolean to check if enemies are moving.
private bool doingSetup = true;//Boolean to check if we're setting up board, prevent Player from moving during setup.

//Awake is always called before any Start functions                                                             单例
void Awake()
{
//Check if instance already exists
if (instance == null)

//if not, set instance to this
instance = this;

//If instance already exists and it's not this:
else if (instance != this)

//Then destroy this. This enforces our singleton pattern, meaning there can only ever be one instance of a GameManager.
Destroy(gameObject);

//Sets this to not be destroyed when reloading scene
DontDestroyOnLoad(gameObject);                                                    过场景不销毁

//Assign enemies to a new List of Enemy objects.
enemies = new List<Enemy>();

//Get a component reference to the attached BoardManager script
boardScript = GetComponent<BoardManager>();

//Call the InitGame function to initialize the first level 
InitGame();
}

//This is called each time a scene is loaded.
void OnLevelWasLoaded(int index)
{
//Add one to our level number.
level++;
//Call InitGame to initialize our level.
InitGame();
}

//Initializes the game for each level.
void InitGame()
{
//While doingSetup is true the player can't move, prevent player from moving while title card is up.
doingSetup = true;

//Get a reference to our image LevelImage by finding it by name.
levelImage = GameObject.Find("LevelImage");

//Get a reference to our text LevelText's text component by finding it by name and calling GetComponent.
levelText = GameObject.Find("LevelText").GetComponent<Text>();

//Set the text of levelText to the string "Day" and append the current level number.
levelText.text = "Day " + level;

//Set levelImage to active blocking player's view of the game board during setup.
levelImage.SetActive(true);

//Call the HideLevelImage function with a delay in seconds of levelStartDelay.
Invoke("HideLevelImage", levelStartDelay);

//Clear any Enemy objects in our List to prepare for next level.
enemies.Clear();

//Call the SetupScene function of the BoardManager script, pass it current level number.
boardScript.SetupScene(level);

}

//Hides black image used between levels
void HideLevelImage()
{
//Disable the levelImage gameObject.
levelImage.SetActive(false);

//Set doingSetup to false allowing player to move again.
doingSetup = false;
}

//Update is called every frame.
void Update()
{

//Check that playersTurn or enemiesMoving or doingSetup are not currently true. 

//有三个条件控制，看得出对update的严格使用 return是精髓 3个条件一下变成了反义精辟

if(playersTurn || enemiesMoving || doingSetup)

//If any of these are true, return and do not start MoveEnemies.
return;

//Start moving enemies.
StartCoroutine (MoveEnemies ());
}

//Call this to add the passed in Enemy to the List of Enemy objects.
public void AddEnemyToList(Enemy script)
{
//Add Enemy to List enemies.
enemies.Add(script);
}

//GameOver is called when the player reaches 0 food points
public void GameOver()
{
//Set levelText to display number of levels passed and game over message
levelText.text = "After " + level + " days, you starved.";

//Enable black background image gameObject.
levelImage.SetActive(true);

//Disable this GameManager.
enabled = false;
}

//Coroutine to move enemies in sequence.
IEnumerator MoveEnemies()
{
//While enemiesMoving is true player is unable to move.
enemiesMoving = true;

//Wait for turnDelay seconds, defaults to .1 (100 ms).
yield return new WaitForSeconds(turnDelay);

//If there are no enemies spawned (IE in first level):
if (enemies.Count == 0) 
{
//Wait for turnDelay seconds between moves, replaces delay caused by enemies moving when there are none.
yield return new WaitForSeconds(turnDelay);
}

//Loop through List of Enemy objects.
for (int i = 0; i < enemies.Count; i++)
{
//Call the MoveEnemy function of Enemy at index i in the enemies List.
enemies[i].MoveEnemy ();

//Wait for Enemy's moveTime before moving next Enemy, 
yield return new WaitForSeconds(enemies[i].moveTime);
}
//Once Enemies are done moving, set playersTurn to true so player can move.
playersTurn = true;

//Enemies are done moving, set enemiesMoving to false.
enemiesMoving = false;
}
}

}