游戏开发中的设计模式

单例模式

实例化单一对象，懒加载

//单例模式
class GameManagerSingleton
{
    private constructor(){}
    private static instance:GameManagerSingleton;
    public static Instance()
    {
        if(!GameManagerSingleton.instance)
        {
            this.instance = new GameManagerSingleton();
        }
        return this.instance;
    }


    Init(){}

}

GameManagerSingleton.Instance().Init();

代理模式

根据不同的代理者，具体化实际方法操作

//代理模式
interface ICall
{
    DealNum(x1:number,x2:number):number;
}

class NPC1 implements ICall
{
    DealNum(x1: number, x2: number): number {
        return x1 + x2;
    }
}

class NPC2 implements ICall
{
    DealNum(x1: number, x2: number): number {
        return x1 - x2;
    }
}

class Person
{
    public delegate : ICall;
    public DealNum(x1,x2) : number
    {
        let retNum = this.delegate.DealNum(x1,x2);
        return retNum;
    }
}

观察者模式

设置观察者后，对象的变更会告知观察者

//观察者模式
interface IObserver
{
    nameChanged(newName);
}

class Test implements IObserver
{
  //捕捉变化
    nameChanged(newName : string) 
    {
        console.log("NewName:"+newName)
    }
}

class People
{
    private name : string;
    /**
     *
     */
    constructor() {
        this.name = ""
    }
    public get Name()
    {
       return this.name;
    }

    public set Name(value)
    {
        if(this.name != value)
        {
            this.name = value;
            //发生变化会向观察者发消息
            for(let observer of this.Observers)
            {
                observer.nameChanged(this.name);
            }
        }
        
    }
    Observers : Array<IObserver> = new Array<IObserver>();
}



let People1 = new People()
let observer1  = new Test()
//设置观察者
People1.Observers.push(observer1)
//改变对象
People1.Name = "Tom"

工厂模式

游戏中构建item群体的常用模式

enum CarType
{
    BMW,
    Benz,
    Audi,
}


class Car 
{
   name : string;
   static CreateCar(type :  CarType)
    {
        switch(type)
        {
            case CarType.BMW:
                return new BMW();
            case CarType.Benz:
                return new Benz();
        }
    }
}

class BMW extends Car
{
    /**
     *
     */
    constructor() {
        super();
        this.name = "BMW"
    }
}
class Benz extends Car
{
    /**
     *
     */
    constructor() {
        super();
        this.name = "Benz"
    }
}

Car.CreateCar(CarType.Benz)
Car.CreateCar(CarType.BMW)