将不同的对象添加到不同级别的对象数组列表仅适用于一个级别 [Slick2D]

Question

我正在创建一个游戏，其中每个级别都有不同的 Enemies，它们是圆形。对于 init 方法中 Play class 的第一级，我调用 class 将圆圈添加到 ArrayList，我就这样做了一旦 Player 到达关卡的末端，一个名为 level 的变量增加 1，Player 重生，ArrayList 清除并调用圆圈添加 class 具有更新的级别变量。

由于某种原因，添加新圈子后程序关闭。我已经尝试使用它，以便在 init 方法中我有 if 语句来确定 level 的值，但我找不到多次调用 init 方法的方法。我尝试过其他方法，但似乎没有任何效果。这个添加圈子的方法是我在向你们寻求帮助之前的最后一次尝试。

这是我的 Play Class:

 package tricky.game;
import java.util.*;
import org.newdawn.slick.*;
import org.newdawn.slick.state.*;
import org.newdawn.slick.geom.*;
public class Play extends BasicGameState{

public Shape border,bg,sZone,eZone;
public Player p;
public Options o;
public int level = 1;
public addCircles a;

public Play(int play){
}
@Override
public void init(GameContainer container, StateBasedGame sbg) throws SlickException {
    sZone = new Rectangle(280,180,100,100);
    eZone = new Rectangle(820,520,100,100);
    border = new Rectangle(380,180,440,440);
    bg= new Rectangle(0,0,1200,800);

    a = new addCircles();

    p = new Player();
    p.init(container, sbg);

    o = new Options();

    a.setLevel(level);
    a.setCircles();

}
@Override
public void render(GameContainer container, StateBasedGame sbg, Graphics g) throws SlickException {

    Input input = container.getInput();

    g.setColor(Color.white);
    g.fill(bg);
    g.setColor(Color.black);
    g.drawString("X: "+input.getMouseX()+"\t Y: "+input.getMouseY(), 50, 50);   
    g.setColor(Color.lightGray);
    g.fill(border);
    g.fill(sZone);
    g.fill(eZone);
    g.setLineWidth(3f);
    g.setColor(Color.black);
    g.draw(border);
    g.draw(sZone);
    g.draw(eZone);
    g.resetLineWidth();
    g.setColor(Color.red);
    g.drawString("START",302,225);
    g.drawString("END",854,564);
    p.render(container, sbg, g);
    o.render(container, sbg, g);
    g.drawString("Level:"+level,540,135);
    g.drawString("ArrayList size:"+a.circle.size(),540,100);
    for (int i = 0; i < a.circle.size(); i++) {
        a.circle.get(i).render(container, sbg, g);
    }

}

@Override
public void update(GameContainer container, StateBasedGame sbg, int delta) throws SlickException {
    Input input = container.getInput();

    p.update(container, sbg, delta);
    o.update(container, sbg, delta);

    for (int i = 0; i < a.circle.size(); i++) {
        a.circle.get(i).update(container, sbg, delta);
        if(p.getHB().intersects(a.circle.get(i).getCircle())){
            p.respawn();
        }
    }

    if(p.getHB().intersects(eZone)){ 
        level++;
        a.circle.clear();
        p.respawn();
        a.setLevel(level);
        a.setCircles();
    }

    if(p.getHB().intersects(border) && !(p.getHB().intersects(sZone))){
        p.setBorders(381,180,820,620);
    }
    if(p.getHB().intersects(sZone) && !(p.getHB().intersects(border))){
        p.setBorders(280,180,820,280);
    }
    if(p.getHB().intersects(sZone) && (p.getHB().intersects(border))){
        p.setBorders(380,180,820,280);
    }

}




    @Override
    public int getID() {
        return 2;
    }
}

这是我的EnemiesClass

package tricky.game;
import org.newdawn.slick.*;
import org.newdawn.slick.state.*;
import org.newdawn.slick.geom.*;
public class Enemies {

private float x,y,maxX,maxY,minX,minY; 
public boolean dir=false;
private Shape circle;
public int type,radius;
public Enemies(int x,int y,int maxX,int minX,int maxY,int minY,int type,int radius,boolean dir){
    this.x=x;
    this.y=y;
    this.maxX=maxX;
    this.minX=minX;
    this.maxY=maxY;
    this.minY=minY;
    this.type=type;
    this.radius=radius;
    this.dir=dir;
}
public void init(GameContainer container, StateBasedGame sbg) throws SlickException{

}

public void render(GameContainer container, StateBasedGame sbg, Graphics g) throws SlickException{

    g.setColor(Color.cyan);
    g.fill(circle);
    g.setLineWidth(1.5f);
    g.setColor(Color.black);
    g.draw(circle);
    g.resetLineWidth();
}

public void update(GameContainer container, StateBasedGame sbg, int delta) throws SlickException {

    circle = new Circle(x, y, radius);
    if(type==1){
        if (!dir) {
            x+=4;
        } 
        if (x>=maxX) {
            dir=true;
        }      
        if (dir) {
            x-=4;
        }   
        if (x<=minX) {
            dir=false;
        }
    }
    if(type==2){
        if (!dir) {
            y+=4;
        } 
        if (y>=maxY) {
            dir=true;
        }      
        if (dir) {
            y-=4;
        }   
        if (y<=minY) {
            dir=false;
        }
    }

    if(type==3){
        if(!dir){
            y+=4;
            x+=4;
        }
        if(y>=maxY-20 && x>=maxX-20){
            dir=true;
        }
        if(dir){
            y-=4;
            x-=4;
        }

        if(y<=minY+20 && x<=minX+20){
            dir=false;
        }
    }
}
   public Shape getCircle(){
        return circle;
    }

}

这是我的 addCircles class:

package tricky.game;

import java.util.*;
public class addCircles {
    public ArrayList<Enemies> circle = new ArrayList();
    public int level;

    public void setLevel(int level){
        this.level = level;
    }


    public void setCircles(){
        if(level==1){
            circle.add(new Enemies(420,220,780,420,0,0,1,20,false));
            circle.add(new Enemies(780,580,780,420,0,0,1,20,true));
            circle.add(new Enemies(600,260,0,0,540,260,2,20,false));
        }
        if(level==2){
            circle.add(new Enemies(600,400,820,380,620,180,3,20,false));
        }
    }
}

编辑：我所说的关闭是指它给我以下错误：

Mon Jan 15 08:40:03 EST 2018 ERROR:null
java.lang.NullPointerException
    at org.newdawn.slick.geom.ShapeRenderer.validFill(ShapeRenderer.java:94)
    at org.newdawn.slick.geom.ShapeRenderer.fill(ShapeRenderer.java:107)
    at org.newdawn.slick.Graphics.fill(Graphics.java:554)
    at tricky.game.Enemies.render(Enemies.java:29)
    at tricky.game.Play.render(Play.java:63)
    at org.newdawn.slick.state.StateBasedGame.render(StateBasedGame.java:199)
    at org.newdawn.slick.GameContainer.updateAndRender(GameContainer.java:688)
    at org.newdawn.slick.AppGameContainer.gameLoop(AppGameContainer.java:411)
    at org.newdawn.slick.AppGameContainer.start(AppGameContainer.java:321)
    at tricky.game.TrickyGame.main(TrickyGame.java:32)
Mon Jan 15 08:40:03 EST 2018 ERROR:Game.render() failure - check the game code.
org.newdawn.slick.SlickException: Game.render() failure - check the game code.
    at org.newdawn.slick.GameContainer.updateAndRender(GameContainer.java:691)
    at org.newdawn.slick.AppGameContainer.gameLoop(AppGameContainer.java:411)
    at org.newdawn.slick.AppGameContainer.start(AppGameContainer.java:321)
    at tricky.game.TrickyGame.main(TrickyGame.java:32)
BUILD SUCCESSFUL (total time: 9 seconds)

编辑 2：我发现将新敌人渲染到屏幕上的操作是破坏程序的原因。我完成了第一个级别，添加了新的 Enemies 对象并且它起作用了，只是出于某种原因程序不想渲染它。

编辑 3：我修复了所有问题。这是我渲染对象的方式。我之前使用 g.draw() 现在我使用 g.fillOval()

Answer 1

我已经解决了我遇到的问题。由于某些原因，在使用 g.draw() 函数进行渲染时，程序不想渲染它。我现在正在使用 g.drawOval() function 并且一切正常。

将不同的对象添加到不同级别的对象数组列表仅适用于一个级别 [Slick2D]

Adding Different Objects To An ArrayList of Objects For Different Levels Only Working For One Level [Slick2D]

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