将实例添加到数组 LibGDX

Question

我试图在关卡地图中做到这一点，只要有“g”，就会将一个新的Ground 实例附加到 ArrayList。当我使用.add() 方法时，似乎每次调用函数后数组列表都会重置。这是我的代码：

package com.mygdx.thetimetraveller;

import com.badlogic.gdx.graphics.g2d.SpriteBatch;

import java.util.ArrayList;
import java.util.List;

public class Game implements Screen {
    SpriteBatch batch = new SpriteBatch();

    List<Ground> groundList = new ArrayList<Ground>();

    String[] level = {
        "                    ",
        "                    ",
        "                    ",
        "                    ",
        "                    ",
        "                    ",
        "      g             ",
        "g                   ",
        "ggggggggggggg ggg gg",
        "g                   "
    };

    Game(SpriteBatch batch) {
        this.batch = batch;
        this.load();
    }

    @Override
    public void load() {
        for(int c = 0; c < level.length; c ++){
            for(int r = 0; r < level[c].length(); r ++){
                switch(level[c].charAt(r)) {
                    case 'g':
                        groundList.add(new Ground(r * 108, c * 108, this.batch));
                        break;
                }
            }
        }
    }

    @Override
    public void display() {
        for(int i = 0; i < groundList.size(); i ++) {
            groundList.get(i).Draw();
        }
    }
}

当我运行它时，只显示一个地面块，这是数组中的最后一个“g”（底行，第一个字符）。那么，我怎样才能将一个新实例推入arraylist？或者，我可以使用 arraylist 的替代方法吗？总体而言，我希望能够遍历所有列表，并在 load() 方法的嵌套 for 循环中附加的每个实例上调用 .Draw() 方法。我知道有很多人在 StackOverflow 论坛上询问如何在常规 java 中附加到数组列表，但是 LibGDX 的行为不同，所以我找不到任何帮助。提前致谢！

该代码在“Game.java”中。这是其余的代码： “Main.java”：

package com.mygdx.thetimetraveller;

import com.badlogic.gdx.ApplicationAdapter;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;

public class Main extends ApplicationAdapter {
    SpriteBatch batch;
    OrthographicCamera camera;
    Screen gameState;

    private int gameScene = 4;

    @Override
    public void create () {
        batch = new SpriteBatch();
        gameState = new Game(batch);
        camera = new OrthographicCamera();
        camera.setToOrtho(true, 1920, 1080);
        Assets.imagesLoad();
    }

    @Override
    public void dispose () {
        batch.dispose();
    }

    @Override
    public void render () {
        Gdx.gl.glClearColor(1, 1, 1, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
        switch (gameScene) {
            case 1:
                break;
            case 2:
                break;
            case 3:
                break;
            case 4:
                gameState = new Game(batch);
                break;
        }
        camera.update();
        batch.setProjectionMatrix(camera.combined);
        batch.begin();
            gameState.display();
        batch.end();
    }
}

“Ground.java”：

package com.mygdx.thetimetraveller;

import com.badlogic.gdx.graphics.g2d.SpriteBatch;

public class Ground extends GameBlock {
    Ground(double x, double y, SpriteBatch batch) {
        setX(x);
        setY(y);
        setBatch(batch);
    }

    @Override
    public void Draw() {
        batch.draw(Assets.simpleBlockTexture01_sprite, (float) x, (float) y);
    }
}

“GameBlock.java”：

package com.mygdx.thetimetraveller;

import com.badlogic.gdx.graphics.g2d.SpriteBatch;

public abstract class GameBlock {
    protected static double x;
    protected static double y;
    protected static SpriteBatch batch = new SpriteBatch();

    public void setX(double x) {
        this.x = x;
    }
    public void setY(double y) {
        this.y = y;
    }
    public double getX() {
        return this.x;
    }
    public double getY() {
        return this.y;
    }
    public void setBatch(SpriteBatch batch) {
        this.batch = batch;
    }
    public abstract void Draw();
}

“Screen.java”：

package com.mygdx.thetimetraveller;

public interface Screen {
    void load();
    void display();
}

对于这种情况，我仍然省略了不必要的类，例如其他对象类和资产类。

Answer 1

为什么要将这些理由添加到列表中？为什么你不使用你的数组直接绘制你需要的东西？我也会选择多维数组。请看以下内容：

String[][] level = {
  {"g", "r", "g"},
  {" ", "x", "t"},
  //...
};

for (int y = 0; y < level[0].length; y++)
{
  for (int x = 0; x < level.length; x++)
  {
      if (level[x][y].equals("g"))
        draw(groundTile, x * tilewidth, y * tileheight);
      else if (level[x][y].equals("x"))
        draw(otherTile, x * tilewidth, y * tileheight);
  }
}

这在您有大关卡时特别方便。您可以根据相机位置、分辨率和图块大小确切地知道要绘制什么。现在你只需要遍历数组的必要部分而不是整个列表。