Java libGdx：FreeTypeFontGenerator 不工作（黑屏）

Question

我添加了一个自定义字体 Aller_light.ttf，当我尝试运行程序时没有错误地绘制字体，屏幕是黑色的，所以我不确定它是在屏幕外的其他地方渲染还是在全部。
如果你能捐出你的 2 美分，那对我来说会很有价值。

编辑 现在它说我有一个 nullPointerExeption

Exception in thread "LWJGL Application" java.lang.NullPointerException
    at com.mygdx.finis.states.MenuState.draw(MenuState.java:43)
    at com.mygdx.finis.states.GameStateManager.draw(GameStateManager.java:31)
    at com.mygdx.finis.Main.render(Main.java:36)
    at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:215)
    at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:120)

This is what should be happening:

MenuState 类

package com.mygdx.finis.states;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL30;
import com.badlogic.gdx.graphics.g2d.BitmapFont;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.graphics.g2d.freetype.FreeTypeFontGenerator;
import com.mygdx.finis.Assets;
import com.mygdx.finis.Main;

public class MenuState extends GameState{

    private SpriteBatch sb;

    private BitmapFont font;

    private int currentItem;
    private String[] menuItems;

    protected MenuState(GameStateManager gsm) {
        super(gsm);
    }

    public void init() {

        sb = new SpriteBatch();

        FreeTypeFontGenerator gen = new FreeTypeFontGenerator(
            Gdx.files.internal(null));

        font = gen.generateFont(20);

        menuItems = new String[]{
            "Play"
        };
    }

    public void update(float dt) {
        handleInput();
    }

    public void draw() {
        sb.setProjectionMatrix(Main.cam.combined);//*** This is where the null pointer starts *********

        sb.begin();
            font.draw(sb, "Quack", Main.WIDTH / 2, Main.HEIGHT / 2);//*** This does not work *******************
        sb.end();

    }

    public void handleInput() {

    }

    public void dispose() {

    }

}

主类

package com.mygdx.finis;

import com.badlogic.gdx.ApplicationListener;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL30;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.mygdx.finis.states.GameStateManager;

public class Main implements ApplicationListener{

    public static int WIDTH;
    public static int HEIGHT;

    public static OrthographicCamera cam;

    private GameStateManager gsm;

    public void create(){
        WIDTH = Gdx.graphics.getWidth();
        HEIGHT = Gdx.graphics.getHeight();

        cam = new OrthographicCamera(WIDTH, HEIGHT);
        cam.translate(WIDTH / 2, HEIGHT / 2);
        cam.update();

        gsm = new GameStateManager();
    }

    public void render(){
        Gdx.gl.glClearColor(0.1f, 0.1f, 0.1f, 1);
        Gdx.gl.glClear(GL30.GL_COLOR_BUFFER_BIT);

        gsm.update(Gdx.graphics.getDeltaTime());
        gsm.draw();//****** THIS IS WHERE THE ISSUE ENDS ******
    }

    public void resize(int width, int height){}
    public void pause(){}
    public void resume(){}
    public void dispose(){}
}

Answer 1

您的SpriteBatch sb 很可能为空。你确定 init() 被调用了吗？

唯一的另一种选择是Main.cam 为空。

它必须是其中之一。

顺便说一句，这对我来说很奇怪......

Gdx.files.internal(null));

你为什么要这么做？