问题[libgdx]

我正在制作一个应用程序，我想添加ImageButton按钮。我不明白为什么我的addListener()不起作用，即使按钮

1. 初始化
2. 添加到场景中
3. 正确渲染

在MainGameScreen类的构造函数中，实例化setInputProcessor并将其设置为当前场景：

_viewport = new ScreenViewport();
_stage = new Stage();
iniatilizeButtons();
Gdx.input.setInputProcessor(_stage);

iniatilizeButtons ()函数描述了按钮的样式，按钮立即添加到场景中并定义了addListener()：

buttonTextureAtlas = new TextureAtlas("ui/joystick/joystick.atlas");

skin = new Skin();
skin.addRegions(buttonTextureAtlas);

buttonRightStyle = new ImageButton.ImageButtonStyle();
buttonRightStyle.down = skin.getDrawable("touchBackground");
buttonRightStyle.up = skin.getDrawable("touchKnob");
buttonRightStyle.checked = skin.getDrawable("touchKnob");

buttonRight = new ImageButton(buttonRightStyle);
buttonRight.setPosition(20, 20);
buttonRight.setTransform(true);
buttonRight.setScale(0.001f*Gdx.graphics.getHeight());

_stage.addActor(buttonRight);

buttonRight.addListener(new ClickListener(){
    @Override
    public void touchUp(InputEvent event, float x, float y, int pointer, int button) {
        super.touchUp(event, x, y, pointer, button);
        Gdx.app.log(TAG, "Button Pressed");
        hide();
    }
});

当调用render()我这样做：

_stage.act(delta);
_stage.draw();

稍微清楚一点，按下按钮并释放它不会输出我在 touchUp() 中指定的“按下按钮”。我已经添加了 touchDown() 和 clicked()，但它们在单击时也不显示任何内容。

我正在尝试使用样条曲线，我想自己解决在 github 上阅读本指南后出现的问题。这是我设法从该指南中收集的代码：

public class MyCatmullRomSpline {

private int mCountSections; //кол-во делений(точек) между основными точками указанными в dataPoints
private Vector2[] mSections; //массив делений
private ShapeRenderer mShapeRenderer;
private CatmullRomSpline<Vector2> mSpline;
private Vector2 out; 
private float speed; //скорость перемещения чего-либо по кривой


public GCatmullRomSpline(Vector2[] dataPoints, boolean closed, int countSections){

    speed = dataPoints.length - 1;

    mSpline = new CatmullRomSpline<Vector2>(dataPoints, closed);
    mSections = new Vector2[countSections];

    mCountSections = countSections;

    mShapeRenderer  = new ShapeRenderer();

    initSpline();
}

private void initSpline(){
    out = new Vector2();

    mSpline.valueAt(out, Gdx.graphics.getDeltaTime()); //?????
    mSpline.derivativeAt(out, Gdx.graphics.getDeltaTime()); //?????

    for (int i = 0; i < mCountSections; ++i){
        mSections[i] = new Vector2();
        mSpline.valueAt(mSections[i], ((float)i)/((float)mCountSections-1));//?????
    }
}

float current = 0;

public void render(SpriteBatch batch, Texture texture){
    mShapeRenderer.begin(ShapeRenderer.ShapeType.Line);

    float derivativeAverage = 0;
    for (float i = 0; i < 1; i += 1f/mCountSections) {
        mSpline.derivativeAt(out, i); //?????
        derivativeAverage += out.len();
    }
    derivativeAverage /= mCountSections;

    mSpline.derivativeAt(out, current);
    current += derivativeAverage / speed * Gdx.graphics.getDeltaTime() / out.len();
    current %= 1;

    if (current >= 1) current -= 1;
    mSpline.valueAt(out, current);

    batch.begin();
    batch.draw(texture, out.x - 18, out.y - 18, 36, 36);
    batch.end();


    for (int i = 0; i < mCountSections-1; ++i){
        mShapeRenderer.line(
                mSpline.valueAt(mSections[i], ((float)i)/((float)mCountSections-1)),
                mSpline.valueAt(mSections[i+1], ((float)(i+1))/((float)mCountSections-1)));
    }

    mShapeRenderer.end();
    }
}

这是我理解的图像：

问题一：

方法： mSpline.valueAt(out, Gdx.graphics.getDeltaTime()); 和 mSpline.derivativeAt(out, Gdx.graphics.getDeltaTime()); - 包含相同的正文和语法。

public T valueAt (T out, float t) {
    final int n = spanCount;
    float u = t * n;
    int i = (t >= 1f) ? (n - 1) : (int)u;
    u -= i;
    return valueAt(out, i, u);
}

public T derivativeAt (T out, float t) {
    final int n = spanCount;
    float u = t * n;
    int i = (t >= 1f) ? (n - 1) : (int)u;
    u -= i;
    return derivativeAt(out, i, u);
}

他们有什么区别？

PS：我的微分数学很弱。

如何从外部访问 actor 中的 moveX、moveY 变量？

我在组中创建一个按钮

menubutton = new Button(style);
    menubutton.setPosition(topbar.getX() + 910, topbar.getY() + 22);
    menubutton.setBounds(menubutton.getX(), menubutton.getY(), menubutton.getWidth(), menubutton.getPrefHeight());
    menubutton.addListener(new ClickListener() {
        @Override
        public void clicked(InputEvent event, float x, float y) {
            Gdx.app.log("Log", "Test");
        }
    });
    this.addActor(menubutton);

然后我在那里创建一个表

table = new Table();
    table.setSize(1100, 600);
    table.setBackground(new TextureRegionDrawable(new TextureRegion(new Texture(Gdx.files.internal("bkgd.png")))));
    table.setPosition(90, 60);

    this.addActor(table);

表格与按钮重叠，但是在按钮所在位置的表格区域中点击，clicked事件触发

问候！在 libgdx 表中，我正在交换来自服务器的照片。我实现了从上到下的加载，但我只想优化和加载用户滚动屏幕上可见的那部分行。我可以使用 libgdx 以某种方式获得这个范围，还是我需要发明一些东西？