Question

我对Libgdx框架有疑问。我试图创建一个类扩展Sprite，但是当我渲染它时，我意识到body没有与精灵纹理对齐。

以下是显示问题的图片：

here is the image

您可以看到以下代码：

public class GamePlay implements Screen {

private GameMain game;
private OrthographicCamera mainCamera;
private Viewport viewport;

private OrthographicCamera b2dcam;
private Box2DDebugRenderer debugRenderer;
private World world;

private Texture background;

private Brick brick;
float timer = 0;


public GamePlay(GameMain game)
{
    this.game = game;

    mainCamera = new OrthographicCamera(GameInfo.WIDTH, GameInfo.HEIGHT);
    mainCamera.position.set(GameInfo.WIDTH/2, GameInfo.HEIGHT/2,0);

    viewport = new FitViewport(GameInfo.WIDTH, GameInfo.HEIGHT, mainCamera);

    b2dcam = new OrthographicCamera();
    b2dcam.setToOrtho(false, GameInfo.WIDTH/GameInfo.PPM, GameInfo.HEIGHT / GameInfo.PPM);
    b2dcam.position.set(GameInfo.WIDTH/2f, GameInfo.HEIGHT/2f, 0);

    debugRenderer = new Box2DDebugRenderer();
    world = new World(new Vector2(0,0), true);

    background = new Texture("BGS/GameBG.png");

    brick = new Brick(world, "my brick");
    brick.setBricksPosition(cgp(20), cgp(20));


}

//region Screen Methods
@Override
public void show() {

}

@Override
public void render(float delta) {
    Gdx.gl.glClearColor(0,0,0,1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

    game.getBatch().begin();
    game.getBatch().draw(background,0,0);
    brick.draw(game.getBatch());
    game.getBatch().end();

    debugRenderer.render(world, b2dcam.combined);

    world.step(Gdx.graphics.getDeltaTime(), 6,2);
}

@Override
public void resize(int width, int height) {

}

@Override
public void pause() {

}

@Override
public void resume() {

}

@Override
public void hide() {

}

@Override
public void dispose() {
    background.dispose();

}
//endregion


private float cgp(int gridPos)
{
    return gridPos * GameInfo.gridSize;
}}



public class Brick extends Sprite {

private World world;
private Body body;
private String name;
private Fixture fixture;

public  Brick(World world, String name)
{
    super(new Texture("Bricks/brick.png"));
    this.world = world;
    this.name = name;


}

void createBody()
{
    BodyDef bodyDef = new BodyDef();
    bodyDef.type = BodyDef.BodyType.DynamicBody;

    bodyDef.position.set((getX() - getWidth())/ GameInfo.PPM, (getY() + getHeight()/2)/ GameInfo.PPM);

    body = world.createBody(bodyDef);

    PolygonShape shape = new PolygonShape();

    shape.setAsBox((getWidth()/2)/GameInfo.PPM, (getHeight()/2)/GameInfo.PPM);

    FixtureDef fixtureDef = new FixtureDef();
    fixtureDef.shape = shape;

    fixture = body.createFixture(fixtureDef);

    shape.dispose();

}

public void setBricksPosition(float x, float y)
{
    setPosition(x,y);
    createBody();
}

public void draw(SpriteBatch batch)
{
    batch.draw(this, getX(), getY());
}}

Answer 1

box2d调试渲染（显示身体的实际位置），你的精灵“非常接近”，所以我猜你不远了，问题很可能在你的box2d位置vs的计算/翻译中屏幕位置与像素对米。

你做PPM转换，这样做很好。我没有时间查看您的所有代码，但由于2项非常接近，请再次检查您的计算。这一行：

bodyDef.position.set((getX() - getWidth())/ GameInfo.PPM, (getY() + getHeight()/2)/ GameInfo.PPM);

引起了我的注意。就y而言，渲染调试和精灵是正确的，但在x上是关闭的。你的身高使用getHeight（）/ 2，但getWidth不会除以2.也许这就是你所有的缺失（将宽度除以2）？

Answer 2

最后我找到了解决方案。出现问题的原因是我的PPM值。我把它设置为100，当你把它分成屏幕尺寸时，它不会产生整数。所以我将它改为160，可以分为800和480，问题解决了。

Libgdx Box2D正文和Sprite对齐问题

2 个答案: