Question

我有一个围绕其中心点旋转的精灵（矩形）。我用过：

setOriginCenter();
setRotation(angleDegrees);

工作正常。

我使用CircleShape定义了一个DynamicBody（box2d）。

在精灵的更新方法中，我想将精灵（旋转的精灵）居中与DynamicBody的中心。我尝试了几种方法，但我无法得到解决方案：

这不起作用

Rectangle rect = myRotatedSprite.getBoundingRectangle();
myRotatedSprite.setPosition(b2body.getPosition().x - rect.getWidth() / 2, b2body.getPosition().y - rect.getHeight() / 2);

这不起作用

myRotatedSprite.setPosition(b2body.getPosition().x - myRotatedSprite.getWidth() / 2, b2body.getPosition().y - myRotatedSprite.getHeight() / 2);

这不起作用

float rot = myRotatedSprite.getRotation();
myRotatedSprite.setRotation(0);
Rectangle rect = getBoundingRectangle();
myRotatedSprite.setPosition(b2body.getPosition().x - rect.width / 2, 
b2body.getPosition().y - rect.height / 2);
myRotatedSprite.setRotation(rot);
myRotatedSprite.getBoundingRectangle();

我做错了什么？在我看来，当精灵旋转时getBoundingRectangle()不正确......

这是我的完整代码：

public class HeroBullet extends Weapon {
private static final String TAG = HeroBullet.class.getName();

private float stateTimer;
private Animation heroBulletAnimation;
private Vector2 tmp; // Temp GC friendly vector

public HeroBullet(PlayScreen screen, float x, float y, float width, float height, float circleShapeRadius, float angle, Animation animation) {
    super(screen, x, y, circleShapeRadius > 0 ? circleShapeRadius : Constants.HEROBULLET_CIRCLESHAPE_RADIUS_METERS);

    setOriginCenter();

    width = width > 0 ? width : Constants.HEROBULLET_WIDTH_METERS;
    height = height > 0 ? height : Constants.HEROBULLET_HEIGHT_METERS;

    setBounds(getX(), getY(), width, height);

    velocity = new Vector2(Constants.HEROBULLET_VELOCITY_X, Constants.HEROBULLET_VELOCITY_Y);
    if (angle > 0) {
        velocity.rotate(angle);
        setRotation(angle);
    }
    if (animation != null) {
        heroBulletAnimation = animation;
    } else {
        heroBulletAnimation = Assets.instance.heroBullet.heroBulletAnimation;
    }

    stateTimer = 0;
    currentState = State.SHOT;

    AudioManager.instance.play(Assets.instance.sounds.heroShoot, 0.2f, MathUtils.random(1.0f, 1.1f));

    tmp = new Vector2();
}

@Override
protected void defineWeapon() {
    BodyDef bdef = new BodyDef();
    bdef.position.set(getX(), getY()); // In b2box the origin is at the center of the body
    bdef.type = BodyDef.BodyType.DynamicBody;
    b2body = world.createBody(bdef);

    FixtureDef fdef = new FixtureDef();
        CircleShape shape = new CircleShape();
    shape.setRadius(circleShapeRadius);
    fdef.filter.categoryBits = Constants.HERO_WEAPON_BIT; // Depicts what this fixture is
    fdef.filter.maskBits = Constants.BORDERS_BIT |
            Constants.OBSTACLE_BIT |
            Constants.POWERBOX_BIT |
            Constants.FINAL_ENEMY_LEVEL_ONE_BIT |
            Constants.ENEMY_BIT; // Depicts what this Fixture can collide with

    fdef.shape = shape;
    b2body.createFixture(fdef).setUserData(this);
}

@Override
public void update(float dt) {
    switch (currentState) {
        case SHOT:
            stateShot(dt);
            break;
        case ONTARGET:
            stateOnTarget();
            break;
        case FINISHED:
            break;
        default:
            break;
    }
    super.checkBoundaries();
}

private void stateShot(float dt) {
    b2body.setLinearVelocity(velocity);

    /* ***********
    Here I want to center the sprite (rotated sprite) with the center of the DynamicBody, but I don't know how
    ******** */

    setRegion((TextureRegion) heroBulletAnimation.getKeyFrame(stateTimer, true));
    stateTimer += dt;
}

private void stateOnTarget() {
    world.destroyBody(b2body);
    currentState = State.FINISHED;
}

@Override
public void renderDebug(ShapeRenderer shapeRenderer) {
    shapeRenderer.rect(getBoundingRectangle().x, getBoundingRectangle().y, getBoundingRectangle().width, getBoundingRectangle().height);
}

@Override
public void onTarget() {
    currentState = State.ONTARGET;
}

public void draw(Batch batch) {
    if (currentState == State.SHOT) {
        super.draw(batch);
    }
}

}

将旋转的Sprite与DinamicBody libgdx对齐

0 个答案: