Box2d跟随鼠标移动的身体

时间:2015-06-21 11:15:50

标签: libgdx box2d game-physics

我正在尝试使用鼠标旋转box2d机身。这是一张图片来澄清我的意思。 enter image description here

红色和蓝色圆圈是鼠标的当前点,并且身体(相应颜色)移动/旋转以跟随它。基本上矩形应旋转,其一端指向鼠标指针所在的位置。

到目前为止我的代码

 World world;
    Body body, bullet;
    Box2DDebugRenderer debugRenderer;
    OrthographicCamera camera;

    @Override
    public void create() {

        world = new World(new Vector2(0, 0f), true);
        debugRenderer = new Box2DDebugRenderer();
        float w = Gdx.graphics.getWidth();
        float h = Gdx.graphics.getHeight();

        BodyDef bodyDef = new BodyDef();
        bodyDef.type = BodyDef.BodyType.DynamicBody;
        bodyDef.position.set(10, 10);
        body = world.createBody(bodyDef);

        PolygonShape shape = new PolygonShape();
        shape.setAsBox(2, 5);
        FixtureDef fixtureDef = new FixtureDef();
        fixtureDef.shape = shape;
        fixtureDef.density = 1f;
        Fixture fixture = body.createFixture(fixtureDef);

        shape.dispose();

        Gdx.input.setInputProcessor(this);

        camera = new OrthographicCamera(200, 100 * (h / w));
        camera.position.set(camera.viewportWidth / 2f, camera.viewportHeight / 2f, 0);
        camera.update();

    }
 @Override
    public void render() {

        Gdx.gl.glClearColor(1, 1, 1, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
        world.step(Gdx.graphics.getDeltaTime(), 6, 2);
        camera.update();
        debugRenderer.render(world, camera.combined);
    }

  @Override
    public boolean mouseMoved(int screenX, int screenY) {
        int mouseX = screenX;
        int mouseY = Gdx.graphics.getHeight() - screenY;
        float rotateAngle = MathUtils.radiansToDegrees * MathUtils.atan2((float) mouseY - (float) body.getPosition().y, (float) mouseX - (float) body.getPosition().x);
        body.setTransform(body.getPosition(), rotateAngle / 57.2957795f);
        return true;
    }

这里有一个关于它现在如何出现的GIF。 enter image description here

因为你可以看到身体歪斜,也没有正确旋转。我错过了什么?

1 个答案:

答案 0 :(得分:0)

倾斜看起来像是方面修正的问题,试试,

camera = OrthographicCamera(200, 100 * (w / h));

甚至,

camera = OrthographicCamera(200, 100);

要使框的末尾跟随图片中的鼠标,只需重新定义框,

shape.setAsBox(5, 2, Vector2(offset, 0), 0);