Libgdx游戏每秒加速和减速

Question

   public void update(float dt){
        world.step(1 / 60f, 2, 2);

        handleInput(dt);

        camX();

        player.moveMario();

        hud.update();

        gameCam.update();
        renderer.setView(gameCam);
    }

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

        renderer.render();

        game.batch.setProjectionMatrix(hud.stage.getCamera().combined);
        hud.stage.draw();

        game.batch.setProjectionMatrix(gameCam.combined);
        game.batch.begin();
        game.batch.draw(ball, player.b2Body.getPosition().x - MarioBros.RADIUS_CHARACTER / MarioBros.PPM, player.b2Body.getPosition().y - MarioBros.RADIUS_CHARACTER / MarioBros.PPM, 70 / MarioBros.PPM, 70 / MarioBros.PPM);
        mapCreator.createSpikeBalls(map, animation, game.batch);
        endOfGame();
        game.batch.end();

        b2dr.render(world, gameCam.combined);
    }

    public void camX(){
            gameCam.position.x = gamePort.getWorldWidth() / 2;
            if(player.b2Body.getPosition().x  >= gamePort.getWorldWidth() / 2){
                gameCam.position.x  = player.b2Body.getPosition().x;
            }
    }

 public void moveMario(){
        if (b2Body.getLinearVelocity().x < 4){
            b2Body.applyLinearImpulse(new Vector2(2.7f, 0), b2Body.getWorldCenter(), true);
        }
    }

Answer 1

你没有写任何关于你的世界和身体设置的东西，但我猜下面会发生：

• 你给马里奥施加一个冲动=>他的速度加快
• 在以下几个世界步骤中，身体摩擦使马里奥减速
• 一旦b2body.getLinearVelocity().x<4为true，就再次对Mario施加脉冲
• 摩擦又让他慢了下来
• ...

除此之外，你绝对应该把deltaTime传递给世界的步法