final int FRAMERATE = 60;

    @Override
    public void run() {
        long lastTime = System.nanoTime();
        long frameTime = 1_000_000_000 / FRAMERATE;

        while (true) {
            long currentTime = System.nanoTime();
            long updateTime = currentTime - lastTime;
            lastTime = currentTime;

            world.getProj().deplaceX(this);
            world.getProj().deplaceY(this);
            world.gravityAction(updateTime);
            repaint();


            long sleepDuration = (frameTime - updateTime) / 1_000_000;
            if (sleepDuration > 0) {
                try {
                    Thread.sleep(sleepDuration);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }