public void getInput() {
        if (Keyboard.isKeyDown(Keyboard.KEY_W) || Keyboard.isKeyDown(Keyboard.KEY_UP)) {
            if (player.yPos < ((Display.getHeight() - topWall.getSizeY()) - player.sizeY))
                player.move(1);
        } else if (Keyboard.isKeyDown(Keyboard.KEY_S) || Keyboard.isKeyDown(Keyboard.KEY_DOWN)) {
            if (player.yPos > bottomWall.getSizeY())
                player.move(-1);
        }
    }