maintaining the infinite ground

main.dart

if (groundlet.getRect(screenSize, runDistance).right < 0) {
  setState(() {
    ground.remove(groundlet);
    ground.add(Ground(
        worldLocation: Offset(
            ground.last.worldLocation.dx +
                groundSprite.imageWidth / WORLD_TO_PIXEL_RATIO,
            0)));
    });
}