private void Sync(Point index, out Tile?prevTile, out Sprite prevSprite, out Point prevIndex)
{
prevSprite = ground.GetSprite(index);
prevTile = tiles[index.X, index.Y];
prevIndex = index;
tiles[index.X, index.Y] = null;
ground.ClearSprite(index);
OnSpriteChanged(new SpriteChangedEventArgs(index, ground.GetSprite(index)));
}