The thwack of hammers and the whine of power saws are vying for attention with the beeping of slot machines and the clack of the bouncing roulette ball at many Atlantic City casinos this spring as the gambling halls spend millions on updating their properties. The projects come as the gambling industry anticipates a busy summer with pandemic fears lessening and the casino industry seeing its business increase. Hotel room makeovers, casino floor redesigns, new restaurants and swimming pools are all being built this spring, with more to come later in the year.