I've got a 2D game that I'm working on that is in a single aspect ratio. When I switch it to fullscreen mode on my widescreen monitor it stretches. I tried using two viewports to give a black background to where the game shouldn't stretch to, but that left the game in the same size as before. I couldn't get it to fill the viewport that was supposed to hold the whole game.
How can I get it to go fullscreen without stretching and without me needing to modify every position and draw statement in the game?