Real time warped spherical camera (panoramic) viewport display

3ds Max has a warped spherical (old style) render output to produce cylindrically mapped renders for doing photomontage work with panoramas but the viewport stays as standard when this output is selected. This means if you're trying to align cameras you have to nudge the camera and test render over and over until you get alignment. It would be massively helpful if Blender could output this render type but also could actually warp the viewport to let you align the camera in real time without having to produce endless test renders.