When you mouse wheel in perspective mode, the scene zooms in and out. When you do so in orthographic mode, nothing happens. If Visual::ortho_rt and Visual::ortho_lb were scaled with mouse wheel movements, then the ortho projection would also zoom. This should be straightforward to implement.
When you mouse wheel in perspective mode, the scene zooms in and out. When you do so in orthographic mode, nothing happens. If Visual::ortho_rt and Visual::ortho_lb were scaled with mouse wheel movements, then the ortho projection would also zoom. This should be straightforward to implement.