Use ViewportParams rather than AbstractProjection for projection calculations regarding the visible area
Review Request #5539 - Created Oct. 6, 2010 and updated - Latest diff uploaded
Using ViewportParams rather than AbstractProjection simpliefies statements like viewport->currentProjection()->screenCoordinates(...,viewport,...) to viewport->screenCoordinates(...). That way, in the future, ViewportParams could be used for projection calculations that need to take the current viewport (and possibly an elevation model) into account, while AbstractProjections represent the pure mathematical concept (i.e. no elevation model).
Works for me (KDE version of Marble).