That creates too much duplicated logic for me. A single manager class can be formation aware, receive movement notices from units, and set their magnetism properties as needed. Okay, edited to add you can have multiple armies. Thus it would not be a single instance of the manager class. It would still be less then adding the logic to the unit itself, and more logical I think. The class doesn't really care if it's managing civilians, combat units, or some mix. It's just trying to match units to a pattern (formation).
It would have to communicate with other manager instances though, so it can inform them of the units it's interested in managing and avoid 'fighting' over them. All I need now is to write a simple (j/king) algorithm that turns a sparse distributed pattern of units into a tight formation of units in the minimal number of turns while co-operating with other algorithms trying to do the same thing, all in mountainous terrain while being attacked. Let's see Whoward link an existing post for that one!
I'm just going to keep editing this post, sort of a developers diary. That seems less like talking to myself.
If we assume that we are going to let all the pathing be done by Firaxes (badly, but done) then the manager class simply needs to decide what units to magnetize and how for a given formation. Still a lot of work, but much less work.
If I use one of Whowad's plot iterators, I can find nearby units for my command unit (oh yeah, while you where not in the loop I decided a formation needs a command unit, leader, whatever) to magnetize. It would make it's best guess at where to put the unit in the formation, and adjust as it finds new units. Once the formation is created, the magnetism of the units keep it alive. I still need to work out the UI, and looks up some good pattern/formation code to use as a start...
I think the UI is going to require a DLL mode which I can hopeful talk a certain someone into. Ideally we'd have a button that worked much like the build button (a popout button menu on unitpanel with choices for formation types). Since I already need this functionality for Follow and Cover it's double useful. Otherwise I'm going to have to get real creative and have a lot of headache doing some major rewrites on unitpanel.lua/xml and it's little friend.
The button would change to 'disband formation' when a formation is active. Or perhaps disband will simply be one of the actions in the new popout ''build" menu, since that would allow switching of formations without disbanding. I think I like that better.
Since we don't have the ability to select multiple units, the leader unit that starts the formation will have to choose between preset formation sizes. e.g. 5 man flying V. 4 man double row.
Smart placement within the formation of melee vs. range units would be a possibly nice feature also. Perhaps that should be built into the formation types. If the leader can't pick up enough units of the type it needs within range, we'll have to decide on behavior. There are a number of ways we could handle it; proceed with a partial formation; fail with an error message; wait and broadcast a request for more of a specific unit type... with the right information we could even 'grey out' certain formation types if the units weren't in range.
But, you are right, it doesn't really matter. Except...
