[Freeciv-Dev] Re: (PR#2581) Layers Patch

[Juhani Heino <juhani.heino@xxxxxxxxxx>]

I already made the second patch version, but I'll postpone it
until we get some consensus so I can add more corrections.

> > They were not weights, but priorities given - only the units
> > at the highest priority are compared otherwise. So this is meant
> > to be totally predictable (if you know what units there are).
> Why is it necessary? What problem does it solve?

It was made to support get_defender() for the layer idea.
So, not a problem but the new feature. I thought that a
separate function is cleaner than all this mixed in
get_defender().

IMO, get_defender() must have these priorities to choose the
defender. Raimar's comment (that priority 0 should be given
by can_unit_attack) was very valid, but I don't know yet if
it will simplify anything - now it seems quite clear to me,
but let's see after this discussion and possible addition of
exceptions   8-)

> I am thinking we should keep which-unit-can-attack-which-unit rules
> out of
> this. They are fine as they are, and layers based rules to replace
> them will be rather complicated, I fear.

OK, sounds fine to me.

> (In any case, I don't see a problem with sea and ground units being
> in the
> same layer. We will have to special case attacks into terrain where
> you cannot ever move, anyway.)

I'll see if I can find (others are welcome too) a cleaner
approach, but so far this distinction solves quite a lot on
very general level. Ships will target ships first and so on.

Especially I would welcome a long list of what can be done
and what cannot. For example:

If there is a fighter, should it really prevent aerial attacks
against the units beneath until it's destroyed? Here I think
that it can be attacked only by a fighter. Attacking it with
bomber or AEGIS seems silly and unnatural. Anyway, the present
fighter is quite clumsy to be used this way because it must
return to a base. The enemy could wait for its departure...

And I'm not sure of the marines. In my latest patch they can
attack also ships, although they prefer cargo if present.
Sure they have heavier weaponry than ordinary infantry, but
do you see something odd in this?

And then we must make all this into simple rules...   8-)

Juhani