Re: (PR#14529) AI keeps building already present in a city.

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=14529 >

Per I. Mathisen wrote:
> <URL: http://bugs.freeciv.org/Ticket/Display.html?id=14529 >
> 
> On Wed, 2 Nov 2005, Mateusz Stefek wrote:
> 
>>Look what Romans do in Eridu. It switches production to Barracks which
>>are already present in the city.
> 
> 
> This looks like an effects bug. The military advisor thinks it does not
> have barracks, and wishes to build one before it builds military units.
> Jason was the last one to touch this code, I think, with the land defense
> patch.
> 
> 2: Tiberius's Eridu(7,9) [s11 d8344 u94 g28] overriding Destroyer(691)
> with Destroyer(1574) [attack=3600,value=20,move_time=1,vuln=225,bcost=60]
> 2: Tiberius's Eridu(7,9) [s11 d8344 u94 g28] ksw: Eridu has chosen
> attacker, Destroyer, want=1574
> 2: Tiberius's Eridu(7,9) [s11 d8344 u94 g28] military advisor choice:
> Barracks II (want 1574)
> 
> See adjust_ai_unit_choice() in ai/advmilitary.c; I no longer understand
> what goes on in this code.

This is probably the same as the bug causing city walls not to be 
displayed.  I really don't know what to do about it.

However it's an AI bug too because this code should be able to handle 
multiple barracks.  We might have one barracks but want to build a 
second one (in a ruleset which has barracks1 and barracks2) before 
building a larger unit.

E.g.:

   Barracks1: +1 veterancy, costs 30 shields
   Barracks2: +1 veterancy, costs 30 shields

The first barracks increases military effectiveness by 50%.  So if we're 
building more than 60 shields worth of units it's worth it.  The second 
barracks increases effectiveness by only 25%.  So if we're building more 
than 120 shields worth of units it's worth it.  This is the kind of 
logic the code should follow (though actually a +50% bonus to offense 
and defense might be worth more than +50% shields).

-jason