[Freeciv-Dev] Re: build_cost_prime (PR#1197)

[Chris Richards <chrisr@xxxxxxxxxxxxxxxx>]

My one suggestion would be to pass in unit_types[i] instead of just
the index.  Later, someone for some reason may want to apply the same
operation to a copy of unit_types or whatnot.

Cheers,
cjr


Gregory Berkolaiko <gberkolaiko@xxxxxxxxxxx> writes:
> Hi,
> 
> the variable with an expressive name "fprime" is calculated in the same
> way in 3 different places.  I propose to separate the calculation into a
> function and supply it with a comment.  The patch is attached.
> 
> Patch from todays CVS.
> Compiles smooth.
> Savegames identical.
> 
> Best,
> G.
> 
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> Index: ai/advmilitary.c
> ===================================================================
> RCS file: /home/freeciv/CVS/freeciv/ai/advmilitary.c,v
> retrieving revision 1.80
> diff -u -r1.80 advmilitary.c
> --- ai/advmilitary.c  2001/12/21 11:17:30     1.80
> +++ ai/advmilitary.c  2002/01/03 13:12:29
> @@ -603,9 +603,7 @@
>            !unit_type_flag(i, F_IGWALL) && !city_got_citywalls(acity)) d *= 
> 9; 
>  
>        f = unit_types[i].build_cost;
> -      fprime = f * 2 * unit_types[i].attack_strength /
> -           (unit_types[i].attack_strength +
> -            unit_types[i].defense_strength);
> +      fprime = build_cost_prime(i);
>  
>        if (acity) g = unit_list_size(&(map_get_tile(acity->x, 
> acity->y)->units)) + 1;
>        else g = 1;
> @@ -802,9 +800,7 @@
>      if (is_ground_unit(myunit) && !sanity && !boatid)
>        needferry = 40; /* cost of ferry */
>      f = unit_types[v].build_cost;
> -    fprime = f * 2 * unit_types[v].attack_strength /
> -           (unit_types[v].attack_strength +
> -            unit_types[v].defense_strength);
> +    fprime = build_cost_prime(v);
>  
>      if (acity) g = unit_list_size(&(map_get_tile(acity->x, 
> acity->y)->units)) + 1;
>      else g = 1;
> Index: ai/aiunit.c
> ===================================================================
> RCS file: /home/freeciv/CVS/freeciv/ai/aiunit.c,v
> retrieving revision 1.158
> diff -u -r1.158 aiunit.c
> --- ai/aiunit.c       2001/11/05 01:59:59     1.158
> +++ ai/aiunit.c       2002/01/03 13:12:32
> @@ -416,6 +416,25 @@
>  }
>  
>  /**************************************************************************
> +In the words of Syela:
> +"Using funky fprime variable instead of f in the denom, so
> +that def=1 units are penalized correctly."
> +Translation (GB):
> +build_cost_prime is used in the denominator of the want equation (see, e.g.
> +find_something_to_kill) instead of just build_cost to make AI build more 
> +balanced units.
> +**************************************************************************/
> +int build_cost_prime(Unit_Type_id i)
> +{
> +  int res;
> +
> +  res = 2 * unit_types[i].build_cost * unit_types[i].attack_strength /
> +    (unit_types[i].attack_strength + unit_types[i].defense_strength);
> +  return res;
> +}
> +
> +
> +/**************************************************************************
>  ...
>  **************************************************************************/
>  static int unit_belligerence_primitive(struct unit *punit)
> @@ -1229,9 +1248,7 @@
>    if (unit_flag(punit, F_IGTER)) m *= SINGLE_MOVE;
>    maxd = MIN(6, m) * THRESHOLD + 1;
>    f = unit_type(punit)->build_cost;
> -  fprime = f * 2 * unit_type(punit)->attack_strength /
> -           (unit_type(punit)->attack_strength +
> -            unit_type(punit)->defense_strength);
> +  fprime = build_cost_prime(punit->type);
>  
>    generate_warmap(map_get_city(*x, *y), punit);
>                               /* most flexible but costs milliseconds */
> Index: ai/aiunit.h
> ===================================================================
> RCS file: /home/freeciv/CVS/freeciv/ai/aiunit.h,v
> retrieving revision 1.24
> diff -u -r1.24 aiunit.h
> --- ai/aiunit.h       2001/01/10 18:50:45     1.24
> +++ ai/aiunit.h       2002/01/03 13:12:32
> @@ -29,6 +29,7 @@
>                              int *x, int *y);
>  int find_beachhead(struct unit *punit, int dest_x, int dest_y, int *x, int 
> *y);
>  
> +int build_cost_prime(Unit_Type_id i);
>  int unit_belligerence_basic(struct unit *punit);
>  int unit_belligerence(struct unit *punit);
>  int unit_vulnerability_basic(struct unit *punit, struct unit *pdef);