[Freeciv-Dev] Re: (PR#6669) Topology and generators

["rwetmore@xxxxxxxxxxxx" <rwetmore@xxxxxxxxxxxx>]

The separatepoles server option should be all that is needed to handle
make_passable() controls. The fix below is a mistake and if there are
problems in the code they need to be fixed (it works fine in the
corecleanups, so this is just an issue with the current implementation).

There are changes to understand that a wrapped N-S pole with separatepoles
means only one polar continent, its just a line in a couple of spots, so
no big deal.

The suggestion that this is not useful is just a red herring to avoid
having to figure out where bugs have been introduced. SOP for Jason
when ducking :-).

Cheers,
RossW
=====

Jason Short wrote:
> ue80@xxxxxxxxxxxxxxxxxxxxx wrote:
> 
>>Hi,
>>
>>Gen 2,3 and 4 aren't working with top 3.
>>
>>And it should be possible to remove the poles in top 2 and 3.
> 
> 
> PR#6652 provides a patch to not (always) generate poles.
> 
> The gen2/3/4 bug is closely related to that.  It happens because the 
> poles are still being generated, but the code doesn't realize they're 
> all one continent.
> 
> The easy fix would just be to _never_ generate poles in a N-S wrapping 
> map.  That's what the gen-topology patch does; it only takes a few 
> lines.  The attached patch "A" does it this way.
> 
> PR#6652 does it differently since Ross wanted this to be a server 
> option.  This will make the fix harder: we actually have to figure out 
> the continent numbering and do it right (e.g., more code).  I have a 
> patch to do this but it doesn't work (I don't know why).
> 
> Personally, I'm in favor of completely ditching poles with the map wraps 
> north-south.  I can't imagine why anyone would ever want them, and it 
> makes the code significantly simpler.
> 
> jason
> 
> 
> 
> 
> ------------------------------------------------------------------------
> 
> Index: server/mapgen.c
> ===================================================================
> RCS file: /home/freeciv/CVS/freeciv/server/mapgen.c,v
> retrieving revision 1.119
> diff -u -r1.119 mapgen.c
> --- server/mapgen.c   2003/10/21 22:04:53     1.119
> +++ server/mapgen.c   2003/10/28 21:00:07
> @@ -59,6 +59,7 @@
>  static int *height_map;
>  static int maxval=0;
>  static int forests=0;
> +static bool has_poles;
>  
>  struct isledata {
>    int goodies;
> @@ -854,7 +855,7 @@
>        tres*=9;
>      tres/=10;
>    } while (abs(total-count)> maxval/40);
> -  if (map.separatepoles) {
> +  if (map.separatepoles && has_poles) {
>      make_passable();
>    }
>    make_mountains(maxval*8/10);
> @@ -862,7 +863,9 @@
>    make_swamps();
>    make_deserts();
>    make_plains();
> -  make_polar();
> +  if (has_poles) {
> +    make_polar();
> +  }
>    make_fair();
>    make_rivers();
>  }
> @@ -937,7 +940,7 @@
>      map_set_continent(x, y, 0);
>    } whole_map_iterate_end;
>  
> -  if (map.generator != 0) {
> +  if (map.generator != 0 && has_poles) {
>      assign_continent_flood(0, 0, 1);
>      assign_continent_flood(0, map.ysize-1, 2);
>      isle = 3;
> @@ -970,7 +973,7 @@
>    islands = fc_calloc((map.num_continents + 1), sizeof(struct isledata));
>    
>    /* the arctic and the antarctic are continents 1 and 2 for generator > 0 */
> -  if ((map.generator > 0) && map.separatepoles) {
> +  if (map.generator > 0 && map.separatepoles && has_poles) {
>      firstcont = 3;
>    } else {
>      firstcont = 1;
> @@ -1155,6 +1158,8 @@
>  
>    mysrand(map.seed);
>    
> +  has_poles = !topo_has_flag(TF_WRAPY);
> +
>    /* don't generate tiles with mapgen==0 as we've loaded them from file */
>    /* also, don't delete (the handcrafted!) tiny islands in a scenario */
>    if (map.generator != 0) {
> @@ -1771,21 +1776,25 @@
>        map_clear_all_specials(x, y);
>        map_set_owner(x, y, NULL);
>      }
> -  for (x = 0 ; x < map.xsize; x++) {
> -    map_set_terrain(x, 0, myrand(9) > 0 ? T_ARCTIC : T_TUNDRA);
> -    map_set_continent(x, 0, 1);
> -    if (myrand(9) == 0) {
> -      map_set_terrain(x, 1, myrand(9) > 0 ? T_TUNDRA : T_ARCTIC);
> -      map_set_continent(x, 1, 1);
> -    }
> -    map_set_terrain(x, map.ysize-1, myrand(9) > 0 ? T_ARCTIC : T_TUNDRA);
> -    map_set_continent(x, map.ysize-1, 2);
> -    if (myrand(9) == 0) {
> -      map_set_terrain(x, map.ysize-2, myrand(9) > 0 ? T_TUNDRA : T_ARCTIC);
> -      map_set_continent(x, map.ysize-2, 2);
> +  if (has_poles) {
> +    for (x = 0 ; x < map.xsize; x++) {
> +      map_set_terrain(x, 0, myrand(9) > 0 ? T_ARCTIC : T_TUNDRA);
> +      map_set_continent(x, 0, 1);
> +      if (myrand(9) == 0) {
> +     map_set_terrain(x, 1, myrand(9) > 0 ? T_TUNDRA : T_ARCTIC);
> +     map_set_continent(x, 1, 1);
> +      }
> +      map_set_terrain(x, map.ysize-1, myrand(9) > 0 ? T_ARCTIC : T_TUNDRA);
> +      map_set_continent(x, map.ysize-1, 2);
> +      if (myrand(9) == 0) {
> +     map_set_terrain(x, map.ysize-2, myrand(9) > 0 ? T_TUNDRA : T_ARCTIC);
> +     map_set_continent(x, map.ysize-2, 2);
> +      }
>      }
> +    map.num_continents = 2;
> +  } else {
> +    map.num_continents = 0;
>    }
> -  map.num_continents = 2;
>    make_island(0, 0, pstate, 0);
>    islands[2].starters = 0;
>    islands[1].starters = 0;
> @@ -2140,7 +2149,7 @@
>      for (y = 0; y < ydiv2; y++) {
>        hmap(0, y * ymax / ydiv) -= avoidedge;
>        hmap(xmax, y * ymax / ydiv) -= avoidedge;
> -      if (map.separatepoles) {
> +      if (map.separatepoles && has_poles) {
>       hmap(2, y * ymax / ydiv) = hmap(0, y * ymax / ydiv) 
>                                                       - myrand(3*avoidedge);
>       hmap(xmax - 2, y * ymax / ydiv) 
> @@ -2153,7 +2162,7 @@
>      for (x = 0; x < xdiv2; x++) {
>        hmap(x * xmax / xdiv, 0) -= avoidedge;
>        hmap(x * xmax / xdiv, ymax) -= avoidedge;
> -      if (map.separatepoles){
> +      if (map.separatepoles && has_poles){
>       hmap(x * xmax / xdiv, 2) = hmap(x * xmax / xdiv, 0) 
>                                                         - myrand(3*avoidedge);
>       hmap(x * xmax / xdiv, ymax - 2)