[Freeciv-Dev] (PR#9069) rewrite find_city_near_tile

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=9069 >

Find_city_near_tile tracks the "last" city, which it gives priority to 
in all cases.  This is to help the old "t" behavior, where if you cycle 
through a city you can then assign workers to that city.

But with city selections and the new behavior, this doesn't make too 
much sense anymore.  It's not consistent since "last" can get 
overwritten all the time.  It's not a good use of a static variable.

However we also have some new information: cities may be selected.  So 
we should make use of this information.  The new rules then become:

     a.  If a city is working the tile, return that city.
     b.  If another player's city is working the tile, return NULL.
     c.  If any selected cities are within range, return the closest one.
     d.  If any cities are within range, return the closest one.
     e.  If nobody can work it, return NULL.

which this patch implements.

The most obvious result is that "t" now works as it should.

jason

? gmon.out
Index: client/mapview_common.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/mapview_common.c,v
retrieving revision 1.130
diff -u -r1.130 mapview_common.c
--- client/mapview_common.c     21 Jun 2004 15:14:43 -0000      1.130
+++ client/mapview_common.c     22 Jun 2004 16:44:19 -0000
@@ -1878,24 +1878,19 @@
 
 /**************************************************************************
   Find the "best" city to associate with the selected tile.
-    a.  A city working the tile is the best
-    b.  If another player is working the tile, return NULL.
-    c.  If no city is working the tile, choose a city that could work
-        the tile.
-    d.  If multiple cities could work it, choose the most recently
-        "looked at".
-    e.  If none of the cities were looked at last, choose "randomly".
-    f.  If no cities can work it, return NULL.
+    a.  If a city is working the tile, return that city.
+    b.  If another player's city is working the tile, return NULL.
+    c.  If any selected cities are within range, return the closest one.
+    d.  If any cities are within range, return the closest one.
+    e.  If nobody can work it, return NULL.
 **************************************************************************/
 struct city *find_city_near_tile(int x, int y)
 {
-  struct city *pcity = map_get_tile(x, y)->worked, *pcity2;
-  static struct city *last_pcity = NULL;
+  struct city *pcity = map_get_tile(x, y)->worked, *closest_city;
 
   if (pcity) {
     if (pcity->owner == game.player_idx) {
       /* rule a */
-      last_pcity = pcity;
       return pcity;
     } else {
       /* rule b */
@@ -1903,30 +1898,33 @@
     }
   }
 
-  pcity2 = NULL;               /* rule f */
+  /* rule e */
+  closest_city = NULL;
+
   city_map_checked_iterate(x, y, city_x, city_y, map_x, map_y) {
     pcity = map_get_city(map_x, map_y);
     if (pcity && pcity->owner == game.player_idx
        && get_worker_city(pcity, CITY_MAP_SIZE - 1 - city_x,
                           CITY_MAP_SIZE - 1 - city_y) == C_TILE_EMPTY) {
-      /* rule c */
       /*
        * Note, we must explicitly check if the tile is workable (with
        * get_worker_city(), above) since it is possible that another
        * city (perhaps an unseen enemy city) may be working it,
        * causing it to be marked as C_TILE_UNAVAILABLE.
        */
-      if (pcity == last_pcity) {
-       return pcity;           /* rule d */
+      
+      if (map_get_tile(pcity->x, pcity->y)->client.hilite == HILITE_CITY) {
+       /* rule c */
+       return pcity;
+      }
+      if (!closest_city) {
+       closest_city = pcity;
       }
-      pcity2 = pcity;
     }
-  }
-  city_map_checked_iterate_end;
+  } city_map_checked_iterate_end;
 
-  /* rule e */
-  last_pcity = pcity2;
-  return pcity2;
+  /* rule d */
+  return closest_city;
 }
 
 /**************************************************************************